// --- Tiny API client ---
const api = {
  async req(method, path, body) {
    const res = await fetch(path, {
      method,
      headers: body ? { "Content-Type": "application/json" } : undefined,
      body: body ? JSON.stringify(body) : undefined,
    });
    const data = res.status === 204 ? null : await res.json().catch(() => null);
    if (!res.ok) throw new Error((data && data.error) || "Request failed");
    return data;
  },
  ideas: () => api.req("GET", "/api/ideas"),
  createIdea: (title, description) =>
    api.req("POST", "/api/ideas", { title, description }),
  deleteIdea: (id) => api.req("DELETE", `/api/ideas/${id}`),
  notes: (id) => api.req("GET", `/api/ideas/${id}/notes`),
  addNote: (id, body) => api.req("POST", `/api/ideas/${id}/notes`, { body }),
  deleteNote: (id) => api.req("DELETE", `/api/notes/${id}`),
};

// --- State ---
let ideas = [];
let selectedId = null;

// --- Helpers ---
const $ = (sel) => document.querySelector(sel);

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

// SQLite stores UTC datetimes as "YYYY-MM-DD HH:MM:SS"; parse as UTC.
function parseUTC(s) {
  return new Date(s.replace(" ", "T") + "Z");
}

function relativeTime(s) {
  const then = parseUTC(s);
  const diff = (Date.now() - then.getTime()) / 1000;
  if (diff < 45) return "just now";
  if (diff < 90) return "a minute ago";
  if (diff < 3600) return `${Math.round(diff / 60)} min ago`;
  if (diff < 7200) return "an hour ago";
  if (diff < 86400) return `${Math.round(diff / 3600)} hours ago`;
  if (diff < 172800) return "yesterday";
  if (diff < 604800) return `${Math.round(diff / 86400)} days ago`;
  return then.toLocaleDateString(undefined, {
    month: "short",
    day: "numeric",
    year: "numeric",
  });
}

function fullTime(s) {
  return parseUTC(s).toLocaleString(undefined, {
    dateStyle: "medium",
    timeStyle: "short",
  });
}

let toastTimer;
function toast(msg, isError = false) {
  const el = $("#toast");
  el.textContent = msg;
  el.classList.toggle("error", isError);
  el.classList.add("show");
  clearTimeout(toastTimer);
  toastTimer = setTimeout(() => el.classList.remove("show"), 2600);
}

// --- Rendering ---
function renderList() {
  const list = $("#ideas-list");
  $("#idea-count").textContent = ideas.length;

  if (ideas.length === 0) {
    list.innerHTML =
      '<div class="empty" style="padding:30px 10px">No ideas yet. Add your first one!</div>';
    return;
  }

  list.innerHTML = ideas
    .map(
      (idea) => `
      <div class="idea-item ${idea.id === selectedId ? "active" : ""}" data-id="${idea.id}">
        <h3>${escapeHtml(idea.title)}</h3>
        <div class="meta">
          <span class="pill">${idea.note_count} note${idea.note_count === 1 ? "" : "s"}</span>
          <span>updated ${relativeTime(idea.updated_at)}</span>
        </div>
      </div>`
    )
    .join("");

  list.querySelectorAll(".idea-item").forEach((el) => {
    el.addEventListener("click", () => selectIdea(Number(el.dataset.id)));
  });
}

async function renderDetail() {
  const panel = $("#detail-panel");
  const idea = ideas.find((i) => i.id === selectedId);

  if (!idea) {
    panel.innerHTML =
      '<div class="empty"><span class="big">👈</span>Select an idea to see its notes, or create one to get started.</div>';
    return;
  }

  panel.innerHTML = `
    <div class="detail-head">
      <h2>${escapeHtml(idea.title)}</h2>
      <button class="btn btn-danger btn-sm" id="del-idea">Delete idea</button>
    </div>
    ${idea.description ? `<p class="detail-desc">${escapeHtml(idea.description)}</p>` : ""}
    <div class="detail-meta">Created ${fullTime(idea.created_at)}</div>
    <div class="divider"></div>
    <h2 style="font-size:1.05rem;margin-bottom:4px">Notes</h2>
    <div id="notes-container"><div class="empty" style="padding:20px">Loading…</div></div>
    <form class="note-composer" id="note-form">
      <textarea id="note-body" rows="2" placeholder="Add a note… (Cmd/Ctrl+Enter to post)" required></textarea>
      <div class="row"><button type="submit" class="btn btn-primary btn-sm">💬 Post note</button></div>
    </form>
  `;

  $("#del-idea").addEventListener("click", () => onDeleteIdea(idea.id));

  const form = $("#note-form");
  form.addEventListener("submit", (e) => {
    e.preventDefault();
    onAddNote(idea.id);
  });
  $("#note-body").addEventListener("keydown", (e) => {
    if ((e.metaKey || e.ctrlKey) && e.key === "Enter") {
      e.preventDefault();
      onAddNote(idea.id);
    }
  });

  loadNotes(idea.id);
}

function renderNotes(notes) {
  const container = $("#notes-container");
  if (!container) return;
  if (notes.length === 0) {
    container.innerHTML =
      '<div class="empty" style="padding:24px">No notes yet — add the first one below.</div>';
    return;
  }
  container.innerHTML = notes
    .map(
      (n) => `
      <div class="note">
        <div class="avatar">📝</div>
        <div class="note-body">
          <div class="text">${escapeHtml(n.body)}</div>
          <div class="note-time">
            <span title="${escapeHtml(fullTime(n.created_at))}">${relativeTime(n.created_at)}</span>
            <span class="del" data-note="${n.id}">delete</span>
          </div>
        </div>
      </div>`
    )
    .join("");

  container.querySelectorAll(".del").forEach((el) => {
    el.addEventListener("click", () => onDeleteNote(Number(el.dataset.note)));
  });
}

// --- Actions ---
async function refresh() {
  try {
    ideas = await api.ideas();
    renderList();
    renderDetail();
  } catch (e) {
    toast(e.message, true);
  }
}

function selectIdea(id) {
  selectedId = id;
  renderList();
  renderDetail();
}

async function loadNotes(id) {
  try {
    const notes = await api.notes(id);
    if (selectedId === id) renderNotes(notes);
  } catch (e) {
    toast(e.message, true);
  }
}

async function onCreateIdea(e) {
  e.preventDefault();
  const title = $("#idea-title").value.trim();
  const description = $("#idea-desc").value.trim();
  if (!title) return;
  try {
    const idea = await api.createIdea(title, description);
    $("#idea-form").reset();
    await refresh();
    selectIdea(idea.id);
    toast("Idea added ✨");
  } catch (err) {
    toast(err.message, true);
  }
}

async function onDeleteIdea(id) {
  if (!confirm("Delete this idea and all its notes?")) return;
  try {
    await api.deleteIdea(id);
    if (selectedId === id) selectedId = null;
    await refresh();
    toast("Idea deleted");
  } catch (err) {
    toast(err.message, true);
  }
}

async function onAddNote(id) {
  const input = $("#note-body");
  const body = input.value.trim();
  if (!body) return;
  try {
    await api.addNote(id, body);
    input.value = "";
    // Refresh notes immediately, plus list for the updated count/order.
    await Promise.all([loadNotes(id), refreshListOnly()]);
  } catch (err) {
    toast(err.message, true);
  }
}

async function refreshListOnly() {
  ideas = await api.ideas();
  renderList();
}

async function onDeleteNote(noteId) {
  try {
    await api.deleteNote(noteId);
    if (selectedId) await Promise.all([loadNotes(selectedId), refreshListOnly()]);
    toast("Note deleted");
  } catch (err) {
    toast(err.message, true);
  }
}

// --- Init ---
$("#idea-form").addEventListener("submit", onCreateIdea);
refresh();