import { Body, Controller, Get, HttpCode, Inject, Param, Post, Query, UseGuards } from "@nestjs/common";
import { ZodValidate } from "../../common/pipes/zod-validation.pipe.js";
import { InternalServiceGuard } from "../../common/guards/internal-service.guard.js";
import { InternalBlocksService } from "./internal.service.js";
import {
  InternalFlushDto,
  type InternalFlushInput,
  InternalReadQuery,
  type InternalReadQueryInput
} from "./internal.dto.js";

/**
 * Internal block endpoints (TASK-0092 slice 2) — the service-to-service
 * surface the realtime gateway uses to hydrate a room and flush a CRDT
 * doc.
 *
 *  - Auth: `InternalServiceGuard` (the shared `INTERNAL_SERVICE_TOKEN`,
 *    fail-closed when unset). A user JWT / API key is rejected here —
 *    the internal surface accepts ONLY the service token.
 *  - Routing: EXCLUDED from the global `api/v1` prefix (`main.ts`) → the
 *    canonical paths are `/internal/blocks/:pageId` +
 *    `/internal/blocks/flush` (never on the public route table).
 *  - No permission re-check: the room's join matrix (VIEW to join, EDIT
 *    to send doc updates) already gated the edits; the flush is a system
 *    write attributed `actor: 'realtime-flush'`.
 */
@Controller("internal")
@UseGuards(InternalServiceGuard)
export class InternalBlocksController {
  constructor(
    @Inject(InternalBlocksService) private readonly internal: InternalBlocksService
  ) {}

  /**
   * Hydrator read: position-ordered blocks + the `pages.version` (the
   * flush's CAS base), cursor-paginated by `position` (the 100k-block
   * hydration streams per page — doc §4.2).
   */
  @Get("blocks/:pageId")
  read(
    @Param("pageId") pageId: string,
    @Query(ZodValidate(InternalReadQuery)) query: InternalReadQueryInput
  ) {
    return this.internal.internalRead(pageId, query);
  }

  /**
   * Persister write: the page's full block set under the `pages.version`
   * CAS. A stale `baseVersion` → no-op + `conflict.externalBlocks` (the
   * room rebases — the "flush wins" rule).
   */
  @Post("blocks/flush")
  @HttpCode(200) // an idempotent persist (CAS write), not a resource creation
  flush(@Body(ZodValidate(InternalFlushDto)) body: InternalFlushInput) {
    return this.internal.internalFlush(body);
  }
}