/**
 * Loop Detector
 *
 * Detects "stuck in loop" patterns that indicate:
 * - Repeated failed attempts on same problem
 * - Same file being edited multiple times without progress
 * - User frustration signals
 *
 * Used by:
 * - MetacognitiveVerifier (triggers verification on loop detection)
 * - ContextPressureMonitor (elevates pressure on loop detection)
 *
 * Copyright 2025 Tractatus Project
 * Licensed under Apache License 2.0
 */

const fs = require('fs');
const path = require('path');

class LoopDetector {
  constructor(options = {}) {
    this.silent = options.silent || false;
    this.actionPatternsPath = path.join(__dirname, '../../.claude/action-patterns.json');
    this.sessionStatePath = path.join(__dirname, '../../.claude/session-state.json');
    
    // Thresholds
    this.thresholds = {
      same_file_edits: 3,           // Alert after 3 edits to same file
      consecutive_actions: 5,        // Within last 5 actions
      user_frustration_phrases: [
        'you ignored me',
        'i told you',
        'not working',
        'still broken',
        'same error',
        'again',
        'why are you'
      ]
    };
  }

  /**
   * Load action patterns
   */
  loadActionPatterns() {
    try {
      if (fs.existsSync(this.actionPatternsPath)) {
        return JSON.parse(fs.readFileSync(this.actionPatternsPath, 'utf8'));
      }
    } catch (err) {
      if (!this.silent) {
        console.warn(`LoopDetector: Could not load action patterns: ${err.message}`);
      }
    }
    return null;
  }

  /**
   * Detect loops based on action patterns
   */
  detectLoop() {
    const patterns = this.loadActionPatterns();
    if (!patterns || !patterns.actions || patterns.actions.length === 0) {
      return {
        detected: false,
        type: null,
        severity: 'NONE',
        details: null
      };
    }

    // Check 1: Repeated file edits
    const fileEditLoop = this.detectRepeatedFileEdits(patterns);
    if (fileEditLoop.detected) {
      return fileEditLoop;
    }

    // Check 2: Same action type repeated
    const actionLoop = this.detectRepeatedActionType(patterns);
    if (actionLoop.detected) {
      return actionLoop;
    }

    // Check 3: User frustration signals (would need message history)
    // TODO: Implement if message history tracking is added

    return {
      detected: false,
      type: null,
      severity: 'NONE',
      details: null
    };
  }

  /**
   * Detect repeated edits to same file
   */
  detectRepeatedFileEdits(patterns) {
    const recentActions = patterns.actions.slice(-this.thresholds.consecutive_actions);
    
    // Group by file
    const fileGroups = {};
    recentActions.forEach(action => {
      if (action.type === 'edit' || action.type === 'write') {
        if (!fileGroups[action.file]) {
          fileGroups[action.file] = [];
        }
        fileGroups[action.file].push(action);
      }
    });

    // Check for files edited multiple times
    for (const [file, actions] of Object.entries(fileGroups)) {
      if (actions.length >= this.thresholds.same_file_edits) {
        return {
          detected: true,
          type: 'repeated_file_edit',
          severity: 'MEDIUM',
          details: {
            file: file,
            count: actions.length,
            recent_count: actions.length,
            message: `File edited ${actions.length} times in last ${this.thresholds.consecutive_actions} actions`,
            recommendation: 'Pause and run MetacognitiveVerifier to assess approach'
          }
        };
      }
    }

    return { detected: false };
  }

  /**
   * Detect repeated action type (e.g., multiple failed bash commands)
   */
  detectRepeatedActionType(patterns) {
    const recentActions = patterns.actions.slice(-this.thresholds.consecutive_actions);
    
    // Count consecutive actions of same type
    let consecutiveCount = 1;
    let currentType = null;
    
    for (let i = recentActions.length - 1; i >= 0; i--) {
      const action = recentActions[i];
      if (currentType === null) {
        currentType = action.type;
      } else if (action.type === currentType) {
        consecutiveCount++;
      } else {
        break;
      }
    }

    if (consecutiveCount >= 3) {
      return {
        detected: true,
        type: 'repeated_action_type',
        severity: 'LOW',
        details: {
          action_type: currentType,
          count: consecutiveCount,
          message: `${consecutiveCount} consecutive ${currentType} actions`,
          recommendation: 'Consider if current approach is effective'
        }
      };
    }

    return { detected: false };
  }

  /**
   * Get loop status for MetacognitiveVerifier
   */
  getLoopStatus() {
    const loop = this.detectLoop();
    
    if (!loop.detected) {
      return {
        in_loop: false,
        should_verify: false
      };
    }

    return {
      in_loop: true,
      should_verify: loop.severity === 'MEDIUM' || loop.severity === 'HIGH',
      loop_type: loop.type,
      severity: loop.severity,
      details: loop.details
    };
  }

  /**
   * Calculate pressure contribution for ContextPressureMonitor
   */
  calculatePressureContribution() {
    const loop = this.detectLoop();
    
    if (!loop.detected) {
      return 0;
    }

    // Pressure contribution based on severity
    const pressureMap = {
      'LOW': 5,
      'MEDIUM': 15,
      'HIGH': 25,
      'CRITICAL': 40
    };

    return pressureMap[loop.severity] || 0;
  }

  /**
   * Log loop detection result
   */
  log(message, level = 'info') {
    if (this.silent) return;
    
    const colors = {
      info: '\x1b[36m',
      warn: '\x1b[33m',
      error: '\x1b[31m',
      success: '\x1b[32m',
      reset: '\x1b[0m'
    };

    const color = colors[level] || colors.reset;
    console.log(`${color}[LoopDetector] ${message}${colors.reset}`);
  }
}

module.exports = LoopDetector;