import { toast } from 'sonner';
import { logger } from './logger';
import { supabase } from '@/integrations/supabase/client';
import { breadcrumbManager } from './errorBreadcrumbs';
import { captureEnvironmentContext } from './environmentContext';

export type ErrorContext = {
  action: string;
  userId?: string;
  metadata?: Record<string, unknown>;
};

export class AppError extends Error {
  constructor(
    message: string,
    public code: string,
    public userMessage?: string
  ) {
    super(message);
    this.name = 'AppError';
  }
}

export const handleError = (
  error: unknown,
  context: ErrorContext
): string => {
  // Generate or use existing error ID
  const errorId = (context.metadata?.requestId as string) || crypto.randomUUID();
  const shortErrorId = errorId.slice(0, 8);
  
  const errorMessage = error instanceof AppError 
    ? error.userMessage || error.message
    : error instanceof Error 
    ? error.message 
    : 'An unexpected error occurred';

  // Log to console/monitoring with enhanced debugging
  const stack = error instanceof Error ? error.stack : undefined;
  
  logger.error('Error occurred', {
    ...context,
    error: error instanceof Error ? error.message : String(error),
    stack,
    errorId,
    errorType: typeof error,
    errorConstructor: error?.constructor?.name,
    hasStack: !!stack,
  });
  
  // Additional debug logging when stack is missing
  if (!stack) {
    console.error('[handleError] Error without stack trace:', {
      type: typeof error,
      constructor: error?.constructor?.name,
      error: error,
      context,
      errorId
    });
  }

  // Log to database with breadcrumbs (non-blocking)
  try {
    const envContext = captureEnvironmentContext();
    const breadcrumbs = breadcrumbManager.getAll();
    
    // Fire-and-forget database logging
    supabase.rpc('log_request_metadata', {
      p_request_id: errorId,
      p_user_id: context.userId || undefined,
      p_endpoint: context.action,
      p_method: 'ERROR',
      p_status_code: 500,
      p_error_type: error instanceof Error ? error.name : 'UnknownError',
      p_error_message: errorMessage,
      p_error_stack: error instanceof Error ? error.stack : undefined,
      p_user_agent: navigator.userAgent,
      p_breadcrumbs: JSON.stringify(breadcrumbs),
      p_timezone: envContext.timezone,
      p_referrer: document.referrer || undefined,
    }).then(({ error: dbError }) => {
      if (dbError) {
        logger.error('Failed to log error to database', { dbError });
      }
    });
  } catch (logError) {
    logger.error('Failed to capture error context', { logError });
  }

  // Show user-friendly toast with error ID
  toast.error(context.action, {
    description: `${errorMessage}\n\nReference ID: ${shortErrorId}`,
    duration: 5000,
  });

  return errorId;
};

export const handleSuccess = (
  title: string,
  description?: string
): void => {
  toast.success(title, {
    description,
    duration: 3000
  });
};

export const handleInfo = (
  title: string,
  description?: string
): void => {
  toast.info(title, {
    description,
    duration: 4000
  });
};

/**
 * Handle non-critical errors (background failures) that should be logged
 * to the database WITHOUT showing user toasts
 * Use this for fire-and-forget operations where user shouldn't be interrupted
 */
export const handleNonCriticalError = (
  error: unknown,
  context: ErrorContext
): string => {
  const errorId = crypto.randomUUID();
  const shortErrorId = errorId.slice(0, 8);
  
  const errorMessage = error instanceof AppError 
    ? error.userMessage || error.message
    : error instanceof Error 
    ? error.message 
    : 'An unexpected error occurred';

  // Log to console/monitoring (same as handleError)
  logger.error('Non-critical error occurred', {
    ...context,
    error: error instanceof Error ? error.message : String(error),
    stack: error instanceof Error ? error.stack : undefined,
    errorId,
    severity: 'low',
  });

  // Log to database with breadcrumbs (non-blocking, fire-and-forget)
  try {
    const envContext = captureEnvironmentContext();
    const breadcrumbs = breadcrumbManager.getAll();
    
    supabase.rpc('log_request_metadata', {
      p_request_id: errorId,
      p_user_id: context.userId || undefined,
      p_endpoint: context.action,
      p_method: 'NON_CRITICAL_ERROR',
      p_status_code: 500,
      p_error_type: error instanceof Error ? error.name : 'UnknownError',
      p_error_message: errorMessage,
      p_error_stack: error instanceof Error ? error.stack : undefined,
      p_user_agent: navigator.userAgent,
      p_breadcrumbs: JSON.stringify(breadcrumbs),
      p_timezone: envContext.timezone,
      p_referrer: document.referrer || undefined,
    }).then(({ error: dbError }) => {
      if (dbError) {
        logger.error('Failed to log non-critical error to database', { dbError });
      }
    });
  } catch (logError) {
    logger.error('Failed to capture non-critical error context', { logError });
  }

  // NO TOAST - This is the key difference from handleError()
  return errorId;
};

/**
 * Type-safe error message extraction utility
 * Use this instead of `error: any` in catch blocks
 */
export function getErrorMessage(error: unknown): string {
  if (error instanceof Error) {
    return error.message;
  }
  if (typeof error === 'string') {
    return error;
  }
  if (error && typeof error === 'object' && 'message' in error) {
    return String(error.message);
  }
  return 'An unexpected error occurred';
}

/**
 * Type guard to check if error has a code property
 */
export function hasErrorCode(error: unknown): error is { code: string } {
  return (
    error !== null &&
    typeof error === 'object' &&
    'code' in error &&
    typeof (error as { code: unknown }).code === 'string'
  );
}