import { NextRequest, NextResponse } from 'next/server';
import { auth } from '@clerk/nextjs/server';
import { db, projects, users } from '@mcpengine/db';
import { eq, desc, and, count } from 'drizzle-orm';

// ── GET /api/projects — list user's projects with pagination ────────────────

export async function GET(req: NextRequest) {
  try {
    const { userId: clerkId } = await auth();
    if (!clerkId) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const user = await db.query.users.findFirst({
      where: eq(users.clerkId, clerkId),
    });
    if (!user) {
      return NextResponse.json({ error: 'User not found' }, { status: 404 });
    }

    const url = new URL(req.url);
    const page = Math.max(1, parseInt(url.searchParams.get('page') || '1', 10));
    const limit = Math.min(50, Math.max(1, parseInt(url.searchParams.get('limit') || '20', 10)));
    const offset = (page - 1) * limit;

    const [rows, totalResult] = await Promise.all([
      db.query.projects.findMany({
        where: eq(projects.userId, user.id),
        orderBy: [desc(projects.updatedAt)],
        limit,
        offset,
        with: {
          tools: { columns: { id: true, name: true, enabled: true } },
          apps: { columns: { id: true, name: true, pattern: true } },
        },
      }),
      db.select({ count: count() }).from(projects).where(eq(projects.userId, user.id)),
    ]);

    const total = totalResult[0]?.count ?? 0;

    return NextResponse.json({
      data: rows,
      meta: {
        page,
        limit,
        total,
        totalPages: Math.ceil(total / limit),
      },
    });
  } catch (error) {
    console.error('[GET /api/projects]', error);
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 },
    );
  }
}

// ── POST /api/projects — create a new project ──────────────────────────────

export async function POST(req: NextRequest) {
  try {
    const { userId: clerkId } = await auth();
    if (!clerkId) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const user = await db.query.users.findFirst({
      where: eq(users.clerkId, clerkId),
    });
    if (!user) {
      return NextResponse.json({ error: 'User not found' }, { status: 404 });
    }

    const body = await req.json();
    const { name, slug, description, specUrl, templateId } = body;

    if (!name || !slug) {
      return NextResponse.json(
        { error: 'name and slug are required' },
        { status: 400 },
      );
    }

    // Check for duplicate slug under same user
    const existing = await db.query.projects.findFirst({
      where: and(eq(projects.userId, user.id), eq(projects.slug, slug)),
    });
    if (existing) {
      return NextResponse.json(
        { error: 'A project with this slug already exists' },
        { status: 409 },
      );
    }

    const [project] = (await db
      .insert(projects)
      .values({
        userId: user.id,
        teamId: user.teamId,
        name,
        slug,
        description: description || null,
        specUrl: specUrl || null,
        templateId: templateId || null,
        status: 'draft',
      })
      .returning()) as any[];

    return NextResponse.json({ data: project }, { status: 201 });
  } catch (error) {
    console.error('[POST /api/projects]', error);
    return NextResponse.json(
      { error: 'Internal server error' },
      { status: 500 },
    );
  }
}