import { NextResponse } from 'next/server';
import { getDatabase } from '@/db';

/**
 * GET /api/clusters
 * Returns all clusters with statistics
 */
export async function GET() {
  try {
    const db = getDatabase();
    
    const clusters = db.prepare(`
      SELECT 
        c.*,
        COUNT(DISTINCT lcm.library_id) as library_count,
        COUNT(DISTINCT CASE WHEN m.type = 'video' THEN m.id END) as video_count,
        COUNT(DISTINCT CASE WHEN m.type = 'photo' THEN m.id END) as photo_count,
        COUNT(DISTINCT CASE WHEN m.type = 'text' THEN m.id END) as text_count,
        COUNT(DISTINCT m.id) as media_count,
        COALESCE(SUM(m.size), 0) as total_size
      FROM clusters c
      LEFT JOIN library_cluster_mapping lcm ON c.id = lcm.cluster_id
      LEFT JOIN libraries l ON lcm.library_id = l.id
      LEFT JOIN media m ON l.id = m.library_id
      GROUP BY c.id
      ORDER BY c.name
    `).all();
    
    return NextResponse.json(clusters);
  } catch (error: any) {
    console.error('Error fetching clusters:', error);
    return NextResponse.json(
      { error: error.message },
      { status: 500 }
    );
  }
}

/**
 * POST /api/clusters
 * Creates a new cluster
 */
export async function POST(request: Request) {
  try {
    const db = getDatabase();
    const { name, description, color, icon } = await request.json();
    
    // Validation
    if (!name || name.trim().length === 0) {
      return NextResponse.json(
        { error: 'Cluster name is required' }, 
        { status: 400 }
      );
    }
    
    if (name.length > 100) {
      return NextResponse.json(
        { error: 'Cluster name must be 100 characters or less' }, 
        { status: 400 }
      );
    }
    
    // Validate color format (basic hex validation)
    if (color && !/^#[0-9A-Fa-f]{6}$/.test(color)) {
      return NextResponse.json(
        { error: 'Invalid color format. Use hex format (#RRGGBB)' },
        { status: 400 }
      );
    }
    
    const result = db.prepare(`
      INSERT INTO clusters (name, description, color, icon)
      VALUES (?, ?, ?, ?)
    `).run(
      name.trim(),
      description || null,
      color || '#6366f1',
      icon || 'folder'
    );
    
    const cluster = db.prepare('SELECT * FROM clusters WHERE id = ?')
      .get(result.lastInsertRowid);
    
    return NextResponse.json(cluster, { status: 201 });
  } catch (error: any) {
    console.error('Error creating cluster:', error);
    if (error.code === 'SQLITE_CONSTRAINT_UNIQUE') {
      return NextResponse.json(
        { error: 'A cluster with this name already exists' },
        { status: 409 }
      );
    }
    return NextResponse.json(
      { error: error.message },
      { status: 500 }
    );
  }
}