import { NextResponse } from 'next/server';
import { sql } from '@vercel/postgres';
import { verifyToken } from './setup-auth.js';

// GET /api/user-cards - Get user's cards with optional filters
export async function GET(request) {
  try {
    const token = request.headers.get('authorization')?.replace('Bearer ', '');
    const user = await verifyToken(token);
    
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    // Check if tables exist first
    try {
      const tableCheck = await sql.query(`
        SELECT EXISTS (
          SELECT FROM information_schema.tables 
          WHERE table_name = 'user_cards'
        ) as user_cards_exists,
        EXISTS (
          SELECT FROM information_schema.tables 
          WHERE table_name = 'cards'
        ) as cards_exists
      `);
      
      const { user_cards_exists, cards_exists } = tableCheck.rows[0];
      
      if (!user_cards_exists || !cards_exists) {
        console.log('Tables do not exist, returning empty array');
        return NextResponse.json({
          success: true,
          data: [],
          message: 'No cards found (tables not initialized)'
        });
      }
    } catch (error) {
      console.error('Error checking table existence:', error);
      return NextResponse.json({
        success: true,
        data: [],
        message: 'Database not initialized'
      });
    }

    const { searchParams } = new URL(request.url);
    const game = searchParams.get('game');
    const rarity = searchParams.get('rarity');
    const status = searchParams.get('status');
    const search = searchParams.get('search');

    let query = `
      SELECT 
        uc.id,
        uc.user_id,
        uc.card_id,
        uc.status,
        uc.quantity,
        uc.condition,
        uc.notes,
        uc.acquired_date,
        uc.acquired_price,
        uc.acquired_from,
        uc.created_at,
        uc.updated_at,
        c.name,
        c.set_name,
        c.set_code,
        c.card_number,
        c.rarity,
        c.game,
        c.card_type,
        c.mana_cost,
        c.cmc,
        c.colors,
        c.oracle_text,
        c.power,
        c.toughness,
        c.image_url,
        c.stock_image_url,
        c.current_price,
        c.market_price,
        c.verified,
        c.created_at as card_created_at,
        c.updated_at as card_updated_at
      FROM user_cards uc
      JOIN cards c ON uc.card_id = c.id
      WHERE uc.user_id = $1
    `;

    const params = [user.id];
    let paramIndex = 2;

    if (game) {
      query += ` AND c.game = $${paramIndex}`;
      params.push(game);
      paramIndex++;
    }

    if (rarity) {
      query += ` AND c.rarity = $${paramIndex}`;
      params.push(rarity);
      paramIndex++;
    }

    if (status && status !== 'all') {
      query += ` AND uc.status = $${paramIndex}`;
      params.push(status);
      paramIndex++;
    }

    if (search) {
      query += ` AND (c.name ILIKE $${paramIndex} OR c.set_name ILIKE $${paramIndex})`;
      params.push(`%${search}%`);
      paramIndex++;
    }

    query += ` ORDER BY uc.created_at DESC`;

    const result = await sql.query(query, params);

    const userCards = result.rows.map(row => ({
      id: row.id,
      userId: row.user_id,
      cardId: row.card_id,
      status: row.status,
      quantity: row.quantity,
      condition: row.condition,
      notes: row.notes,
      acquiredDate: row.acquired_date,
      acquiredPrice: row.acquired_price,
      acquiredFrom: row.acquired_from,
      createdAt: row.created_at,
      updatedAt: row.updated_at,
      card: {
        id: row.card_id,
        name: row.name,
        set_name: row.set_name,
        set_code: row.set_code,
        card_number: row.card_number,
        rarity: row.rarity,
        game: row.game,
        card_type: row.card_type,
        mana_cost: row.mana_cost,
        cmc: row.cmc,
        colors: row.colors ? JSON.parse(row.colors) : [],
        oracle_text: row.oracle_text,
        power: row.power,
        toughness: row.toughness,
        image_url: row.image_url,
        stock_image_url: row.stock_image_url,
        current_price: row.current_price,
        market_price: row.market_price,
        verified: row.verified,
        createdAt: row.card_created_at,
        updatedAt: row.card_updated_at,
      }
    }));

    return NextResponse.json({
      success: true,
      data: userCards,
      message: `Found ${userCards.length} cards`
    });

  } catch (error) {
    console.error('Error fetching user cards:', error);
    return NextResponse.json(
      { error: 'Failed to fetch user cards' },
      { status: 500 }
    );
  }
}

// POST /api/user-cards - Add card to user collection
export async function POST(request) {
  try {
    const token = request.headers.get('authorization')?.replace('Bearer ', '');
    const user = await verifyToken(token);
    
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const body = await request.json();
    const {
      cardId,
      status = 'owned',
      quantity = 1,
      condition,
      notes,
      acquiredDate,
      acquiredPrice,
      acquiredFrom,
      collectionIds = [],
      deckIds = []
    } = body;

    if (!cardId) {
      return NextResponse.json(
        { error: 'Card ID is required' },
        { status: 400 }
      );
    }

    // Check if card exists
    const cardResult = await sql.query(
      'SELECT id FROM cards WHERE id = $1',
      [cardId]
    );

    if (cardResult.rows.length === 0) {
      return NextResponse.json(
        { error: 'Card not found' },
        { status: 404 }
      );
    }

    // Check if user already has this card
    const existingResult = await sql.query(
      'SELECT id FROM user_cards WHERE user_id = $1 AND card_id = $2',
      [user.id, cardId]
    );

    if (existingResult.rows.length > 0) {
      return NextResponse.json(
        { error: 'Card already in collection' },
        { status: 409 }
      );
    }

    // Add card to user collection
    const result = await sql.query(
      `INSERT INTO user_cards (
        user_id, card_id, status, quantity, condition, notes,
        acquired_date, acquired_price, acquired_from, created_at, updated_at
      ) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, NOW(), NOW())
      RETURNING *`,
      [
        user.id, cardId, status, quantity, condition, notes,
        acquiredDate, acquiredPrice, acquiredFrom
      ]
    );

    const userCard = result.rows[0];

    // Add to collections if specified
    if (collectionIds.length > 0) {
      for (const collectionId of collectionIds) {
        await sql.query(
          'INSERT INTO collection_cards (collection_id, user_card_id) VALUES ($1, $2)',
          [collectionId, userCard.id]
        );
      }
    }

    // Add to decks if specified
    if (deckIds.length > 0) {
      for (const deckId of deckIds) {
        await sql.query(
          'INSERT INTO deck_cards (deck_id, user_card_id, quantity, board) VALUES ($1, $2, $3, $4)',
          [deckId, userCard.id, quantity, 'mainboard']
        );
      }
    }

    return NextResponse.json({
      success: true,
      data: {
        id: userCard.id,
        userId: userCard.user_id,
        cardId: userCard.card_id,
        status: userCard.status,
        quantity: userCard.quantity,
        condition: userCard.condition,
        notes: userCard.notes,
        acquiredDate: userCard.acquired_date,
        acquiredPrice: userCard.acquired_price,
        acquiredFrom: userCard.acquired_from,
        createdAt: userCard.created_at,
        updatedAt: userCard.updated_at,
      },
      message: 'Card added to collection'
    });

  } catch (error) {
    console.error('Error adding card to collection:', error);
    return NextResponse.json(
      { error: 'Failed to add card to collection' },
      { status: 500 }
    );
  }
}

// PUT /api/user-cards/[id] - Update user card
export async function PUT(request, { params }) {
  try {
    const token = request.headers.get('authorization')?.replace('Bearer ', '');
    const user = await verifyToken(token);
    
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { id } = params;
    const body = await request.json();

    // Check if user owns this card
    const ownershipResult = await sql.query(
      'SELECT id FROM user_cards WHERE id = $1 AND user_id = $2',
      [id, user.id]
    );

    if (ownershipResult.rows.length === 0) {
      return NextResponse.json(
        { error: 'Card not found or not owned by user' },
        { status: 404 }
      );
    }

    // Build update query dynamically
    const updateFields = [];
    const updateValues = [];
    let paramIndex = 1;

    if (body.status !== undefined) {
      updateFields.push(`status = $${paramIndex}`);
      updateValues.push(body.status);
      paramIndex++;
    }

    if (body.quantity !== undefined) {
      updateFields.push(`quantity = $${paramIndex}`);
      updateValues.push(body.quantity);
      paramIndex++;
    }

    if (body.condition !== undefined) {
      updateFields.push(`condition = $${paramIndex}`);
      updateValues.push(body.condition);
      paramIndex++;
    }

    if (body.notes !== undefined) {
      updateFields.push(`notes = $${paramIndex}`);
      updateValues.push(body.notes);
      paramIndex++;
    }

    if (body.acquiredDate !== undefined) {
      updateFields.push(`acquired_date = $${paramIndex}`);
      updateValues.push(body.acquiredDate);
      paramIndex++;
    }

    if (body.acquiredPrice !== undefined) {
      updateFields.push(`acquired_price = $${paramIndex}`);
      updateValues.push(body.acquiredPrice);
      paramIndex++;
    }

    if (body.acquiredFrom !== undefined) {
      updateFields.push(`acquired_from = $${paramIndex}`);
      updateValues.push(body.acquiredFrom);
      paramIndex++;
    }

    if (updateFields.length === 0) {
      return NextResponse.json(
        { error: 'No fields to update' },
        { status: 400 }
      );
    }

    updateFields.push(`updated_at = NOW()`);
    updateValues.push(id);

    const query = `
      UPDATE user_cards 
      SET ${updateFields.join(', ')}
      WHERE id = $${paramIndex}
      RETURNING *
    `;

    const result = await sql.query(query, updateValues);
    const userCard = result.rows[0];

    return NextResponse.json({
      success: true,
      data: {
        id: userCard.id,
        userId: userCard.user_id,
        cardId: userCard.card_id,
        status: userCard.status,
        quantity: userCard.quantity,
        condition: userCard.condition,
        notes: userCard.notes,
        acquiredDate: userCard.acquired_date,
        acquiredPrice: userCard.acquired_price,
        acquiredFrom: userCard.acquired_from,
        createdAt: userCard.created_at,
        updatedAt: userCard.updated_at,
      },
      message: 'Card updated successfully'
    });

  } catch (error) {
    console.error('Error updating user card:', error);
    return NextResponse.json(
      { error: 'Failed to update card' },
      { status: 500 }
    );
  }
}

// DELETE /api/user-cards/[id] - Delete user card
export async function DELETE(request, { params }) {
  try {
    const token = request.headers.get('authorization')?.replace('Bearer ', '');
    const user = await verifyToken(token);
    
    if (!user) {
      return NextResponse.json({ error: 'Unauthorized' }, { status: 401 });
    }

    const { id } = params;

    // Check if user owns this card
    const ownershipResult = await sql.query(
      'SELECT id FROM user_cards WHERE id = $1 AND user_id = $2',
      [id, user.id]
    );

    if (ownershipResult.rows.length === 0) {
      return NextResponse.json(
        { error: 'Card not found or not owned by user' },
        { status: 404 }
      );
    }

    // Delete from collections and decks first
    await sql.query('DELETE FROM collection_cards WHERE user_card_id = $1', [id]);
    await sql.query('DELETE FROM deck_cards WHERE user_card_id = $1', [id]);

    // Delete the user card
    await sql.query('DELETE FROM user_cards WHERE id = $1', [id]);

    return NextResponse.json({
      success: true,
      message: 'Card removed from collection'
    });

  } catch (error) {
    console.error('Error deleting user card:', error);
    return NextResponse.json(
      { error: 'Failed to delete card' },
      { status: 500 }
    );
  }
}