import { mascotEventSchema, type MascotProfile } from '@oj2/contract'
import { and, count, countDistinct, desc, eq, gte, inArray, isNull, sql } from 'drizzle-orm'
import { Hono } from 'hono'

import { requireAuth, type AppEnv } from '../auth/middleware'
import { db, schema } from '../db'
import { parseBody, success } from '../http'
import { dayStart, weekStart } from '../time'

export const mascotRoutes = new Hono<AppEnv>()

/**
 * 每人每分钟最多记这么多条。正常点她一分钟到不了十条（连点只记开头、彩蛋和嫌烦那几下），
 * 拿脚本刷的才会撞上；撞上了就静默丢掉，不报错 —— 前台本来也不等这个结果
 */
const EVENTS_PER_MINUTE = 30
const windows = new Map<number, { start: number; count: number }>()

function allow(userId: number) {
  const now = Date.now()
  const entry = windows.get(userId)
  if (!entry || now - entry.start >= 60_000) {
    windows.set(userId, { start: now, count: 1 })
    // 顺手清掉过期的，免得 Map 跟着在线人数一直涨
    if (windows.size > 2000) for (const [id, it] of windows) if (now - it.start >= 60_000) windows.delete(id)
    return true
  }
  entry.count++
  return entry.count <= EVENTS_PER_MINUTE
}

/** 记一条看板娘互动（种类见契约 mascotEventSchema） */
mascotRoutes.post('/mascot/events', requireAuth, async (c) => {
  const parsed = await parseBody(c, mascotEventSchema, '看板娘记录的格式不对')
  if (!parsed.success) return parsed.response
  const user = c.get('user')!
  if (allow(user.id)) {
    const { kind, situation, line, action, path } = parsed.data
    await db.insert(schema.mascotEvent).values({ userId: user.id, kind, situation, line, action, path })
  }
  return success(c, null)
})

/** 最近多少次题库提交拿来看学生常犯哪类错 */
const RECENT_SUBMISSIONS = 20

/** 看板娘按学生的行为挑话用的那几个数（契约 mascotProfileSchema） */
mascotRoutes.get('/mascot/profile', requireAuth, async (c) => {
  const userId = c.get('user')!.id
  const s = schema.submission

  const week = weekStart()
  const e = schema.mascotEvent
  const [pokes, today, recent, tooHard, weekSubmits, weekEvents, weekHints] = await Promise.all([
    db
      .select({ value: count() })
      .from(schema.mascotEvent)
      .where(and(eq(schema.mascotEvent.userId, userId), eq(schema.mascotEvent.kind, 'open'))),
    db
      .select({ value: countDistinct(s.problemId) })
      .from(s)
      .where(and(eq(s.userId, userId), eq(s.result, 0), gte(s.createTime, dayStart()))),
    db
      .select({ result: s.result, errorType: sql<string | null>`${s.statisticInfo}->'runtime_error'->>'type'` })
      .from(s)
      .where(and(eq(s.userId, userId), isNull(s.contestId)))
      .orderBy(desc(s.createTime))
      .limit(RECENT_SUBMISSIONS),
    db
      .select({ value: count() })
      .from(schema.reaction)
      .where(and(eq(schema.reaction.userId, userId), eq(schema.reaction.type, 'too_hard'))),
    db
      .select({ value: count() })
      .from(s)
      .where(and(eq(s.userId, userId), isNull(s.contestId), gte(s.createTime, week))),
    db
      .select({ kind: e.kind, value: count() })
      .from(e)
      .where(and(eq(e.userId, userId), inArray(e.kind, ['trial', 'help']), gte(e.createdAt, week)))
      .groupBy(e.kind),
    db
      .select({ value: count() })
      .from(schema.aiHint)
      .innerJoin(s, eq(s.id, schema.aiHint.submissionId))
      .where(and(eq(s.userId, userId), gte(schema.aiHint.createTime, week))),
  ])
  const eventCount = (kind: string) => weekEvents.find((row) => row.kind === kind)?.value ?? 0

  const types = new Map<string, number>()
  for (const row of recent) if (row.result === 4 && row.errorType) types.set(row.errorType, (types.get(row.errorType) ?? 0) + 1)
  const topType = [...types.entries()].sort((a, b) => b[1] - a[1])[0]?.[0] ?? null
  const tally = (...results: number[]) => recent.filter((row) => results.includes(row.result)).length

  return success(c, {
    pokes: pokes[0]?.value ?? 0,
    todaySolved: today[0]?.value ?? 0,
    tooHard: tooHard[0]?.value ?? 0,
    week: {
      submits: weekSubmits[0]?.value ?? 0,
      trials: eventCount('trial'),
      helps: eventCount('help'),
      aiHints: weekHints[0]?.value ?? 0,
    },
    recent: {
      total: recent.length,
      wrongAnswer: tally(-1),
      compileError: tally(-2),
      runtimeError: tally(4, 3),
      timeout: tally(1, 2),
      runtimeErrorType: topType,
    },
  } satisfies MascotProfile)
})