// 文章附件区共享逻辑（管理员与普通用户的文章新建/编辑页共用）：
// 上传（multipart → 附件接口，写 files 表 type=attachments）、编辑页回填列表、
// 插入正文（图片 ![]() / 其他 []()）、图片一键设封面、删除（引用计数由服务端处理）。
//
// 由页面调用：initArticleAttachments(cfg)
// cfg:
//   uploadURL     上传接口，如 "/api/my/articles/attachments"（DELETE 为 uploadURL + "/<id>"）
//   listURL       列表接口模板，":id" 会被替换为文章 id，如 "/api/my/articles/:id/attachments"
//   editor        EasyMDE 实例（用于在光标处插入 Markdown）
//   articleID     文章 id（编辑页）；新建页为 0
//   sessionToken  新建页的临时归属令牌
//   texts         页面 i18n 文案：{pick, uploading, insert, setCover, coverSet, del, delConfirm, err}
window.initArticleAttachments = function (cfg) {
    var uploadBtn = document.getElementById('attachmentUploadBtn');
    var fileInput = document.getElementById('attachmentInput');
    var msgEl = document.getElementById('attachmentMsg');
    var listEl = document.getElementById('attachmentList');
    var texts = cfg.texts || {};
    if (!uploadBtn || !listEl || !fileInput) { return; }

    var meta = document.querySelector('meta[name="csrf-token"]');
    var csrfToken = meta ? meta.getAttribute('content') : '';

    // Enable the uploader (uploads allowed only while logged in, which is true here).
    uploadBtn.disabled = false;
    fileInput.disabled = false;

    function fmtSize(b) {
        if (b < 1024) { return b + ' B'; }
        var u = ['KiB', 'MiB', 'GiB'], i = -1;
        do { b /= 1024; i++; } while (b >= 1024 && i < u.length - 1);
        return b.toFixed(1) + ' ' + u[i];
    }

    function insertMd(md) {
        var cm = cfg.editor && cfg.editor.codemirror;
        if (!cm) { return; }
        cm.replaceSelection(md + '\n');
        cm.focus();
    }

    function addRow(att) {
        var tr = document.createElement('tr');
        tr.className = 'hover:bg-gray-50';
        tr.dataset.id = att.id;
        var nameTd = document.createElement('td');
        nameTd.className = 'px-3 py-2 text-sm text-gray-800';
        var link = document.createElement('a');
        link.href = att.url; link.target = '_blank'; link.textContent = att.filename;
        nameTd.appendChild(link);
        var sizeTd = document.createElement('td');
        sizeTd.className = 'px-3 py-2 text-sm text-gray-500';
        sizeTd.textContent = fmtSize(att.size);
        var actTd = document.createElement('td');
        actTd.className = 'px-3 py-2 text-sm text-right whitespace-nowrap';
        var insBtn = document.createElement('button');
        insBtn.type = 'button';
        insBtn.textContent = texts.insert || 'Insert';
        insBtn.className = 'text-blue-600 hover:text-blue-800 font-medium mr-3 cursor-pointer bg-transparent border-none';
        insBtn.onclick = function () {
            var md = att.is_image
                ? '![' + att.filename + '](' + att.url + ')'
                : '[' + att.filename + '](' + att.url + ')';
            insertMd(md);
        };

        // Images: extra button to copy the URL into the cover field.
        var coverBtn = null;
        if (att.is_image) {
            coverBtn = document.createElement('button');
            coverBtn.type = 'button';
            coverBtn.textContent = texts.setCover || 'Cover';
            coverBtn.className = 'text-green-600 hover:text-green-800 font-medium mr-3 cursor-pointer bg-transparent border-none';
            coverBtn.onclick = function () {
                var cover = document.querySelector('input[name="cover"]');
                if (cover) { cover.value = att.url; msgEl.textContent = texts.coverSet || ''; }
            };
        }
        var delBtn = document.createElement('button');
        delBtn.type = 'button';
        delBtn.textContent = texts.del || 'Delete';
        delBtn.className = 'text-red-600 hover:text-red-800 font-medium cursor-pointer bg-transparent border-none';
        delBtn.onclick = function () {
            if (!confirm(texts.delConfirm || 'Delete?')) { return; }
            fetch(cfg.uploadURL + '/' + att.id, {
                method: 'DELETE',
                headers: { 'X-CSRF-Token': csrfToken }
            })
                .then(function (r) { return r.json(); })
                .then(function (r) {
                    if (r.ok) { tr.remove(); }
                    else { msgEl.textContent = r.error || 'error'; }
                });
        };
        actTd.appendChild(insBtn);
        if (coverBtn) { actTd.appendChild(coverBtn); }
        actTd.appendChild(delBtn);
        tr.appendChild(nameTd);
        tr.appendChild(sizeTd);
        tr.appendChild(actTd);
        listEl.appendChild(tr);
    }

    uploadBtn.addEventListener('click', function () {
        if (!fileInput.files.length) { msgEl.textContent = texts.pick || 'Pick a file.'; return; }
        var fd = new FormData();
        fd.append('file', fileInput.files[0]);
        if (cfg.articleID) { fd.append('article_id', cfg.articleID); }
        else if (cfg.sessionToken) { fd.append('session_token', cfg.sessionToken); }
        msgEl.textContent = texts.uploading || 'Uploading...';
        fetch(cfg.uploadURL, {
            method: 'POST',
            headers: { 'X-CSRF-Token': csrfToken },
            body: fd
        })
            .then(function (r) { return r.json(); })
            .then(function (r) {
                if (r.error) { msgEl.textContent = r.error; return; }
                msgEl.textContent = '';
                addRow(r);
                fileInput.value = '';
            })
            .catch(function () { msgEl.textContent = texts.err || 'Upload failed.'; });
    });

    // Edit page: load existing attachments.
    if (cfg.articleID) {
        fetch(cfg.listURL.replace(':id', cfg.articleID))
            .then(function (r) { return r.json(); })
            .then(function (r) {
                (r.attachments || []).forEach(addRow);
            });
    }
};