use serde_json::{Map, Value, json};

use crate::{
    ensure_json_object, format_now_rfc3339, read_array_field, read_bool_field, read_field,
    read_i32_field, read_object_field, read_optional_string_field,
};

const CHAPTER_STAGE_OPENING: &str = "opening";
const CHAPTER_STAGE_EXPANSION: &str = "expansion";
const CHAPTER_STAGE_TURNING_POINT: &str = "turning_point";
const CHAPTER_STAGE_CLIMAX: &str = "climax";
const CHAPTER_STAGE_AFTERMATH: &str = "aftermath";

/// 将运行时动作结算后的叙事记忆投影到正式快照。
///
/// 中文注释：这里是从前端 story engine hook 迁出的最小确定性状态机。
/// 它只依赖动作前后 JSON 快照和本轮 functionId，不访问 HTTP、LLM 或外部资源。
pub fn project_story_engine_after_action(
    previous_state: &Value,
    game_state: &mut Value,
    action_text: &str,
    result_text: &str,
    function_id: &str,
    battle_outcome: Option<&str>,
) {
    let mut memory = read_object_field(game_state, "storyEngineMemory")
        .cloned()
        .unwrap_or_else(|| Value::Object(Map::new()));
    ensure_memory_defaults(&mut memory);

    let signals = collect_story_signals(
        previous_state,
        game_state,
        &memory,
        action_text,
        function_id,
        battle_outcome,
    );
    apply_thread_signal_updates(game_state, &mut memory, &signals);
    // 中文注释：NPC 战斗入口只是把当前 NPC 切入战斗结算，
    // 不能顺手触发“首进场景章节任务”。否则玩家点战斗会误以为被系统自动接了任务。
    if should_update_scene_chapter_state(function_id) {
        ensure_scene_chapter_state(game_state, &mut memory);
    }

    let previous_chapter = read_object_field(game_state, "chapterState")
        .or_else(|| read_object_field(&memory, "currentChapter"))
        .cloned();
    let chapter_state =
        resolve_current_chapter_state(game_state, &memory, previous_chapter.as_ref());
    ensure_json_object(game_state).insert("chapterState".to_string(), chapter_state.clone());
    ensure_json_object(&mut memory).insert("currentChapter".to_string(), chapter_state.clone());

    let journey_beat = resolve_current_journey_beat(game_state, &memory, &chapter_state);
    let journey_beat_id = read_optional_string_field(&journey_beat, "id")
        .unwrap_or_else(|| "journey:default".to_string());
    let memory_root = ensure_json_object(&mut memory);
    memory_root.insert("currentJourneyBeatId".to_string(), json!(journey_beat_id));
    memory_root.insert("currentJourneyBeat".to_string(), journey_beat.clone());

    let new_mutations = resolve_world_mutations(game_state, &memory, &signals, &chapter_state);
    let world_mutations = append_world_mutations(&memory, new_mutations);
    ensure_json_object(&mut memory).insert(
        "worldMutations".to_string(),
        Value::Array(world_mutations.clone()),
    );
    apply_world_mutations_to_game_state(game_state, &world_mutations);

    let reactions = build_companion_reactions(game_state, &signals, action_text);
    apply_companion_reactions_to_stance(game_state, &reactions);
    append_recent_companion_reactions(&mut memory, reactions);

    let chronicle = append_chronicle_entries(&memory, &chapter_state, &world_mutations);
    ensure_json_object(&mut memory)
        .insert("chronicle".to_string(), Value::Array(chronicle.clone()));
    ensure_json_object(&mut memory).insert(
        "continueGameDigest".to_string(),
        Value::String(build_continue_digest(
            &chapter_state,
            result_text,
            &chronicle,
        )),
    );
    ensure_json_object(&mut memory).insert(
        "saveMigrationManifest".to_string(),
        json!({
            "version": "story-engine-backend-v1",
            "requiredTransforms": [],
            "backwardCompatible": true
        }),
    );

    ensure_json_object(game_state).insert("storyEngineMemory".to_string(), memory);
}

fn ensure_memory_defaults(memory: &mut Value) {
    let root = ensure_json_object(memory);
    ensure_array_field(root, "discoveredFactIds");
    ensure_array_field(root, "inferredFactIds");
    ensure_array_field(root, "activeThreadIds");
    ensure_array_field(root, "resolvedScarIds");
    ensure_array_field(root, "recentCarrierIds");
    ensure_array_field(root, "openedSceneChapterIds");
    ensure_array_field(root, "recentSignalIds");
    ensure_array_field(root, "recentCompanionReactions");
    ensure_array_field(root, "worldMutations");
    ensure_array_field(root, "chronicle");
    ensure_array_field(root, "factionTensionStates");
    ensure_array_field(root, "consequenceLedger");
    ensure_array_field(root, "companionResolutions");
    ensure_array_field(root, "narrativeCodex");
    root.entry("currentSceneActState".to_string())
        .or_insert(Value::Null);
    root.entry("currentChapter".to_string())
        .or_insert(Value::Null);
    root.entry("currentJourneyBeatId".to_string())
        .or_insert(Value::Null);
    root.entry("currentJourneyBeat".to_string())
        .or_insert(Value::Null);
    root.entry("currentCampEvent".to_string())
        .or_insert(Value::Null);
    root.entry("currentSetpieceDirective".to_string())
        .or_insert(Value::Null);
    root.entry("continueGameDigest".to_string())
        .or_insert(Value::Null);
    root.entry("campaignState".to_string())
        .or_insert(Value::Null);
    root.entry("actState".to_string()).or_insert(Value::Null);
    root.entry("endingState".to_string()).or_insert(Value::Null);
    root.entry("authorialConstraintPack".to_string())
        .or_insert(Value::Null);
    root.entry("branchBudgetStatus".to_string())
        .or_insert(Value::Null);
    root.entry("narrativeQaReport".to_string())
        .or_insert(Value::Null);
    root.entry("releaseGateReport".to_string())
        .or_insert(Value::Null);
    root.entry("playerStyleProfile".to_string())
        .or_insert(Value::Null);
}

fn ensure_array_field(root: &mut Map<String, Value>, key: &str) {
    if !root.get(key).is_some_and(Value::is_array) {
        root.insert(key.to_string(), Value::Array(Vec::new()));
    }
}

fn should_update_scene_chapter_state(function_id: &str) -> bool {
    !matches!(function_id, "npc_fight" | "npc_spar")
}

fn collect_story_signals(
    previous_state: &Value,
    next_state: &Value,
    memory: &Value,
    action_text: &str,
    function_id: &str,
    battle_outcome: Option<&str>,
) -> Vec<Value> {
    let mut signals = Vec::new();
    let active_thread_ids = read_string_array_field(memory, "activeThreadIds");
    let previous_scene_id = current_scene_id(previous_state);
    let next_scene_id = current_scene_id(next_state);

    if previous_scene_id != next_scene_id {
        if let Some(scene_id) = previous_scene_id.as_deref() {
            signals.push(build_signal(
                "leave_scene",
                scene_id,
                json!({
                    "sceneId": scene_id,
                    "threadIds": active_thread_ids,
                }),
            ));
        }
        if let Some(scene_id) = next_scene_id.as_deref() {
            signals.push(build_signal(
                "enter_scene",
                scene_id,
                json!({
                    "sceneId": scene_id,
                    "threadIds": active_thread_ids,
                }),
            ));
        }
    }

    if function_id == "idle_observe_signs" {
        let key = next_scene_id.as_deref().unwrap_or("scene");
        signals.push(build_signal(
            "inspect_scene",
            key,
            json!({
                "sceneId": next_scene_id,
                "threadIds": active_thread_ids,
            }),
        ));
    }

    if is_talk_signal(function_id, action_text, next_state) {
        let actor_id =
            current_encounter_id(next_state).or_else(|| current_encounter_id(previous_state));
        let key = actor_id.as_deref().unwrap_or(action_text);
        signals.push(build_signal(
            "talk_to_actor",
            key,
            json!({
                "actorId": actor_id,
                "threadIds": active_thread_ids,
            }),
        ));
    }

    if function_id == "npc_gift" {
        let actor_id =
            current_encounter_id(previous_state).or_else(|| current_encounter_id(next_state));
        signals.push(build_signal(
            "give_item",
            action_text,
            json!({
                "actorId": actor_id,
                "threadIds": active_thread_ids,
            }),
        ));
    }

    if function_id == "npc_quest_accept" {
        let actor_id =
            current_encounter_id(previous_state).or_else(|| current_encounter_id(next_state));
        signals.push(build_signal(
            "accept_contract",
            action_text,
            json!({
                "actorId": actor_id,
                "threadIds": active_thread_ids,
            }),
        ));
    }

    if is_battle_win_signal(function_id, previous_state, next_state, battle_outcome) {
        let key = next_scene_id.as_deref().unwrap_or("battle");
        signals.push(build_signal(
            "win_battle",
            key,
            json!({
                "sceneId": next_scene_id,
                "threadIds": active_thread_ids,
            }),
        ));
    }

    for item in find_new_inventory_items(previous_state, next_state) {
        let item_id = read_optional_string_field(&item, "id").unwrap_or_else(|| "item".to_string());
        let thread_ids = read_field(&item, "runtimeMetadata")
            .and_then(|metadata| read_field(metadata, "storyFingerprint"))
            .map(|fingerprint| read_string_array_field(fingerprint, "relatedThreadIds"))
            .filter(|ids| !ids.is_empty())
            .unwrap_or_else(|| active_thread_ids.clone());
        signals.push(build_signal(
            "obtain_carrier",
            item_id.as_str(),
            json!({
                "carrierId": item_id,
                "threadIds": thread_ids,
            }),
        ));
    }

    dedupe_value_objects_by_id(signals, 12)
}

fn build_signal(signal_type: &str, key: &str, extra: Value) -> Value {
    let mut signal = extra.as_object().cloned().unwrap_or_default();
    signal.insert(
        "id".to_string(),
        Value::String(format!("{signal_type}:{key}")),
    );
    signal.insert(
        "signalType".to_string(),
        Value::String(signal_type.to_string()),
    );
    Value::Object(signal)
}

fn is_talk_signal(function_id: &str, action_text: &str, next_state: &Value) -> bool {
    matches!(
        function_id,
        "npc_chat"
            | "npc_preview_talk"
            | "npc_help"
            | "story_opening_camp_dialogue"
            | "npc_chat_quest_offer_view"
            | "npc_quest_accept"
            | "npc_quest_turn_in"
    ) || read_object_field(next_state, "currentEncounter")
        .and_then(|encounter| read_optional_string_field(encounter, "kind"))
        .as_deref()
        == Some("npc")
        || action_text.contains('聊')
        || action_text.contains('问')
        || action_text.contains("试探")
}

fn is_battle_win_signal(
    function_id: &str,
    previous_state: &Value,
    next_state: &Value,
    battle_outcome: Option<&str>,
) -> bool {
    if !function_id.starts_with("battle_") && function_id != "inventory_use" {
        return false;
    }
    if let Some(outcome) = battle_outcome {
        // 中文注释：战斗终局已经由 battle resolver 明确给出时，
        // story engine 必须信任该结果，避免败北复活清空战斗态后被误判为胜利信号。
        return matches!(outcome, "victory" | "spar_complete");
    }
    let previous_battle = read_bool_field(previous_state, "inBattle").unwrap_or(false);
    let next_battle = read_bool_field(next_state, "inBattle").unwrap_or(false);
    let outcome = read_optional_string_field(next_state, "currentNpcBattleOutcome");
    matches!(
        outcome.as_deref(),
        Some("fight_victory") | Some("spar_complete")
    ) && previous_battle
        && !next_battle
}

fn find_new_inventory_items(previous_state: &Value, next_state: &Value) -> Vec<Value> {
    let previous_ids = read_array_field(previous_state, "playerInventory")
        .into_iter()
        .filter_map(|item| read_optional_string_field(item, "id"))
        .collect::<std::collections::HashSet<_>>();

    read_array_field(next_state, "playerInventory")
        .into_iter()
        .filter(|item| {
            read_optional_string_field(item, "id").is_some_and(|id| !previous_ids.contains(&id))
        })
        .cloned()
        .collect()
}

fn apply_thread_signal_updates(game_state: &mut Value, memory: &mut Value, signals: &[Value]) {
    if signals.is_empty() {
        return;
    }

    let active_thread_ids = dedupe_strings(
        read_string_array_field(memory, "activeThreadIds")
            .into_iter()
            .chain(
                signals
                    .iter()
                    .flat_map(|signal| read_string_array_field(signal, "threadIds")),
            )
            .collect(),
        8,
    );
    let recent_signal_ids = dedupe_strings(
        read_string_array_field(memory, "recentSignalIds")
            .into_iter()
            .chain(
                signals
                    .iter()
                    .filter_map(|signal| read_optional_string_field(signal, "id")),
            )
            .collect(),
        12,
    );
    let root = ensure_json_object(memory);
    root.insert("activeThreadIds".to_string(), json!(active_thread_ids));
    root.insert("recentSignalIds".to_string(), json!(recent_signal_ids));

    update_quests_from_signals(game_state, signals);
}

fn update_quests_from_signals(game_state: &mut Value, signals: &[Value]) {
    let signal_thread_ids = signals
        .iter()
        .flat_map(|signal| read_string_array_field(signal, "threadIds"))
        .collect::<Vec<_>>();
    if signal_thread_ids.is_empty() {
        return;
    }

    let root = ensure_json_object(game_state);
    let quests = root
        .entry("quests".to_string())
        .or_insert_with(|| json!([]));
    let Some(items) = quests.as_array_mut() else {
        *quests = Value::Array(Vec::new());
        return;
    };

    for quest in items {
        let Some(quest_object) = quest.as_object_mut() else {
            continue;
        };
        let quest_thread_id = quest_object
            .get("threadId")
            .and_then(Value::as_str)
            .map(str::to_string);
        if !quest_thread_id
            .as_ref()
            .is_some_and(|thread_id| signal_thread_ids.iter().any(|id| id == thread_id))
        {
            continue;
        }

        let next_visible_stage = quest_object
            .get("visibleStage")
            .and_then(Value::as_i64)
            .unwrap_or(0)
            .saturating_add(i64::try_from(signals.len()).unwrap_or(0))
            .min(12);
        quest_object.insert("visibleStage".to_string(), json!(next_visible_stage));
        let discovered = dedupe_strings(
            read_string_array_from_object(quest_object, "discoveredFactIds")
                .into_iter()
                .chain(signal_thread_ids.clone())
                .collect(),
            12,
        );
        quest_object.insert("discoveredFactIds".to_string(), json!(discovered));
    }
}

fn ensure_scene_chapter_state(game_state: &mut Value, memory: &mut Value) {
    let current_scene = read_optional_string_field(game_state, "currentScene");
    let world_type = read_optional_string_field(game_state, "worldType");
    let Some(scene) = read_object_field(game_state, "currentScenePreset").cloned() else {
        return;
    };
    let Some(scene_id) = read_optional_string_field(&scene, "id") else {
        return;
    };
    if current_scene.as_deref() != Some("Story") || world_type.is_none() {
        return;
    }

    let opened = dedupe_strings(
        read_string_array_field(memory, "openedSceneChapterIds")
            .into_iter()
            .chain(std::iter::once(scene_id.clone()))
            .collect(),
        64,
    );
    ensure_json_object(memory).insert("openedSceneChapterIds".to_string(), json!(opened));

    if let Some(scene_act_state) =
        build_initial_scene_act_runtime_state(game_state, memory, scene_id.as_str())
    {
        ensure_json_object(memory).insert("currentSceneActState".to_string(), scene_act_state);
    }

    if has_live_scene_chapter_quest(game_state, scene_id.as_str()) {
        return;
    }

    let quest = build_scene_chapter_quest(game_state, &scene, scene_id.as_str());
    let root = ensure_json_object(game_state);
    let quests = root
        .entry("quests".to_string())
        .or_insert_with(|| json!([]));
    if !quests.is_array() {
        *quests = Value::Array(Vec::new());
    }
    quests
        .as_array_mut()
        .expect("quests should be array")
        .push(quest);
}

fn has_live_scene_chapter_quest(game_state: &Value, scene_id: &str) -> bool {
    let chapter_id = build_scene_chapter_id(scene_id);
    read_array_field(game_state, "quests")
        .into_iter()
        .any(|quest| {
            read_optional_string_field(quest, "chapterId").as_deref() == Some(chapter_id.as_str())
                && !matches!(
                    read_optional_string_field(quest, "status").as_deref(),
                    Some("turned_in") | Some("failed") | Some("expired")
                )
        })
}

fn build_scene_chapter_quest(game_state: &Value, scene: &Value, scene_id: &str) -> Value {
    let scene_name =
        read_optional_string_field(scene, "name").unwrap_or_else(|| "当前区域".to_string());
    let scene_description = read_optional_string_field(scene, "description")
        .unwrap_or_else(|| format!("{scene_name} 的局势正在变化。"));
    let (issuer_npc_id, issuer_npc_name) = resolve_scene_chapter_issuer(scene);
    let chapter_id = build_scene_chapter_id(scene_id);
    let quest_id = format!("quest:chapter:{scene_id}");
    let title = compact_title(format!("{scene_name}异动").as_str(), "查明异动");
    let world_type = read_optional_string_field(game_state, "worldType");
    let currency = if world_type.as_deref() == Some("XIANXIA") {
        54
    } else {
        72
    };

    json!({
        "id": quest_id,
        "issuerNpcId": issuer_npc_id,
        "issuerNpcName": issuer_npc_name,
        "sceneId": scene_id,
        "chapterId": chapter_id,
        "actId": read_field(game_state, "storyEngineMemory")
            .and_then(|memory| read_field(memory, "actState"))
            .and_then(|act| read_optional_string_field(act, "id")),
        "threadId": Value::Null,
        "contractId": Value::Null,
        "title": title,
        "description": format!("{scene_description} 这一章需要先把现场线索和压力接住。"),
        "summary": format!("在 {scene_name} 接住这一章的线索并完成收束"),
        "objective": {
            "kind": "talk_to_npc",
            "targetNpcId": issuer_npc_id,
            "requiredCount": 1
        },
        "progress": 0,
        "status": "active",
        "completionNotified": false,
        "reward": {
            "affinityBonus": 12,
            "currency": currency,
            "experience": 40,
            "items": []
        },
        "rewardText": format!("完成后可获得好感 +12、赏金 {currency}、经验 +40。"),
        "narrativeBinding": {
            "origin": "fallback_builder",
            "narrativeType": "investigation",
            "dramaticNeed": format!("{scene_name} 的异常已经足以独立成章。"),
            "issuerGoal": format!("查清 {scene_name} 当前没有说透的异动。"),
            "playerHook": format!("你已经进入 {scene_name}，这一章现在就落在你面前。"),
            "worldReason": format!("{scene_name} 的线索和残痕正在把局势往前推。"),
            "followupHooks": [format!("{scene_name} 的这一章收束后，下一段去向会更明确。")]
        },
        "steps": [
            {
                "id": format!("{quest_id}:opening"),
                "title": "确认现场异样",
                "kind": "talk_to_npc",
                "targetNpcId": issuer_npc_id,
                "requiredCount": 1,
                "progress": 0,
                "revealText": format!("先在 {scene_name} 确认眼前异样，不要让这一章从开口处滑过去。"),
                "completeText": format!("{scene_name} 的表层线索已经确认，可以继续推进收束。")
            },
            {
                "id": format!("{quest_id}:resolve"),
                "title": "收束当前章节",
                "kind": "reach_scene",
                "targetSceneId": scene_id,
                "requiredCount": 1,
                "progress": 0,
                "revealText": format!("继续推进 {scene_name} 的线索，把这一章推向收束。"),
                "completeText": format!("{scene_name} 的这一章已经完成收束。")
            }
        ],
        "activeStepId": format!("{quest_id}:opening"),
        "visibleStage": 0,
        "hiddenFlags": [],
        "discoveredFactIds": [],
        "relatedCarrierIds": [],
        "consequenceIds": []
    })
}

fn resolve_scene_chapter_issuer(scene: &Value) -> (String, String) {
    let npc = read_array_field(scene, "npcs")
        .into_iter()
        .find(|npc| !read_bool_field(npc, "hostile").unwrap_or(false))
        .or_else(|| read_array_field(scene, "npcs").into_iter().next());
    let npc_id = npc
        .and_then(|value| read_optional_string_field(value, "id"))
        .unwrap_or_else(|| "scene-guide".to_string());
    let npc_name = npc
        .and_then(|value| {
            read_optional_string_field(value, "name")
                .or_else(|| read_optional_string_field(value, "npcName"))
        })
        .unwrap_or_else(|| {
            read_optional_string_field(scene, "name").unwrap_or_else(|| "现场线索".to_string())
        });
    (npc_id, npc_name)
}

fn build_initial_scene_act_runtime_state(
    game_state: &Value,
    memory: &Value,
    scene_id: &str,
) -> Option<Value> {
    let profile = read_object_field(game_state, "customWorldProfile")?;
    let chapter = resolve_scene_chapter_blueprint(profile, scene_id)?;
    let chapter_id = read_optional_string_field(chapter, "id")?;
    let acts = read_array_field(chapter, "acts");
    let first_act = acts.first().copied()?;
    let first_act_id = read_optional_string_field(first_act, "id")?;

    if let Some(runtime_state) = read_object_field(memory, "currentSceneActState") {
        if read_optional_string_field(runtime_state, "chapterId").as_deref()
            == Some(chapter_id.as_str())
        {
            let current_act_id = read_optional_string_field(runtime_state, "currentActId");
            if current_act_id.as_ref().is_some_and(|act_id| {
                acts.iter().any(|act| {
                    read_optional_string_field(act, "id").as_deref() == Some(act_id.as_str())
                })
            }) {
                return Some(json!({
                    "sceneId": read_optional_string_field(runtime_state, "sceneId").unwrap_or_else(|| scene_id.to_string()),
                    "chapterId": chapter_id,
                    "currentActId": current_act_id,
                    "currentActIndex": read_i32_field(runtime_state, "currentActIndex").unwrap_or(0).max(0),
                    "completedActIds": read_string_array_field(runtime_state, "completedActIds"),
                    "visitedActIds": read_string_array_field(runtime_state, "visitedActIds"),
                }));
            }
        }
    }

    Some(json!({
        "sceneId": read_optional_string_field(chapter, "sceneId").unwrap_or_else(|| scene_id.to_string()),
        "chapterId": chapter_id,
        "currentActId": first_act_id,
        "currentActIndex": 0,
        "completedActIds": [],
        "visitedActIds": [first_act_id]
    }))
}

fn resolve_scene_chapter_blueprint<'a>(profile: &'a Value, scene_id: &str) -> Option<&'a Value> {
    read_array_field(profile, "sceneChapterBlueprints")
        .into_iter()
        .find(|chapter| {
            read_optional_string_field(chapter, "sceneId").as_deref() == Some(scene_id)
                || read_string_array_field(chapter, "linkedLandmarkIds")
                    .iter()
                    .any(|id| id == scene_id)
                || read_array_field(chapter, "acts").into_iter().any(|act| {
                    read_optional_string_field(act, "sceneId").as_deref() == Some(scene_id)
                })
        })
}

fn resolve_current_chapter_state(
    game_state: &Value,
    memory: &Value,
    previous_chapter: Option<&Value>,
) -> Value {
    let active_thread_ids = read_string_array_field(memory, "activeThreadIds");
    let scene_id = current_scene_id(game_state);
    let scene_name = read_object_field(game_state, "currentScenePreset")
        .and_then(|scene| read_optional_string_field(scene, "name"))
        .unwrap_or_else(|| "当前区域".to_string());

    if let Some((quest, chapter_id)) = scene_id.as_deref().and_then(|id| {
        find_scene_chapter_quest(game_state, id).map(|quest| (quest, build_scene_chapter_id(id)))
    }) {
        let stage = derive_chapter_stage_from_quest(quest);
        let theme = read_optional_string_field(quest, "title")
            .or_else(|| resolve_profile_theme(game_state, &active_thread_ids))
            .unwrap_or_else(|| "旅程推进".to_string());
        let primary_thread_ids = dedupe_strings(
            read_optional_string_field(quest, "threadId")
                .into_iter()
                .chain(active_thread_ids.clone())
                .collect(),
            3,
        );
        return json!({
            "id": chapter_id,
            "title": format!("{scene_name}·{}", stage_label(stage)),
            "theme": theme,
            "primaryThreadIds": primary_thread_ids,
            "stage": stage,
            "chapterSummary": build_scene_chapter_summary(scene_name.as_str(), quest, stage),
            "sceneId": scene_id,
            "chapterQuestId": read_optional_string_field(quest, "id"),
        });
    }

    let stage = resolve_freeform_chapter_stage(game_state, memory, previous_chapter);
    let theme = resolve_profile_theme(game_state, &active_thread_ids)
        .unwrap_or_else(|| "旅程推进".to_string());
    let title = format!("{theme}·{}", stage_label(stage));
    let chapter_id = if previous_chapter
        .and_then(|chapter| read_optional_string_field(chapter, "stage"))
        .as_deref()
        == Some(stage)
        && previous_chapter
            .and_then(|chapter| read_optional_string_field(chapter, "theme"))
            .as_deref()
            == Some(theme.as_str())
    {
        previous_chapter
            .and_then(|chapter| read_optional_string_field(chapter, "id"))
            .unwrap_or_else(|| build_freeform_chapter_id(&active_thread_ids, stage))
    } else {
        build_freeform_chapter_id(&active_thread_ids, stage)
    };

    json!({
        "id": chapter_id,
        "title": title,
        "theme": theme,
        "primaryThreadIds": dedupe_strings(active_thread_ids, 3),
        "stage": stage,
        "chapterSummary": format!("{title} 当前围绕 {theme} 推进。"),
        "sceneId": Value::Null,
        "chapterQuestId": Value::Null,
    })
}

fn find_scene_chapter_quest<'a>(game_state: &'a Value, scene_id: &str) -> Option<&'a Value> {
    let chapter_id = build_scene_chapter_id(scene_id);
    read_array_field(game_state, "quests")
        .into_iter()
        .find(|quest| {
            read_optional_string_field(quest, "chapterId").as_deref() == Some(chapter_id.as_str())
                && !matches!(
                    read_optional_string_field(quest, "status").as_deref(),
                    Some("failed") | Some("expired")
                )
        })
}

fn derive_chapter_stage_from_quest(quest: &Value) -> &'static str {
    match read_optional_string_field(quest, "status").as_deref() {
        Some("turned_in") => return CHAPTER_STAGE_AFTERMATH,
        Some("ready_to_turn_in") | Some("completed") => return CHAPTER_STAGE_CLIMAX,
        _ => {}
    }

    let steps = read_array_field(quest, "steps");
    let active_step_id = read_optional_string_field(quest, "activeStepId");
    let active_step_index = active_step_id
        .as_deref()
        .and_then(|id| {
            steps
                .iter()
                .position(|step| read_optional_string_field(step, "id").as_deref() == Some(id))
        })
        .unwrap_or(0);
    match active_step_index {
        0 => CHAPTER_STAGE_OPENING,
        1 => CHAPTER_STAGE_EXPANSION,
        _ => CHAPTER_STAGE_TURNING_POINT,
    }
}

fn build_scene_chapter_summary(scene_name: &str, quest: &Value, stage: &str) -> String {
    let quest_description = read_optional_string_field(quest, "description")
        .or_else(|| read_optional_string_field(quest, "summary"))
        .unwrap_or_else(|| "这一章仍在推进中。".to_string());
    match stage {
        CHAPTER_STAGE_OPENING => format!("{scene_name} 的这一章刚刚开启。{quest_description}"),
        CHAPTER_STAGE_EXPANSION => format!("{scene_name} 的压力正在展开。{quest_description}"),
        CHAPTER_STAGE_TURNING_POINT => {
            format!("{scene_name} 的线索正在改写当前判断。{quest_description}")
        }
        CHAPTER_STAGE_CLIMAX => {
            format!("{scene_name} 的核心矛盾已经被推到最后一步，只差正式收束。")
        }
        CHAPTER_STAGE_AFTERMATH => {
            format!("{scene_name} 这一章已经完成收束，余波和下一段去向正在显形。")
        }
        _ => format!("{scene_name} 的这一章仍在推进中。"),
    }
}

fn resolve_freeform_chapter_stage(
    game_state: &Value,
    memory: &Value,
    previous_chapter: Option<&Value>,
) -> &'static str {
    let score = i32::try_from(read_string_array_field(memory, "recentSignalIds").len())
        .unwrap_or(0)
        + i32::try_from(read_array_field(memory, "chronicle").len()).unwrap_or(0)
        + i32::try_from(read_string_array_field(memory, "activeThreadIds").len()).unwrap_or(0);
    if score >= 12 {
        CHAPTER_STAGE_AFTERMATH
    } else if score >= 9 {
        CHAPTER_STAGE_CLIMAX
    } else if score >= 6 {
        CHAPTER_STAGE_TURNING_POINT
    } else if score >= 3 {
        CHAPTER_STAGE_EXPANSION
    } else if read_object_field(game_state, "chapterState")
        .and_then(|chapter| read_optional_string_field(chapter, "stage"))
        .or_else(|| {
            previous_chapter.and_then(|chapter| read_optional_string_field(chapter, "stage"))
        })
        .as_deref()
        == Some(CHAPTER_STAGE_AFTERMATH)
    {
        CHAPTER_STAGE_AFTERMATH
    } else {
        CHAPTER_STAGE_OPENING
    }
}

fn resolve_profile_theme(game_state: &Value, active_thread_ids: &[String]) -> Option<String> {
    let profile = read_object_field(game_state, "customWorldProfile")?;
    if let Some(thread_title) = first_thread_title(profile, active_thread_ids) {
        return Some(thread_title);
    }
    read_object_field(profile, "themePack")
        .and_then(|theme_pack| read_optional_string_field(theme_pack, "displayName"))
        .or_else(|| read_optional_string_field(profile, "summary"))
}

fn first_thread_title(profile: &Value, active_thread_ids: &[String]) -> Option<String> {
    let story_graph = read_object_field(profile, "storyGraph")?;
    let threads = read_array_field(story_graph, "visibleThreads")
        .into_iter()
        .chain(read_array_field(story_graph, "hiddenThreads"))
        .collect::<Vec<_>>();
    active_thread_ids.iter().find_map(|thread_id| {
        threads.iter().find_map(|thread| {
            (read_optional_string_field(thread, "id").as_deref() == Some(thread_id.as_str()))
                .then(|| read_optional_string_field(thread, "title"))
                .flatten()
        })
    })
}

fn resolve_current_journey_beat(
    game_state: &Value,
    memory: &Value,
    chapter_state: &Value,
) -> Value {
    let chapter_id = read_optional_string_field(chapter_state, "id")
        .unwrap_or_else(|| "chapter:default".to_string());
    let chapter_title = read_optional_string_field(chapter_state, "title")
        .unwrap_or_else(|| "当前章节".to_string());
    let stage = read_optional_string_field(chapter_state, "stage")
        .unwrap_or_else(|| CHAPTER_STAGE_OPENING.to_string());
    let beat_type = match stage.as_str() {
        CHAPTER_STAGE_OPENING => "approach",
        CHAPTER_STAGE_EXPANSION => "investigation",
        CHAPTER_STAGE_TURNING_POINT => "conflict",
        CHAPTER_STAGE_CLIMAX => "climax",
        CHAPTER_STAGE_AFTERMATH => "recovery",
        _ => "approach",
    };
    let stored_beat_id = read_optional_string_field(memory, "currentJourneyBeatId");
    let id = stored_beat_id.unwrap_or_else(|| format!("{chapter_id}:{beat_type}"));
    let current_scene_id = current_scene_id(game_state).into_iter().collect::<Vec<_>>();
    let emotional_goal = if beat_type == "climax" {
        "把冲突推到最前台。"
    } else if beat_type == "recovery" {
        "让角色和世界消化刚发生的后果。"
    } else {
        "让线索、关系和压力继续叠加。"
    };

    json!({
        "id": id,
        "beatType": beat_type,
        "title": format!("{chapter_title}·当前段落"),
        "triggerThreadIds": read_string_array_field(chapter_state, "primaryThreadIds"),
        "recommendedSceneIds": current_scene_id,
        "emotionalGoal": emotional_goal,
    })
}

fn resolve_world_mutations(
    game_state: &Value,
    memory: &Value,
    signals: &[Value],
    chapter_state: &Value,
) -> Vec<Value> {
    let mut mutations = Vec::new();
    let current_scene_id = current_scene_id(game_state);
    let active_thread_ids = read_string_array_field(memory, "activeThreadIds");
    let chapter_stage = read_optional_string_field(chapter_state, "stage");

    if let Some(scene_id) = current_scene_id.as_deref() {
        let chapter_title = read_optional_string_field(chapter_state, "title")
            .unwrap_or_else(|| "当前章节".to_string());
        mutations.push(json!({
            "id": format!("mutation:scene:{scene_id}:{}", chapter_stage.as_deref().unwrap_or(CHAPTER_STAGE_OPENING)),
            "mutationType": "scene_text",
            "targetId": scene_id,
            "reason": format!("{chapter_title}正在改写这片地界的表面气氛。"),
            "relatedThreadIds": read_string_array_field(chapter_state, "primaryThreadIds"),
        }));
    }

    if current_scene_id.is_some()
        && signals.iter().any(|signal| {
            read_optional_string_field(signal, "signalType").as_deref() == Some("win_battle")
        })
    {
        let scene_id = current_scene_id.as_deref().unwrap_or("scene");
        mutations.push(json!({
            "id": format!("mutation:pressure:{scene_id}:battle"),
            "mutationType": "enemy_pressure",
            "targetId": scene_id,
            "reason": "这一带的敌意正在因交锋结果重新聚拢。",
            "relatedThreadIds": dedupe_strings(active_thread_ids.clone(), 4),
        }));
    }

    if signals.iter().any(|signal| {
        read_optional_string_field(signal, "signalType").as_deref() == Some("obtain_carrier")
    }) {
        let scene_id = current_scene_id.as_deref().unwrap_or("scene");
        mutations.push(json!({
            "id": format!("mutation:attitude:{scene_id}:carrier"),
            "mutationType": "npc_attitude",
            "targetId": scene_id,
            "reason": "关键载体已经落到你手里，相关角色的口风会开始变化。",
            "relatedThreadIds": dedupe_strings(active_thread_ids.clone(), 4),
        }));
    }

    if chapter_stage.as_deref() == Some(CHAPTER_STAGE_CLIMAX) {
        if let Some(scene_id) = current_scene_id.as_deref() {
            mutations.push(json!({
                "id": format!("mutation:route:{scene_id}:climax"),
                "mutationType": "route_unlock",
                "targetId": scene_id,
                "reason": "章节高潮逼近，新的通路或对峙点开始显影。",
                "relatedThreadIds": read_string_array_field(chapter_state, "primaryThreadIds"),
            }));
        }
    }

    dedupe_value_objects_by_id(mutations, 8)
}

fn append_world_mutations(memory: &Value, additions: Vec<Value>) -> Vec<Value> {
    dedupe_value_objects_by_id(
        read_array_field(memory, "worldMutations")
            .into_iter()
            .cloned()
            .chain(additions)
            .collect(),
        24,
    )
}

fn apply_world_mutations_to_game_state(game_state: &mut Value, mutations: &[Value]) {
    let Some(current_scene_id) = current_scene_id(game_state) else {
        return;
    };
    let relevant = mutations
        .iter()
        .filter(|mutation| {
            read_optional_string_field(mutation, "targetId").as_deref()
                == Some(current_scene_id.as_str())
        })
        .collect::<Vec<_>>();
    if relevant.is_empty() {
        return;
    }

    let latest_scene_reason = relevant
        .iter()
        .rev()
        .find(|mutation| {
            read_optional_string_field(mutation, "mutationType").as_deref() == Some("scene_text")
        })
        .and_then(|mutation| read_optional_string_field(mutation, "reason"));
    let latest_attitude_reason = relevant
        .iter()
        .rev()
        .find(|mutation| {
            read_optional_string_field(mutation, "mutationType").as_deref() == Some("npc_attitude")
        })
        .and_then(|mutation| read_optional_string_field(mutation, "reason"));
    let pressure_count = relevant
        .iter()
        .filter(|mutation| {
            read_optional_string_field(mutation, "mutationType").as_deref()
                == Some("enemy_pressure")
        })
        .count();
    let pressure_level = match pressure_count {
        count if count >= 3 => "extreme",
        2 => "high",
        1 => "medium",
        _ => "low",
    };

    let root = ensure_json_object(game_state);
    let Some(scene) = root
        .get_mut("currentScenePreset")
        .and_then(Value::as_object_mut)
    else {
        return;
    };
    let mutation_text = [latest_scene_reason.clone(), latest_attitude_reason.clone()]
        .into_iter()
        .flatten()
        .filter(|text| !text.trim().is_empty())
        .collect::<Vec<_>>()
        .join(" ");
    if !mutation_text.is_empty() {
        scene.insert(
            "mutationStateText".to_string(),
            Value::String(mutation_text),
        );
    }
    scene.insert(
        "currentPressureLevel".to_string(),
        Value::String(pressure_level.to_string()),
    );

    if let Some(reason) = latest_scene_reason {
        let description = scene
            .get("description")
            .and_then(Value::as_str)
            .unwrap_or_default()
            .to_string();
        if !description.contains(reason.as_str()) {
            let next_description = [description.as_str(), reason.as_str()]
                .into_iter()
                .filter(|text| !text.trim().is_empty())
                .collect::<Vec<_>>()
                .join(" ");
            scene.insert("description".to_string(), Value::String(next_description));
        }
    }

    if let Some(attitude_reason) = latest_attitude_reason {
        if let Some(npcs) = scene.get_mut("npcs").and_then(Value::as_array_mut) {
            for npc in npcs {
                if read_bool_field(npc, "hostile").unwrap_or(false) {
                    continue;
                }
                let description =
                    read_optional_string_field(npc, "description").unwrap_or_default();
                if description.contains(attitude_reason.as_str()) {
                    continue;
                }
                if let Some(npc_object) = npc.as_object_mut() {
                    let next_description = [description.as_str(), attitude_reason.as_str()]
                        .into_iter()
                        .filter(|text| !text.trim().is_empty())
                        .collect::<Vec<_>>()
                        .join(" ");
                    npc_object.insert("description".to_string(), Value::String(next_description));
                }
            }
        }
    }
}

fn build_companion_reactions(
    game_state: &Value,
    signals: &[Value],
    action_text: &str,
) -> Vec<Value> {
    let signal_types = signals
        .iter()
        .filter_map(|signal| read_optional_string_field(signal, "signalType"))
        .collect::<Vec<_>>();
    let related_thread_ids = dedupe_strings(
        signals
            .iter()
            .flat_map(|signal| read_string_array_field(signal, "threadIds"))
            .collect(),
        4,
    );
    let companions = read_array_field(game_state, "companions")
        .into_iter()
        .chain(read_array_field(game_state, "roster"))
        .take(2)
        .cloned()
        .collect::<Vec<_>>();
    let reaction_type = resolve_reaction_type(action_text, &signal_types);

    companions
        .into_iter()
        .enumerate()
        .filter_map(|(index, companion)| {
            let character_id = read_optional_string_field(&companion, "characterId")?;
            Some(json!({
                "id": format!("reaction:{character_id}:{}:{}", signal_types.len(), index + 1),
                "characterId": character_id,
                "reactionType": reaction_type,
                "reason": build_reaction_reason(action_text, reaction_type),
                "relatedThreadIds": related_thread_ids,
                "createdAt": format_now_rfc3339(),
            }))
        })
        .collect()
}

fn resolve_reaction_type<'a>(action_text: &str, signal_types: &[String]) -> &'a str {
    if action_text.contains("强行")
        || action_text.contains("掠夺")
        || action_text.contains("恶意")
        || action_text.contains("开战")
        || action_text.contains("威胁")
    {
        "disapprove"
    } else if signal_types
        .iter()
        .any(|signal| signal == "accept_contract")
        || action_text.contains('帮')
        || action_text.contains('援')
        || action_text.contains("调查")
    {
        "approve"
    } else if signal_types
        .iter()
        .any(|signal| signal == "obtain_carrier" || signal == "inspect_scene")
    {
        "curious"
    } else if action_text.contains('礼') || action_text.contains('赠') || action_text.contains('送')
    {
        "concern"
    } else {
        "silence"
    }
}

fn build_reaction_reason(action_text: &str, reaction_type: &str) -> String {
    match reaction_type {
        "approve" => format!("同行角色觉得你这一步接得住局势：{action_text}"),
        "disapprove" => format!("同行角色对这一步明显有保留：{action_text}"),
        "concern" => format!("同行角色觉得你这一步可能会牵出额外代价：{action_text}"),
        "curious" => format!("同行角色被这一步新露出的线索勾住了注意力：{action_text}"),
        _ => format!("同行角色暂时没有正面插话，但显然记住了这一步：{action_text}"),
    }
}

fn apply_companion_reactions_to_stance(game_state: &mut Value, reactions: &[Value]) {
    if reactions.is_empty() {
        return;
    }
    let companions = read_array_field(game_state, "companions")
        .into_iter()
        .chain(read_array_field(game_state, "roster"))
        .cloned()
        .collect::<Vec<_>>();
    let root = ensure_json_object(game_state);
    let Some(npc_states) = root.get_mut("npcStates").and_then(Value::as_object_mut) else {
        return;
    };

    for reaction in reactions {
        let Some(character_id) = read_optional_string_field(reaction, "characterId") else {
            continue;
        };
        let Some(companion) = companions.iter().find(|companion| {
            read_optional_string_field(companion, "characterId").as_deref()
                == Some(character_id.as_str())
        }) else {
            continue;
        };
        let Some(npc_id) = read_optional_string_field(companion, "npcId") else {
            continue;
        };
        let Some(stance) = npc_states
            .get_mut(npc_id.as_str())
            .and_then(|state| state.as_object_mut())
            .and_then(|state| state.get_mut("stanceProfile"))
            .and_then(Value::as_object_mut)
        else {
            continue;
        };
        let reaction_type =
            read_optional_string_field(reaction, "reactionType").unwrap_or_default();
        adjust_stance_for_reaction(stance, reaction, reaction_type.as_str());
    }
}

fn adjust_stance_for_reaction(
    stance: &mut Map<String, Value>,
    reaction: &Value,
    reaction_type: &str,
) {
    match reaction_type {
        "approve" => {
            bump_stance_number(stance, "trust", 2);
            bump_stance_number(stance, "loyalty", 1);
            append_stance_note(stance, "recentApprovals", reaction);
        }
        "disapprove" => {
            bump_stance_number(stance, "fearOrGuard", 3);
            append_stance_note(stance, "recentDisapprovals", reaction);
        }
        "concern" => {
            bump_stance_number(stance, "fearOrGuard", 2);
            append_stance_note(stance, "recentDisapprovals", reaction);
        }
        "curious" => {
            bump_stance_number(stance, "ideologicalFit", 1);
            append_stance_note(stance, "recentApprovals", reaction);
        }
        _ => {}
    }
}

fn bump_stance_number(stance: &mut Map<String, Value>, key: &str, delta: i32) {
    let next = stance
        .get(key)
        .and_then(Value::as_i64)
        .unwrap_or(0)
        .saturating_add(i64::from(delta))
        .clamp(0, 100);
    stance.insert(key.to_string(), json!(next));
}

fn append_stance_note(stance: &mut Map<String, Value>, key: &str, reaction: &Value) {
    let mut notes = stance
        .get(key)
        .and_then(Value::as_array)
        .cloned()
        .unwrap_or_default();
    if let Some(reason) = read_optional_string_field(reaction, "reason") {
        notes.push(Value::String(reason));
    }
    let keep_from = notes.len().saturating_sub(3);
    stance.insert(
        key.to_string(),
        Value::Array(notes.into_iter().skip(keep_from).collect()),
    );
}

fn append_recent_companion_reactions(memory: &mut Value, reactions: Vec<Value>) {
    if reactions.is_empty() {
        return;
    }
    let mut recent = read_array_field(memory, "recentCompanionReactions")
        .into_iter()
        .cloned()
        .chain(reactions)
        .collect::<Vec<_>>();
    let keep_from = recent.len().saturating_sub(6);
    recent = recent.into_iter().skip(keep_from).collect();
    ensure_json_object(memory).insert("recentCompanionReactions".to_string(), Value::Array(recent));
}

fn append_chronicle_entries(
    memory: &Value,
    chapter_state: &Value,
    world_mutations: &[Value],
) -> Vec<Value> {
    let now = format_now_rfc3339();
    let mut entries = read_array_field(memory, "chronicle")
        .into_iter()
        .cloned()
        .collect::<Vec<_>>();
    if let Some(chapter_id) = read_optional_string_field(chapter_state, "id") {
        entries.push(json!({
            "id": format!("chronicle:chapter:{chapter_id}"),
            "category": "chapter",
            "title": read_optional_string_field(chapter_state, "title").unwrap_or_else(|| "当前章节".to_string()),
            "summary": read_optional_string_field(chapter_state, "chapterSummary").unwrap_or_default(),
            "relatedIds": read_string_array_field(chapter_state, "primaryThreadIds"),
            "createdAt": now,
        }));
    }
    for mutation in world_mutations.iter().rev().take(4) {
        let Some(mutation_id) = read_optional_string_field(mutation, "id") else {
            continue;
        };
        entries.push(json!({
            "id": format!("chronicle:world_event:{mutation_id}"),
            "category": "world_event",
            "title": read_optional_string_field(mutation, "reason").unwrap_or_else(|| "世界状态变化".to_string()),
            "summary": format!(
                "{} 影响了 {}",
                read_optional_string_field(mutation, "mutationType").unwrap_or_else(|| "world_event".to_string()),
                read_optional_string_field(mutation, "targetId").unwrap_or_else(|| "scene".to_string())
            ),
            "relatedIds": read_string_array_field(mutation, "relatedThreadIds"),
            "createdAt": format_now_rfc3339(),
        }));
    }

    dedupe_value_objects_by_id(entries, 18)
}

fn build_continue_digest(chapter_state: &Value, result_text: &str, chronicle: &[Value]) -> String {
    let chapter_summary = read_optional_string_field(chapter_state, "chapterSummary")
        .unwrap_or_else(|| "当前章节仍在推进。".to_string());
    let recent = chronicle
        .iter()
        .rev()
        .take(3)
        .filter_map(|entry| {
            Some(format!(
                "- {}：{}",
                read_optional_string_field(entry, "title")?,
                read_optional_string_field(entry, "summary").unwrap_or_default()
            ))
        })
        .collect::<Vec<_>>()
        .join("\n");
    [chapter_summary, result_text.to_string(), recent]
        .into_iter()
        .filter(|text| !text.trim().is_empty())
        .collect::<Vec<_>>()
        .join("\n")
}

fn current_scene_id(game_state: &Value) -> Option<String> {
    read_object_field(game_state, "currentScenePreset")
        .and_then(|scene| read_optional_string_field(scene, "id"))
}

fn current_encounter_id(game_state: &Value) -> Option<String> {
    read_object_field(game_state, "currentEncounter").and_then(|encounter| {
        read_optional_string_field(encounter, "id")
            .or_else(|| read_optional_string_field(encounter, "npcName"))
    })
}

fn build_scene_chapter_id(scene_id: &str) -> String {
    format!("chapter:scene:{scene_id}")
}

fn build_freeform_chapter_id(active_thread_ids: &[String], stage: &str) -> String {
    let key = if active_thread_ids.is_empty() {
        "default".to_string()
    } else {
        active_thread_ids
            .iter()
            .take(2)
            .cloned()
            .collect::<Vec<_>>()
            .join("+")
    };
    format!("chapter:{key}:{stage}")
}

fn stage_label(stage: &str) -> &'static str {
    match stage {
        CHAPTER_STAGE_OPENING => "序章",
        CHAPTER_STAGE_EXPANSION => "展开",
        CHAPTER_STAGE_TURNING_POINT => "转折",
        CHAPTER_STAGE_CLIMAX => "高潮",
        CHAPTER_STAGE_AFTERMATH => "余波",
        _ => "推进",
    }
}

fn compact_title(raw: &str, fallback: &str) -> String {
    let cleaned = raw
        .replace(['《', '》', '「', '」', '“', '”', '"', '\''], "")
        .split([
            '，', '。', '！', '？', '；', '：', ',', '.', '!', '?', ';', ':',
        ])
        .next()
        .unwrap_or_default()
        .trim()
        .to_string();
    if cleaned.is_empty() {
        fallback.to_string()
    } else if cleaned.chars().count() > 12 {
        cleaned.chars().take(10).collect()
    } else {
        cleaned
    }
}

fn read_string_array_field(value: &Value, key: &str) -> Vec<String> {
    read_field(value, key)
        .and_then(Value::as_array)
        .map(|items| {
            items
                .iter()
                .filter_map(Value::as_str)
                .map(str::trim)
                .filter(|text| !text.is_empty())
                .map(ToOwned::to_owned)
                .collect()
        })
        .unwrap_or_default()
}

fn read_string_array_from_object(value: &Map<String, Value>, key: &str) -> Vec<String> {
    value
        .get(key)
        .and_then(Value::as_array)
        .map(|items| {
            items
                .iter()
                .filter_map(Value::as_str)
                .map(str::trim)
                .filter(|text| !text.is_empty())
                .map(ToOwned::to_owned)
                .collect()
        })
        .unwrap_or_default()
}

fn dedupe_strings(values: Vec<String>, limit: usize) -> Vec<String> {
    let mut seen = std::collections::HashSet::new();
    let mut result = Vec::new();
    for value in values {
        let trimmed = value.trim();
        if trimmed.is_empty() || !seen.insert(trimmed.to_string()) {
            continue;
        }
        result.push(trimmed.to_string());
        if result.len() >= limit {
            break;
        }
    }
    result
}

fn dedupe_value_objects_by_id(values: Vec<Value>, limit: usize) -> Vec<Value> {
    let mut seen = std::collections::HashSet::new();
    let mut result = Vec::new();
    for value in values {
        let id = read_optional_string_field(&value, "id").unwrap_or_else(|| value.to_string());
        if !seen.insert(id) {
            continue;
        }
        result.push(value);
    }
    let keep_from = result.len().saturating_sub(limit);
    result.into_iter().skip(keep_from).collect()
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn story_engine_projector_creates_scene_chapter_and_world_mutation() {
        let previous_state = json!({
            "worldType": "WUXIA",
            "currentScene": "Story",
            "storyHistory": [],
            "quests": [],
            "currentScenePreset": {
                "id": "scene-bridge",
                "name": "断桥口",
                "description": "风从桥下吹上来。",
                "npcs": [{
                    "id": "npc-guide",
                    "name": "沈七",
                    "hostile": false,
                    "description": "腰间挂着药囊的行商"
                }]
            },
            "storyEngineMemory": {
                "activeThreadIds": ["thread-bridge"]
            }
        });
        let mut next_state = previous_state.clone();

        project_story_engine_after_action(
            &previous_state,
            &mut next_state,
            "观察周围迹象",
            "你读出桥边留下的新痕。",
            "idle_observe_signs",
            None,
        );

        assert_eq!(
            next_state["chapterState"]["id"],
            json!("chapter:scene:scene-bridge")
        );
        assert_eq!(
            next_state["storyEngineMemory"]["currentChapter"]["stage"],
            json!("opening")
        );
        assert_eq!(
            next_state["quests"][0]["chapterId"],
            json!("chapter:scene:scene-bridge")
        );
        assert!(
            next_state["currentScenePreset"]["mutationStateText"]
                .as_str()
                .is_some_and(|text| text.contains("断桥口"))
        );
        assert!(
            next_state["storyEngineMemory"]["worldMutations"]
                .as_array()
                .is_some_and(|items| !items.is_empty())
        );
    }

    #[test]
    fn story_engine_projector_records_battle_pressure_mutation() {
        let previous_state = json!({
            "worldType": "WUXIA",
            "currentScene": "Story",
            "inBattle": true,
            "quests": [],
            "playerInventory": [],
            "currentScenePreset": {
                "id": "scene-bridge",
                "name": "断桥口",
                "description": "风从桥下吹上来。"
            },
            "storyEngineMemory": {
                "activeThreadIds": []
            }
        });
        let mut next_state = previous_state.clone();
        next_state["inBattle"] = Value::Bool(false);

        project_story_engine_after_action(
            &previous_state,
            &mut next_state,
            "普通攻击",
            "敌人倒下。",
            "battle_attack_basic",
            Some("victory"),
        );

        assert_eq!(
            next_state["currentScenePreset"]["currentPressureLevel"],
            json!("medium")
        );
        assert!(
            next_state["storyEngineMemory"]["worldMutations"]
                .as_array()
                .unwrap()
                .iter()
                .any(|mutation| mutation["mutationType"] == json!("enemy_pressure"))
        );
    }

    #[test]
    fn story_engine_projector_does_not_record_defeat_as_battle_win() {
        let previous_state = json!({
            "worldType": "CUSTOM",
            "currentScene": "Story",
            "inBattle": true,
            "quests": [],
            "playerInventory": [],
            "currentScenePreset": {
                "id": "custom-scene-camp",
                "name": "回潮营地",
                "description": "潮雾暂时压住脚步。"
            },
            "storyEngineMemory": {
                "activeThreadIds": []
            }
        });
        let mut next_state = previous_state.clone();
        next_state["inBattle"] = Value::Bool(false);

        project_story_engine_after_action(
            &previous_state,
            &mut next_state,
            "普通攻击",
            "你在交锋中倒下，随后重新醒来。",
            "battle_attack_basic",
            Some("defeat"),
        );

        assert!(
            next_state["storyEngineMemory"]["recentSignalIds"]
                .as_array()
                .is_none_or(|items| {
                    items
                        .iter()
                        .all(|signal| signal != "win_battle:custom-scene-camp")
                })
        );
        assert!(
            next_state["storyEngineMemory"]["worldMutations"]
                .as_array()
                .unwrap()
                .iter()
                .all(|mutation| mutation["mutationType"] != json!("enemy_pressure"))
        );
    }

    #[test]
    fn story_engine_projector_does_not_create_chapter_quest_on_npc_battle_entry() {
        let previous_state = json!({
            "worldType": "WUXIA",
            "currentScene": "Story",
            "storyHistory": [],
            "quests": [],
            "currentScenePreset": {
                "id": "scene-bridge",
                "name": "断桥口",
                "description": "风从桥下吹上来。",
                "npcs": [{
                    "id": "npc-guide",
                    "name": "沈七",
                    "hostile": false
                }]
            },
            "currentEncounter": {
                "kind": "npc",
                "id": "npc-guide",
                "npcName": "沈七"
            },
            "storyEngineMemory": {
                "activeThreadIds": ["thread-bridge"]
            }
        });
        let mut next_state = previous_state.clone();
        next_state["inBattle"] = Value::Bool(true);
        next_state["currentEncounter"] = Value::Null;

        project_story_engine_after_action(
            &previous_state,
            &mut next_state,
            "与沈七战斗",
            "沈七已经进入战斗节奏。",
            "npc_fight",
            Some("ongoing"),
        );

        assert!(
            next_state["quests"]
                .as_array()
                .is_some_and(|items| items.is_empty())
        );
        assert_eq!(next_state["chapterState"]["chapterQuestId"], Value::Null);
    }
}