// server/supabase/functions/_shared/quota.ts
// 티어별 기능 쿼터 확인 + 증가

// @ts-expect-error — Deno 런타임 import
import { createClient } from 'https://esm.sh/@supabase/supabase-js@2.39.7'

export type Tier = 'free' | 'pro' | 'team'
export type Feature = 'stt_transcribe' | 'llm_process'

/** 일일 쿼터 정책 (-1 = 무제한) */
const DAILY_QUOTA: Record<Tier, Record<Feature, number>> = {
  free: {
    stt_transcribe: 50,
    llm_process: 50
  },
  pro: {
    stt_transcribe: -1,
    llm_process: -1
  },
  team: {
    stt_transcribe: -1,
    llm_process: -1
  }
}

export interface QuotaCheck {
  allowed: boolean
  current: number
  limit: number
  tier: Tier
}

/**
 * 유저의 오늘 사용량을 확인하고 쿼터 초과 여부를 반환.
 * 실제 증가는 performQuotaConsume 호출 시 수행.
 */
export async function checkQuota(
  userId: string,
  feature: Feature,
  serviceRoleClient: ReturnType<typeof createClient>
): Promise<QuotaCheck> {
  // 티어 조회
  const { data: sub } = await serviceRoleClient
    .from('subscriptions')
    .select('tier')
    .eq('user_id', userId)
    .single()

  const tier: Tier = (sub?.tier as Tier) ?? 'free'
  const limit = DAILY_QUOTA[tier][feature]

  if (limit === -1) {
    return { allowed: true, current: 0, limit, tier }
  }

  // 오늘 사용량 조회
  const today = new Date().toISOString().slice(0, 10)
  const { data: usage } = await serviceRoleClient
    .from('daily_usage')
    .select('count')
    .eq('user_id', userId)
    .eq('date', today)
    .eq('feature', feature)
    .maybeSingle()

  const current = (usage?.count as number) ?? 0
  return {
    allowed: current < limit,
    current,
    limit,
    tier
  }
}

/**
 * 쿼터 소비. increment_daily_usage 함수 호출 (service_role 전용).
 */
export async function consumeQuota(
  userId: string,
  feature: Feature,
  serviceRoleClient: ReturnType<typeof createClient>,
  amount: number = 1
): Promise<number> {
  const { data, error } = await serviceRoleClient.rpc('increment_daily_usage', {
    p_user_id: userId,
    p_feature: feature,
    p_amount: amount
  })

  if (error) {
    throw new Error(`Failed to increment quota: ${error.message}`)
  }

  return (data as number) ?? 0
}

/**
 * service role 클라이언트 생성 헬퍼
 */
export function createServiceRoleClient(): ReturnType<typeof createClient> {
  // @ts-expect-error — Deno.env는 Deno 런타임 전역
  const url = Deno.env.get('SUPABASE_URL') ?? ''
  // @ts-expect-error — Deno.env는 Deno 런타임 전역
  const serviceKey = Deno.env.get('SUPABASE_SERVICE_ROLE_KEY') ?? ''
  return createClient(url, serviceKey, {
    auth: { persistSession: false, autoRefreshToken: false }
  })
}