import { z } from 'zod'
import type { XuqmRemoteConfig } from './config'

const endpointSchema = z.string().refine(value => {
  if (value === '') return true
  try {
    const protocol = new URL(value).protocol
    return (
      protocol === 'http:' || protocol === 'https:' || protocol === 'ws:' || protocol === 'wss:'
    )
  } catch {
    return false
  }
}, 'endpoint must be an absolute HTTP(S) or WS(S) URL')

const flatRemoteConfigSchema = z.object({
  apiUrl: endpointSchema.optional(),
  imApiUrl: endpointSchema.optional(),
  imWsUrl: endpointSchema.optional(),
  fileServiceUrl: endpointSchema.optional(),
  imEnabled: z.boolean().optional(),
  pushEnabled: z.boolean().optional(),
  bugCollectApiUrl: endpointSchema.optional(),
  bugCollectEnabled: z.boolean().optional(),
  updateEnabled: z.boolean().optional(),
  updateRequiresLogin: z.boolean().optional(),
})
const strictCachedRemoteConfigSchema = flatRemoteConfigSchema.strict()
const REMOTE_CONFIG_CACHE_FORMAT = 'XUQM-REMOTE-CONFIG-LKG-V1'
const remoteConfigCacheSchema = z
  .object({
    cachedAt: z.number().int().nonnegative(),
    format: z.literal(REMOTE_CONFIG_CACHE_FORMAT),
    remote: strictCachedRemoteConfigSchema,
  })
  .strict()

export type CachedRemoteConfig = {
  cachedAt: number
  remote: XuqmRemoteConfig
}

const remoteConfigResponseSchema = flatRemoteConfigSchema
  .extend({
    allowAnonymousUpdateCheck: z.boolean().optional(),
    features: z
      .object({
        im: z.boolean().optional(),
        push: z.boolean().optional(),
        bugCollect: z.boolean().optional(),
        update: z.boolean().optional(),
      })
      .optional(),
  })
  .loose()

/** 平台远程配置的唯一归一化入口；features 字段优先于历史 flat 字段。 */
export function normalizeRemoteConfig(value: unknown): XuqmRemoteConfig {
  const raw = remoteConfigResponseSchema.parse(value)
  const features = raw.features ?? {}
  return {
    apiUrl: raw.apiUrl,
    imApiUrl: raw.imApiUrl,
    imWsUrl: raw.imWsUrl,
    fileServiceUrl: raw.fileServiceUrl,
    imEnabled: features.im ?? raw.imEnabled,
    pushEnabled: features.push ?? raw.pushEnabled,
    bugCollectApiUrl: raw.bugCollectApiUrl,
    bugCollectEnabled: features.bugCollect ?? raw.bugCollectEnabled,
    updateEnabled: features.update ?? raw.updateEnabled,
    updateRequiresLogin:
      raw.updateRequiresLogin ??
      (raw.allowAnonymousUpdateCheck === undefined ? undefined : !raw.allowAnonymousUpdateCheck),
  }
}

/** 缓存只接受归一化后的非敏感字段，并拒绝所有未知字段。 */
export function parseCachedRemoteConfig(value: unknown): XuqmRemoteConfig | null {
  const parsed = strictCachedRemoteConfigSchema.safeParse(value)
  return parsed.success ? parsed.data : null
}

/** 非敏感 LKG 的唯一序列化入口；不加密、不携带任何客户端共享秘密。 */
export function serializeRemoteConfigCache(remote: XuqmRemoteConfig, cachedAt: number): string {
  return JSON.stringify(
    remoteConfigCacheSchema.parse({
      cachedAt,
      format: REMOTE_CONFIG_CACHE_FORMAT,
      remote,
    }),
  )
}

/** 损坏、旧格式或含额外字段的缓存全部视为无效。 */
export function parseRemoteConfigCache(value: string): CachedRemoteConfig | null {
  try {
    const parsed = remoteConfigCacheSchema.safeParse(JSON.parse(value))
    return parsed.success ? { cachedAt: parsed.data.cachedAt, remote: parsed.data.remote } : null
  } catch {
    return null
  }
}