/**
 * API Health Check Utility
 * Verifies that all external API keys are working correctly
 */

import { nebiusClient } from './nebius-client';
import { modalClient } from './modal-client';

interface APIHealthStatus {
  service: string;
  status: 'healthy' | 'error' | 'missing_key';
  message: string;
  responseTime?: number;
}

export async function checkAPIHealth(): Promise<APIHealthStatus[]> {
  const results: APIHealthStatus[] = [];

  // Check Nebius API
  try {
    if (!process.env.NEBIUS_API_KEY) {
      results.push({
        service: 'Nebius AI',
        status: 'missing_key',
        message: 'NEBIUS_API_KEY environment variable not set'
      });
    } else {
      const startTime = Date.now();
      await nebiusClient.createEmbeddings({
        input: "test",
        model: "text-embedding-3-small"
      });
      const responseTime = Date.now() - startTime;
      
      results.push({
        service: 'Nebius AI',
        status: 'healthy',
        message: 'Successfully generated test embeddings',
        responseTime
      });
    }
  } catch (error) {
    results.push({
      service: 'Nebius AI',
      status: 'error',
      message: `API Error: ${error instanceof Error ? error.message : 'Unknown error'}`
    });
  }

  // Check Modal API
  try {
    if (!process.env.MODAL_TOKEN_ID || !process.env.MODAL_TOKEN_SECRET) {
      results.push({
        service: 'Modal',
        status: 'missing_key',
        message: 'MODAL_TOKEN_ID or MODAL_TOKEN_SECRET environment variable not set'
      });
    } else {
      const startTime = Date.now();
      // Try to get a non-existent task status (should return 404 but proves API is accessible)
      try {
        await modalClient.getTaskStatus('health-check-test');
      } catch (error) {
        // Expected 404 error means API is accessible
        if (error instanceof Error && error.message.includes('404')) {
          const responseTime = Date.now() - startTime;
          results.push({
            service: 'Modal',
            status: 'healthy',
            message: 'API accessible and responding',
            responseTime
          });
        } else {
          throw error;
        }
      }
    }
  } catch (error) {
    results.push({
      service: 'Modal',
      status: 'error',
      message: `API Error: ${error instanceof Error ? error.message : 'Unknown error'}`
    });
  }

  // Check Nebius Chat Completions (DeepSeek model)
  try {
    if (!process.env.NEBIUS_API_KEY) {
      results.push({
        service: 'Nebius Chat (DeepSeek)',
        status: 'missing_key',
        message: 'NEBIUS_API_KEY environment variable not set'
      });
    } else {
      const startTime = Date.now();
      await nebiusClient.createChatCompletion({
        model: "deepseek-ai/DeepSeek-R1-0528",
        messages: [{ role: "user", content: "Hello" }],
        max_tokens: 5
      });
      const responseTime = Date.now() - startTime;
      
      results.push({
        service: 'Nebius Chat (DeepSeek)',
        status: 'healthy',
        message: 'Successfully completed test chat with DeepSeek model',
        responseTime
      });
    }
  } catch (error) {
    results.push({
      service: 'Nebius Chat (DeepSeek)',
      status: 'error',
      message: `API Error: ${error instanceof Error ? error.message : 'Unknown error'}`
    });
  }

  // Check GitHub API
  try {
    if (!process.env.GITHUB_TOKEN) {
      results.push({
        service: 'GitHub',
        status: 'missing_key',
        message: 'GITHUB_TOKEN environment variable not set'
      });
    } else {
      const startTime = Date.now();
      const response = await fetch('https://api.github.com/user', {
        headers: {
          'Authorization': `token ${process.env.GITHUB_TOKEN}`,
          'User-Agent': 'Knowledge-Base-Browser'
        }
      });
      const responseTime = Date.now() - startTime;
      
      if (response.ok) {
        results.push({
          service: 'GitHub',
          status: 'healthy',
          message: 'Successfully authenticated with GitHub API',
          responseTime
        });
      } else {
        results.push({
          service: 'GitHub',
          status: 'error',
          message: `HTTP ${response.status}: ${response.statusText}`
        });
      }
    }
  } catch (error) {
    results.push({
      service: 'GitHub',
      status: 'error',
      message: `API Error: ${error instanceof Error ? error.message : 'Unknown error'}`
    });
  }

  return results;
}