import { after, type NextRequest } from 'next/server';
import { nanoid } from 'nanoid';
import { apiError, apiSuccess } from '@/lib/server/api-response';
import { type GenerateClassroomInput } from '@/lib/server/classroom-generation';
import { runClassroomGenerationJob } from '@/lib/server/classroom-job-runner';
import { createClassroomGenerationJob } from '@/lib/server/classroom-job-store';
import { buildRequestOrigin } from '@/lib/server/classroom-storage';
import { createLogger } from '@/lib/logger';
import {
  authorizeClassroomJobCreation,
  authorizeClassroomJobList,
  classroomJobAccessError,
} from '@/lib/server/authz/classroom-job-access';
import { resolveIdentityEnforcementMode } from '@/lib/server/authz/identity-enforcement';

const log = createLogger('GenerateClassroom API');

export const maxDuration = 30;

export async function POST(req: NextRequest) {
  let requirementSnippet: string | undefined;
  try {
    const rawBody = (await req.json()) as Partial<GenerateClassroomInput>;
    requirementSnippet = rawBody.requirement?.substring(0, 60);
    const body: GenerateClassroomInput = {
      requirement: rawBody.requirement || '',
      ...(rawBody.pdfContent ? { pdfContent: rawBody.pdfContent } : {}),

      ...(rawBody.enableWebSearch != null ? { enableWebSearch: rawBody.enableWebSearch } : {}),
      ...(rawBody.webSearchProviderId ? { webSearchProviderId: rawBody.webSearchProviderId } : {}),
      ...(rawBody.webSearchApiKey ? { webSearchApiKey: rawBody.webSearchApiKey } : {}),
      ...(rawBody.webSearchModelId ? { webSearchModelId: rawBody.webSearchModelId } : {}),
      ...(rawBody.baiduSubSources ? { baiduSubSources: rawBody.baiduSubSources } : {}),
      ...(rawBody.enableImageGeneration != null
        ? { enableImageGeneration: rawBody.enableImageGeneration }
        : {}),
      ...(rawBody.enableVideoGeneration != null
        ? { enableVideoGeneration: rawBody.enableVideoGeneration }
        : {}),
      ...(rawBody.enableTTS != null ? { enableTTS: rawBody.enableTTS } : {}),
      ...(rawBody.interactiveMode != null ? { interactiveMode: rawBody.interactiveMode } : {}),
      ...(rawBody.taskEngineMode != null ? { taskEngineMode: rawBody.taskEngineMode } : {}),
    };
    const { requirement } = body;

    if (!requirement) {
      return apiError('MISSING_REQUIRED_FIELD', 400, 'Missing required field: requirement');
    }

    const creationAccess = await authorizeClassroomJobCreation(req);
    if (!creationAccess.allowed) return classroomJobAccessError(creationAccess);

    const baseUrl = buildRequestOrigin(req);
    const jobId = nanoid(10);
    const job = await createClassroomGenerationJob(jobId, body, creationAccess.ownership);
    const pollUrl = `${baseUrl}/api/generate-classroom/${jobId}`;

    after(() => runClassroomGenerationJob(jobId, body, baseUrl));

    return apiSuccess(
      {
        jobId,
        status: job.status,
        step: job.step,
        message: job.message,
        pollUrl,
        pollIntervalMs: 5000,
      },
      202,
    );
  } catch (error) {
    log.error(
      `Classroom generation job creation failed [requirement="${requirementSnippet ?? 'unknown'}..."]:`,
      error,
    );
    return apiError(
      'INTERNAL_ERROR',
      500,
      'Failed to create classroom generation job',
      error instanceof Error ? error.message : 'Unknown error',
    );
  }
}

/**
 * GET /api/generate-classroom?limit=N — list recent background generation
 * jobs (newest first) for the ops task panel.
 */
export async function GET(request: NextRequest) {
  try {
    const limitParam = Number(new URL(request.url).searchParams.get('limit') ?? 20);
    const limit = Number.isFinite(limitParam) && limitParam > 0 ? Math.min(limitParam, 50) : 20;
    const { listClassroomGenerationJobs } = await import('@/lib/server/classroom-job-store');
    const enforcementMode = resolveIdentityEnforcementMode();
    const jobs = await listClassroomGenerationJobs(
      enforcementMode === 'required' ? Number.MAX_SAFE_INTEGER : limit,
    );
    const listAccess = await authorizeClassroomJobList(request, jobs, {
      mode: enforcementMode,
    });
    if (!listAccess.allowed) return classroomJobAccessError(listAccess);
    return apiSuccess({
      items: listAccess.jobs.slice(0, limit).map((job) => ({
        jobId: job.id,
        status: job.status,
        step: job.step,
        progress: job.progress,
        message: job.message,
        createdAt: job.createdAt,
        updatedAt: job.updatedAt,
        completedAt: job.completedAt,
        requirement: job.inputSummary.requirementPreview,
        scenesGenerated: job.scenesGenerated,
        totalScenes: job.totalScenes,
        result: job.result,
        error: job.error,
        done: job.status === 'succeeded' || job.status === 'failed' || job.status === 'cancelled',
      })),
    });
  } catch (error) {
    log.error('Classroom job listing failed:', error);
    return apiError(
      'INTERNAL_ERROR',
      500,
      'Failed to list classroom generation jobs',
      error instanceof Error ? error.message : String(error),
    );
  }
}