/**
 * 笔记页面交互逻辑
 */
var currentNoteId = null;
var saveTimer = null;
var viewMode = "edit";

function setViewMode(mode) {
    viewMode = mode;
    var editPane = document.querySelector("#editPane");
    var previewPane = document.querySelector("#previewPane");
    document.querySelectorAll(".toggle-group button").forEach(function(b) {
        b.classList.toggle("active", b.dataset.mode === mode);
    });
    editPane.classList.remove("hidden");
    previewPane.classList.remove("hidden");
    if (mode === "edit") { previewPane.classList.add("hidden"); }
    else if (mode === "preview") { editPane.classList.add("hidden"); }
    updatePreview();
}

function createNote() {
    var folderId = getActiveFolderId();
    fetch("/api/notes", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ title: "无标题笔记", content: "", folder_id: folderId }),
    }).then(function(r) { return r.json(); })
      .then(function(note) { loadNote(note.id); refreshFolderNotes(); });
}

function loadNote(noteId) {
    fetch("/api/notes/" + noteId)
        .then(function(r) { return r.json(); })
        .then(function(note) {
            currentNoteId = note.id;
            document.querySelector("#currentNoteId").value = note.id;
            document.querySelector("#noteTitle").value = note.title;
            initEditor(note.content || "");
            document.querySelectorAll(".note-list-item").forEach(function(el) {
                el.classList.toggle("active", parseInt(el.dataset.noteId) === note.id);
            });
        });
}

function scheduleSave() {
    var s = document.querySelector("#saveStatus");
    if (s) { s.textContent = "保存中…"; s.style.color = "#F5A623"; }
    clearTimeout(saveTimer);
    saveTimer = setTimeout(saveNote, 800);
}

function saveNote() {
    if (!currentNoteId) return;
    var title = document.querySelector("#noteTitle").value;
    var content = editor ? editor.getHTML() : "";
    fetch("/api/notes/" + currentNoteId, {
        method: "PUT",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ title: title, content: content }),
    }).then(function(r) {
        if (r.ok) { var s = document.querySelector("#saveStatus"); if (s) { s.textContent = "已保存"; s.style.color = ""; } }
    });
}

function filterByFolder(folderId, el) {
    document.querySelectorAll(".folder-item").forEach(function(f) { f.classList.remove("active"); });
    el.classList.add("active");
    fetch("/api/notes?folder_id=" + folderId)
        .then(function(r) { return r.json(); })
        .then(function(notes) { renderNoteList(notes); });
}

function renderNoteList(notes) {
    var listDiv = document.querySelector("#folderNoteList");
    if (!listDiv) return;
    listDiv.classList.remove("hidden");

    var html = '<div style="padding:4px 0; cursor:pointer; color:var(--brand); font-size:11px;" onclick="showFolderList()">← 返回文件夹</div>';
    if (!notes.length) {
        html += '<div style="color:#ccc; padding:8px; text-align:center; font-size:12px;">暂无笔记</div>';
    } else {
        notes.forEach(function(note) {
            var title = note.title || "无标题";
            var date = (note.updated_at || "").substr(0, 10);
            html += '<div class="note-list-item" data-note-id="' + note.id + '" onclick="loadNote(' + note.id + ')">' +
                '<span class="note-title-s">' + escapeHtml(title) + '</span>' +
                '<span class="note-date">' + date + '</span></div>';
        });
    }
    listDiv.innerHTML = html;
}

function showFolderList() {
    var listDiv = document.querySelector("#folderNoteList");
    if (listDiv) listDiv.classList.add("hidden");
}

function getActiveFolderId() {
    var active = document.querySelector(".folder-item.active");
    return active ? parseInt(active.dataset.folderId) : null;
}

function refreshFolderNotes() {
    var af = document.querySelector(".folder-item.active");
    if (af) filterByFolder(parseInt(af.dataset.folderId), af);
}

function addFolder() {
    var name = prompt("输入新文件夹名称：");
    if (!name) return;
    fetch("/api/folders", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ name: name, type: "note" }) })
        .then(function() { window.location.reload(); });
}

function toggleFolderMenu(btn) {
    document.querySelectorAll(".folder-menu").forEach(function(m) { if (m !== btn.nextElementSibling) m.classList.add("hidden"); });
    var menu = btn.nextElementSibling;
    if (menu) menu.classList.toggle("hidden");
    setTimeout(function() {
        document.addEventListener("click", function close() { if (menu) menu.classList.add("hidden"); document.removeEventListener("click", close); }, { once: true });
    }, 0);
}

function renameFolder(folderId) {
    var name = prompt("新名称："); if (!name) return;
    fetch("/api/folders/" + folderId, { method: "PUT", headers: { "Content-Type": "application/json" }, body: JSON.stringify({ name: name }) })
        .then(function() { window.location.reload(); });
}

function deleteFolder(folderId) {
    if (!confirm("确定删除此文件夹？内容将移至「未分类」")) return;
    fetch("/api/folders/" + folderId, { method: "DELETE" }).then(function() { window.location.reload(); });
}

function deleteCurrentNote() {
    if (!currentNoteId || !confirm("确定删除？")) return;
    fetch("/api/notes/" + currentNoteId, { method: "DELETE" }).then(function() { window.location.reload(); });
}

function filterByTag(tagId, el) { el.classList.toggle("active"); }
function addTag() { var n = prompt("标签名："); if (n) window.location.reload(); }

function escapeHtml(s) { return s ? s.replace(/&/g,"&amp;").replace(/</g,"&lt;").replace(/>/g,"&gt;").replace(/"/g,"&quot;") : ""; }

document.addEventListener("DOMContentLoaded", function() {
    document.querySelector("#noteTitle").addEventListener("input", scheduleSave);
    var firstId = document.querySelector("#firstNoteId");
    if (firstId && firstId.value) loadNote(parseInt(firstId.value)); else createNote();
});