import { NextRequest, NextResponse } from 'next/server';
import { authenticateIntegrationRequest } from '@/lib/integrations-auth';
import { createClient } from '@supabase/supabase-js';
import { ASSETS_BUCKET, serviceSupabase } from '@/lib/assets';
import {
  parseGenerationRequestIdFromNotes,
  stripGenerationRequestMarker,
} from '@/lib/rrss-generation';

export const dynamic = 'force-dynamic';

function admin() {
  return createClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.SUPABASE_SERVICE_ROLE_KEY!
  );
}

async function downloadToStorage(opts: {
  tenantId: string;
  pipelineId: string;
  url: string;
  filename: string;
}): Promise<string | null> {
  const svc = serviceSupabase();
  if (!svc) return null;
  try {
    const r = await fetch(opts.url, { cache: 'no-store' });
    if (!r.ok) return null;
    const buf = Buffer.from(await r.arrayBuffer());
    const contentType = r.headers.get('content-type') || 'image/jpeg';
    const ext = contentType.includes('png')
      ? 'png'
      : contentType.includes('webp')
        ? 'webp'
        : 'jpg';
    const path = `${opts.tenantId}/pipeline/${opts.pipelineId}/${opts.filename}.${ext}`;
    const up = await svc.storage.from(ASSETS_BUCKET).upload(path, buf, {
      contentType,
      upsert: true,
    });
    if (up.error) return null;
    return path;
  } catch {
    return null;
  }
}

/**
 * POST — n8n write-back for RRSS auto-generation.
 * Body: {
 *   generation_request_id?,
 *   pipeline_id?,
 *   asset_url?,          // final or Freepik raw
 *   stories_asset_url?,
 *   caption?,
 *   hook?, support?,
 *   slide_urls?: string[],
 *   status?: 'borrador'|'revision_agencia',
 *   mark_request?: 'completada'|'fallida',
 *   error?: string
 * }
 */
export async function POST(req: NextRequest) {
  let body: Record<string, unknown>;
  try {
    body = await req.json();
  } catch {
    return NextResponse.json({ error: 'Invalid JSON' }, { status: 400 });
  }

  const auth = await authenticateIntegrationRequest(req, {
    requireTenant: true,
    parsedBody: body,
  });
  if (!auth.ok) return auth.errorResponse!;

  const tenantId = auth.tenantId!;
  const db = admin();

  const grId =
    typeof body.generation_request_id === 'string'
      ? body.generation_request_id
      : null;

  let pipelineId =
    typeof body.pipeline_id === 'string' ? body.pipeline_id : null;

  if (!pipelineId && grId) {
    const { data: gr } = await db
      .from('generation_requests')
      .select('brief')
      .eq('id', grId)
      .eq('tenant_id', tenantId)
      .maybeSingle();
    const brief = (gr?.brief || {}) as {
      source_pipeline_id?: string;
      write_back?: { pipeline_id?: string };
    };
    pipelineId =
      brief.source_pipeline_id || brief.write_back?.pipeline_id || null;
  }

  if (!pipelineId) {
    return NextResponse.json(
      { error: 'pipeline_id or generation_request_id with source_pipeline_id required' },
      { status: 400 }
    );
  }

  const { data: item } = await db
    .from('creative_pipeline')
    .select('id, notes, caption, format')
    .eq('id', pipelineId)
    .eq('tenant_id', tenantId)
    .maybeSingle();

  if (!item) {
    return NextResponse.json({ error: 'Pipeline piece not found' }, { status: 404 });
  }

  const assetUrl =
    typeof body.asset_url === 'string'
      ? body.asset_url
      : typeof body.stories_asset_url === 'string'
        ? body.stories_asset_url
        : null;

  let coverPath: string | null = null;
  if (assetUrl) {
    if (assetUrl.startsWith('http')) {
      coverPath = await downloadToStorage({
        tenantId,
        pipelineId,
        url: assetUrl,
        filename: 'cover-ai',
      });
      // Fallback: store URL so UI can still show something via <img src>
      if (!coverPath) coverPath = assetUrl;
    } else {
      coverPath = assetUrl;
    }
  }

  const slideUrls = Array.isArray(body.slide_urls)
    ? body.slide_urls.filter((u): u is string => typeof u === 'string')
    : [];
  const slidePaths: string[] = [];
  for (let i = 0; i < slideUrls.length; i++) {
    const u = slideUrls[i];
    if (u.startsWith('http')) {
      const p = await downloadToStorage({
        tenantId,
        pipelineId,
        url: u,
        filename: `slide-${i + 1}-ai`,
      });
      slidePaths.push(p || u);
    } else {
      slidePaths.push(u);
    }
  }

  const caption =
    typeof body.caption === 'string'
      ? body.caption
      : [body.hook, body.support, body.primary_text]
          .filter((x) => typeof x === 'string' && x.trim())
          .join('\n\n') || item.caption;

  const status =
    body.status === 'revision_agencia' || body.status === 'borrador'
      ? body.status
      : coverPath
        ? 'revision_agencia'
        : 'borrador';

  const cleanNotes = stripGenerationRequestMarker(item.notes);
  const grMarker = grId || parseGenerationRequestIdFromNotes(item.notes);
  const notes = [
    cleanNotes,
    grMarker ? `[[generation_request:${grMarker}]]` : null,
    coverPath ? 'Generado: Claude + Freepik + Canva' : null,
  ]
    .filter(Boolean)
    .join('\n');

  const patch: Record<string, unknown> = {
    notes,
    updated_at: new Date().toISOString(),
    status,
  };
  if (coverPath) {
    patch.cover_path = coverPath;
    patch.cover_mime = coverPath.includes('.png')
      ? 'image/png'
      : coverPath.includes('.webp')
        ? 'image/webp'
        : 'image/jpeg';
  }
  if (caption) patch.caption = caption;
  if (slidePaths.length) patch.slide_paths = slidePaths;

  const { data: updated, error } = await db
    .from('creative_pipeline')
    .update(patch)
    .eq('id', pipelineId)
    .eq('tenant_id', tenantId)
    .select('*')
    .single();

  if (error) {
    return NextResponse.json({ error: error.message }, { status: 500 });
  }

  if (grId) {
    const mark =
      body.mark_request === 'fallida'
        ? 'fallida'
        : body.error
          ? 'fallida'
          : 'completada';
    await db
      .from('generation_requests')
      .update({
        status: mark,
        completed_at: new Date().toISOString(),
        error: typeof body.error === 'string' ? body.error : null,
        result: {
          pipeline_id: pipelineId,
          cover_path: coverPath,
          notes: 'rrss write-back',
        },
      })
      .eq('id', grId)
      .eq('tenant_id', tenantId);
  }

  return NextResponse.json({ ok: true, item: updated });
}