use module_puzzle::{PuzzleAgentStage, PuzzleAnchorPack, PuzzleAnchorStatus, empty_anchor_pack};
use platform_llm::LlmClient;
use serde::{Deserialize, Serialize};
use serde_json::Value as JsonValue;
use spacetime_client::{PuzzleAgentMessageFinalizeRecordInput, PuzzleAgentSessionRecord};

use crate::creation_agent_llm_turn::{
    CreationAgentLlmTurnErrorMessages, stream_creation_agent_json_turn,
};
use crate::prompt::puzzle::agent_chat::{
    PUZZLE_AGENT_JSON_TURN_USER_PROMPT, PUZZLE_AGENT_SYSTEM_PROMPT, build_puzzle_agent_prompt,
    serialize_puzzle_record_anchor_pack,
};

#[derive(Clone, Debug)]
pub(crate) struct PuzzleAgentTurnRequest<'a> {
    pub llm_client: Option<&'a LlmClient>,
    pub session: &'a PuzzleAgentSessionRecord,
    pub quick_fill_requested: bool,
    pub enable_web_search: bool,
}

#[derive(Clone, Debug)]
pub(crate) struct PuzzleAgentTurnResult {
    pub assistant_reply_text: String,
    pub stage: String,
    pub progress_percent: u32,
    pub anchor_pack_json: String,
    pub error_message: Option<String>,
}

#[derive(Clone, Debug)]
pub(crate) struct PuzzleAgentTurnError {
    message: String,
}

impl PuzzleAgentTurnError {
    fn new(message: impl Into<String>) -> Self {
        Self {
            message: message.into(),
        }
    }
}

impl std::fmt::Display for PuzzleAgentTurnError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str(&self.message)
    }
}

impl std::error::Error for PuzzleAgentTurnError {}

#[derive(Clone, Debug, Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
struct PuzzleAgentModelOutput {
    reply_text: String,
    progress_percent: u32,
    next_anchor_pack: PuzzleAnchorPack,
}

pub(crate) async fn run_puzzle_agent_turn<F>(
    request: PuzzleAgentTurnRequest<'_>,
    on_reply_update: F,
) -> Result<PuzzleAgentTurnResult, PuzzleAgentTurnError>
where
    F: FnMut(&str),
{
    let prompt = build_puzzle_agent_prompt(request.session, request.quick_fill_requested);
    let turn_output = stream_creation_agent_json_turn(
        request.llm_client,
        format!("{PUZZLE_AGENT_SYSTEM_PROMPT}\n\n{prompt}"),
        PUZZLE_AGENT_JSON_TURN_USER_PROMPT,
        request.enable_web_search,
        CreationAgentLlmTurnErrorMessages {
            model_unavailable: "当前模型不可用，请稍后重试。",
            generation_failed: "拼图聊天生成失败，请稍后重试。",
            parse_failed: "拼图聊天结果解析失败，请稍后重试。",
        },
        on_reply_update,
        PuzzleAgentTurnError::new,
    )
    .await?;
    let output = parse_model_output(&turn_output.parsed)?;

    Ok(PuzzleAgentTurnResult {
        assistant_reply_text: output.reply_text,
        stage: resolve_puzzle_agent_stage(output.progress_percent)
            .as_str()
            .to_string(),
        progress_percent: if request.quick_fill_requested {
            100
        } else {
            output.progress_percent
        },
        anchor_pack_json: serde_json::to_string(&output.next_anchor_pack).unwrap_or_else(|_| {
            serde_json::to_string(&empty_anchor_pack()).unwrap_or_else(|_| "{}".to_string())
        }),
        error_message: None,
    })
}

pub(crate) fn build_finalize_record_input(
    session_id: String,
    owner_user_id: String,
    assistant_message_id: String,
    result: PuzzleAgentTurnResult,
    updated_at_micros: i64,
) -> PuzzleAgentMessageFinalizeRecordInput {
    PuzzleAgentMessageFinalizeRecordInput {
        session_id,
        owner_user_id,
        assistant_message_id: Some(assistant_message_id),
        assistant_reply_text: Some(result.assistant_reply_text),
        stage: result.stage,
        progress_percent: result.progress_percent,
        anchor_pack_json: result.anchor_pack_json,
        error_message: result.error_message,
        updated_at_micros,
    }
}

pub(crate) fn build_failed_finalize_record_input(
    session_id: String,
    owner_user_id: String,
    session: &PuzzleAgentSessionRecord,
    error_message: String,
    updated_at_micros: i64,
) -> PuzzleAgentMessageFinalizeRecordInput {
    PuzzleAgentMessageFinalizeRecordInput {
        session_id,
        owner_user_id,
        assistant_message_id: None,
        assistant_reply_text: None,
        stage: session.stage.clone(),
        progress_percent: session.progress_percent,
        anchor_pack_json: serialize_puzzle_record_anchor_pack(&session.anchor_pack),
        error_message: Some(error_message),
        updated_at_micros,
    }
}

fn parse_model_output(parsed: &JsonValue) -> Result<PuzzleAgentModelOutput, PuzzleAgentTurnError> {
    let reply_text = parsed
        .get("replyText")
        .and_then(JsonValue::as_str)
        .map(str::trim)
        .filter(|value| !value.is_empty())
        .ok_or_else(|| PuzzleAgentTurnError::new("拼图聊天结果缺少有效回复，请稍后重试。"))?
        .to_string();
    let progress_percent = parsed
        .get("progressPercent")
        .and_then(JsonValue::as_u64)
        .map(|value| value.min(100) as u32)
        .unwrap_or(0);
    let next_anchor_pack_value = parsed
        .get("nextAnchorPack")
        .cloned()
        .ok_or_else(|| PuzzleAgentTurnError::new("拼图聊天结果缺少 nextAnchorPack。"))?;
    let next_anchor_pack = parse_model_anchor_pack(&next_anchor_pack_value)?;
    Ok(PuzzleAgentModelOutput {
        reply_text,
        progress_percent,
        next_anchor_pack,
    })
}

fn parse_model_anchor_pack(value: &JsonValue) -> Result<PuzzleAnchorPack, PuzzleAgentTurnError> {
    Ok(PuzzleAnchorPack {
        // LLM 输出契约面向前端与 prompt，使用 camelCase；Rust 领域模型仍保持 snake_case，
        // 因此这里显式做边界翻译，避免把 JSON 命名差异扩散到领域 crate。
        theme_promise: parse_model_anchor_item(value, "themePromise")?,
        visual_subject: parse_model_anchor_item(value, "visualSubject")?,
        visual_mood: parse_model_anchor_item(value, "visualMood")?,
        composition_hooks: parse_model_anchor_item(value, "compositionHooks")?,
        tags_and_forbidden: parse_model_anchor_item(value, "tagsAndForbidden")?,
    })
}

fn parse_model_anchor_item(
    pack: &JsonValue,
    field_name: &str,
) -> Result<module_puzzle::PuzzleAnchorItem, PuzzleAgentTurnError> {
    let value = pack.get(field_name).ok_or_else(|| {
        PuzzleAgentTurnError::new(format!("拼图 anchor pack 缺少 {field_name}。"))
    })?;
    let key = value
        .get("key")
        .and_then(JsonValue::as_str)
        .map(str::trim)
        .filter(|text| !text.is_empty())
        .unwrap_or(field_name)
        .to_string();
    let label = value
        .get("label")
        .and_then(JsonValue::as_str)
        .map(str::trim)
        .filter(|text| !text.is_empty())
        .unwrap_or_else(|| default_puzzle_anchor_label(field_name))
        .to_string();
    let item_value = value
        .get("value")
        .and_then(JsonValue::as_str)
        .map(str::trim)
        .unwrap_or_default()
        .to_string();
    let status = value
        .get("status")
        .and_then(JsonValue::as_str)
        .map(parse_anchor_status)
        .unwrap_or(PuzzleAnchorStatus::Missing);

    Ok(module_puzzle::PuzzleAnchorItem {
        key,
        label,
        value: item_value,
        status,
    })
}

fn default_puzzle_anchor_label(field_name: &str) -> &'static str {
    match field_name {
        "themePromise" => "题材承诺",
        "visualSubject" => "画面主体",
        "visualMood" => "视觉气质",
        "compositionHooks" => "拼图记忆点",
        "tagsAndForbidden" => "标签与禁忌",
        _ => "拼图锚点",
    }
}

fn resolve_puzzle_agent_stage(progress_percent: u32) -> PuzzleAgentStage {
    if progress_percent >= 85 {
        PuzzleAgentStage::DraftReady
    } else {
        PuzzleAgentStage::CollectingAnchors
    }
}

fn parse_anchor_status(value: &str) -> PuzzleAnchorStatus {
    match value {
        "confirmed" => PuzzleAnchorStatus::Confirmed,
        "locked" => PuzzleAnchorStatus::Locked,
        "inferred" => PuzzleAnchorStatus::Inferred,
        _ => PuzzleAnchorStatus::Missing,
    }
}

#[cfg(test)]
mod tests {
    use module_puzzle::PuzzleAnchorStatus;
    use serde_json::json;

    use super::parse_model_output;
    use crate::creation_agent_llm_turn::extract_reply_text_from_partial_json;

    #[test]
    fn extract_reply_text_from_partial_json_preserves_chinese_characters() {
        let partial_json = r#"{"replyText":"夜雨猫咪遗迹","progressPercent":42"#;

        let extracted = extract_reply_text_from_partial_json(partial_json);

        assert_eq!(extracted.as_deref(), Some("夜雨猫咪遗迹"));
    }

    #[test]
    fn parse_model_output_accepts_camel_case_anchor_pack_contract() {
        let model_output = json!({
            "replyText": "我先把雨夜猫咪的方向收住。",
            "progressPercent": 46,
            "nextAnchorPack": {
                "themePromise": {
                    "key": "themePromise",
                    "label": "题材承诺",
                    "value": "雨夜中的奇幻探索",
                    "status": "confirmed"
                },
                "visualSubject": {
                    "key": "visualSubject",
                    "label": "画面主体",
                    "value": "发光猫咪站在遗迹台阶上",
                    "status": "confirmed"
                },
                "visualMood": {
                    "key": "visualMood",
                    "label": "视觉气质",
                    "value": "潮湿、梦幻、带轻微悬疑",
                    "status": "inferred"
                },
                "compositionHooks": {
                    "key": "compositionHooks",
                    "label": "拼图记忆点",
                    "value": "台阶透视、倒影、远处遗迹门洞",
                    "status": "inferred"
                },
                "tagsAndForbidden": {
                    "key": "tagsAndForbidden",
                    "label": "标签与禁忌",
                    "value": "雨夜、猫咪、神庙遗迹；禁止文字水印",
                    "status": "inferred"
                }
            }
        });

        let parsed = parse_model_output(&model_output).expect("camelCase 契约应能解析");

        assert_eq!(parsed.progress_percent, 46);
        assert_eq!(
            parsed.next_anchor_pack.theme_promise.value,
            "雨夜中的奇幻探索"
        );
        assert_eq!(
            parsed.next_anchor_pack.theme_promise.status,
            PuzzleAnchorStatus::Confirmed
        );
        assert_eq!(
            parsed.next_anchor_pack.tags_and_forbidden.value,
            "雨夜、猫咪、神庙遗迹；禁止文字水印"
        );
    }
}