/**
 * Reliability Validation Utilities
 * Checks for retry policies, fallbacks, monitoring presence
 */
import type { WorkflowGraph, N8nWorkflow } from '../../apps/worker/src/types/workflow';

export interface ReliabilityCheckResult {
  passed: boolean;
  score: number;
  findings: string[];
  recommendations: string[];
}

export function checkReliability(workflow: N8nWorkflow, graph: WorkflowGraph): ReliabilityCheckResult {
  const findings: string[] = [];
  const recommendations: string[] = [];
  let deductions = 0;

  // Check retry on external API nodes
  const externalNodes = workflow.nodes.filter((n) =>
    n.type.includes('httpRequest') ||
    n.type.includes('openAi') ||
    n.type.includes('telegram') ||
    n.type.includes('slack') ||
    n.type.includes('gmail'),
  );

  externalNodes.forEach((node) => {
    if (!node.retryOnFail) {
      findings.push(`Node "${node.name}" calls external service without retry policy`);
      recommendations.push(`Add retryOnFail: true, maxTries: 3, waitBetweenTries: 1000 to "${node.name}"`);
      deductions += 10;
    }
  });

  // Check for error workflow
  if (!workflow.settings?.errorWorkflow) {
    findings.push('No error workflow configured for global error handling');
    recommendations.push('Set settings.errorWorkflow to an alert/notification workflow ID');
    deductions += 8;
  }

  // Check for monitoring nodes
  const monitoringNodes = graph.nodes.filter((n) => n.layer === 'monitoring');
  if (monitoringNodes.length === 0) {
    findings.push('No monitoring layer nodes detected in workflow');
    recommendations.push('Add at least one structured logging or notification node');
    deductions += 10;
  }

  // Check for fallback nodes on critical nodes
  const criticalWithoutFallback = graph.nodes.filter(
    (n) => n.isCritical && !n.fallbackNodeId,
  );
  if (criticalWithoutFallback.length > 0) {
    criticalWithoutFallback.forEach((n) => {
      findings.push(`Critical node "${n.label}" has no fallback path`);
      recommendations.push(`Add fallbackNodeId to "${n.label}" pointing to an error handler`);
      deductions += 8;
    });
  }

  const score = Math.max(0, 100 - deductions);
  return {
    passed: deductions < 30,
    score,
    findings,
    recommendations,
  };
}