/**
 * EvolutionLoop — Skill 进化 RL 闭环引擎
 *
 * 实现完整的 Perceive → Reason/Plan → Execute → Evaluate → Reflect 循环，
 * 将 Skill 质量从初始状态迭代到 Goal Score (默认 ≥ 90)。
 *
 * 哲学方法论映射:
 *   Perceive       → _perceive()    — 评估当前 Skill 状态
 *   Reason & Plan  → _plan()        — 制定进化策略 (参考 Memory)
 *   Execute        → _execute()     — 调用 Hunt/Digest/Evolve agents
 *   Feedback       → _evaluate()    — 调用 Benchmark agent 评分
 *   Reflect & Adapt→ _reflect()     — 分析失分 / 提取教训
 *   Memory         → EvolutionMemory — 存储历史经验
 *   Goal Check     → score >= goalScore
 */

const fs = require('fs');
const path = require('path');
const { EvolutionMemory } = require('../src/core/evolution-memory');

// 默认配置
const DEFAULT_MAX_ITERATIONS = 5;
const DEFAULT_GOAL_SCORE = 90;
const STAGNATION_ROUNDS = 3;
const STAGNATION_THRESHOLD = 2;

class EvolutionLoop {
  /**
   * @param {object} opts
   * @param {string} opts.skillName - Skill 名称
   * @param {string} opts.description - Skill 描述
   * @param {string} opts.skillDir - Skill 目录绝对路径
   * @param {string} [opts.instructions] - 用户额外要求
   * @param {object} opts.manager - AgentManager 实例
   * @param {object} [opts.jobManager] - JobManager 实例
   * @param {object} [opts.job] - Job 对象
   * @param {object} [opts.logger] - ConversationLogger 实例
   * @param {object} [opts.taskMgr] - SkillTaskManager 模块
   * @param {number} [opts.maxIterations] - 最大迭代次数
   * @param {number} [opts.goalScore] - 目标分数
   * @param {function} [opts.onData] - 流式数据回调
   */
  constructor(opts) {
    this.skillName = opts.skillName;
    this.description = opts.description;
    this.skillDir = opts.skillDir;
    this.instructions = opts.instructions || '';
    this.manager = opts.manager;
    this.jobManager = opts.jobManager || null;
    this.job = opts.job || null;
    this.logger = opts.logger || null;
    this.taskMgr = opts.taskMgr || null;

    this.maxIterations = opts.maxIterations || DEFAULT_MAX_ITERATIONS;
    this.goalScore = opts.goalScore || DEFAULT_GOAL_SCORE;
    this.onData = opts.onData || (() => {});

    this.memory = new EvolutionMemory(this.skillDir);

    // 运行时状态
    this._currentIteration = 0;
    this._lastScore = null;
    this._bestScore = null;
    this._bestIteration = -1;
  }

  /**
   * 执行完整的 RL 进化循环
   *
   * @returns {Promise<EvolutionResult>}
   */
  async run() {
    this._log(`🔄 EvolutionLoop 启动: ${this.skillName} (Goal: ≥${this.goalScore}, Max: ${this.maxIterations}轮)`);

    for (let i = 0; i < this.maxIterations; i++) {
      this._currentIteration = i;
      this._log(`\n═══ 迭代 ${i + 1}/${this.maxIterations} ═══`);
      this._updateJob('evolving', `🔄 迭代 ${i + 1}/${this.maxIterations}...`);

      // ── 1. PERCEIVE: 感知当前状态 ──
      this._updateJob('perceiving', `👁️ 迭代 ${i + 1}: 感知环境...`);
      const state = await this._perceive();
      this._log(`[Perceive] 状态: hasSkillMd=${state.hasSkillMd}, hasKnowhow=${state.hasKnowhow}, previousScore=${state.previousScore}`);

      // ── 2. REASON & PLAN: 制定策略 ──
      this._updateJob('planning', `🧠 迭代 ${i + 1}: 制定策略...`);
      const strategy = this._plan(state, i);
      this._log(`[Plan] 策略: ${strategy.approach}, 步骤: [${strategy.steps.join(', ')}]`);

      // ── 3. EXECUTE: 执行进化 ──
      this._updateJob('executing', `⚡ 迭代 ${i + 1}: 执行 [${strategy.steps.join('→')}]...`);
      const execResult = await this._execute(strategy);

      // ── 4. FEEDBACK: 评分 ──
      this._updateJob('evaluating', `📊 迭代 ${i + 1}: Benchmark 评分...`);
      const score = await this._evaluate();
      this._log(`[Feedback] 分数: ${score.totalScore}/${this.goalScore} (passed: ${score.passed})`);

      // 更新最佳分数
      if (this._bestScore === null || score.totalScore > this._bestScore) {
        this._bestScore = score.totalScore;
        this._bestIteration = i;
      }
      this._lastScore = score.totalScore;

      // ── 5. REFLECT & ADAPT: 反思 ──
      this._updateJob('reflecting', `🔍 迭代 ${i + 1}: 反思分析...`);
      const reflection = this._reflect(score, strategy);

      // ── 6. MEMORY: 记录 ──
      this.memory.record({
        iteration: i,
        strategy: { approach: strategy.approach, steps: strategy.steps, focus: strategy.focus },
        score: score.totalScore,
        weakDimensions: reflection.weakDimensions,
        strongDimensions: reflection.strongDimensions,
        adjustments: reflection.adjustments,
        lessonsLearned: reflection.lessonsLearned,
      });

      // ── GOAL CHECK ──
      if (reflection.goalAchieved) {
        this._log(`✅ Goal Achieved! Score: ${score.totalScore} ≥ ${this.goalScore} (迭代 ${i + 1} 轮)`);
        return {
          status: 'goal_achieved',
          finalScore: score.totalScore,
          iterations: i + 1,
          bestScore: this._bestScore,
          scoreDetails: score,
        };
      }

      // 停滞检测
      if (this.memory.isStagnant(STAGNATION_ROUNDS, STAGNATION_THRESHOLD)) {
        this._log(`⚠️ 停滞检测: 连续 ${STAGNATION_ROUNDS} 轮分数变化 < ${STAGNATION_THRESHOLD}，停止迭代`);
        return {
          status: 'stagnant',
          finalScore: score.totalScore,
          iterations: i + 1,
          bestScore: this._bestScore,
          scoreDetails: score,
        };
      }

      this._log(`[Reflect] 未达标 (${score.totalScore} < ${this.goalScore}), 继续迭代...`);
    }

    // 最大迭代次数用尽
    this._log(`⚠️ 达到最大迭代次数 ${this.maxIterations}, 最佳分数: ${this._bestScore}`);
    return {
      status: 'max_iterations',
      finalScore: this._lastScore,
      iterations: this.maxIterations,
      bestScore: this._bestScore,
      scoreDetails: null,
    };
  }

  // ══════════════════════════════════════════════
  //  1. PERCEIVE — 感知当前状态
  // ══════════════════════════════════════════════

  async _perceive() {
    const state = {
      hasSkillMd: fs.existsSync(path.join(this.skillDir, 'SKILL.md')),
      hasKnowhow: false,
      hasBenchmark: false,
      previousScore: this._lastScore,
      totalAttempts: this.memory.getHistory().totalAttempts,
      bestHistoricalScore: this.memory.getHistory().bestScore,
      skillMdSummary: '',
      knowhowSummary: '',
    };

    // 检查 knowhow (可能在 hunt/ 或 hunter/ 目录下)
    const knowhowPaths = [
      path.join(this.skillDir, 'hunt', 'knowhow.md'),
      path.join(this.skillDir, 'hunter', 'knowhow.md'),
    ];
    for (const p of knowhowPaths) {
      if (fs.existsSync(p)) {
        state.hasKnowhow = true;
        state.knowhowSummary = this._readFirst(p, 500);
        break;
      }
    }

    // 检查 benchmark
    const benchmarkPath = path.join(this.skillDir, 'digest', 'benchmark.md');
    if (fs.existsSync(benchmarkPath)) {
      state.hasBenchmark = true;
    }

    // 读取 SKILL.md 摘要
    if (state.hasSkillMd) {
      state.skillMdSummary = this._readFirst(path.join(this.skillDir, 'SKILL.md'), 500);
    }

    return state;
  }

  // ══════════════════════════════════════════════
  //  2. REASON & PLAN — 策略制定
  // ══════════════════════════════════════════════

  _plan(state, iteration) {
    const lessons = this.memory.getLessons();
    const recentWeaks = this.memory.getRecentWeakDimensions(3);

    // 第一轮 + 没有基础内容: 完整流程
    if (iteration === 0 && !state.hasSkillMd) {
      return {
        approach: 'full',
        steps: ['hunt', 'digest', 'skill_create'],
        focus: [],
        avoid: lessons,
        reasoning: '首次创建，需要完整 Hunt→Digest→SkillCreate 流程',
      };
    }

    // 第一轮 + 有 SKILL.md 但没有 benchmark: 需要先 Digest
    if (iteration === 0 && state.hasSkillMd && !state.hasBenchmark) {
      return {
        approach: 'build_benchmark',
        steps: state.hasKnowhow ? ['digest', 'evolve'] : ['hunt', 'digest', 'evolve'],
        focus: [],
        avoid: lessons,
        reasoning: '已有 SKILL.md 但缺少评估基准，需先生成 benchmark',
      };
    }

    // 有分数且 ≥ 70: 局部优化 (仅 Evolve)
    if (state.previousScore && state.previousScore >= 70) {
      return {
        approach: 'refine',
        steps: ['evolve'],
        focus: recentWeaks,
        avoid: lessons,
        reasoning: `分数 ${state.previousScore} ≥ 70，仅对弱项维度做局部优化`,
      };
    }

    // 有分数但 < 70: 深度重构
    if (state.previousScore && state.previousScore < 70) {
      return {
        approach: 'restructure',
        steps: ['hunt', 'digest', 'evolve'],
        focus: recentWeaks,
        avoid: lessons,
        reasoning: `分数 ${state.previousScore} < 70，需要深度重构 (Re-Hunt + Re-Digest + Evolve)`,
      };
    }

    // 非第一轮、有基础内容: 默认 evolve
    return {
      approach: 'refine',
      steps: ['evolve'],
      focus: recentWeaks,
      avoid: lessons,
      reasoning: '默认局部优化策略',
    };
  }

  // ══════════════════════════════════════════════
  //  3. EXECUTE — 按策略执行
  // ══════════════════════════════════════════════

  async _execute(strategy) {
    const agentMap = {
      'hunt': { agent: 'l3-hunt', label: '🔍 Hunt' },
      'digest': { agent: 'l2-digest', label: '📝 Digest' },
      'skill_create': { agent: 'skill-creator', label: '🔨 SkillCreate' },
      'evolve': { agent: 'innovator-evolver', label: '🔄 Evolve' },
    };

    const results = {};

    for (const step of strategy.steps) {
      const mapping = agentMap[step];
      if (!mapping) {
        this._log(`[Execute] 跳过未知步骤: ${step}`);
        continue;
      }

      this._log(`[Execute] ${mapping.label} — ${mapping.agent}`);
      if (this.taskMgr) {
        try { this.taskMgr.updateStep(this.skillDir, step, 'running'); } catch {}
      }

      const prompt = this._buildStepPrompt(step, strategy);

      try {
        const result = await this.manager.callAgent(mapping.agent, prompt, {
          onData: (chunk) => {
            if (chunk?.trim()) {
              this.onData(mapping.agent, chunk);
              if (this.logger) this.logger.logStreamChunk(mapping.agent, chunk);
            }
          },
        });
        results[step] = { success: true, output: result?.output || '' };

        if (this.taskMgr) {
          try { this.taskMgr.updateStep(this.skillDir, step, 'done'); } catch {}
        }
        this._log(`[Execute] ✅ ${step} 完成`);
      } catch (err) {
        results[step] = { success: false, error: err.message };
        if (this.taskMgr) {
          try { this.taskMgr.updateStep(this.skillDir, step, 'failed', err.message); } catch {}
        }
        this._log(`[Execute] ❌ ${step} 失败: ${err.message}`);
        throw err; // 关键步骤失败，中断 Loop
      }
    }

    return results;
  }

  /**
   * 构建单步 Agent Prompt (注入历史教训 + 聚焦指令)
   */
  _buildStepPrompt(step, strategy) {
    const instructionBlock = this.instructions
      ? `\n\n## 用户额外要求\n${this.instructions}\n`
      : '';

    // 教训 + 聚焦信息
    let guidanceBlock = '';
    if (strategy.focus && strategy.focus.length > 0) {
      guidanceBlock += `\n\n## 聚焦改进维度\n以下维度在之前的评估中得分较低，请重点关注:\n${strategy.focus.map(d => `- ${d}`).join('\n')}\n`;
    }
    if (strategy.avoid && strategy.avoid.length > 0) {
      guidanceBlock += `\n\n## 历史教训 (避免重复)\n${strategy.avoid.map(l => `- ${l}`).join('\n')}\n`;
    }

    const workDir = path.dirname(this.skillDir);

    switch (step) {
      case 'hunt':
        return [
          `请为 "${this.skillName}" 猎取领域知识。`,
          `- 描述: ${this.description}`,
          `- 目标: 在 ${this.skillName}/hunt/ 下生成 knowhow.md`,
          `- 工作目录: ${workDir}`,
          instructionBlock,
          guidanceBlock,
        ].join('\n');

      case 'digest':
        return [
          `请消化 ${this.skillName}/hunt/ 下的知识，生成 benchmark。`,
          `- 描述: ${this.description}`,
          `- 目标: 在 ${this.skillName}/digest/ 下生成 benchmark.md`,
          `- 工作目录: ${workDir}`,
          instructionBlock,
          guidanceBlock,
        ].join('\n');

      case 'skill_create':
        return [
          `请为 "${this.skillName}" 创建 SKILL.md。`,
          `- 描述: ${this.description}`,
          `- 知识库: ${this.skillName}/hunt/knowhow.md`,
          `- 评估基准: ${this.skillName}/digest/benchmark.md`,
          `- SKILL.md 输出位置: ${this.skillName}/SKILL.md`,
          `- 工作目录: ${workDir}`,
          instructionBlock,
          guidanceBlock,
        ].join('\n');

      case 'evolve':
        return [
          `请对 Skill "${this.skillName}" 进行进化优化：`,
          `- skillName: ${this.skillName}`,
          `- 当前 SKILL.md: ${this.skillName}/SKILL.md`,
          `- 知识库: ${this.skillName}/hunt/knowhow.md 或 ${this.skillName}/hunter/knowhow.md`,
          `- 评估基准: ${this.skillName}/digest/benchmark.md`,
          `- 通过阈值: ${this.goalScore} 分`,
          `- 最大迭代: 3 次 (这是内循环，外循环会再次调用你)`,
          `- 工作目录: ${workDir}`,
          instructionBlock,
          guidanceBlock,
          `请执行 evolve 循环: 执行 → 评分 → 分析弱项 → 改写 SKILL.md → 重复。`,
          `结果保存到 ${this.skillName}/evolve/ 目录。`,
          `最终更新 ${this.skillName}/SKILL.md。`,
        ].join('\n');

      default:
        return `请执行 ${step} 步骤。\n${this.description}${instructionBlock}${guidanceBlock}`;
    }
  }

  // ══════════════════════════════════════════════
  //  4. FEEDBACK — Benchmark 评分
  // ══════════════════════════════════════════════

  async _evaluate() {
    // 读取当前 SKILL.md
    const skillMdPath = path.join(this.skillDir, 'SKILL.md');
    if (!fs.existsSync(skillMdPath)) {
      this._log('[Evaluate] SKILL.md 不存在，返回 0 分');
      return { totalScore: 0, passed: false, dimensions: [], weakDimensions: [], overallFeedback: 'SKILL.md 不存在' };
    }
    const skillMd = fs.readFileSync(skillMdPath, 'utf-8');

    // 读取 benchmark 定义
    const benchmarkPath = path.join(this.skillDir, 'digest', 'benchmark.md');
    if (!fs.existsSync(benchmarkPath)) {
      this._log('[Evaluate] benchmark.md 不存在，返回 0 分');
      return { totalScore: 0, passed: false, dimensions: [], weakDimensions: [], overallFeedback: 'benchmark.md 不存在' };
    }
    const benchmarkDef = fs.readFileSync(benchmarkPath, 'utf-8');

    // 调用 benchmark agent 做评估
    const evalPrompt = [
      `请评估以下 Skill 的质量。`,
      ``,
      `## 模式: 评估 Skill 输出`,
      ``,
      `- skillName: ${this.skillName}`,
      ``,
      `### benchmarkDef (评分标准):`,
      ``,
      benchmarkDef,
      ``,
      `### taskOutput (待评估的 SKILL.md 内容):`,
      ``,
      skillMd,
      ``,
      `### testTask:`,
      `评估 SKILL.md 的方法论完整性、可执行性和质量标准覆盖度。`,
      ``,
      `请严格按 benchmark 的 Detailed Rubric 逐维度评分，输出 JSON 格式结果。`,
    ].join('\n');

    try {
      const result = await this.manager.callAgent('benchmark', evalPrompt, {
        onData: (chunk) => {
          if (chunk?.trim()) {
            this.onData('benchmark', chunk);
            if (this.logger) this.logger.logStreamChunk('benchmark', chunk);
          }
        },
      });

      return this._parseScoreFromOutput(result?.output || '');
    } catch (err) {
      this._log(`[Evaluate] benchmark agent 调用失败: ${err.message}`);
      // 降级: 从 evolve 输出中正则提取
      return this._fallbackScore();
    }
  }

  /**
   * 解析 benchmark agent 输出的结构化分数
   */
  _parseScoreFromOutput(output) {
    // 优先: 解析 JSON 块
    const jsonMatch = output.match(/```json\n([\s\S]*?)\n```/);
    if (jsonMatch) {
      try {
        const parsed = JSON.parse(jsonMatch[1]);
        return {
          totalScore: parsed.totalScore || 0,
          passed: parsed.passed || false,
          dimensions: parsed.dimensions || [],
          weakDimensions: parsed.weakDimensions || [],
          strongDimensions: parsed.strongDimensions || [],
          overallFeedback: parsed.overallFeedback || '',
        };
      } catch {}
    }

    // 降级 1: 直接 JSON 解析 (可能无 code fence)
    try {
      const plainJsonMatch = output.match(/\{[\s\S]*"totalScore"[\s\S]*\}/);
      if (plainJsonMatch) {
        const parsed = JSON.parse(plainJsonMatch[0]);
        return {
          totalScore: parsed.totalScore || 0,
          passed: parsed.passed || false,
          dimensions: parsed.dimensions || [],
          weakDimensions: parsed.weakDimensions || [],
          strongDimensions: parsed.strongDimensions || [],
          overallFeedback: parsed.overallFeedback || '',
        };
      }
    } catch {}

    // 降级 2: 正则提取
    const scorePatterns = [
      /totalScore["\s:]+(\d+)/,
      /总分[：:\s]+(\d+)/,
      /评分[：:\s]+(\d+)/,
      /最终分数[：:\s]+(\d+)/,
      /score["\s:]+(\d+)/,
    ];

    for (const pattern of scorePatterns) {
      const match = output.match(pattern);
      if (match) {
        const score = parseInt(match[1]);
        return {
          totalScore: score,
          passed: score >= this.goalScore,
          dimensions: [],
          weakDimensions: [],
          strongDimensions: [],
          overallFeedback: output.substring(0, 500),
        };
      }
    }

    // 最后降级: 无法解析
    this._log('[Evaluate] 无法从输出中解析分数，使用降级评分');
    return this._fallbackScore();
  }

  /**
   * 降级评分 (无法调用 benchmark 时)
   * 基于文件存在性做简单估分
   */
  _fallbackScore() {
    let score = 30; // 基础分
    if (fs.existsSync(path.join(this.skillDir, 'SKILL.md'))) {
      const content = fs.readFileSync(path.join(this.skillDir, 'SKILL.md'), 'utf-8');
      if (content.length > 500) score += 15;
      if (content.length > 2000) score += 10;
      if (content.includes('## 执行流程') || content.includes('## Methodology')) score += 10;
      if (content.includes('## 输出格式') || content.includes('## Output')) score += 5;
      if (content.includes('---\nname:')) score += 5; // YAML frontmatter
    }
    return {
      totalScore: score,
      passed: score >= this.goalScore,
      dimensions: [],
      weakDimensions: [],
      strongDimensions: [],
      overallFeedback: '降级评分 (benchmark agent 不可用)',
    };
  }

  // ══════════════════════════════════════════════
  //  5. REFLECT & ADAPT — 反思
  // ══════════════════════════════════════════════

  _reflect(score, strategy) {
    const reflection = {
      goalAchieved: score.totalScore >= this.goalScore,
      score: score.totalScore,
      weakDimensions: score.weakDimensions || [],
      strongDimensions: score.strongDimensions || [],
      adjustments: [],
      lessonsLearned: [],
    };

    if (!reflection.goalAchieved) {
      // 分析弱项
      for (const dim of (score.dimensions || [])) {
        if (dim.score && dim.score < 70) {
          reflection.adjustments.push({
            dimension: dim.name,
            currentScore: dim.score,
            feedback: dim.feedback,
            action: `聚焦改进 ${dim.name}: ${dim.feedback || '需要加强'}`,
          });
        }
      }

      // 提取策略级教训
      if (strategy.approach === 'refine' && score.totalScore < 50) {
        reflection.lessonsLearned.push(
          `refine 策略对极低分 (${score.totalScore} < 50) 无效，应使用 restructure 策略`
        );
      }

      if (strategy.approach === 'full' && score.totalScore < 40) {
        reflection.lessonsLearned.push(
          `首次 full 创建仅得 ${score.totalScore} 分，可能需要更详细的用户指令或更深度的 Hunt`
        );
      }

      // 得高分但未达标的教训
      if (score.totalScore >= 80 && score.totalScore < this.goalScore) {
        const weakNames = (score.weakDimensions || []).join(', ');
        if (weakNames) {
          reflection.lessonsLearned.push(
            `接近达标 (${score.totalScore})，瓶颈在: ${weakNames}，需要精准优化这几个维度`
          );
        }
      }
    }

    return reflection;
  }

  // ══════════════════════════════════════════════
  //  辅助方法
  // ══════════════════════════════════════════════

  _readFirst(filePath, maxLen = 500) {
    try {
      const content = fs.readFileSync(filePath, 'utf-8');
      return content.substring(0, maxLen);
    } catch {
      return '';
    }
  }

  _log(msg) {
    console.log(`[EvolutionLoop:${this.skillName}] ${msg}`);
  }

  _updateJob(status, progress) {
    if (this.jobManager && this.job) {
      try {
        this.jobManager.updateJob(this.job.jobId, { status, progress });
      } catch {}
    }
  }
}

module.exports = { EvolutionLoop, DEFAULT_MAX_ITERATIONS, DEFAULT_GOAL_SCORE };