import dotenv from 'dotenv';
import Joi from 'joi';

// Load environment variables
dotenv.config();

// Environment validation schema
const envSchema = Joi.object({
  NODE_ENV: Joi.string().valid('development', 'production', 'test').default('development'),
  PORT: Joi.number().default(5000),
  
  // Supabase Configuration (Required for cloud-only architecture)
  SUPABASE_URL: Joi.string().required(),
  SUPABASE_ANON_KEY: Joi.string().required(),
  SUPABASE_SERVICE_KEY: Joi.string().required(),
  
  // Google Cloud Configuration (Required)
  GCLOUD_PROJECT_ID: Joi.string().required(),
  DOCUMENT_AI_LOCATION: Joi.string().default('us'),
  DOCUMENT_AI_PROCESSOR_ID: Joi.string().required(),
  GCS_BUCKET_NAME: Joi.string().required(),
  DOCUMENT_AI_OUTPUT_BUCKET_NAME: Joi.string().required(),
  GOOGLE_APPLICATION_CREDENTIALS: Joi.string().default('./serviceAccountKey.json'),
  
  // Vector Database Configuration
  VECTOR_PROVIDER: Joi.string().valid('supabase', 'pinecone').default('supabase'),
  
  // Pinecone Configuration (optional, only if using Pinecone)
  PINECONE_API_KEY: Joi.string().when('VECTOR_PROVIDER', {
    is: 'pinecone',
    then: Joi.string().required(),
    otherwise: Joi.string().allow('').optional()
  }),
  PINECONE_INDEX: Joi.string().when('VECTOR_PROVIDER', {
    is: 'pinecone',
    then: Joi.string().required(),
    otherwise: Joi.string().allow('').optional()
  }),
  
  // JWT - Optional for Firebase Auth
  JWT_SECRET: Joi.string().default('default-jwt-secret-change-in-production'),
  JWT_EXPIRES_IN: Joi.string().default('1h'),
  JWT_REFRESH_SECRET: Joi.string().default('default-refresh-secret-change-in-production'),
  JWT_REFRESH_EXPIRES_IN: Joi.string().default('7d'),
  
  // File Upload Configuration (Cloud-only)
  MAX_FILE_SIZE: Joi.number().default(104857600), // 100MB
  ALLOWED_FILE_TYPES: Joi.string().default('application/pdf'),
  
  // LLM
  LLM_PROVIDER: Joi.string().valid('openai', 'anthropic').default('openai'),
  OPENAI_API_KEY: Joi.string().when('LLM_PROVIDER', {
    is: 'openai',
    then: Joi.string().required(),
    otherwise: Joi.string().allow('').optional()
  }),
  ANTHROPIC_API_KEY: Joi.string().when('LLM_PROVIDER', {
    is: 'anthropic',
    then: Joi.string().required(),
    otherwise: Joi.string().allow('').optional()
  }),
  LLM_MODEL: Joi.string().default('gpt-4'),
  LLM_MAX_TOKENS: Joi.number().default(3500),
  LLM_TEMPERATURE: Joi.number().min(0).max(2).default(0.1),
  LLM_PROMPT_BUFFER: Joi.number().default(500),
  
  // Security
  BCRYPT_ROUNDS: Joi.number().default(12),
  RATE_LIMIT_WINDOW_MS: Joi.number().default(900000), // 15 minutes
  RATE_LIMIT_MAX_REQUESTS: Joi.number().default(100),
  
  // Logging
  LOG_LEVEL: Joi.string().valid('error', 'warn', 'info', 'debug').default('info'),
  LOG_FILE: Joi.string().default('logs/app.log'),
  
  // Processing Strategy
  PROCESSING_STRATEGY: Joi.string().valid('document_ai_agentic_rag').default('document_ai_agentic_rag'),
  
  // Agentic RAG Configuration
  AGENTIC_RAG_ENABLED: Joi.boolean().default(false),
  AGENTIC_RAG_MAX_AGENTS: Joi.number().default(6),
  AGENTIC_RAG_PARALLEL_PROCESSING: Joi.boolean().default(true),
  AGENTIC_RAG_VALIDATION_STRICT: Joi.boolean().default(true),
  AGENTIC_RAG_RETRY_ATTEMPTS: Joi.number().default(3),
  AGENTIC_RAG_TIMEOUT_PER_AGENT: Joi.number().default(60000),
  
  // Agent-Specific Configuration
  AGENT_DOCUMENT_UNDERSTANDING_ENABLED: Joi.boolean().default(true),
  AGENT_FINANCIAL_ANALYSIS_ENABLED: Joi.boolean().default(true),
  AGENT_MARKET_ANALYSIS_ENABLED: Joi.boolean().default(true),
  AGENT_INVESTMENT_THESIS_ENABLED: Joi.boolean().default(true),
  AGENT_SYNTHESIS_ENABLED: Joi.boolean().default(true),
  AGENT_VALIDATION_ENABLED: Joi.boolean().default(true),
  
  // Quality Control
  AGENTIC_RAG_QUALITY_THRESHOLD: Joi.number().min(0).max(1).default(0.8),
  AGENTIC_RAG_COMPLETENESS_THRESHOLD: Joi.number().min(0).max(1).default(0.9),
  AGENTIC_RAG_CONSISTENCY_CHECK: Joi.boolean().default(true),
  
  // Monitoring and Logging
  AGENTIC_RAG_DETAILED_LOGGING: Joi.boolean().default(true),
  AGENTIC_RAG_PERFORMANCE_TRACKING: Joi.boolean().default(true),
  AGENTIC_RAG_ERROR_REPORTING: Joi.boolean().default(true),
}).unknown();

// Validate environment variables
const { error, value: envVars } = envSchema.validate(process.env);

if (error) {
  // In a serverless environment (like Firebase Functions or Cloud Run),
  // environment variables are often injected at runtime, not from a .env file.
  // Therefore, we log a warning instead of throwing a fatal error.
  // Throwing an error would cause the container to crash on startup
  // before the runtime has a chance to provide the necessary variables.
  console.warn(`[Config Validation Warning] ${error.message}`);
}

// Export validated configuration
export const config = {
  env: envVars.NODE_ENV,
  nodeEnv: envVars.NODE_ENV,
  port: envVars.PORT,
  frontendUrl: process.env['FRONTEND_URL'] || 'http://localhost:3000',
  
  supabase: {
    url: envVars.SUPABASE_URL,
    anonKey: envVars.SUPABASE_ANON_KEY,
    serviceKey: envVars.SUPABASE_SERVICE_KEY,
  },
  
  // Google Cloud Configuration
  googleCloud: {
    projectId: envVars.GCLOUD_PROJECT_ID,
    documentAiLocation: envVars.DOCUMENT_AI_LOCATION,
    documentAiProcessorId: envVars.DOCUMENT_AI_PROCESSOR_ID,
    gcsBucketName: envVars.GCS_BUCKET_NAME,
    documentAiOutputBucketName: envVars.DOCUMENT_AI_OUTPUT_BUCKET_NAME,
    applicationCredentials: envVars.GOOGLE_APPLICATION_CREDENTIALS,
  },
  
  jwt: {
    secret: envVars.JWT_SECRET,
    expiresIn: envVars.JWT_EXPIRES_IN,
    refreshSecret: envVars.JWT_REFRESH_SECRET,
    refreshExpiresIn: envVars.JWT_REFRESH_EXPIRES_IN,
  },
  
  upload: {
    maxFileSize: envVars.MAX_FILE_SIZE,
    allowedFileTypes: envVars.ALLOWED_FILE_TYPES.split(','),
    // Cloud-only: No local upload directory needed
    uploadDir: '/tmp/uploads', // Temporary directory for file processing
  },
  
  llm: {
    provider: envVars['LLM_PROVIDER'] || 'anthropic', // Default to Claude for cost efficiency
    
    // Anthropic Configuration (Primary)
    anthropicApiKey: envVars['ANTHROPIC_API_KEY'],
    
    // OpenAI Configuration (Fallback)
    openaiApiKey: envVars['OPENAI_API_KEY'],
    
    // Model Selection - Hybrid approach optimized for different tasks
    model: envVars['LLM_MODEL'] || 'claude-3-7-sonnet-20250219', // Primary model for analysis
    fastModel: envVars['LLM_FAST_MODEL'] || 'claude-3-5-haiku-20241022', // Fast model for cost optimization
    fallbackModel: envVars['LLM_FALLBACK_MODEL'] || 'gpt-4.5-preview-2025-02-27', // Fallback for creativity
    
    // Task-specific model selection
    financialModel: envVars['LLM_FINANCIAL_MODEL'] || 'claude-3-7-sonnet-20250219', // Best for financial analysis
    creativeModel: envVars['LLM_CREATIVE_MODEL'] || 'gpt-4.5-preview-2025-02-27', // Best for creative content
    reasoningModel: envVars['LLM_REASONING_MODEL'] || 'claude-3-7-sonnet-20250219', // Best for complex reasoning
    
    // Token Limits - Optimized for CIM documents with hierarchical processing
    maxTokens: parseInt(envVars['LLM_MAX_TOKENS'] || '4000'), // Output tokens (increased for better analysis)
    maxInputTokens: parseInt(envVars['LLM_MAX_INPUT_TOKENS'] || '200000'), // Input tokens (increased for larger context)
    chunkSize: parseInt(envVars['LLM_CHUNK_SIZE'] || '15000'), // Chunk size for section analysis (increased from 4000)
    promptBuffer: parseInt(envVars['LLM_PROMPT_BUFFER'] || '1000'), // Buffer for prompt tokens (increased)
    
    // Processing Configuration
    temperature: parseFloat(envVars['LLM_TEMPERATURE'] || '0.1'), // Low temperature for consistent output
    timeoutMs: parseInt(envVars['LLM_TIMEOUT_MS'] || '180000'), // 3 minutes timeout (increased for complex analysis)
    
    // Cost Optimization
    enableCostOptimization: envVars['LLM_ENABLE_COST_OPTIMIZATION'] === 'true',
    maxCostPerDocument: parseFloat(envVars['LLM_MAX_COST_PER_DOCUMENT'] || '3.00'), // Max $3 per document (increased for better quality)
    useFastModelForSimpleTasks: envVars['LLM_USE_FAST_MODEL_FOR_SIMPLE_TASKS'] === 'true',
    
    // Hybrid approach settings
    enableHybridApproach: envVars['LLM_ENABLE_HYBRID_APPROACH'] === 'true',
    useClaudeForFinancial: envVars['LLM_USE_CLAUDE_FOR_FINANCIAL'] === 'true',
    useGPTForCreative: envVars['LLM_USE_GPT_FOR_CREATIVE'] === 'true',
  },
  
  security: {
    bcryptRounds: envVars.BCRYPT_ROUNDS,
    rateLimit: {
      windowMs: envVars.RATE_LIMIT_WINDOW_MS,
      maxRequests: envVars.RATE_LIMIT_MAX_REQUESTS,
    },
  },
  
  logging: {
    level: envVars.LOG_LEVEL,
    file: envVars.LOG_FILE,
  },
  
  // Processing Strategy
  processingStrategy: envVars['PROCESSING_STRATEGY'] || 'agentic_rag', // 'chunking' | 'rag' | 'agentic_rag'
  enableRAGProcessing: envVars['ENABLE_RAG_PROCESSING'] === 'true',
  enableProcessingComparison: envVars['ENABLE_PROCESSING_COMPARISON'] === 'true',
  
  // Agentic RAG Configuration
  agenticRag: {
    enabled: envVars.AGENTIC_RAG_ENABLED,
    maxAgents: parseInt(envVars.AGENTIC_RAG_MAX_AGENTS || '6'),
    parallelProcessing: envVars.AGENTIC_RAG_PARALLEL_PROCESSING,
    validationStrict: envVars.AGENTIC_RAG_VALIDATION_STRICT,
    retryAttempts: parseInt(envVars.AGENTIC_RAG_RETRY_ATTEMPTS || '3'),
    timeoutPerAgent: parseInt(envVars.AGENTIC_RAG_TIMEOUT_PER_AGENT || '60000'),
  },
  
  // Agent-Specific Configuration
  agentSpecific: {
    documentUnderstandingEnabled: envVars['AGENT_DOCUMENT_UNDERSTANDING_ENABLED'] === 'true',
    financialAnalysisEnabled: envVars['AGENT_FINANCIAL_ANALYSIS_ENABLED'] === 'true',
    marketAnalysisEnabled: envVars['AGENT_MARKET_ANALYSIS_ENABLED'] === 'true',
    investmentThesisEnabled: envVars['AGENT_INVESTMENT_THESIS_ENABLED'] === 'true',
    synthesisEnabled: envVars['AGENT_SYNTHESIS_ENABLED'] === 'true',
    validationEnabled: envVars['AGENT_VALIDATION_ENABLED'] === 'true',
  },
  
  // Quality Control
  qualityControl: {
    qualityThreshold: parseFloat(envVars['AGENTIC_RAG_QUALITY_THRESHOLD'] || '0.8'),
    completenessThreshold: parseFloat(envVars['AGENTIC_RAG_COMPLETENESS_THRESHOLD'] || '0.9'),
    consistencyCheck: envVars['AGENTIC_RAG_CONSISTENCY_CHECK'] === 'true',
  },
  
  // Monitoring and Logging
  monitoringAndLogging: {
    detailedLogging: envVars['AGENTIC_RAG_DETAILED_LOGGING'] === 'true',
    performanceTracking: envVars['AGENTIC_RAG_PERFORMANCE_TRACKING'] === 'true',
    errorReporting: envVars['AGENTIC_RAG_ERROR_REPORTING'] === 'true',
  },
  
  // Vector Database Configuration (Cloud-only)
  vector: {
    provider: envVars['VECTOR_PROVIDER'] || 'supabase', // 'pinecone' | 'supabase'
    
    // Pinecone Configuration (if used)
    pineconeApiKey: envVars['PINECONE_API_KEY'],
    pineconeIndex: envVars['PINECONE_INDEX'],
  },
  
  // Legacy database configuration (for compatibility - using Supabase)
  database: {
    url: envVars.SUPABASE_URL,
    host: 'db.supabase.co',
    port: 5432,
    name: 'postgres',
    user: 'postgres',
    password: envVars.SUPABASE_SERVICE_KEY,
  },
  
  // Legacy Redis configuration (for compatibility - using in-memory or cloud Redis)
  redis: {
    url: process.env['REDIS_URL'] || 'redis://localhost:6379',
    host: 'localhost',
    port: 6379,
  },
};

export default config;