/**
 * GET /api/servers - Server list with filtering handler
 */

import type { Env } from '../types';
import { jsonResponse, isValidServer } from '../utils';
import {
  DEFAULT_ANVIL_REGION_FILTER_SQL,
  buildFlexibleRegionConditionsAnvil
} from '../region-utils';

/**
 * GET /api/servers - Server list with filtering
 * Uses anvil_* tables for pricing data
 */
export async function handleGetServers(
  request: Request,
  env: Env,
  corsHeaders: Record<string, string>
): Promise<Response> {
  try {
    const url = new URL(request.url);
    const minCpu = url.searchParams.get('minCpu');
    const minMemory = url.searchParams.get('minMemory');
    const region = url.searchParams.get('region');

    console.log('[GetServers] Query params:', {
      minCpu,
      minMemory,
      region,
    });

    // Generate cache key from query parameters
    const cacheKey = `servers:${url.search || 'all'}`;

    // Check cache first
    if (env.CACHE) {
      const cached = await env.CACHE.get(cacheKey);
      if (cached) {
        console.log('[GetServers] Cache hit for:', cacheKey);
        return jsonResponse({ ...JSON.parse(cached), cached: true }, 200, corsHeaders);
      }
    }

    // Build SQL query using anvil_* tables
    let query = `
      SELECT
        ai.id,
        'Anvil' as provider_name,
        ai.name as instance_id,
        ai.display_name as instance_name,
        ai.vcpus as vcpu,
        CAST(ai.memory_gb * 1024 AS INTEGER) as memory_mb,
        ai.memory_gb,
        ai.disk_gb as storage_gb,
        ai.network_gbps as network_speed_gbps,
        ai.category as instance_family,
        CASE WHEN ai.gpu_model IS NOT NULL THEN 1 ELSE 0 END as gpu_count,
        ai.gpu_model as gpu_type,
        ap.monthly_price,
        ar.display_name as region_name,
        ar.name as region_code
      FROM anvil_instances ai
      JOIN anvil_pricing ap ON ap.anvil_instance_id = ai.id
      JOIN anvil_regions ar ON ap.anvil_region_id = ar.id
      WHERE ai.active = 1 AND ar.active = 1
        AND ${DEFAULT_ANVIL_REGION_FILTER_SQL}
    `;

    const params: (string | number)[] = [];

    if (minCpu) {
      const parsedCpu = parseInt(minCpu, 10);
      if (isNaN(parsedCpu)) {
        return jsonResponse({ error: 'Invalid minCpu parameter' }, 400, corsHeaders);
      }
      query += ` AND ai.vcpus >= ?`;
      params.push(parsedCpu);
    }

    if (minMemory) {
      const parsedMemory = parseInt(minMemory, 10);
      if (isNaN(parsedMemory)) {
        return jsonResponse({ error: 'Invalid minMemory parameter' }, 400, corsHeaders);
      }
      // minMemory is in GB, anvil_instances stores memory_gb
      query += ` AND ai.memory_gb >= ?`;
      params.push(parsedMemory);
    }

    if (region) {
      // Flexible region matching: supports country names, codes, city names
      const { conditions, params: regionParams } = buildFlexibleRegionConditionsAnvil([region]);
      query += ` AND (${conditions.join(' OR ')})`;
      params.push(...regionParams);
    }

    query += ` ORDER BY ap.monthly_price ASC LIMIT 100`;

    const result = await env.DB.prepare(query).bind(...params).all();

    if (!result.success) {
      throw new Error('Database query failed');
    }

    // Add USD currency to each result and validate with type guard
    const serversWithCurrency = (result.results as unknown[]).map(server => {
      if (typeof server === 'object' && server !== null) {
        return { ...server, currency: 'USD' };
      }
      return server;
    });

    const servers = serversWithCurrency.filter(isValidServer);
    const invalidCount = result.results.length - servers.length;
    if (invalidCount > 0) {
      console.warn(`[GetServers] Filtered out ${invalidCount} invalid server records`);
    }

    console.log('[GetServers] Found servers:', servers.length);

    const responseData = {
      servers,
      count: servers.length,
      filters: { minCpu, minMemory, region },
    };

    // Cache successful results (only if we have servers)
    if (env.CACHE && servers.length > 0) {
      await env.CACHE.put(cacheKey, JSON.stringify(responseData), {
        expirationTtl: 300, // 5 minutes
      });
    }

    return jsonResponse(responseData, 200, corsHeaders);
  } catch (error) {
    console.error('[GetServers] Error:', error);
    const requestId = crypto.randomUUID();
    return jsonResponse(
      {
        error: 'Failed to retrieve servers',
        request_id: requestId,
      },
      500,
      corsHeaders
    );
  }
}