#!/usr/bin/env node

/**
 * load-core-context.ts
 *
 * Automatically loads your CORE skill context at session start by reading and injecting
 * the CORE SKILL.md file contents directly into Claude's context as a system-reminder.
 *
 * Purpose:
 * - Read CORE SKILL.md file content
 * - Output content as system-reminder for Claude to process
 * - Ensure complete context (contacts, preferences, security, identity) available at session start
 * - Bypass skill activation logic by directly injecting context
 *
 * Setup:
 * 1. Customize your ${ADAPTER_DIR}/skills/CORE/SKILL.md with your personal context
 * 2. Add this hook to settings.json SessionStart hooks
 * 3. Ensure ADAPTER_DIR environment variable is set (defaults to $HOME/.claude)
 *
 * How it works:
 * - Runs at the start of every Claude Code session
 * - Skips execution for subagent sessions (they don't need CORE context)
 * - Reads your CORE SKILL.md file
 * - Injects content as <system-reminder> which Claude processes automatically
 * - Gives your AI immediate access to your complete personal context
 */

import { isWorkerSession } from "../lib/worker-session.js";
import { readFileSync, existsSync } from 'fs';
import { join } from 'path';
import { SKILLS_DIR } from '../lib/pai-paths';
import { isProbeSession } from '../lib/project-utils';
import { stripFrontmatter } from '../lib/frontmatter.js';

async function main() {
  if (isWorkerSession()) return; // disposable worker: no per-session bookkeeping
  try {
    // Check if this is a subagent session - if so, exit silently
    const claudeProjectDir = process.env.CLAUDE_PROJECT_DIR || '';
    const isSubagent = claudeProjectDir.includes('/.claude/agents/') ||
                      process.env.CLAUDE_AGENT_TYPE !== undefined;

    if (isSubagent) {
      // Subagent sessions don't need CORE context loading
      console.error('Subagent session - skipping CORE context loading');
      process.exit(0);
    }

    // Skip probe/health-check sessions (e.g. CodexBar ClaudeProbe)
    if (isProbeSession()) {
      console.error('Probe session detected - skipping CORE context loading');
      process.exit(0);
    }

    // Get CORE skill path using PAI paths library
    const coreSkillPath = join(SKILLS_DIR, 'CORE/SKILL.md');

    // Verify CORE skill file exists
    if (!existsSync(coreSkillPath)) {
      console.error(`CORE skill not found at: ${coreSkillPath}`);
      console.error(`Ensure CORE/SKILL.md exists or check ADAPTER_DIR environment variable`);
      process.exit(1);
    }

    console.error('Reading CORE context from skill file...');

    // Read the CORE SKILL.md file content
    let coreContent = readFileSync(coreSkillPath, 'utf-8');

    // Perform Dynamic Variable Substitution
    // This allows SKILL.md to be generic while the session is personalized
    const daName = process.env.DA || 'PAI';
    const daColor = process.env.DA_COLOR || 'blue';
    const engineerName = process.env.ENGINEER_NAME || '';

    // Replace placeholders {{DA}}, {{DA_COLOR}}, {{ENGINEER_NAME}}
    coreContent = coreContent
      .replace(/\{\{DA\}\}/g, daName)
      .replace(/\{\{DA_COLOR\}\}/g, daColor)
      .replace(/\{\{ENGINEER_NAME\}\}/g, engineerName);

    console.error(`Read ${coreContent.length} characters from CORE SKILL.md (Personalized for ${engineerName} & ${daName})`);

    // Output the CORE content as a system-reminder, minus the frontmatter
    // (catalogue metadata the session already has from its skill list) —
    // this will be injected into Claude's context at session start
    const message = `<system-reminder>
PAI CORE CONTEXT

${stripFrontmatter(coreContent)}
</system-reminder>`;

    // Write to stdout (will be captured by Claude Code)
    console.log(message);

    console.error('CORE context injected into session');
    process.exit(0);
  } catch (error) {
    console.error('Error in load-core-context hook:', error);
    process.exit(1);
  }
}

main();