#!/usr/bin/env node
/**
 * UserPromptSubmit Hook: 剪贴板图片自动检测 (v2.0 — Python 加速版)
 *
 * 解决 MINGW64/Git Bash 环境下 Ctrl+V 无法粘贴图片的问题。
 * v2.0: PowerShell (~500ms) → Python ctypes+PIL (~80ms)，提速 6x
 *
 * 触发方式:
 *   1. 显式触发: 消息中包含 [img] 或 [截图]
 *   2. 关键词触发: 截图、图片、screenshot、paste、粘贴、看这、看看这 等
 *   3. 组合触发: Ctrl+V 字符 (\x16) + 任意文本
 *
 * 工作流程:
 *   1. 解析用户 prompt，检测触发条件
 *   2. Python ctypes 快速检测剪贴板是否有图片 (~50ms)
 *   3. Python PIL 保存图片到临时目录 (~80ms)
 *   4. MD5 去重，注入 additionalContext
 *
 * stdin: { session_id, prompt, ... }
 * stdout: JSON { hookSpecificOutput: { additionalContext } }
 * 退出码: 0 (始终放行, fail-open)
 */

'use strict';

const { execSync, spawnSync } = require('child_process');
const fs = require('fs');
const path = require('path');
const crypto = require('crypto');

// === 配置 ===
const SCRIPTS_DIR = path.join(__dirname, '..', 'scripts');
const CHECK_SCRIPT = path.join(SCRIPTS_DIR, 'clipboard-check.py');
const SAVE_SCRIPT = path.join(SCRIPTS_DIR, 'clipboard-save.py');
const TEMP_DIR = path.join(
  process.env.TEMP || process.env.TMP || 'C:\\Temp',
  'claude-clipboard-images'
);
const STATE_FILE = path.join(TEMP_DIR, '.clipboard-state.json');
const MAX_IMAGES = 10;

// Python 路径缓存
let _pythonPath = null;
function getPython() {
  if (_pythonPath) return _pythonPath;
  // 优先使用完整路径，避免 PATH 查找开销 [CLIPBOARD_PYTHON_PORTABLE_2026_04_21]
  const _os = require('os');
  const _path = require('path');
  const candidates = [
    process.env.PYTHON_EXE,
    _path.join(_os.homedir(), 'AppData/Local/Programs/Python/Python312/python.exe'),
    'python',
    'python3',
  ].filter(Boolean);
  for (const p of candidates) {
    try {
      const r = spawnSync(p, ['--version'], { timeout: 2000, encoding: 'utf8', windowsHide: true });
      if (r.status === 0) { _pythonPath = p; return p; }
    } catch {}
  }
  return null;
}

// === 触发检测 ===
const EXPLICIT_MARKERS = /\[img\]|\[截图\]|\[paste\]|\[image\]/i;
const KEYWORD_TRIGGERS = /截图|图片|看图|screenshot|paste image|粘贴图|看这[张个]|看看这|这[张个]图|帮我看|分析.{0,4}图|识别.{0,4}图|图[中里上下]|图片[中里]|看下|看一下|这是什么|什么意思|帮我分析/i;
const CTRL_V_CHAR = /\x16/;

function shouldTrigger(prompt) {
  if (EXPLICIT_MARKERS.test(prompt)) return 'explicit';
  if (CTRL_V_CHAR.test(prompt)) return 'ctrlv';
  if (KEYWORD_TRIGGERS.test(prompt)) return 'keyword';
  return null;
}

// === 文件管理 ===
function ensureDir(dir) {
  try {
    if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
  } catch {}
}

function readState() {
  try {
    return JSON.parse(fs.readFileSync(STATE_FILE, 'utf8'));
  } catch {
    return { lastHash: '', lastPath: '', lastTime: 0 };
  }
}

function writeState(state) {
  try {
    fs.writeFileSync(STATE_FILE, JSON.stringify(state));
  } catch {}
}

function cleanOldImages() {
  try {
    const files = fs.readdirSync(TEMP_DIR)
      .filter(f => f.startsWith('cb_') && f.endsWith('.png'))
      .map(f => ({
        name: f,
        full: path.join(TEMP_DIR, f),
        time: fs.statSync(path.join(TEMP_DIR, f)).mtimeMs
      }))
      .sort((a, b) => b.time - a.time);

    files.slice(MAX_IMAGES).forEach(f => {
      try { fs.unlinkSync(f.full); } catch {}
    });
  } catch {}
}

// === 剪贴板操作 (Python 加速) ===
function hasClipboardImage() {
  const python = getPython();
  if (!python) return hasClipboardImageFallback();

  try {
    const r = spawnSync(python, [CHECK_SCRIPT], {
      timeout: 2000, encoding: 'utf8', windowsHide: true
    });
    return r.stdout.trim() === 'true';
  } catch {
    return hasClipboardImageFallback();
  }
}

function saveClipboardImage(imgPath) {
  const python = getPython();
  if (!python) return saveClipboardImageFallback(imgPath);

  try {
    const winPath = imgPath.replace(/\//g, '\\');
    const r = spawnSync(python, [SAVE_SCRIPT, winPath], {
      timeout: 5000, encoding: 'utf8', windowsHide: true
    });
    return r.status === 0 && fs.existsSync(imgPath);
  } catch {
    return saveClipboardImageFallback(imgPath);
  }
}

// === PowerShell 回退 (Python 不可用时) ===
function hasClipboardImageFallback() {
  try {
    const result = execSync(
      'powershell.exe -NoProfile -Command "(Get-Clipboard -Format Image) -ne $null"',
      { timeout: 3000, encoding: 'utf8', windowsHide: true }
    ).trim();
    return result === 'True';
  } catch {
    return false;
  }
}

function saveClipboardImageFallback(imgPath) {
  try {
    const winPath = imgPath.replace(/\//g, '\\').replace(/'/g, "''");
    execSync(
      `powershell.exe -NoProfile -Command "$img = Get-Clipboard -Format Image; if ($img) { $img.Save('${winPath}', [System.Drawing.Imaging.ImageFormat]::Png) }"`,
      { timeout: 5000, windowsHide: true }
    );
    return fs.existsSync(imgPath);
  } catch {
    return false;
  }
}

function getFileHash(filePath) {
  try {
    const content = fs.readFileSync(filePath);
    return crypto.createHash('md5').update(content).digest('hex');
  } catch {
    return '';
  }
}

// === 主流程 ===
function main() {
  let rawInput = '';
  process.stdin.setEncoding('utf8');
  process.stdin.on('data', (chunk) => {
    rawInput += chunk;
    if (rawInput.length > 128 * 1024) {
      process.stdout.write(JSON.stringify({}));
      process.exit(0);
    }
  });

  process.stdin.on('end', () => {
    try {
      const input = JSON.parse(rawInput);
      const prompt = (input.prompt || '').trim();

      // 检查触发条件
      const trigger = shouldTrigger(prompt);
      if (!trigger) {
        process.stdout.write(JSON.stringify({}));
        process.exit(0);
        return;
      }

      ensureDir(TEMP_DIR);

      // 检测剪贴板图片 (Python: ~50ms, 回退 PowerShell: ~500ms)
      if (!hasClipboardImage()) {
        process.stdout.write(JSON.stringify({}));
        process.exit(0);
        return;
      }

      // 保存图片 (Python: ~80ms, 回退 PowerShell: ~300ms)
      const timestamp = Date.now();
      const imgPath = path.join(TEMP_DIR, `cb_${timestamp}.png`);

      if (!saveClipboardImage(imgPath)) {
        process.stdout.write(JSON.stringify({}));
        process.exit(0);
        return;
      }

      // MD5 去重
      const hash = getFileHash(imgPath);
      const state = readState();

      if (hash === state.lastHash && state.lastPath && fs.existsSync(state.lastPath)) {
        // 相同图片，删除新文件，复用旧路径
        try { fs.unlinkSync(imgPath); } catch {}
        // 任何触发方式都返回旧图片路径（用户可能多次引用同一张截图）
        outputResult(state.lastPath, trigger);
        process.exit(0);
        return;
      }

      // 新图片
      writeState({ lastHash: hash, lastPath: imgPath, lastTime: timestamp });
      cleanOldImages();
      outputResult(imgPath, trigger);

    } catch {
      process.stdout.write(JSON.stringify({}));
    }
    process.exit(0);
  });
}

function outputResult(imgPath, trigger) {
  const cleanPrompt = trigger === 'explicit'
    ? '（用户使用了 [img] 标记请求查看剪贴板图片）'
    : '（检测到用户可能想分享剪贴板中的截图）';

  process.stdout.write(JSON.stringify({
    hookSpecificOutput: {
      additionalContext: [
        `[CLIPBOARD_IMAGE_DETECTED]`,
        `触发方式: ${trigger}`,
        `${cleanPrompt}`,
        `剪贴板截图已保存到: ${imgPath}`,
        `请用 Read 工具读取此图片文件查看截图内容，然后回答用户的问题。`
      ].join('\n')
    }
  }));
}

if (require.main === module) {
  main();
}