const AGENTS = [
  { id: 'pm', name: 'Product Manager', icon: '📋', color: 'blue' },
  { id: 'architect', name: 'Architect', icon: '🏗️', color: 'purple' },
  { id: 'planner', name: 'Task Planner', icon: '📝', color: 'indigo' },
  { id: 'backend', name: 'Backend Dev', icon: '⚙️', color: 'green' },
  { id: 'frontend', name: 'Frontend Dev', icon: '🎨', color: 'pink' },
  { id: 'devops', name: 'DevOps', icon: '🚀', color: 'orange' },
  { id: 'qa', name: 'QA Agent', icon: '🧪', color: 'yellow' },
  { id: 'reviewer', name: 'Code Review', icon: '🔍', color: 'cyan' },
  { id: 'security', name: 'Security', icon: '🔐', color: 'red' },
  { id: 'docs', name: 'Documentation', icon: '📖', color: 'teal' },
  { id: 'knowledge', name: 'Knowledge Mgr', icon: '🧠', color: 'violet' },
];

const WORKFLOW_STEPS = [
  { phase: 'Planning', agents: ['pm', 'architect', 'planner'], description: 'Define requirements and architecture' },
  { phase: 'Execution', agents: ['backend', 'frontend', 'devops'], description: 'Implement and deploy' },
  { phase: 'Validation', agents: ['qa', 'security', 'reviewer'], description: 'Test, secure, and review' },
  { phase: 'Documentation', agents: ['docs'], description: 'Update all documentation' },
  { phase: 'Learning', agents: ['knowledge'], description: 'Extract and store learnings' },
];

const SAMPLE_TASKS = [
  'Build a REST API for user management',
  'Create a real-time chat feature',
  'Implement authentication with OAuth2',
  'Build a dashboard analytics module',
  'Create a file upload service',
  'Implement search functionality with Elasticsearch',
];

const KNOWLEDGE_ENTRIES = [
  {
    task: 'JWT Authentication Implementation',
    error: 'Token expiration not validated on server side',
    root_cause: 'Missing expiration check in middleware',
    fix: 'Added exp claim validation in auth middleware',
    prevention_rule: 'IF using JWT THEN validate expiration config BECAUSE misconfiguration causes auth issues',
    success_score: 0.85,
    tags: ['auth', 'jwt', 'security'],
  },
  {
    task: 'Database Migration',
    error: 'Data loss during column rename',
    root_cause: 'Direct column rename without backup',
    fix: 'Added backup step and incremental migration',
    prevention_rule: 'IF modifying schema THEN create backup first BECAUSE direct changes can cause data loss',
    success_score: 0.72,
    tags: ['database', 'migration', 'data'],
  },
  {
    task: 'API Rate Limiting',
    error: 'Legitimate users blocked',
    root_cause: 'Rate limit too aggressive for normal usage',
    fix: 'Adjusted limits based on traffic analysis',
    prevention_rule: 'IF implementing rate limits THEN analyze traffic patterns first BECAUSE aggressive limits block valid users',
    success_score: 0.91,
    tags: ['api', 'rate-limiting', 'performance'],
  },
];

function generateCommunication(agentId, step, task) {
  const agent = AGENTS.find(a => a.id === agentId);
  const statuses = ['pending', 'in_progress', 'done'];
  const status = statuses[Math.floor(Math.random() * 2) + 1];
  
  const outputs = {
    pm: `Requirements defined for: ${task}`,
    architect: `System design completed for: ${task}`,
    planner: `Task decomposed into 5 subtasks`,
    backend: `API endpoints implemented`,
    frontend: `UI components built and integrated`,
    devops: `CI/CD pipeline configured`,
    qa: `12 tests written, all passing`,
    reviewer: `Code reviewed, 3 improvements suggested`,
    security: `No critical vulnerabilities found`,
    docs: `Documentation updated`,
    knowledge: `Experience logged to knowledge base`,
  };

  return {
    agent: agent.name,
    task: step.description,
    input: task,
    output: outputs[agentId] || 'Task completed',
    issues: status === 'in_progress' ? ['Awaiting dependency'] : [],
    status,
    next_step: status === 'done' ? 'Proceed to next phase' : 'Continue current work',
    timestamp: new Date().toISOString(),
  };
}

export default function handler(req, res) {
  if (req.method !== 'POST') {
    return res.status(405).json({ error: 'Method not allowed' });
  }

  const { task, mode = 'safe' } = req.body;
  const selectedTask = task || SAMPLE_TASKS[Math.floor(Math.random() * SAMPLE_TASKS.length)];

  const simulation = {
    task: selectedTask,
    mode,
    startedAt: new Date().toISOString(),
    phases: WORKFLOW_STEPS.map((step, phaseIndex) => {
      const communications = step.agents.map(agentId => 
        generateCommunication(agentId, step, selectedTask)
      );
      return {
        phase: step.phase,
        description: step.description,
        order: phaseIndex + 1,
        communications,
        status: 'done',
      };
    }),
    knowledge: KNOWLEDGE_ENTRIES,
    definitionOfDone: {
      code_compiles: true,
      tests_pass: true,
      security_checks: mode !== 'fast',
      code_reviewed: mode !== 'fast',
      docs_updated: mode === 'safe',
    },
    completedAt: new Date().toISOString(),
  };

  res.status(200).json(simulation);
}