import { redis } from './redis'

export type LogLevel = 'info' | 'warn' | 'error'

export interface AppLogEntry {
  id: number
  level: LogLevel
  message: string
  detail?: string
  timestamp: string
}

const REDIS_KEY = 'app:logs'
const MAX_ENTRIES = 500
const ID_KEY = 'app:logs:next_id'

export async function appLog(level: LogLevel, message: string, detail?: string) {
  if (!redis) return
  const id = await redis.incr(ID_KEY)
  const entry: AppLogEntry = { id, level, message, detail, timestamp: new Date().toISOString() }
  await redis.lpush(REDIS_KEY, JSON.stringify(entry))
  await redis.ltrim(REDIS_KEY, 0, MAX_ENTRIES - 1)
}

export async function getAppLogs(options?: {
  level?: LogLevel
  limit?: number
  afterId?: number
}): Promise<AppLogEntry[]> {
  if (!redis) return []
  const limit = options?.limit ?? 100
  const fetchCount = options?.level || options?.afterId ? MAX_ENTRIES : limit
  const raw = await redis.lrange(REDIS_KEY, 0, fetchCount - 1)
  let logs: AppLogEntry[] = raw.map((s: string) => JSON.parse(s))
  if (options?.afterId) logs = logs.filter((l) => l.id > options.afterId!)
  if (options?.level) logs = logs.filter((l) => l.level === options.level)
  logs.reverse()
  return logs.slice(-limit)
}

export async function clearAppLogs() {
  if (!redis) return
  await redis.del(REDIS_KEY)
  await redis.del(ID_KEY)
}