import type { RpcRequest, RpcResponse } from './mock-server-rpc-handlers'

type Respond = (response: RpcResponse) => void
type Success = (id: string, result: unknown, streaming?: boolean) => RpcResponse
type ErrorResponse = (id: string, code: string, message: string) => RpcResponse

const MOCK_IMAGE_PNG_BASE64 =
  'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8BQDwAFgwJ/l8sm7wAAAABJRU5ErkJggg=='

const MOCK_FILE_CONTENT: Record<string, string> = {
  'README.md': '# Mobile preview\n\nThis markdown file is served by the mock desktop.',
  'src/app.ts': "export const mobilePreview = 'ready'\n",
  'public/index.html': '<main><h1>Mobile preview</h1><p>HTML preview is ready.</p></main>'
}

const MOCK_FILE_LIST = [
  { relativePath: 'README.md', basename: 'README.md', kind: 'text' },
  { relativePath: 'src/app.ts', basename: 'app.ts', kind: 'text' },
  { relativePath: 'public/index.html', basename: 'index.html', kind: 'text' },
  { relativePath: 'assets/logo.png', basename: 'logo.png', kind: 'binary' },
  { relativePath: 'dist/archive.zip', basename: 'archive.zip', kind: 'binary' }
]

function readMockDirectory(relativePath: string): Array<{ name: string; isDirectory: boolean }> {
  const prefix = relativePath ? `${relativePath}/` : ''
  const children = new Map<string, boolean>()
  for (const file of MOCK_FILE_LIST) {
    if (!file.relativePath.startsWith(prefix)) {
      continue
    }
    const rest = file.relativePath.slice(prefix.length)
    if (!rest) {
      continue
    }
    const [name, ...descendants] = rest.split('/')
    if (!name) {
      continue
    }
    children.set(name, children.get(name) === true || descendants.length > 0)
  }
  return Array.from(children, ([name, isDirectory]) => ({ name, isDirectory })).sort((a, b) => {
    if (a.isDirectory !== b.isDirectory) {
      return a.isDirectory ? -1 : 1
    }
    return a.name.localeCompare(b.name)
  })
}

export function handleMockFilePreviewRequest(
  request: RpcRequest,
  respond: Respond,
  success: Success,
  error: ErrorResponse
): boolean {
  switch (request.method) {
    case 'files.list':
      respond(
        success(request.id, {
          worktree: request.params?.worktree ?? 'id:mock',
          rootPath: '/tmp/orca-mobile-repro/orca',
          files: MOCK_FILE_LIST,
          totalCount: MOCK_FILE_LIST.length,
          truncated: false
        })
      )
      return true

    case 'files.readDir':
      respond(success(request.id, readMockDirectory(String(request.params?.relativePath ?? ''))))
      return true

    case 'files.read': {
      const relativePath = String(request.params?.relativePath ?? '')
      const content = MOCK_FILE_CONTENT[relativePath]
      if (content == null) {
        respond(error(request.id, 'not_found', 'File not found'))
        return true
      }
      respond(
        success(request.id, {
          worktree: request.params?.worktree ?? 'id:mock',
          relativePath,
          content,
          truncated: false,
          byteLength: Buffer.byteLength(content, 'utf8')
        })
      )
      return true
    }

    case 'files.readPreview': {
      const relativePath = String(request.params?.relativePath ?? '')
      if (relativePath !== 'assets/logo.png') {
        respond(error(request.id, 'binary_file', 'binary_file'))
        return true
      }
      respond(
        success(request.id, {
          content: MOCK_IMAGE_PNG_BASE64,
          isBinary: true,
          isImage: true,
          mimeType: 'image/png'
        })
      )
      return true
    }

    default:
      return false
  }
}