/**
 * TASK-0126 — AI page-generation endpoint (SSE).
 *
 *   POST /workspaces/:workspaceId/ai/generate   (body `{ prompt, parentId? }`,
 *   header `Idempotency-Key?`)
 *
 * Route style mirrors `rag.controller.ts` (explicit `@Inject`, `ZodValidate`
 * body, `requireUser`, `@Res()` passthrough — the service owns the socket;
 * pre-stream failures throw → global filter JSON envelope). Frames: `tool`
 * (per-step progress), then a terminal `done` (with `pageId` + `created`),
 * `cancelled`, or `error` (invalid plan / step failure / timeout / budget).
 */
import { Body, Controller, Inject, Param, Post, Req, Res } from "@nestjs/common";
import type { Request, Response } from "express";

import { AiGenerateService } from "./generate.service.js";
import { ZodValidate } from "../../../common/pipes/zod-validation.pipe.js";
import { requireActor } from "../../../common/types.js";
import { SkipIdempotency } from "../../../common/middleware/idempotency.js";
import { AiGenerateDto, type AiGenerateInput } from "./generate.dto.js";

@Controller()
export class AiGenerateController {
  constructor(@Inject(AiGenerateService) private readonly generateService: AiGenerateService) {}

  /**
   * Generate a page (SSE). Pre-stream: 404 (non-member workspace, fail-closed),
   * 403 (no EDIT), 402 (budget), 429 (shared ai.calls cap), 400/422 (validation).
   * First frames after the headers are the per-step `tool` progress events; the
   * stream ends with a terminal `done` (the created `pageId` + `created` counts)
   * or an in-band `error` / `cancelled`.
   *
   * The `Idempotency-Key` header memoizes a cancelled run's created page so a
   * retried request does not double-create (the 24 h idempotency contract).
   */
  @Post("workspaces/:workspaceId/ai/generate")
  @SkipIdempotency()
  generatePage(
    @Param("workspaceId") workspaceId: string,
    @Body(ZodValidate(AiGenerateDto)) body: AiGenerateInput,
    @Req() req: Request,
    @Res() res: Response,
  ) {
    const keyHeader = req.header("idempotency-key");
    const idempotencyKey = keyHeader && keyHeader.trim() ? keyHeader.trim() : undefined;
    return this.generateService.generate(workspaceId, requireActor(req), body, idempotencyKey, req, res);
  }
}