<?php
session_start();
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type');
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') { exit; }

$action = $_GET['action'] ?? '';
$dataDir = __DIR__ . DIRECTORY_SEPARATOR . 'data';
$exportDir = $dataDir . DIRECTORY_SEPARATOR . 'exports';
$uploadDir = $dataDir . DIRECTORY_SEPARATOR . 'uploads';
$dataFile = $dataDir . DIRECTORY_SEPARATOR . 'projects.json';
// 存储AI润色结果的JSON文件
$aiTextFile = $dataDir . DIRECTORY_SEPARATOR . 'ai_reminder.json';

if (!is_dir($dataDir)) { @mkdir($dataDir, 0777, true); }
if (!is_dir($exportDir)) { @mkdir($exportDir, 0777, true); }
if (!is_dir($uploadDir)) { @mkdir($uploadDir, 0777, true); }
if (!file_exists($dataFile)) { file_put_contents($dataFile, json_encode([])); }
if (!file_exists($aiTextFile)) { file_put_contents($aiTextFile, json_encode(new stdClass())); }

function readJson($file) {
  $raw = @file_get_contents($file);
  $arr = json_decode($raw, true);
  if (!is_array($arr)) $arr = [];
  return $arr;
}
function writeJson($file, $arr) {
  $json = json_encode($arr, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT);
  $fp = fopen($file, 'w');
  if ($fp) {
    // 简单写锁
    if (flock($fp, LOCK_EX)) {
      fwrite($fp, $json);
      fflush($fp);
      flock($fp, LOCK_UN);
    }
    fclose($fp);
    return true;
  }
  return false;
}
function uid() { return uniqid('', true); }
function nowStr() { return date('Y-m-d H:i:s'); }

function body_json() {
  $raw = file_get_contents('php://input');
  $json = json_decode($raw, true);
  return is_array($json) ? $json : [];
}

function resp_json($data) {
  header('Content-Type: application/json; charset=utf-8');
  echo json_encode($data, JSON_UNESCAPED_UNICODE);
  exit;
}

function find_index_by_id(&$arr, $id) {
  foreach ($arr as $i => $it) { if (($it['id'] ?? '') === $id) return $i; }
  return -1;
}

// 未登录则阻止除 login 以外的操作
if ($action !== 'login') {
  if (!isset($_SESSION['auth']) || !$_SESSION['auth']) {
    resp_json(['ok' => false, 'message' => '未登录', 'need_login' => true]);
  }
}

switch ($action) {
  case 'login': {
    $b = body_json();
    $pwd = trim($b['password'] ?? '');
    if ($pwd === '123123') {
      $_SESSION['auth'] = 1;
      // 设置简单 Cookie，供导出HTML等静态页前端校验
      setcookie('auth_ok', '1', time() + 7*24*3600, '/');
      resp_json(['ok' => true]);
    } else {
      resp_json(['ok' => false, 'message' => '密码错误']);
    }
  }
  case 'logout': {
    $_SESSION['auth'] = 0; unset($_SESSION['auth']);
    setcookie('auth_ok', '', time() - 3600, '/');
    resp_json(['ok' => true]);
  }
  case 'list_projects': {
    $projects = readJson($dataFile);
    resp_json(['ok' => true, 'projects' => $projects]);
  }
  case 'get_project': {
    $id = $_GET['id'] ?? '';
    if ($id === '') resp_json(['ok' => false, 'message' => '缺少项目ID']);
    $projects = readJson($dataFile);
    $idx = find_index_by_id($projects, $id);
    if ($idx < 0) resp_json(['ok' => false, 'message' => '项目不存在']);
    resp_json(['ok' => true, 'project' => $projects[$idx]]);
  }
  case 'cleanup_unused_uploads': {
    // 主动触发一次清理：删除 data/uploads 下未被任何笔记引用的文件
    $projects = readJson($dataFile);
    $clean = cleanup_unused_uploads($projects, $uploadDir);
    resp_json(['ok' => true, 'cleanup' => $clean]);
  }
  case 'create_project': {
    $b = body_json();
    $name = trim($b['name'] ?? '');
    if ($name === '') resp_json(['ok' => false, 'message' => '项目名称不能为空']);
    $projects = readJson($dataFile);
    $p = [
      'id' => uid(),
      'name' => $name,
      'status' => '待做',
      'notes' => [],
      'created_at' => nowStr(),
      'updated_at' => nowStr()
    ];
    $projects[] = $p;
    writeJson($dataFile, $projects);
    resp_json(['ok' => true, 'project' => $p]);
  }
  case 'update_project': {
    $b = body_json();
    $id = $b['id'] ?? '';
    if ($id === '') resp_json(['ok' => false, 'message' => '缺少项目ID']);
    $projects = readJson($dataFile);
    $idx = find_index_by_id($projects, $id);
    if ($idx < 0) resp_json(['ok' => false, 'message' => '项目不存在']);
    $name = isset($b['name']) ? trim($b['name']) : null;
    $status = isset($b['status']) ? trim($b['status']) : null;
    if ($name !== null && $name !== '') $projects[$idx]['name'] = $name;
    if ($status !== null && in_array($status, ['待做','进行','完成','异常'])) $projects[$idx]['status'] = $status;
    $projects[$idx]['updated_at'] = nowStr();
    writeJson($dataFile, $projects);
    resp_json(['ok' => true, 'project' => $projects[$idx]]);
  }
  case 'delete_project': {
    $b = body_json();
    $id = $b['id'] ?? '';
    if ($id === '') resp_json(['ok' => false, 'message' => '缺少项目ID']);
    $projects = readJson($dataFile);
    $idx = find_index_by_id($projects, $id);
    if ($idx < 0) resp_json(['ok' => false, 'message' => '项目不存在']);
    array_splice($projects, $idx, 1);
    writeJson($dataFile, $projects);
    // 同步删除该项目的AI润色存档
    $aiMap = readJson($aiTextFile);
    if (isset($aiMap[$id])) { unset($aiMap[$id]); writeJson($aiTextFile, $aiMap); }
    // 删除项目后，清理未被任何笔记引用的上传文件
    $clean = cleanup_unused_uploads($projects, $uploadDir);
    resp_json(['ok' => true, 'cleanup' => $clean]);
  }
  case 'add_note': {
    $b = body_json();
    $pid = $b['project_id'] ?? '';
    $content = trim($b['content'] ?? '');
    if ($pid === '' || $content === '') resp_json(['ok' => false, 'message' => '缺少参数']);
    $projects = readJson($dataFile);
    $idx = find_index_by_id($projects, $pid);
    if ($idx < 0) resp_json(['ok' => false, 'message' => '项目不存在']);
    $note = [ 'id' => uid(), 'content' => $content, 'created_at' => nowStr(), 'updated_at' => nowStr() ];
    if (!isset($projects[$idx]['notes']) || !is_array($projects[$idx]['notes'])) $projects[$idx]['notes'] = [];
    $projects[$idx]['notes'][] = $note;
    writeJson($dataFile, $projects);
    resp_json(['ok' => true, 'note' => $note]);
  }
  case 'update_note': {
    $b = body_json();
    $pid = $b['project_id'] ?? '';
    $nid = $b['note_id'] ?? '';
    $content = trim($b['content'] ?? '');
    if ($pid === '' || $nid === '') resp_json(['ok' => false, 'message' => '缺少参数']);
    $projects = readJson($dataFile);
    $pidx = find_index_by_id($projects, $pid);
    if ($pidx < 0) resp_json(['ok' => false, 'message' => '项目不存在']);
    $notes = $projects[$pidx]['notes'] ?? [];
    $nidx = -1; foreach ($notes as $i => $n) { if (($n['id'] ?? '') === $nid) { $nidx = $i; break; } }
    if ($nidx < 0) resp_json(['ok' => false, 'message' => '笔记不存在']);
    if ($content !== '') { $projects[$pidx]['notes'][$nidx]['content'] = $content; }
    $projects[$pidx]['notes'][$nidx]['updated_at'] = nowStr();
    writeJson($dataFile, $projects);
    // 更新笔记后尝试清理未使用的上传文件（防止删除了图片引用后残留）
    $clean = cleanup_unused_uploads($projects, $uploadDir);
    resp_json(['ok' => true, 'note' => $projects[$pidx]['notes'][$nidx], 'cleanup' => $clean]);
  }
  case 'delete_note': {
    $b = body_json();
    $pid = $b['project_id'] ?? '';
    $nid = $b['note_id'] ?? '';
    if ($pid === '' || $nid === '') resp_json(['ok' => false, 'message' => '缺少参数']);
    $projects = readJson($dataFile);
    $pidx = find_index_by_id($projects, $pid);
    if ($pidx < 0) resp_json(['ok' => false, 'message' => '项目不存在']);
    $notes = $projects[$pidx]['notes'] ?? [];
    $nidx = -1; foreach ($notes as $i => $n) { if (($n['id'] ?? '') === $nid) { $nidx = $i; break; } }
    if ($nidx < 0) resp_json(['ok' => false, 'message' => '笔记不存在']);
    array_splice($projects[$pidx]['notes'], $nidx, 1);
    writeJson($dataFile, $projects);
    // 删除笔记后，清理未被任何笔记引用的上传文件
    $clean = cleanup_unused_uploads($projects, $uploadDir);
    resp_json(['ok' => true, 'cleanup' => $clean]);
  }
  case 'export_project_html': {
    $id = $_GET['id'] ?? '';
    if ($id === '') resp_json(['ok' => false, 'message' => '缺少项目ID']);
    $projects = readJson($dataFile);
    $idx = find_index_by_id($projects, $id);
    if ($idx < 0) resp_json(['ok' => false, 'message' => '项目不存在']);
    $p = $projects[$idx];
    $safeName = preg_replace('/[^\w\x{4e00}-\x{9fa5}]+/u', '_', $p['name']);
    $fname = $exportDir . DIRECTORY_SEPARATOR . 'project_' . $safeName . '_' . substr($p['id'], 0, 8) . '.html';
    $html = "<!DOCTYPE html><html lang=\"zh-CN\"><meta charset=\"utf-8\"><title>" . htmlspecialchars($p['name']) . " - 导出</title><style>body{font-family:Arial,Microsoft YaHei;padding:16px}h1{margin-top:0} .note{border:1px dashed #ccc; padding:8px; border-radius:8px; margin:8px 0}</style><body>";
    $html .= '<h1>' . htmlspecialchars($p['name']) . '</h1>';
    $html .= '<p>状态：' . htmlspecialchars($p['status']) . '</p>';
    $html .= '<h2>笔记</h2>';
    foreach (($p['notes'] ?? []) as $n) {
      $html .= '<div class="note"><div>' . render_note_content($n['content'] ?? '') . '</div>';
      $html .= '<div style="color:#666;font-size:12px">创建：' . htmlspecialchars($n['created_at'] ?? '') . ' 更新：' . htmlspecialchars($n['updated_at'] ?? '') . '</div></div>';
    }
    $html .= '</body></html>';
    file_put_contents($fname, $html);
    // 构造相对URL，便于在浏览器打开
    $rel = 'data/exports/' . basename($fname);
    resp_json(['ok' => true, 'url' => $rel]);
  }
  case 'ai_enrich_reminder': {
    // 使用火山引擎 Doubao 模型对提醒文案进行情感润色
    $b = body_json();
    $raw = trim($b['raw'] ?? '');
    $proj = $b['project'] ?? [];
    $apiKey = trim($b['api_key'] ?? '');
    if ($raw === '') resp_json(['ok' => false, 'message' => '缺少原始提醒内容']);
    if ($apiKey === '') {
      // 尝试从本地文件读取 Key（可选）
      $kf = $dataDir . DIRECTORY_SEPARATOR . 'ark_api_key.txt';
      if (is_file($kf)) { $apiKey = trim(@file_get_contents($kf)); }
    }
    if ($apiKey === '') resp_json(['ok' => false, 'message' => '缺少AI Key（请将密钥写入 data/ark_api_key.txt）']);
    $name = isset($proj['name']) ? $proj['name'] : '';
    $status = isset($proj['status']) ? $proj['status'] : '';
    $pid = isset($proj['id']) ? $proj['id'] : '';
    // 可选：结合项目最近笔记进行润色
    $includeNotes = isset($b['include_notes']) ? !!($b['include_notes']) : true; // 默认结合笔记
    $notesSummary = '';
    if ($includeNotes && $pid !== '') {
      $projectsAll = readJson($dataFile);
      $pidx2 = find_index_by_id($projectsAll, $pid);
      if ($pidx2 >= 0) {
        $notesArr = $projectsAll[$pidx2]['notes'] ?? [];
        // 取最近3条（末尾3条）
        $cnt = count($notesArr);
        $recent = [];
        if ($cnt > 0) {
          $recent = array_slice($notesArr, max(0, $cnt - 3));
        }
        $pieces = [];
        foreach ($recent as $nn) {
          $content = trim($nn['content'] ?? '');
          if ($content !== '') {
            // 去掉图片Markdown、URL等噪声
            $content = preg_replace('/!\[[^\]]*\]\([^\)]*\)/', '', $content);
            $content = preg_replace('/https?:\/\/\S+/i', '', $content);
            $content = trim($content);
            // 截断避免过长
            if (function_exists('mb_strlen') && function_exists('mb_substr')) {
              if (mb_strlen($content, 'UTF-8') > 120) { $content = mb_substr($content, 0, 120, 'UTF-8') . '…'; }
            } else {
              if (strlen($content) > 200) { $content = substr($content, 0, 200) . '…'; }
            }
            if ($content !== '') $pieces[] = $content;
          }
        }
        if (!empty($pieces)) { $notesSummary = implode('；', $pieces); }
      }
    }
    $prompt = "请将以下项目提醒改写为更具同理心、简洁明确且可执行的中文提示，长度不超过60字，并适当使用 emoji（最多2个），避免官方语气。\n" .
              "只输出一条润色后的中文提醒，不要附加任何解释、评分、括号中的说明、标签或代码块。\n" .
              "项目名称：" . $name . "\n状态：" . $status . "\n提醒：" . $raw;
    if ($notesSummary !== '') {
      $prompt .= "\n参考最近笔记要点：" . $notesSummary;
    }
    $payload = [
      'model' => 'doubao-seed-1-6-251015',
      'max_completion_tokens' => 1024,
      'messages' => [ [ 'role' => 'user', 'content' => [ [ 'type' => 'text', 'text' => $prompt ] ] ] ],
      'reasoning_effort' => 'medium'
    ];
    $ch = curl_init('https://ark.cn-beijing.volces.com/api/v3/chat/completions');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_HTTPHEADER, [ 'Content-Type: application/json', 'Authorization: Bearer ' . $apiKey ]);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($payload, JSON_UNESCAPED_UNICODE));
    curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 10);
    curl_setopt($ch, CURLOPT_TIMEOUT, 20);
    $resp = curl_exec($ch);
    $err = curl_error($ch);
    $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);
    if ($resp === false) resp_json(['ok' => false, 'message' => '请求失败: ' . $err]);
    $j = json_decode($resp, true);
    if (!is_array($j)) resp_json(['ok' => false, 'message' => '响应解析失败', 'code' => $code]);
    // 提取文本内容
    $txt = '';
    // 1) 直接读取 output_text（有些版本会提供该字段）
    if (isset($j['output_text']) && is_string($j['output_text'])) { $txt = $j['output_text']; }
    // 2) choices.message.content 可能是字符串或数组
    if ($txt === '' && isset($j['choices'][0]['message']['content'])) {
      $content = $j['choices'][0]['message']['content'];
      if (is_string($content)) { $txt = $content; }
      elseif (is_array($content)) {
        foreach ($content as $c) { if (isset($c['text'])) { $txt .= $c['text']; } }
      }
    }
    // 3) 兜底读取常见位置
    if ($txt === '' && isset($j['choices'][0]['message']['content'][0]['text'])) {
      $txt = $j['choices'][0]['message']['content'][0]['text'];
    }
    if ($txt === '' && isset($j['data']['output_text'])) { $txt = $j['data']['output_text']; }
    if ($txt === '') resp_json(['ok' => false, 'message' => '未获取到AI文本', 'raw_resp' => $j]);
    // 仅保留第一行，并去掉末尾的括号型说明（例如：（字数合规…）或(...））
    $txt = trim((string)$txt);
    $firstLine = preg_split('/\r?\n/', $txt)[0];
    $firstLine = trim($firstLine);
    // 去掉结尾括号段，但保留正文中的内容
    $firstLine = preg_replace('/(?:（[^）]*）|\([^\)]*\))\s*$/u', '', $firstLine);
    $firstLine = trim($firstLine);
    if ($firstLine === '') $firstLine = $txt; // 兜底
    $txt = $firstLine;
    // 写入到 ai_reminder.json 中，按项目ID持久化
    if ($pid !== '') {
      $aiMap = readJson($aiTextFile);
      if (!is_array($aiMap)) $aiMap = [];
      $aiMap[$pid] = [ 'text' => $txt, 'raw' => $raw, 'updated_at' => nowStr(), 'notes' => $notesSummary ];
      writeJson($aiTextFile, $aiMap);
    }
    resp_json(['ok' => true, 'text' => $txt, 'saved' => ($pid !== '')]);
  }
  case 'get_ai_reminder': {
    // 获取指定项目的AI润色文本（如果存在）
    $id = $_GET['id'] ?? ($_POST['id'] ?? '');
    if ($id === '') resp_json(['ok' => false, 'message' => '缺少项目ID']);
    $aiMap = readJson($aiTextFile);
    if (isset($aiMap[$id]) && isset($aiMap[$id]['text'])) {
      $item = $aiMap[$id];
      resp_json(['ok' => true, 'text' => $item['text'], 'updated_at' => ($item['updated_at'] ?? '')]);
    } else {
      resp_json(['ok' => true, 'text' => '', 'updated_at' => '']);
    }
  }
  case 'list_exports': {
    // 列出 data/exports 下的导出文件（仅 .html）
    $files = [];
    if (is_dir($exportDir)) {
      foreach (scandir($exportDir) as $f) {
        if ($f === '.' || $f === '..') continue;
        if (!preg_match('/\.html?$/i', $f)) continue;
        $path = $exportDir . DIRECTORY_SEPARATOR . $f;
        if (is_file($path)) {
          $files[] = [
            'name' => $f,
            'url' => 'data/exports/' . $f,
            'size' => filesize($path),
            'mtime' => date('Y-m-d H:i:s', filemtime($path))
          ];
        }
      }
    }
    // 最新时间倒序
    usort($files, function($a,$b){ return strcmp($b['mtime'],$a['mtime']); });
    resp_json(['ok' => true, 'files' => $files]);
  }
  case 'delete_export': {
    // 删除指定的导出文件（仅限 data/exports）
    $b = body_json();
    $name = $b['name'] ?? '';
    if ($name === '') resp_json(['ok' => false, 'message' => '缺少文件名']);
    $base = basename($name); // 防止路径穿越
    $path = $exportDir . DIRECTORY_SEPARATOR . $base;
    if (!is_file($path)) resp_json(['ok' => false, 'message' => '文件不存在']);
    if (!@unlink($path)) resp_json(['ok' => false, 'message' => '删除失败']);
    resp_json(['ok' => true]);
  }
  case 'upload_file': {
    // 允许上传图片或常见文档，保存到 data/uploads
    if ($_SERVER['REQUEST_METHOD'] !== 'POST') resp_json(['ok' => false, 'message' => '仅支持POST']);
    $file = $_FILES['file'] ?? ($_FILES['image'] ?? null);
    if (!$file) resp_json(['ok' => false, 'message' => '未选择文件']);
    if (($file['error'] ?? UPLOAD_ERR_OK) !== UPLOAD_ERR_OK) resp_json(['ok' => false, 'message' => '上传错误: ' . ($file['error'] ?? '未知')]);
    $name = $file['name'] ?? ('img_' . uniqid());
    $ext = strtolower(pathinfo($name, PATHINFO_EXTENSION));
    $allow = ['png','jpg','jpeg','gif','webp','pdf','doc','docx','xls','xlsx','ppt','pptx','txt','csv','zip','rar','7z'];
    if (!$ext) $ext = 'bin';
    if (!in_array($ext, $allow)) resp_json(['ok' => false, 'message' => '不支持的文件类型: ' . $ext]);
    $size = $file['size'] ?? 0; if ($size > 30 * 1024 * 1024) resp_json(['ok' => false, 'message' => '文件过大，限制30MB']);
    $target = $uploadDir . DIRECTORY_SEPARATOR . ('up_' . date('Ymd_His') . '_' . substr(uniqid('', true), -6) . '.' . $ext);
    if (!@move_uploaded_file($file['tmp_name'], $target)) resp_json(['ok' => false, 'message' => '保存失败']);
    $rel = 'data/uploads/' . basename($target);
    $mime = mime_content_type($target);
    resp_json(['ok' => true, 'url' => $rel, 'name' => $name, 'mime' => $mime]);
  }
  default: resp_json(['ok' => false, 'message' => '未知操作']);
}

// 将笔记文本转换为HTML（支持 Markdown 图片：![alt](url)），其余文本安全转义
function render_note_content($text) {
  if ($text === null) $text = '';
  $out = '';
  $last = 0;
  while (true) {
    $img = preg_match('/!\[([^\]]*)\]\(([^\)]+)\)/u', $text, $im, PREG_OFFSET_CAPTURE, $last) ? $im : null;
    $lnk = preg_match('/(?<!\!)\[([^\]]+)\]\(([^\)]+)\)/u', $text, $lm, PREG_OFFSET_CAPTURE, $last) ? $lm : null;
    $ipos = $img ? $img[0][1] : -1;
    $lpos = $lnk ? $lnk[0][1] : -1;
    if ($ipos < 0 && $lpos < 0) break;
    $nextPos = ($ipos >=0 && ($lpos < 0 || $ipos <= $lpos)) ? $ipos : $lpos;
    $out .= nl2br(htmlspecialchars(substr($text, $last, $nextPos - $last), ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8'));
    if ($nextPos === $ipos) {
      $alt = htmlspecialchars($img[1][0], ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
      $urlAdj = adjust_url_for_export($img[2][0]);
      $url = htmlspecialchars($urlAdj, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
      $out .= '<img src="' . $url . '" alt="' . $alt . '" style="max-width:100%">';
      $last = $ipos + strlen($img[0][0]);
    } else {
      $label = htmlspecialchars($lnk[1][0], ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
      $urlRaw = $lnk[2][0];
      $urlAdj = adjust_url_for_export($urlRaw);
      $urlEsc = htmlspecialchars($urlAdj, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
      if (is_image_url($urlRaw)) {
        $out .= '<img src="' . $urlEsc . '" alt="' . $label . '" style="max-width:100%">';
      } else {
        $out .= '<a href="' . $urlEsc . '" target="_blank" rel="noopener noreferrer">' . $label . '</a>';
      }
      $last = $lpos + strlen($lnk[0][0]);
    }
  }
  $out .= nl2br(htmlspecialchars(substr($text, $last), ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8'));
  return $out;
}

function is_image_url($url) {
  return preg_match('/\.(png|jpg|jpeg|gif|webp)(\?.*)?$/i', $url) || preg_match('/^data:image\//i', $url);
}

// 导出HTML时将相对路径调整为以导出文件为基准的相对路径
// 例如：原始插入为 data/uploads/xxx.png，导出文件位于 data/exports/ 下，
// 浏览器在 exports 页面中引用 uploads 需使用 ../uploads/xxx.png
function adjust_url_for_export($url) {
  if (!$url) return $url;
  // 只处理本项目的相对路径
  if (preg_match('/^data\/uploads\//i', $url)) {
    // 去掉可能的查询参数
    $parts = explode('?', $url, 2);
    return '../uploads/' . substr($parts[0], strlen('data/uploads/')) . (isset($parts[1]) ? ('?' . $parts[1]) : '');
  }
  return $url;
}

// 提取笔记文本中所有 Markdown 链接/图片的 URL
function extract_note_urls($text) {
  $urls = [];
  if ($text === null) $text = '';
  // 图片
  if (preg_match_all('/!\[[^\]]*\]\(([^\)]+)\)/u', $text, $m1)) {
    foreach ($m1[1] as $u) { $urls[] = $u; }
  }
  // 普通链接
  if (preg_match_all('/\[[^\]]+\]\(([^\)]+)\)/u', $text, $m2)) {
    foreach ($m2[1] as $u) { $urls[] = $u; }
  }
  return $urls;
}

// 仅清理 data/uploads 下未被任何笔记引用的文件
function cleanup_unused_uploads($projects, $uploadDir) {
  try {
    $used = [];
    foreach ($projects as $p) {
      $notes = $p['notes'] ?? [];
      foreach ($notes as $n) {
        $urls = extract_note_urls($n['content'] ?? '');
        foreach ($urls as $u) {
          // 只统计本地上传目录的相对路径
          $pos = strpos($u, 'data/uploads/');
          if ($pos !== false) {
            $rel = substr($u, $pos);
            // 去掉查询串
            $rel = explode('?', $rel)[0];
            $base = basename($rel);
            if ($base) $used[$base] = true;
          }
        }
      }
    }
    $deleted = 0;
    if (is_dir($uploadDir)) {
      $files = @scandir($uploadDir);
      foreach ($files as $f) {
        if ($f === '.' || $f === '..') continue;
        if (!isset($used[$f])) {
          $path = $uploadDir . DIRECTORY_SEPARATOR . $f;
          if (is_file($path)) { @unlink($path); $deleted++; }
        }
      }
    }
    return [ 'deleted' => $deleted, 'kept' => count($used) ];
  } catch (Throwable $e) {
    return [ 'deleted' => 0, 'error' => $e->getMessage() ];
  }
}