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

use crate::{
    ensure_json_object, first_hostile_npc_string_field, read_array_field, read_bool_field,
    read_field, read_i32_field, read_object_field, read_optional_string_field, write_i32_field,
};

/// 这批 helper 只负责 runtime story 的纯快照读写。
///
/// 目标是先把 encounter / inventory / equipment 的基础状态工具从 `api-server`
/// 边界模块里收口出来，后续 battle / forge / equipment 规则迁移时直接复用。
pub fn ensure_inventory_action_available(
    game_state: &Value,
    missing_character_message: &str,
    battle_locked_message: &str,
) -> Result<(), String> {
    if read_field(game_state, "playerCharacter").is_none() {
        return Err(missing_character_message.to_string());
    }
    if read_bool_field(game_state, "inBattle").unwrap_or(false) {
        return Err(battle_locked_message.to_string());
    }
    Ok(())
}

pub fn battle_mode_text(value: &str) -> &'static str {
    if value == "spar" { "切磋" } else { "战斗" }
}

pub fn current_encounter_name(game_state: &Value) -> String {
    read_object_field(game_state, "currentEncounter")
        .and_then(|encounter| {
            read_optional_string_field(encounter, "npcName")
                .or_else(|| read_optional_string_field(encounter, "name"))
        })
        .unwrap_or_else(|| "对方".to_string())
}

pub fn current_encounter_name_from_battle(game_state: &Value) -> String {
    read_object_field(game_state, "currentEncounter")
        .and_then(|encounter| {
            read_optional_string_field(encounter, "npcName")
                .or_else(|| read_optional_string_field(encounter, "name"))
        })
        .or_else(|| first_hostile_npc_string_field(game_state, "name"))
        .unwrap_or_else(|| "眼前的敌人".to_string())
}

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

pub fn find_player_inventory_entry<'a>(game_state: &'a Value, item_id: &str) -> Option<&'a Value> {
    read_array_field(game_state, "playerInventory")
        .into_iter()
        .find(|entry| read_optional_string_field(entry, "id").as_deref() == Some(item_id))
}

pub fn read_player_inventory_values(game_state: &Value) -> Vec<Value> {
    read_array_field(game_state, "playerInventory")
        .into_iter()
        .cloned()
        .collect()
}

pub fn write_player_inventory_values(game_state: &mut Value, items: Vec<Value>) {
    ensure_json_object(game_state).insert("playerInventory".to_string(), Value::Array(items));
}

pub fn read_inventory_item_name(item: &Value) -> String {
    read_optional_string_field(item, "name")
        .or_else(|| read_optional_string_field(item, "id"))
        .unwrap_or_else(|| "未命名物品".to_string())
}

pub fn has_giftable_player_inventory(game_state: &Value) -> bool {
    read_array_field(game_state, "playerInventory")
        .into_iter()
        .any(|item| read_i32_field(item, "quantity").unwrap_or(0) > 0)
}

pub fn clone_inventory_item_with_quantity(item: &Value, quantity: i32) -> Value {
    let mut next_item = item.clone();
    if let Some(entry) = next_item.as_object_mut() {
        entry.insert("quantity".to_string(), json!(quantity.max(1)));
    }
    next_item
}

pub fn normalize_equipped_item(item: &Value) -> Value {
    clone_inventory_item_with_quantity(item, 1)
}

pub fn add_inventory_items_to_list(mut base: Vec<Value>, additions: Vec<Value>) -> Vec<Value> {
    for addition in additions {
        let add_id = read_optional_string_field(&addition, "id");
        let add_quantity = read_i32_field(&addition, "quantity").unwrap_or(1).max(1);
        if let Some(add_id) = add_id {
            if let Some(existing) = base.iter_mut().find(|item| {
                read_optional_string_field(item, "id").as_deref() == Some(add_id.as_str())
            }) {
                let next_quantity =
                    read_i32_field(existing, "quantity").unwrap_or(0).max(0) + add_quantity;
                if let Some(existing_object) = existing.as_object_mut() {
                    existing_object.insert("quantity".to_string(), json!(next_quantity));
                }
                continue;
            }
        }
        base.push(addition);
    }
    base
}

pub fn remove_inventory_item_from_list(
    mut base: Vec<Value>,
    item_id: &str,
    quantity: i32,
) -> Vec<Value> {
    if quantity <= 0 {
        return base;
    }
    let Some(index) = base
        .iter()
        .position(|entry| read_optional_string_field(entry, "id").as_deref() == Some(item_id))
    else {
        return base;
    };
    let current_quantity = read_i32_field(&base[index], "quantity").unwrap_or(0).max(0);
    let next_quantity = current_quantity - quantity;
    if next_quantity <= 0 {
        base.remove(index);
        return base;
    }
    if let Some(item) = base[index].as_object_mut() {
        item.insert("quantity".to_string(), json!(next_quantity));
    }
    base
}

pub fn read_player_equipment_item(game_state: &Value, slot_id: &str) -> Option<Value> {
    read_field(game_state, "playerEquipment")
        .and_then(|equipment| read_field(equipment, slot_id))
        .filter(|item| !item.is_null())
        .cloned()
}

pub fn write_player_equipment_item(game_state: &mut Value, slot_id: &str, item: Option<Value>) {
    let root = ensure_json_object(game_state);
    let equipment = root
        .entry("playerEquipment".to_string())
        .or_insert_with(|| {
            json!({
                "weapon": null,
                "armor": null,
                "relic": null,
            })
        });
    if !equipment.is_object() {
        *equipment = json!({
            "weapon": null,
            "armor": null,
            "relic": null,
        });
    }
    equipment
        .as_object_mut()
        .expect("playerEquipment should be object")
        .insert(slot_id.to_string(), item.unwrap_or(Value::Null));
}

pub fn equipment_slot_label(slot_id: &str) -> &'static str {
    match slot_id {
        "weapon" => "武器",
        "armor" => "护甲",
        "relic" => "饰品",
        _ => "装备",
    }
}

pub fn normalize_equipment_slot_id(slot_id: &str) -> Option<&'static str> {
    let normalized = slot_id.trim().to_ascii_lowercase();
    match normalized.as_str() {
        "weapon" => Some("weapon"),
        "armor" => Some("armor"),
        "relic" | "accessory" => Some("relic"),
        _ => {
            // 支持历史 payload 里直接传中文槽位名或物品类别文案的情况。
            if slot_id.contains("武器")
                || slot_id.contains('剑')
                || slot_id.contains('弓')
                || slot_id.contains('刀')
                || slot_id.contains("拳套")
                || slot_id.contains("战刃")
                || slot_id.contains('枪')
                || slot_id.contains('刃')
            {
                return Some("weapon");
            }
            if slot_id.contains("护甲")
                || slot_id.contains('甲')
                || slot_id.contains("护臂")
                || slot_id.contains('衣')
                || slot_id.contains('袍')
                || slot_id.contains('铠')
            {
                return Some("armor");
            }
            if slot_id.contains("饰品")
                || slot_id.contains("护符")
                || slot_id.contains("徽章")
                || slot_id.contains('玉')
                || slot_id.contains('珠')
                || slot_id.contains('坠')
                || slot_id.contains('铃')
                || slot_id.contains('盘')
                || slot_id.contains('令')
                || slot_id.contains('匣')
            {
                return Some("relic");
            }
            None
        }
    }
}

pub fn resolve_equipment_slot_for_item(item: &Value) -> Option<&'static str> {
    if let Some(slot_id) = read_optional_string_field(item, "equipmentSlotId") {
        return match slot_id.as_str() {
            "weapon" => Some("weapon"),
            "armor" => Some("armor"),
            "relic" => Some("relic"),
            _ => None,
        };
    }
    let tags = read_array_field(item, "tags")
        .into_iter()
        .filter_map(|tag| tag.as_str().map(|value| value.to_string()))
        .collect::<Vec<_>>();
    if tags.iter().any(|tag| tag == "weapon") {
        return Some("weapon");
    }
    if tags.iter().any(|tag| tag == "armor") {
        return Some("armor");
    }
    if tags.iter().any(|tag| tag == "relic") {
        return Some("relic");
    }
    let category_text = read_optional_string_field(item, "category").unwrap_or_default();
    let name_text = read_inventory_item_name(item);
    let mixed_text = format!("{category_text} {name_text}");
    if mixed_text.contains("武器") || mixed_text.contains("剑") || mixed_text.contains("刀") {
        return Some("weapon");
    }
    if mixed_text.contains("护甲") || mixed_text.contains("甲") || mixed_text.contains("袍") {
        return Some("armor");
    }
    if mixed_text.contains("饰品") || mixed_text.contains("护符") || mixed_text.contains("玉")
    {
        return Some("relic");
    }
    None
}

pub fn item_rarity_key(item: &Value) -> String {
    read_optional_string_field(item, "rarity").unwrap_or_else(|| "common".to_string())
}

pub fn equipment_bonus_fallbacks(slot_id: &str, rarity: &str) -> (i32, i32, f64, f64) {
    match slot_id {
        "weapon" => {
            let outgoing = match rarity {
                "uncommon" => 0.10,
                "rare" => 0.14,
                "epic" => 0.20,
                "legendary" => 0.28,
                _ => 0.06,
            };
            (0, 0, outgoing, 1.0)
        }
        "armor" => {
            let hp = match rarity {
                "uncommon" => 22,
                "rare" => 32,
                "epic" => 44,
                "legendary" => 58,
                _ => 14,
            };
            let incoming = match rarity {
                "uncommon" => 0.94,
                "rare" => 0.90,
                "epic" => 0.86,
                "legendary" => 0.80,
                _ => 0.97,
            };
            (hp, 0, 0.0, incoming)
        }
        _ => {
            let mana = match rarity {
                "uncommon" => 18,
                "rare" => 28,
                "epic" => 40,
                "legendary" => 54,
                _ => 10,
            };
            let outgoing = match rarity {
                "uncommon" => 0.04,
                "rare" => 0.06,
                "epic" => 0.09,
                "legendary" => 0.12,
                _ => 0.02,
            };
            (0, mana, outgoing, 1.0)
        }
    }
}

pub fn equipment_item_bonuses(item: &Value, slot_id: &str) -> (i32, i32, f64, f64) {
    let rarity = item_rarity_key(item);
    let fallback = equipment_bonus_fallbacks(slot_id, rarity.as_str());
    let stat_profile = read_field(item, "statProfile");
    let hp_bonus = stat_profile
        .and_then(|profile| read_i32_field(profile, "maxHpBonus"))
        .unwrap_or(fallback.0);
    let mana_bonus = stat_profile
        .and_then(|profile| read_i32_field(profile, "maxManaBonus"))
        .unwrap_or(fallback.1);
    let outgoing_bonus = stat_profile
        .and_then(|profile| read_field(profile, "outgoingDamageBonus"))
        .and_then(Value::as_f64)
        .unwrap_or(fallback.2);
    let incoming_multiplier = stat_profile
        .and_then(|profile| read_field(profile, "incomingDamageMultiplier"))
        .and_then(Value::as_f64)
        .unwrap_or(fallback.3);
    (hp_bonus, mana_bonus, outgoing_bonus, incoming_multiplier)
}

pub fn read_equipment_total_bonuses(game_state: &Value) -> (i32, i32, f64, f64) {
    let equipment = read_field(game_state, "playerEquipment");
    let mut hp_bonus = 0;
    let mut mana_bonus = 0;
    let mut outgoing_bonus = 0.0;
    let mut incoming_multiplier = 1.0;
    for slot_id in ["weapon", "armor", "relic"] {
        let Some(item) = equipment.and_then(|value| read_field(value, slot_id)) else {
            continue;
        };
        if item.is_null() {
            continue;
        }
        let (slot_hp, slot_mana, slot_outgoing, slot_incoming) =
            equipment_item_bonuses(item, slot_id);
        hp_bonus += slot_hp;
        mana_bonus += slot_mana;
        outgoing_bonus += slot_outgoing;
        incoming_multiplier *= slot_incoming;
    }
    (hp_bonus, mana_bonus, outgoing_bonus, incoming_multiplier)
}

pub fn apply_equipment_loadout_to_state(game_state: &mut Value) {
    let (hp_bonus, mana_bonus, _outgoing_bonus, _incoming_multiplier) =
        read_equipment_total_bonuses(game_state);
    let current_max_hp = read_i32_field(game_state, "playerMaxHp")
        .unwrap_or(1)
        .max(1);
    let current_max_mana = read_i32_field(game_state, "playerMaxMana")
        .unwrap_or(1)
        .max(1);
    let current_hp = read_i32_field(game_state, "playerHp").unwrap_or(current_max_hp);
    let base_max_hp = current_max_hp
        .saturating_sub(read_runtime_equipment_bonus_cache(game_state, "maxHpBonus"))
        .max(1);
    let base_max_mana = current_max_mana
        .saturating_sub(read_runtime_equipment_bonus_cache(
            game_state,
            "maxManaBonus",
        ))
        .max(1);
    let next_max_hp = base_max_hp.saturating_add(hp_bonus).max(1);
    let next_max_mana = base_max_mana.saturating_add(mana_bonus).max(1);
    write_i32_field(game_state, "playerMaxHp", next_max_hp);
    write_i32_field(game_state, "playerHp", current_hp.min(next_max_hp));
    write_i32_field(game_state, "playerMaxMana", next_max_mana);
    write_i32_field(game_state, "playerMana", next_max_mana);
    write_runtime_equipment_bonus_cache(game_state, "maxHpBonus", hp_bonus);
    write_runtime_equipment_bonus_cache(game_state, "maxManaBonus", mana_bonus);
}

pub fn read_runtime_equipment_bonus_cache(game_state: &Value, key: &str) -> i32 {
    read_field(game_state, "runtimeEquipmentBonusCache")
        .and_then(|cache| read_i32_field(cache, key))
        .unwrap_or(0)
}

pub fn write_runtime_equipment_bonus_cache(game_state: &mut Value, key: &str, value: i32) {
    let root = ensure_json_object(game_state);
    let cache = root
        .entry("runtimeEquipmentBonusCache".to_string())
        .or_insert_with(|| Value::Object(Map::new()));
    if !cache.is_object() {
        *cache = Value::Object(Map::new());
    }
    cache
        .as_object_mut()
        .expect("runtimeEquipmentBonusCache should be object")
        .insert(key.to_string(), json!(value));
}

pub fn build_current_build_toast(game_state: &Value) -> String {
    let (_hp_bonus, _mana_bonus, outgoing_bonus, _incoming_multiplier) =
        read_equipment_total_bonuses(game_state);
    let build_multiplier = (1.0 + outgoing_bonus).max(1.0);
    format!("当前 Build 倍率 x{build_multiplier:.2}")
}