"use strict";
(function () {
  var KEY = "focusdesk.tasks.v1";
  var tasks = load();
  var editingId = null;

  var $ = function (id) { return document.getElementById(id); };
  var form = $("task-form"), titleIn = $("task-title"), notesIn = $("task-notes"),
      prioIn = $("task-priority"), dueIn = $("task-due"), titleErr = $("title-error"),
      searchIn = $("search"), statusSel = $("status-filter"), prioSel = $("priority-filter"),
      listEl = $("task-list"), emptyEl = $("empty-state");

  function load() {
    try {
      var raw = localStorage.getItem(KEY);
      if (!raw) return [];
      var data = JSON.parse(raw);
      if (!Array.isArray(data)) return [];
      return data.filter(function (t) {
        return t && typeof t.id === "string" && typeof t.title === "string";
      }).map(function (t) {
        return {
          id: t.id, title: t.title,
          notes: typeof t.notes === "string" ? t.notes : "",
          priority: ["low", "medium", "high"].indexOf(t.priority) >= 0 ? t.priority : "medium",
          due: typeof t.due === "string" ? t.due : "",
          completed: !!t.completed
        };
      });
    } catch (e) { return []; }
  }
  function save() {
    try { localStorage.setItem(KEY, JSON.stringify(tasks)); } catch (e) {}
  }
  function uid() {
    return Date.now().toString(36) + Math.random().toString(36).slice(2, 8);
  }
  function el(tag, cls, text) {
    var n = document.createElement(tag);
    if (cls) n.className = cls;
    if (text != null) n.textContent = text;
    return n;
  }

  form.addEventListener("submit", function (e) {
    e.preventDefault();
    var title = titleIn.value.trim();
    if (!title) {
      titleErr.hidden = false;
      titleIn.setAttribute("aria-invalid", "true");
      titleIn.focus();
      return;
    }
    titleErr.hidden = true;
    titleIn.removeAttribute("aria-invalid");
    tasks.unshift({
      id: uid(), title: title, notes: notesIn.value.trim(),
      priority: prioIn.value, due: dueIn.value, completed: false
    });
    save();
    form.reset();
    prioIn.value = "medium";
    titleIn.focus();
    render();
  });

  [searchIn, statusSel, prioSel].forEach(function (c) {
    c.addEventListener("input", render);
    c.addEventListener("change", render);
  });

  function matches(t) {
    var q = searchIn.value.trim().toLowerCase();
    if (q && t.title.toLowerCase().indexOf(q) < 0 && t.notes.toLowerCase().indexOf(q) < 0) return false;
    var s = statusSel.value;
    if (s === "active" && t.completed) return false;
    if (s === "completed" && !t.completed) return false;
    var p = prioSel.value;
    if (p !== "all" && t.priority !== p) return false;
    return true;
  }

  function todayStr() {
    var d = new Date();
    return d.getFullYear() + "-" + String(d.getMonth() + 1).padStart(2, "0") + "-" + String(d.getDate()).padStart(2, "0");
  }

  function render() {
    listEl.textContent = "";
    var shown = tasks.filter(matches);
    shown.forEach(function (t) {
      listEl.appendChild(editingId === t.id ? editItem(t) : viewItem(t));
    });
    emptyEl.hidden = shown.length > 0;
    $("count-total").textContent = tasks.length;
    $("count-active").textContent = tasks.filter(function (t) { return !t.completed; }).length;
    $("count-completed").textContent = tasks.filter(function (t) { return t.completed; }).length;
  }

  function viewItem(t) {
    var li = el("li", "task-item" + (t.completed ? " done" : ""));
    li.setAttribute("data-testid", "task-item");

    var cb = document.createElement("input");
    cb.type = "checkbox";
    cb.className = "task-check";
    cb.checked = t.completed;
    cb.setAttribute("data-testid", "task-toggle");
    cb.setAttribute("aria-label", "Mark “" + t.title + "” as " + (t.completed ? "active" : "completed"));
    cb.addEventListener("change", function () {
      t.completed = cb.checked;
      save(); render();
    });

    var body = el("div", "task-body");
    body.appendChild(el("div", "task-title-text", t.title));
    if (t.notes) body.appendChild(el("p", "task-notes-text", t.notes));
    var meta = el("div", "task-meta");
    meta.appendChild(el("span", "badge " + t.priority, t.priority));
    if (t.due) {
      var overdue = !t.completed && t.due < todayStr();
      meta.appendChild(el("span", "due" + (overdue ? " overdue" : ""), "Due " + t.due + (overdue ? " (overdue)" : "")));
    }
    body.appendChild(meta);

    var actions = el("div", "task-actions");
    var editBtn = el("button", "btn ghost", "Edit");
    editBtn.type = "button";
    editBtn.setAttribute("data-testid", "task-edit");
    editBtn.setAttribute("aria-label", "Edit “" + t.title + "”");
    editBtn.addEventListener("click", function () { editingId = t.id; render(); });
    var delBtn = el("button", "btn danger", "Delete");
    delBtn.type = "button";
    delBtn.setAttribute("data-testid", "task-delete");
    delBtn.setAttribute("aria-label", "Delete “" + t.title + "”");
    delBtn.addEventListener("click", function () {
      tasks = tasks.filter(function (x) { return x.id !== t.id; });
      if (editingId === t.id) editingId = null;
      save(); render();
    });
    actions.appendChild(editBtn);
    actions.appendChild(delBtn);

    li.appendChild(cb); li.appendChild(body); li.appendChild(actions);
    return li;
  }

  function editItem(t) {
    var li = el("li", "task-item");
    li.setAttribute("data-testid", "task-item");
    var f = el("form", "edit-form");

    var titleField = el("div", "field");
    var tl = el("label", null, "Title"); tl.setAttribute("for", "edit-title-" + t.id);
    var ti = document.createElement("input");
    ti.id = "edit-title-" + t.id;
    ti.type = "text"; ti.value = t.title; ti.required = true; ti.maxLength = 200;
    ti.setAttribute("data-testid", "edit-title");
    titleField.appendChild(tl); titleField.appendChild(ti);

    var notesField = el("div", "field");
    var nl = el("label", null, "Notes"); nl.setAttribute("for", "edit-notes-" + t.id);
    var ni = document.createElement("textarea");
    ni.id = "edit-notes-" + t.id; ni.rows = 2; ni.value = t.notes; ni.maxLength = 1000;
    notesField.appendChild(nl); notesField.appendChild(ni);

    var row = el("div", "edit-row");
    var pf = el("div", "field");
    var pl = el("label", null, "Priority"); pl.setAttribute("for", "edit-prio-" + t.id);
    var ps = document.createElement("select");
    ps.id = "edit-prio-" + t.id;
    ["low", "medium", "high"].forEach(function (v) {
      var o = document.createElement("option");
      o.value = v; o.textContent = v[0].toUpperCase() + v.slice(1);
      if (t.priority === v) o.selected = true;
      ps.appendChild(o);
    });
    pf.appendChild(pl); pf.appendChild(ps);
    var df = el("div", "field");
    var dl = el("label", null, "Due date"); dl.setAttribute("for", "edit-due-" + t.id);
    var di = document.createElement("input");
    di.id = "edit-due-" + t.id; di.type = "date"; di.value = t.due;
    df.appendChild(dl); df.appendChild(di);
    row.appendChild(pf); row.appendChild(df);

    var acts = el("div", "edit-actions");
    var saveBtn = el("button", "btn primary", "Save");
    saveBtn.type = "submit";
    saveBtn.style.width = "auto";
    saveBtn.setAttribute("data-testid", "save-edit");
    var cancelBtn = el("button", "btn ghost", "Cancel");
    cancelBtn.type = "button";
    cancelBtn.addEventListener("click", function () { editingId = null; render(); });
    acts.appendChild(saveBtn); acts.appendChild(cancelBtn);

    f.appendChild(titleField); f.appendChild(notesField); f.appendChild(row); f.appendChild(acts);
    f.addEventListener("submit", function (e) {
      e.preventDefault();
      var v = ti.value.trim();
      if (!v) { ti.focus(); return; }
      t.title = v; t.notes = ni.value.trim(); t.priority = ps.value; t.due = di.value;
      editingId = null;
      save(); render();
    });
    li.appendChild(f);
    return li;
  }

  render();
})();