// ============================================================================
// query-expansion.js - 检索查询生成器（三层 themes 版）
// ============================================================================

import { callLLM, parseJson } from './llm-service.js';
import { xbLog } from '../../../../core/debug-core.js';
import { filterText } from '../utils/text-filter.js';
import { getContext } from '../../../../../../../extensions.js';
import { getSummaryStore } from '../../data/store.js';

const MODULE_ID = 'query-expansion';
const SESSION_ID = 'xb6';

// ============================================================================
// 系统提示词
// ============================================================================

const SYSTEM_PROMPT = `你是检索查询生成器。根据当前对话上下文，生成用于检索历史剧情的查询语句。

## 输出格式（严格JSON）
{
  "focus": ["焦点人物"],
  "fn": ["叙事功能"],
  "pt": ["互动模式"],
  "kw": ["关键词"],
  "queries": ["DSL查询语句"]
}

## fn（叙事功能）枚举
establish=建立设定 | escalate=升级加剧 | reveal=揭示发现 | challenge=挑战试探
commit=承诺锁定 | conflict=冲突对抗 | resolve=解决收束 | transform=转变逆转
bond=连接羁绊 | break=断裂破坏

## pt（互动模式）枚举
power_down=上对下 | power_up=下对上 | power_equal=对等 | power_contest=争夺
asymmetric=信息不对称 | witnessed=有观众 | secluded=隔绝私密
ritual=仪式正式 | routine=日常惯例 | triangular=三方介入

## DSL 查询格式
- <act> 主体 -> 动作 (-> 客体)? (在地点)?
- <emo> 主体 -> 情绪 (对客体)?
- <dec> 主体 -> 决定/承诺 (对客体)?
- <rev> 揭示: 内容 (关于客体)?
- <ten> 主体A <-> 主体B: 冲突内容
- <loc> 场景: 地点/状态

## 规则
- focus: 核心人物，1-4个
- fn: 当前对话涉及的叙事功能，1-3个
- pt: 当前对话涉及的互动模式，1-3个
- kw: 具体关键词，1-4个
- queries: 2-4条 DSL 查询

## 示例

输入：艾拉说"那把剑...我记得它的重量，在火山口的时候"
输出：
{
  "focus": ["艾拉", "古龙"],
  "fn": ["commit", "bond"],
  "pt": ["power_down", "ritual"],
  "kw": ["圣剑", "战斗", "火山口"],
  "queries": [
    "<act> 艾拉 -> 战斗/使用圣剑 -> 古龙 [commit/power_down]",
    "<loc> 场景: 火山口 [ritual]",
    "<emo> 艾拉 -> 牺牲/决绝 [commit]"
  ]
}`;

// ============================================================================
// 上下文构建
// ============================================================================

function getCharacterContext() {
    const context = getContext();
    const char = context.characters?.[context.characterId];

    if (!char) {
        return { name: '', description: '', personality: '' };
    }

    return {
        name: char.name || '',
        description: (char.description || '').slice(0, 500),
        personality: (char.personality || '').slice(0, 300),
    };
}

function getPersonaContext() {
    const context = getContext();

    if (typeof window !== 'undefined' && window.power_user?.persona_description) {
        return String(window.power_user.persona_description).slice(0, 500);
    }

    if (context.persona_description) {
        return String(context.persona_description).slice(0, 500);
    }

    return '';
}

function getRecentEvents(count = 8) {
    const store = getSummaryStore();
    const events = store?.json?.events || [];

    return events
        .slice(-count)
        .map(e => {
            const time = e.timeLabel || '';
            const title = e.title || '';
            const participants = (e.participants || []).join('/');
            const summary = (e.summary || '').replace(/\s*\(#\d+(?:-\d+)?\)\s*$/, '').slice(0, 80);

            return time
                ? `[${time}] ${title || participants}: ${summary}`
                : `${title || participants}: ${summary}`;
        });
}

function getRelevantArcs(focusHint = []) {
    const store = getSummaryStore();
    const arcs = store?.json?.arcs || [];

    if (!arcs.length) return [];

    const hintSet = new Set(focusHint.map(s => String(s).toLowerCase()));

    const sorted = [...arcs].sort((a, b) => {
        const aHit = hintSet.has(String(a.name || '').toLowerCase()) ? 1 : 0;
        const bHit = hintSet.has(String(b.name || '').toLowerCase()) ? 1 : 0;
        return bHit - aHit;
    });

    return sorted.slice(0, 4).map(a => {
        const progress = Math.round((a.progress || 0) * 100);
        return `${a.name}: ${a.trajectory || '未知状态'} (${progress}%)`;
    });
}

function extractNamesFromMessages(messages) {
    const names = new Set();

    for (const m of messages) {
        if (m.name) names.add(m.name);
    }

    const text = messages.map(m => m.mes || '').join(' ');
    const namePattern = /[\u4e00-\u9fff]{2,4}/g;
    const matches = text.match(namePattern) || [];

    const freq = {};
    for (const name of matches) {
        freq[name] = (freq[name] || 0) + 1;
    }

    Object.entries(freq)
        .filter(([, count]) => count >= 2)
        .forEach(([name]) => names.add(name));

    return Array.from(names).slice(0, 6);
}

// ============================================================================
// 主函数
// ============================================================================

export async function expandQuery(messages, options = {}) {
    const { pendingUserMessage = null, timeout = 6000 } = options;

    if (!messages?.length && !pendingUserMessage) {
        return { focus: [], fn: [], pt: [], kw: [], queries: [] };
    }

    const T0 = performance.now();

    const character = getCharacterContext();
    const persona = getPersonaContext();
    const nameHints = extractNamesFromMessages(messages || []);
    const recentEvents = getRecentEvents(8);
    const arcs = getRelevantArcs(nameHints);

    const dialogueParts = [];

    for (const m of (messages || [])) {
        const speaker = m.is_user ? '用户' : (m.name || '角色');
        const text = filterText(m.mes || '').trim();
        if (text) {
            dialogueParts.push(`【${speaker}】\n${text.slice(0, 400)}`);
        }
    }

    if (pendingUserMessage) {
        dialogueParts.push(`【用户（刚输入）】\n${filterText(pendingUserMessage).slice(0, 400)}`);
    }

    const inputParts = [];

    if (character.name) {
        inputParts.push(`## 当前角色\n${character.name}: ${character.description || character.personality || '无描述'}`);
    }

    if (persona) {
        inputParts.push(`## 用户人设\n${persona}`);
    }

    if (recentEvents.length) {
        inputParts.push(`## 近期剧情\n${recentEvents.map((e, i) => `${i + 1}. ${e}`).join('\n')}`);
    }

    if (arcs.length) {
        inputParts.push(`## 角色状态\n${arcs.join('\n')}`);
    }

    inputParts.push(`## 最近对话\n${dialogueParts.join('\n\n')}`);

    const input = inputParts.join('\n\n');

    try {
        const response = await callLLM([
            { role: 'system', content: SYSTEM_PROMPT },
            { role: 'user', content: input },
        ], {
            temperature: 0.15,
            max_tokens: 500,
            timeout,
            sessionId: SESSION_ID,
        });

        const parsed = parseJson(response);
        if (!parsed) {
            xbLog.warn(MODULE_ID, 'JSON解析失败', response?.slice(0, 200));
            return { focus: [], fn: [], pt: [], kw: [], queries: [] };
        }

        const result = {
            focus: Array.isArray(parsed.focus) ? parsed.focus.slice(0, 5) : [],
            fn: Array.isArray(parsed.fn) ? parsed.fn.slice(0, 4) : [],
            pt: Array.isArray(parsed.pt) ? parsed.pt.slice(0, 4) : [],
            kw: Array.isArray(parsed.kw) ? parsed.kw.slice(0, 5) : [],
            queries: Array.isArray(parsed.queries) ? parsed.queries.slice(0, 5) : [],
        };

        xbLog.info(MODULE_ID, `完成 (${Math.round(performance.now() - T0)}ms) focus=[${result.focus.join(',')}] fn=[${result.fn.join(',')}]`);
        return result;

    } catch (e) {
        xbLog.error(MODULE_ID, '调用失败', e);
        return { focus: [], fn: [], pt: [], kw: [], queries: [] };
    }
}

// ============================================================================
// 缓存
// ============================================================================

const cache = new Map();
const CACHE_TTL = 300000;

function hashMessages(messages, pending = '') {
    const text = (messages || [])
        .slice(-3)
        .map(m => (m.mes || '').slice(0, 100))
        .join('|') + '|' + (pending || '').slice(0, 100);

    let h = 0;
    for (let i = 0; i < text.length; i++) {
        h = ((h << 5) - h + text.charCodeAt(i)) | 0;
    }
    return h.toString(36);
}

export async function expandQueryCached(messages, options = {}) {
    const key = hashMessages(messages, options.pendingUserMessage);
    const cached = cache.get(key);

    if (cached && Date.now() - cached.time < CACHE_TTL) {
        return cached.result;
    }

    const result = await expandQuery(messages, options);

    if (result.focus.length || result.queries.length) {
        if (cache.size > 50) {
            cache.delete(cache.keys().next().value);
        }
        cache.set(key, { result, time: Date.now() });
    }

    return result;
}

// ============================================================================
// 辅助函数：构建检索文本
// ============================================================================

/**
 * 将 expansion 结果转换为检索文本
 * 三层 themes 自然拼入，让向量自动编码
 */
export function buildSearchText(expansion) {
    const parts = [];

    // focus 人物
    if (expansion.focus?.length) {
        parts.push(expansion.focus.join(' '));
    }

    // fn + pt + kw 合并为标签
    const tags = [
        ...(expansion.fn || []),
        ...(expansion.pt || []),
        ...(expansion.kw || []),
    ].filter(Boolean);

    if (tags.length) {
        parts.push(`[${tags.join('/')}]`);
    }

    // queries
    if (expansion.queries?.length) {
        parts.push(...expansion.queries);
    }

    return parts.filter(Boolean).join(' ').slice(0, 1500);
}

/**
 * 提取实体列表（兼容旧接口）
 */
export function getEntitiesFromExpansion(expansion) {
    return expansion?.focus || [];
}