/**
 * 开发期 Mock（VITE_MOCK=1 时启用）：在 service worker 之前仅用于本地调试，
 * 通过拦截 fetch/XHR 实现无后端推进前端。
 */
import type { MockRoute } from './types'

const ok = (data: unknown, msg = '') => ({ code: 200, msg, data })
const err = (code: number, msg: string) => ({ code, msg, data: null })

let seq = 1

function textToCode(text: string): string {
  let h = 0
  for (let i = 0; i < text.length; i++) h = (h * 31 + text.charCodeAt(i)) >>> 0
  return (h % 100000).toString().padStart(5, '0')
}

const shares: { code: string; kind: 'text' | 'file'; name: string; size: number; text?: string }[] = []

const routes: MockRoute[] = [
  { method: 'GET', pattern: /\/api\/v1\/health$/, reply: () => ok({ status: 'ok', version: 'mock', storage: 'local', cache: 'memory' }) },
  {
    method: 'GET',
    pattern: /\/api\/v1\/config$/,
    reply: () =>
      ok({
        config: {
          name: '文件快传 (Mock)',
          site_domain: '',
          description: '开发 Mock 模式 · 开箱即用的文件快传系统',
          explain: '',
          uploadSize: 10 * 1024 * 1024,
          allowedFileTypes: [],
          expireStyle: ['day', 'hour', 'minute', 'forever', 'count'],
          enableChunk: true,
          openUpload: true,
          notify_enabled: 1,
          notify_title: '系统通知',
          notify_content: '欢迎使用文件快传（Mock）。',
          logo_url: '',
          favicon_url: '',
          background_url: '',
          footer_text: '',
          footer_beian: '',
          max_file_size: 0,
          max_save_seconds: 0,
          max_save_count: 0,
          uploadCount: 10,
          uploadMinute: 1,
        },
        meta: { version: 'mock', features: { chunkUpload: true, guestUpload: true } },
      }),
  },
  {
    method: 'POST',
    pattern: /\/share\/text$/,
    reply: (_m, body) => {
      const text = String((body as Record<string, string>)?.text ?? '')
      const code = textToCode(text + seq++)
      shares.push({ code, kind: 'text', name: 'Text.txt', size: new Blob([text]).size, text })
      return ok({ code })
    },
  },
  {
    method: 'POST',
    pattern: /\/share\/file$/,
    reply: (_m, body) => {
      const fd = body as FormData
      const file = fd?.get?.('file')
      if (!(file instanceof File)) return err(400, '缺少文件')
      const code = textToCode(file.name + seq++)
      shares.push({ code, kind: 'file', name: file.name, size: file.size })
      return ok({ code, name: file.name })
    },
  },
  {
    method: 'GET',
    pattern: /\/share\/metadata$/,
    reply: (_m, _body, q) => {
      const s = shares.find((x) => x.code === q?.get('code'))
      if (!s) return err(404, '文件不存在')
      return ok({
        code: s.code,
        name: s.name,
        size: s.size,
        type: s.kind,
        is_text: s.kind === 'text',
        created_at: new Date().toISOString(),
        expired_at: null,
        expired_count: -1,
        used_count: 0,
        remaining_downloads: null,
      })
    },
  },
  {
    method: 'GET',
    pattern: /\/share\/select$/,
    reply: (_m, _body, q) => {
      const s = shares.find((x) => x.code === q?.get('code'))
      if (!s) return { __rawError: 404 }
      if (s.kind === 'text') return { __rawText: s.text ?? '' }
      return { __rawBlob: new Blob([`mock-content-of-${s.name}`], { type: 'application/octet-stream' }), __rawName: s.name }
    },
  },
  {
    method: 'POST',
    pattern: /\/chunk\/upload\/init$/,
    reply: (_m, body) => {
      const b = body as Record<string, unknown>
      const total = Math.ceil(Number(b?.file_size ?? 0) / Number(b?.chunk_size ?? 1024))
      return ok({ existed: false, upload_id: `mock-${seq++}`, chunk_size: b?.chunk_size, total_chunks: total, uploaded_chunks: [] })
    },
  },
  { method: 'POST', pattern: /\/chunk\/upload\/[^/]+\/\d+$/, reply: () => ok({ chunk_hash: 'mockhash' }) },
  {
    method: 'GET',
    pattern: /\/chunk\/upload\/status\/[^/]+$/,
    reply: (m) => {
      const id = String(m?.[0]?.split('/').pop() ?? 'mock')
      return ok({ upload_id: id, chunk_size: 1024, total_chunks: 1, uploaded_chunks: [0] })
    },
  },
  {
    method: 'POST',
    pattern: /\/chunk\/upload\/complete\/[^/]+$/,
    reply: () => {
      const code = textToCode('chunk' + seq++)
      shares.push({ code, kind: 'file', name: 'chunked.bin', size: 1024 })
      return ok({ code, name: 'chunked.bin' })
    },
  },
  { method: 'DELETE', pattern: /\/chunk\/upload\/[^/]+$/, reply: () => ok({ message: '已取消' }) },
  { method: 'POST', pattern: /\/admin\/login$/, reply: (_m, body) => ((body as { password?: string })?.password === 'admin123' ? ok({ id: 'admin', username: 'admin', token: 'mock-token', token_type: 'Bearer', expires_in: 86400 }) : err(401, '密码错误')) },
  { method: 'GET', pattern: /\/admin\/verify$/, reply: (_m, _b, _q) => (getToken() === 'mock-token' ? ok({ is_admin: true }) : err(401, '未登录')) },
  { method: 'POST', pattern: /\/admin\/logout$/, reply: () => ok({ ok: true }) },
  {
    method: 'GET',
    pattern: /\/admin\/file\/list$/,
    reply: () =>
      ok({
        page: 1,
        size: 10,
        total: shares.length,
        data: shares.map((s, i) => ({
          id: i + 1,
          code: s.code,
          name: s.name,
          suffix: s.name.includes('.') ? s.name.split('.').pop() : '',
          size: s.size,
          isText: s.kind === 'text',
          expiredAt: null,
          expiredCount: -1,
          usedCount: 0,
          createdAt: new Date().toISOString(),
          isExpired: false,
        })),
      }),
  },
  { method: 'DELETE', pattern: /\/admin\/file\/delete$/, reply: () => ok(null) },
  { method: 'POST', pattern: /\/admin\/file\/batch-delete$/, reply: () => ok(null) },
  { method: 'PATCH', pattern: /\/admin\/file\/update$/, reply: () => ok('更新成功') },
  {
    method: 'GET',
    pattern: /\/admin\/config\/get$/,
    reply: () =>
      ok({
        site_name: '文件快传 (Mock)',
        logo_url: '',
        favicon_url: '',
        background_url: '',
        footer_text: '',
        footer_beian: '',
        notify_enabled: 1,
        notify_title: '系统通知',
        notify_content: '欢迎使用文件快传（Mock）。',
        max_save_seconds: 0,
        max_save_count: 0,
        max_file_size: 0,
        allowed_file_types: ['*'],
        uploadCount: 10,
        uploadMinute: 1,
        openUpload: 1,
      }),
  },
  { method: 'PATCH', pattern: /\/admin\/config\/update$/, reply: () => ok(null) },
  {
    method: 'GET',
    pattern: /\/admin\/audit\/list$/,
    reply: () =>
      ok({
        page: 1,
        size: 20,
        total: 2,
        data: [
          { id: 1, action: 'upload', result: 'success', file_code: shares[0]?.code ?? '10001', file_name: 'demo.txt', size_bytes: 1024, transferred_bytes: 1024, ip: '127.0.0.1', user_agent: 'Mozilla/5.0 (Mock)', device_os: 'macOS', device_browser: 'Chrome', device_type: 'desktop', actor: 'guest', error_msg: '', duration_ms: 42, created_at: new Date().toISOString() },
          { id: 2, action: 'download', result: 'success', file_code: shares[0]?.code ?? '10001', file_name: 'demo.txt', size_bytes: 1024, transferred_bytes: 1024, ip: '192.168.1.2', user_agent: 'Mozilla/5.0 (iPhone)', device_os: 'iOS', device_browser: 'Safari', device_type: 'mobile', actor: 'guest', error_msg: '', duration_ms: 88, created_at: new Date().toISOString() },
        ],
      }),
  },
]

function getToken(): string {
  try {
    return localStorage.getItem('fcb_admin_token') ?? ''
  } catch {
    return ''
  }
}

/** 安装 fetch 拦截（dev-only，不覆盖 XHR —— mock 下上传走 XHR 也会失败，可接受） */
export function installMock(): void {
  if (import.meta.env.VITE_MOCK !== '1') return
  const origFetch = globalThis.fetch.bind(globalThis)
  globalThis.fetch = async (input: RequestInfo | URL, init?: RequestInit): Promise<Response> => {
    const url = typeof input === 'string' ? input : input instanceof URL ? input.toString() : input.url
    const method = (init?.method ?? 'GET').toUpperCase()
    const qIndex = url.indexOf('?')
    const path = qIndex >= 0 ? url.slice(0, qIndex) : url
    const query = qIndex >= 0 ? new URL(url, location.origin).searchParams : undefined

    for (const r of routes) {
      if (r.method !== method) continue
      const m = r.pattern.exec(path)
      if (!m) continue
      let body: unknown = undefined
      if (init?.body) {
        if (typeof init.body === 'string') {
          try {
            body = JSON.parse(init.body)
          } catch {
            body = Object.fromEntries(new URLSearchParams(init.body))
          }
        } else if (init.body instanceof FormData) {
          body = init.body
        }
      }
      const res = r.reply(m, body, query)
      await new Promise((res) => setTimeout(res, 120)) // 模拟网络延迟
      if (res && typeof res === 'object' && '__rawText' in (res as Record<string, unknown>)) {
        return new Response((res as { __rawText: string }).__rawText, { status: 200, headers: { 'content-type': 'text/plain; charset=utf-8' } })
      }
      if (res && typeof res === 'object' && '__rawBlob' in (res as Record<string, unknown>)) {
        const rb = res as { __rawBlob: Blob; __rawName: string }
        return new Response(rb.__rawBlob, { status: 200, headers: { 'content-type': 'application/octet-stream', 'content-disposition': `attachment; filename*=UTF-8''${encodeURIComponent(rb.__rawName)}` } })
      }
      if (res && typeof res === 'object' && '__rawError' in (res as Record<string, unknown>)) {
        const e = err((res as { __rawError: number }).__rawError, '文件不存在')
        return new Response(JSON.stringify(e), { status: 200, headers: { 'content-type': 'application/json' } })
      }
      return new Response(JSON.stringify(res), { status: 200, headers: { 'content-type': 'application/json' } })
    }
    return origFetch(input, init)
  }
  console.info('[mock] 文件快传 API mock enabled (VITE_MOCK=1)')
}