import { Hono } from 'hono';
import { db } from '../db/index';
import { gitCommits, gitPRs, users } from '../db/schema';
import { eq, and, gte, desc } from 'drizzle-orm';
import { AppError } from '../middleware/error-handler';
import dayjs from 'dayjs';

export const gitRoutes = new Hono();

// GET /api/git/activity
gitRoutes.get('/git/activity', async (c) => {
  const user = c.get('user');
  const queryUserId = c.req.query('userId');
  const weeks = parseInt(c.req.query('weeks') || '12');

  if (user.role === 'viewer') {
    throw new AppError(40103, 'Insufficient permissions', 403);
  }

  let targetUserId: string | undefined;
  if (user.role === 'developer') {
    targetUserId = user.sub;
  } else if (queryUserId) {
    targetUserId = queryUserId;
  }

  const startDate = dayjs().subtract(weeks, 'week').startOf('week').toDate();

  // 所有 commits
  const commitQuery = targetUserId
    ? db.select().from(gitCommits).where(and(eq(gitCommits.userId, targetUserId), gte(gitCommits.committedAt, startDate)))
    : db.select().from(gitCommits).where(gte(gitCommits.committedAt, startDate));
  const commits = await commitQuery;

  // Heatmap（按天）
  const dayMap: Record<string, { commits: number; additions: number; deletions: number }> = {};
  const today = dayjs();
  for (let d = dayjs(startDate); d.isBefore(today) || d.isSame(today, 'day'); d = d.add(1, 'day')) {
    dayMap[d.format('YYYY-MM-DD')] = { commits: 0, additions: 0, deletions: 0 };
  }
  for (const commit of commits) {
    const day = dayjs(commit.committedAt).format('YYYY-MM-DD');
    if (dayMap[day]) {
      dayMap[day].commits++;
      dayMap[day].additions += commit.additions || 0;
      dayMap[day].deletions += commit.deletions || 0;
    }
  }
  const heatmap = Object.entries(dayMap).map(([date, data]) => ({ date, ...data }));

  // 统计指标（替代原来的 PR 指标）
  const allCommits = await db.select().from(gitCommits);
  const thisMonthStart = dayjs().startOf('month').toDate();
  const thisMonthCommits = allCommits.filter(c => dayjs(c.committedAt).isAfter(thisMonthStart));
  const activeContributors = new Set(allCommits.filter(c => c.userId).map(c => c.userId)).size;
  const activeRepos = new Set(allCommits.map(c => c.repoName)).size;

  const stats = {
    totalCommits: allCommits.length,
    activeContributors,
    thisMonthCommits: thisMonthCommits.length,
    activeRepos,
  };

  // 每周趋势（按人堆叠）
  const allUsers = await db.select().from(users);
  const userMap = new Map(allUsers.map(u => [u.id, u.displayName]));

  const weeklyTrend = [];
  for (let i = 0; i < weeks; i++) {
    const weekStart = dayjs().subtract(weeks - 1 - i, 'week').startOf('week');
    const weekEnd = weekStart.add(7, 'day');
    const weekCommits = commits.filter(c => {
      const d = dayjs(c.committedAt);
      return d.isAfter(weekStart) && d.isBefore(weekEnd);
    });

    // 按人分组
    const byUser: Record<string, number> = {};
    for (const c of weekCommits) {
      const uid = c.userId || 'unknown';
      byUser[uid] = (byUser[uid] || 0) + 1;
    }

    weeklyTrend.push({
      weekStart: weekStart.format('YYYY-MM-DD'),
      total: weekCommits.length,
      additions: weekCommits.reduce((sum, c) => sum + (c.additions || 0), 0),
      deletions: weekCommits.reduce((sum, c) => sum + (c.deletions || 0), 0),
      byUser: Object.entries(byUser).map(([userId, count]) => ({
        userId,
        name: userMap.get(userId) || '未关联',
        commits: count,
      })),
    });
  }

  return c.json({
    code: 0,
    data: { heatmap, stats, weeklyTrend },
    message: 'success',
  });
});