#!/usr/bin/env node

/**
 * Plan Detection Hook (UserPromptSubmit)
 *
 * Detects planning discussions in user prompts and tracks them.
 * Part of the enforcement mechanism for inst_comm_plan_001.
 *
 * INCIDENT REFERENCE: 2025-12-01 lost plan documentation
 *
 * When a user initiates a planning discussion:
 * 1. Detect planning keywords
 * 2. Track the plan as in-progress
 * 3. Inject a reminder to Claude about persisting plans
 *
 * Hook Input (JSON via stdin):
 * {
 *   "session_id": "abc123",
 *   "hook_event_name": "UserPromptSubmit",
 *   "user_message": "Let's create a plan for the landing page redesign"
 * }
 *
 * Hook Output (JSON to stdout):
 * {
 *   "hookSpecificOutput": { ... },
 *   "systemMessage": "Planning discussion detected...",
 *   "continue": true
 * }
 */

const path = require('path');

// Import the plan persistence manager
const planManager = require('./plan-persistence-manager.js');

/**
 * Read JSON input from stdin
 */
function readStdin() {
  return new Promise((resolve, reject) => {
    let data = '';
    process.stdin.on('data', chunk => { data += chunk; });
    process.stdin.on('end', () => {
      try {
        resolve(JSON.parse(data));
      } catch (err) {
        reject(new Error('Invalid JSON input'));
      }
    });
    process.stdin.on('error', reject);
  });
}

/**
 * Output hook response
 */
function outputResponse(analysis, systemMessage = null) {
  const response = {
    hookSpecificOutput: {
      hookEventName: 'UserPromptSubmit',
      planDetection: analysis
    },
    continue: true,
    suppressOutput: false
  };

  if (systemMessage) {
    response.systemMessage = systemMessage;
  }

  console.log(JSON.stringify(response));
}

/**
 * Main hook logic
 */
async function main() {
  let input;

  try {
    input = await readStdin();
  } catch (err) {
    // Invalid input, allow execution
    outputResponse({ error: 'Invalid hook input' });
    process.exit(0);
  }

  const { session_id, user_message } = input;

  if (!user_message) {
    outputResponse({ detected: false });
    process.exit(0);
  }

  // Clean up old plans periodically
  planManager.cleanupOldPlans();

  // Detect if this is a planning discussion
  const detection = planManager.detectPlanningDiscussion(user_message);

  if (!detection.isPlanningDiscussion) {
    // Not a planning discussion, check for unpersisted plans
    const unpersisted = planManager.checkUnpersistedPlans(session_id);

    if (unpersisted.hasUnpersistedPlans && unpersisted.hasHighPriority) {
      // High priority unpersisted plans - CRITICAL warning
      outputResponse(
        { detected: false, unpersistedCheck: unpersisted },
        unpersisted.warningMessage
      );
    } else {
      outputResponse({ detected: false });
    }

    process.exit(0);
  }

  // Track the plan in progress
  const trackedPlan = planManager.trackPlanInProgress(
    session_id,
    detection.topic,
    detection.confidence,
    detection.isHighPriority
  );

  // Build system message
  let systemMessage;

  if (detection.isHighPriority) {
    systemMessage =
      `🚨 PLAN PERSISTENCE REQUIRED (inst_comm_plan_001)\n\n` +
      `User has EXPLICITLY requested plan documentation.\n` +
      `Topic: "${detection.topic}"\n\n` +
      `BEFORE this session ends, you MUST:\n` +
      `1. Create a comprehensive plan document\n` +
      `2. Save it to: docs/plans/PLAN_[TOPIC]_${new Date().toISOString().slice(0, 10).replace(/-/g, '')}.md\n` +
      `3. This is MANDATORY - do NOT rely on internal memory\n\n` +
      `⚠️  INCIDENT 2025-12-01: User's plan was lost because Claude kept it in memory. Never again.`;
  } else if (detection.confidence >= 0.7) {
    systemMessage =
      `📋 Planning Discussion Detected (${Math.round(detection.confidence * 100)}% confidence)\n\n` +
      `Topic: "${detection.topic}"\n\n` +
      `Per inst_comm_plan_001: If this discussion produces a significant plan, ` +
      `save it to docs/plans/ directory before session ends.\n\n` +
      `Recommended file: docs/plans/PLAN_[TOPIC]_${new Date().toISOString().slice(0, 10).replace(/-/g, '')}.md`;
  } else {
    // Lower confidence - just note it
    systemMessage =
      `📝 Possible planning discussion detected.\n` +
      `If significant plans emerge, save to docs/plans/.`;
  }

  outputResponse({
    detected: true,
    topic: detection.topic,
    confidence: detection.confidence,
    isHighPriority: detection.isHighPriority,
    tracked: true
  }, systemMessage);

  process.exit(0);
}

// Run hook
main().catch(err => {
  console.error(JSON.stringify({
    hookSpecificOutput: { error: err.message },
    continue: true,
    suppressOutput: false
  }));
  process.exit(0);
});