/** Host HTTP bridge for browser-client RPC. */
import type { Context } from 'cordis'
import z from 'schemastery'
// Activates the httpServer Context merge used below.
import type { WebRoute } from '@deepseek-ai/dsh-host-webserver'
import { toFetchHandler } from '@deepseek-ai/dsh-host-apiproxy'
import { API_PATH } from './api-path.ts'
import { bridge } from './http-bridge.ts'
import { assertTrustedAuthority, isTrustedApiRequest } from './api-request-trust.ts'

export { API_PATH } from './api-path.ts'

/** Stable Cordis plugin name. */
export const name = 'client-connection'

/** Services required before mounting the route. */
export const inject = ['httpServer', 'apiProxy']

/** Plugin config: the deployment's non-loopback serving authorities. */
export interface ConnectionConfig {
  /**
   * Authorities this deployment serves beyond loopback: exact `host:port`, or
   * port-less `host` matching any port. The /api trust fence refuses any
   * request whose Host is neither loopback nor listed here, so a
   * non-loopback (`0.0.0.0`) deployment must declare the names it is reached
   * by (the dsh CLI derives the machine's LAN IP literals itself). An entry
   * that is not a bare, canonical authority fails the plugin load.
   */
  trustedHosts?: string[]
}

export const Config: z<ConnectionConfig> = z.object({
  trustedHosts: z.array(String).default([]),
})

/**
 * Mounts the API gateway under the browser transport prefix. Every request on
 * the prefix passes the browser-trust fence first (DNS-rebinding and
 * cross-site defense — [api-request-trust](./api-request-trust.ts)).
 * @param ctx - Host plugin context.
 * @param config - resolved plugin config (schema defaults applied).
 */
export function apply(ctx: Context, config?: ConnectionConfig): void {
  // The Loader resolves schema defaults; hand-built test contexts may pass none.
  const trustedHosts = config?.trustedHosts ?? []
  // Config boundary: a malformed entry fails the load loudly here rather than
  // silently authorizing its hostname prefix at request time.
  for (const entry of trustedHosts) assertTrustedAuthority(entry)
  const apiHandler = toFetchHandler(ctx.apiProxy)
  const route: WebRoute = {
    kind: 'prefix',
    path: API_PATH,
    handler: async (req, res) => {
      if (!isTrustedApiRequest(req, trustedHosts)) {
        res.writeHead(403)
        res.end('forbidden')
        return
      }
      await bridge(req, res, apiHandler)
    },
  }
  ctx.effect(() => ctx.httpServer.register(route), 'client-connection: /api route')
}