import { prisma } from '@/lib/prisma'

export interface DayCount {
  day: string
  queued: number
  claimed: number
  running: number
  done: number
  failed: number
  cancelled: number
}

export interface ThroughputKpi {
  todayCount: number
  successRate7d: number
  avgDurationSeconds7d: number | null
}

export interface JobsPerDayResult {
  perDay: DayCount[]
  kpi: ThroughputKpi
}

const STATUSES = ['queued', 'claimed', 'running', 'done', 'failed', 'cancelled'] as const

type RawDayRow = { day: Date; status: string; count: bigint }
type RawKpiRow = { today_count: bigint; done_7d: bigint; terminal_7d: bigint; avg_seconds: number | null }

function toDateStr(d: Date): string {
  return d.toISOString().slice(0, 10)
}

export async function getJobsPerDay(
  userId: string,
  days = 14,
  productId?: string,
): Promise<JobsPerDayResult> {
  const [dayRows, kpiRows] = await Promise.all([
    productId
      ? prisma.$queryRaw<RawDayRow[]>`
          SELECT DATE(created_at) AS day, LOWER(status::text) AS status, COUNT(*) AS count
          FROM claude_jobs
          WHERE user_id = ${userId}
            AND product_id = ${productId}
            AND created_at > NOW() - (${days} || ' days')::INTERVAL
          GROUP BY DATE(created_at), status
          ORDER BY day ASC
        `
      : prisma.$queryRaw<RawDayRow[]>`
          SELECT DATE(created_at) AS day, LOWER(status::text) AS status, COUNT(*) AS count
          FROM claude_jobs
          WHERE user_id = ${userId}
            AND created_at > NOW() - (${days} || ' days')::INTERVAL
          GROUP BY DATE(created_at), status
          ORDER BY day ASC
        `,
    productId
      ? prisma.$queryRaw<RawKpiRow[]>`
          SELECT
            COUNT(*) FILTER (WHERE DATE(created_at) = CURRENT_DATE) AS today_count,
            COUNT(*) FILTER (WHERE status = 'DONE' AND created_at > NOW() - INTERVAL '7 days') AS done_7d,
            COUNT(*) FILTER (WHERE status IN ('DONE','FAILED','CANCELLED') AND created_at > NOW() - INTERVAL '7 days') AS terminal_7d,
            AVG(EXTRACT(EPOCH FROM (finished_at - claimed_at))) FILTER (WHERE status = 'DONE' AND created_at > NOW() - INTERVAL '7 days') AS avg_seconds
          FROM claude_jobs
          WHERE user_id = ${userId}
            AND product_id = ${productId}
        `
      : prisma.$queryRaw<RawKpiRow[]>`
          SELECT
            COUNT(*) FILTER (WHERE DATE(created_at) = CURRENT_DATE) AS today_count,
            COUNT(*) FILTER (WHERE status = 'DONE' AND created_at > NOW() - INTERVAL '7 days') AS done_7d,
            COUNT(*) FILTER (WHERE status IN ('DONE','FAILED','CANCELLED') AND created_at > NOW() - INTERVAL '7 days') AS terminal_7d,
            AVG(EXTRACT(EPOCH FROM (finished_at - claimed_at))) FILTER (WHERE status = 'DONE' AND created_at > NOW() - INTERVAL '7 days') AS avg_seconds
          FROM claude_jobs
          WHERE user_id = ${userId}
        `,
  ])

  // Build lookup: dayStr → status → count
  const lookup = new Map<string, Map<string, number>>()
  for (const row of dayRows) {
    const d = toDateStr(row.day)
    if (!lookup.has(d)) lookup.set(d, new Map())
    lookup.get(d)!.set(row.status, Number(row.count))
  }

  // Generate full date range with zero-fills
  const now = new Date()
  const perDay: DayCount[] = []
  for (let i = days - 1; i >= 0; i--) {
    const d = new Date(now)
    d.setUTCDate(d.getUTCDate() - i)
    const key = toDateStr(d)
    const statusMap = lookup.get(key) ?? new Map()
    perDay.push({
      day: key,
      queued: statusMap.get('queued') ?? 0,
      claimed: statusMap.get('claimed') ?? 0,
      running: statusMap.get('running') ?? 0,
      done: statusMap.get('done') ?? 0,
      failed: statusMap.get('failed') ?? 0,
      cancelled: statusMap.get('cancelled') ?? 0,
    })
  }

  const kpiRow = kpiRows[0]
  const done7d = Number(kpiRow?.done_7d ?? 0)
  const terminal7d = Number(kpiRow?.terminal_7d ?? 0)

  return {
    perDay,
    kpi: {
      todayCount: Number(kpiRow?.today_count ?? 0),
      successRate7d: terminal7d === 0 ? 0 : Math.round((done7d / terminal7d) * 100) / 100,
      avgDurationSeconds7d: kpiRow?.avg_seconds != null ? Math.round(Number(kpiRow.avg_seconds)) : null,
    },
  }
}