'use strict';

/**
 * 路由状态写入 — writeRouteState + appendRouteLog + 遥测
 * @module scripts/route-state
 *
 * 从 route-interceptor-bundle.js 提取 (Phase 0 宪法合规拆分)
 * 原始位置: bundle L486-599
 */

const fs = require('fs');
const path = require('path');
const crypto = require('crypto');
const { safeAppendJsonl } = require('../hooks/lib/safe-append.js');

const CLAUDE_ROOT = require('../hooks/lib/root.js');
const DEBUG_DIR = path.join(CLAUDE_ROOT, 'debug');
const SCRIPTS_DIR = path.join(CLAUDE_ROOT, 'scripts');

const { MUST_INVOKE_EXEMPT_INTENTS } = require('./bwr-builder.js');

// 日志脱敏
const sanitizePrompt = (() => {
  try { return require('./sanitize.js').sanitize; }
  catch { return (text) => text || ''; }
})();

// 安全加载模块
function safeRequire(modulePath) {
  try { return require(modulePath); } catch { return null; }
}

/**
 * 追加路由决策到每日路由日志
 * @param {string} prompt - 用户输入
 * @param {object} routing - 路由结果
 * @param {string} traceId - 追踪 ID
 */
function appendRouteLog(prompt, routing, traceId) {
  try {
    if (prompt && prompt.includes('<task-notification>')) return;

    const dateStr = new Date().toISOString().slice(0, 10);
    const logFile = path.join(DEBUG_DIR, 'route-' + dateStr + '.jsonl');
    const entry = {
      ts: new Date().toISOString(),
      traceId,
      query: sanitizePrompt((prompt || '').slice(0, 200)),
      topResult: routing.primary,
      topConfidence: routing.confidence,
      candidates: (routing.candidates || []).slice(0, 3).map(c => c.name),
    };
    safeAppendJsonl(logFile, entry);

    // 低置信度 developer-expert 回退日志
    if (routing.primary === 'developer-expert' && routing.confidence < 0.4) {
      const blindFile = path.join(DEBUG_DIR, 'route-blind-spots.jsonl');
      safeAppendJsonl(blindFile, {
        ts: entry.ts, traceId,
        query: entry.query,
        confidence: routing.confidence,
        candidates: (routing.candidates || []).slice(0, 5).map(c => ({ n: c.name, c: Math.round((c.confidence || 0) * 100) })),
      });
    }

    // 每日路由统计
    try {
      const dailyStatsFile = path.join(DEBUG_DIR, `route-stats-daily-${dateStr}.jsonl`);
      const complexity = routing._complexity || 'unknown';
      const isExempt = (routing._intents || []).some(i => MUST_INVOKE_EXEMPT_INTENTS.has(i));
      const mustInvoke = complexity === 'complex' ||
        (!isExempt && complexity === 'medium' && routing.confidence >= 0.5 &&
         routing.primary !== 'developer-expert' && routing.primary !== 'none');
      safeAppendJsonl(dailyStatsFile, {
        ts: entry.ts, date: dateStr,
        skill: routing.primary,
        confidence: routing.confidence,
        mustInvoke,
      });
    } catch {}
  } catch {}
}

/**
 * 写入路由状态文件 (供下游 hook 消费)
 * @param {string} traceId - 追踪 ID
 * @param {string} prompt - 用户输入
 * @param {object} intent - 意图分类结果
 * @param {object} routing - 路由结果
 * @param {string|null} sessionId - 会话 ID
 * @returns {object} 写入的状态对象
 */
function writeRouteState(traceId, prompt, intent, routing, sessionId) {
  const state = {
    traceId,
    ts: new Date().toISOString(),
    promptHash: crypto.createHash('sha256').update(prompt).digest('hex').slice(0, 12),
    promptRaw: sanitizePrompt(prompt.slice(0, 200)),
    intent: {
      intents: intent.intents,
      modifiers: intent.modifiers,
      entities: intent.entities,
      complexity: intent.complexity,
    },
    routing: {
      primary: routing.primary,
      candidates: routing.candidates,
      confidence: routing.confidence,
      chain: routing.chain,
      experiment: routing.experiment || null,
      domain: routing.domain || null,
    },
    recommendation: {
      action: routing.confidence >= 0.8 ? 'route' : routing.confidence >= 0.5 ? 'recommend' : 'fallback',
      skill: routing.primary,
    },
    mustInvoke: intent.complexity === 'complex' ||
      (!intent.intents.some(i => MUST_INVOKE_EXEMPT_INTENTS.has(i)) &&
       intent.complexity === 'medium' && routing.confidence >= 0.5 &&
       routing.primary !== 'developer-expert' && routing.primary !== 'none'),
    version: (() => { try { return require('../feature-flags.json').version; } catch { return 'v6.2'; } })(),
    sessionId: sessionId || null,
  };

  try {
    if (!fs.existsSync(DEBUG_DIR)) fs.mkdirSync(DEBUG_DIR, { recursive: true });
    const _tmpState = path.join(DEBUG_DIR, 'route-state-current.json.tmp.' + process.pid);
    fs.writeFileSync(_tmpState, JSON.stringify(state, null, 2) + '\n');
    fs.renameSync(_tmpState, path.join(DEBUG_DIR, 'route-state-current.json'));
  } catch {}

  // 注入 intent 信息供 appendRouteLog 统一计算 mustInvoke
  routing._complexity = intent.complexity;
  routing._intents = intent.intents;
  appendRouteLog(prompt, routing, traceId);

  // 路由遥测指标
  try {
    const telemetry = safeRequire(path.join(SCRIPTS_DIR, 'route-telemetry.js'));
    if (telemetry && telemetry.emitRouteMetric) {
      telemetry.emitRouteMetric({
        queryLength: (prompt || '').split(/\s+/).length,
        selectedSkill: routing.primary,
        topScore: routing.candidates?.[0]?.confidence || 0,
        gap12: (routing.candidates?.[0]?.confidence || 0) - (routing.candidates?.[1]?.confidence || 0),
        confidence: routing.confidence,
        rulesFired: routing._firedRules || [],
        coldStartApplied: routing._coldStartApplied || false,
        coldStartSkills: routing._coldStartSkills || [],
        latencyMs: Date.now() - (routing._startTs || Date.now()),
        experimentId: routing.experiment?.id || null,
      });
    }
  } catch {}

  return state;
}

module.exports = { writeRouteState, appendRouteLog };