import { v4 as uuid } from 'uuid';
import { and, desc, eq, gte } from 'drizzle-orm';
import dayjs from 'dayjs';
import { db } from '../../db/index';
import {
  projects, projectRepos, gitCommits, objectives,
  roiDriverFactors, syncLogs,
} from '../../db/schema';
import { callLLM, parseLLMJson } from '../llm-client';
import { aggregate } from './aggregator';

export interface DriverFactor {
  type: '现金流驱动' | '降本增效驱动' | '技术资产驱动';
  text: string;
}

const SYSTEM_PROMPT = `你是软件项目价值分析师。给定项目本月 ROI 数据和近期工作内容,生成 1-3 条"价值驱动因子"文案,告诉管理者这个项目的价值来源是什么。

三种驱动因子类型:
- 现金流驱动: 项目直接产生营收,推动现金流入
- 降本增效驱动: 项目通过工具化/自动化节省了内部成本
- 技术资产驱动: 项目沉淀了技术能力/数据/算法,形成长期资产

请基于真实数据判断该项目最显著的 1-3 个驱动因子。回复严格 JSON 格式:
{
  "factors": [
    { "type": "现金流驱动" | "降本增效驱动" | "技术资产驱动", "text": "60字内的简短说明" }
  ]
}

不要添加其他字段或文本。每条 text 必须 ≤60 字,客观陈述,不要使用营销语言。`;

const ALLOWED_TYPES = new Set(['现金流驱动', '降本增效驱动', '技术资产驱动']);

/**
 * 为单个项目生成"上月"的驱动因子,写入 roi_driver_factors 表。
 * periodKey = 上月 YYYY-MM
 */
export async function generateDriverFactorsForProject(projectId: string, asOf: Date = new Date()): Promise<DriverFactor[]> {
  const lastMonth = dayjs(asOf).subtract(1, 'month');
  const periodKey = lastMonth.format('YYYY-MM');

  // 上月 ROI
  const monthStart = lastMonth.startOf('month').toDate();
  const monthEnd = lastMonth.endOf('month').toDate();
  const monthAgg = await aggregate(projectId, monthStart, monthEnd);

  // 累计 ROI(从 launchedAt 起)
  const [project] = await db.select().from(projects).where(eq(projects.id, projectId)).limit(1);
  if (!project) throw new Error(`Project not found: ${projectId}`);
  const launchedAt = project.launchedAt ? new Date(project.launchedAt) : monthStart;
  const lifetimeAgg = await aggregate(projectId, launchedAt, monthEnd);

  // 近期 commits 摘要
  const repos = await db.select().from(projectRepos).where(eq(projectRepos.projectId, projectId));
  const repoNames = new Set(repos.map(r => r.repoName));
  let commitSummary = '(无近期提交)';
  if (repoNames.size > 0) {
    const recent = await db.select().from(gitCommits)
      .where(gte(gitCommits.committedAt, monthStart))
      .orderBy(desc(gitCommits.committedAt))
      .limit(30);
    const projCommits = recent.filter(c => repoNames.has(c.repoName));
    if (projCommits.length > 0) {
      commitSummary = projCommits
        .map(c => `- ${(c.message || '').split('\n')[0].slice(0, 80)}`)
        .slice(0, 15)
        .join('\n');
    }
  }

  // OKR 进展
  const objs = await db.select().from(objectives).where(eq(objectives.projectId, projectId)).limit(5);
  const okrSummary = objs.length > 0
    ? objs.map(o => `- ${o.title} (进度 ${Math.round((o.progress || 0) * 100)}%)`).join('\n')
    : '(无 OKR)';

  const userPrompt = `项目: ${project.name} (定位: ${project.category || '未打标'})

上月 ROI 数据 (${periodKey}):
- 总成本: ¥${monthAgg.totalCost.toLocaleString()}
- 总产出: ¥${monthAgg.totalRevenue.toLocaleString()}
- 月 ROI: ${monthAgg.roiValue === null ? 'N/A' : monthAgg.roiValue + '%'}
- 直接营收占比: ¥${monthAgg.revenueBreakdown.directRevenue}
- 节约成本占比: ¥${monthAgg.revenueBreakdown.savedCost}
- 资产增值占比: ¥${monthAgg.revenueBreakdown.assetValueAdd}

累计 ROI (立项至今): ${lifetimeAgg.roiValue === null ? 'N/A' : lifetimeAgg.roiValue + '%'}

上月关键 commits:
${commitSummary}

OKR 进展:
${okrSummary}

请输出 JSON 驱动因子。`;

  const raw = await callLLM(SYSTEM_PROMPT, userPrompt);
  const parsed = parseLLMJson<{ factors: DriverFactor[] }>(raw);

  // 校验
  if (!Array.isArray(parsed.factors)) throw new Error('LLM response missing factors array');
  const validFactors = parsed.factors
    .filter(f => f && ALLOWED_TYPES.has(f.type) && typeof f.text === 'string')
    .map(f => ({ type: f.type, text: f.text.slice(0, 80) }))
    .slice(0, 3);

  if (validFactors.length === 0) throw new Error('LLM returned no valid factors');

  // upsert: 先 delete 旧的(同 project + period),再 insert 新的
  await db.delete(roiDriverFactors).where(and(
    eq(roiDriverFactors.projectId, projectId),
    eq(roiDriverFactors.periodKey, periodKey),
  ));
  await db.insert(roiDriverFactors).values({
    id: uuid(),
    projectId,
    periodKey,
    factors: validFactors,
    context: {
      monthRoi: monthAgg.roiValue,
      lifetimeRoi: lifetimeAgg.roiValue,
      monthCost: monthAgg.totalCost,
      monthRevenue: monthAgg.totalRevenue,
    },
    generatedAt: new Date(),
  });

  return validFactors;
}

/**
 * 月度 cron:为所有打标项目生成驱动因子。失败的项目记录但不中断。
 */
export async function runMonthlyDriverFactorsGeneration(): Promise<void> {
  const startedAt = Date.now();
  let okCount = 0, failCount = 0;
  const errors: string[] = [];

  // 仅为已打标的项目生成
  const allProjects = await db.select().from(projects);
  const candidates = allProjects.filter(p => p.category !== null);

  for (const p of candidates) {
    try {
      await generateDriverFactorsForProject(p.id);
      okCount += 1;
    } catch (e) {
      failCount += 1;
      const msg = `${p.identifier || p.id}: ${(e as Error).message}`;
      errors.push(msg);
      console.warn('[ROI-AI-DRIVER]', msg);
    }
    // 简单速率控制:每项目间隔 1 秒,避免 LLM 限流
    await new Promise(r => setTimeout(r, 1000));
  }

  const elapsed = Date.now() - startedAt;
  await db.insert(syncLogs).values({
    id: uuid(),
    source: 'roi_ai_driver',
    status: failCount === 0 ? 'success' : 'error',
    message: `driver factors: ok=${okCount} fail=${failCount} elapsed=${elapsed}ms${errors.length > 0 ? ' errors=' + errors.slice(0, 3).join('|') : ''}`,
    recordsProcessed: okCount,
    syncedAt: new Date(),
  }).catch(() => {});
}