/* =======================================================================
   File: static/js/dashboard.js
   Purpose:
       Dashboard interactions:
         - Select active book_idx
         - Live logs & progress
         - Bookcard AJAX start/abort
       NOTE:
         updateLogs() is provided by log_view.js
   ======================================================================= */

/* ---------------------------------------------------------
   Utility: Safe fetch wrapper
   --------------------------------------------------------- */
async function apiGet(url) {
  try {
    const r = await fetch(url);
    if (!r.ok) return null;
    return await r.json();
  } catch (e) {
    console.error("API GET failed:", url, e);
    return null;
  }
}

/* ---------------------------------------------------------
   Dashboard state
   --------------------------------------------------------- */
let ACTIVE_BOOK_IDX = null;
let REFRESH_INTERVAL = null;

console.log(">>> dashboard.js LOADED");

/* ---------------------------------------------------------
   DOM READY
   --------------------------------------------------------- */
document.addEventListener("DOMContentLoaded", () => {
  console.log(">>> dashboard.js DOMContentLoaded");

  // Fallback: global logs when no active book_idx
  setInterval(() => {
    if (!ACTIVE_BOOK_IDX) refreshBook(null);
  }, 2000);

  // Sidebar items
  const items = $$(".book-list-item");
  items.forEach((item) => {
    item.addEventListener("click", () => {
      selectBook(item.dataset.bookIdx);
    });
  });

  // Auto-select first book
  if (!ACTIVE_BOOK_IDX && items[0]) {
    selectBook(items[0].dataset.bookIdx);
  }

  // Bind start/abort buttons inside cards
  bindBookCardButtons();

  // Refresh sidebar every few seconds
  setInterval(refreshActiveBooks, 2800);
});

/* ---------------------------------------------------------
   Select a book_idx
   --------------------------------------------------------- */
function selectBook(bookIdx) {
  ACTIVE_BOOK_IDX = bookIdx;
  console.log(">>> Selecting book_idx", bookIdx);

  // Highlight sidebar
  $$(".book-list-item").forEach((el) => {
    el.classList.toggle("active", el.dataset.bookIdx === bookIdx);
  });

  // Reset polling
  if (REFRESH_INTERVAL) clearInterval(REFRESH_INTERVAL);

  REFRESH_INTERVAL = setInterval(() => {
    refreshBook(ACTIVE_BOOK_IDX);
  }, 2000);

  refreshBook(ACTIVE_BOOK_IDX);
}

/* ---------------------------------------------------------
   Refresh sidebar list
   --------------------------------------------------------- */
async function refreshActiveBooks() {
  const books = await apiGet("/api/books");
  if (!books) return;

  const container = $("#book-list");
  if (!container) return;

  container.innerHTML = "";

  books.forEach((b) => {
    const div = document.createElement("div");
    div.className = "book-list-item";
    div.dataset.bookIdx = b.book_idx;

    div.innerHTML = `
      <div class="book-title">${b.title}</div>
      <div class="book-status">${b.status}</div>
      <div class="book-progress">
        ${b.download_done}/${b.download_total} downloaded,
        ${b.audio_done}/${b.audio_total} audio
      </div>
    `;

    div.addEventListener("click", () => selectBook(b.book_idx));
    container.appendChild(div);
  });

  if (!ACTIVE_BOOK_IDX && books.length > 0) {
    selectBook(books[0].book_idx);
  }
}

/* ---------------------------------------------------------
   Fetch logs + progress
   --------------------------------------------------------- */
async function refreshBook(bookIdx) {
  if (!bookIdx) {
    const data = await apiGet("/logs");
    if (data) updateLogs(data);
    return;
  }

  const state = await apiGet(`/api/book/${bookIdx}/status`);
  const logs = await apiGet(`/api/book/${bookIdx}/logs`);

  if (state) {
    updateProgressBars(state);
    refreshBookCards();
  }
  if (logs) updateLogs(logs);
}

/* ---------------------------------------------------------
   BOOKCARD BUTTON BINDING (idempotent)
   --------------------------------------------------------- */
function bindBookCardButtons() {
  console.log(">>> bindBookCardButtons() scanning…");

  // START BUTTONS
  document.querySelectorAll(".book-card .icon-start").forEach((btn) => {
    if (btn.dataset.bound === "1") return;
    btn.dataset.bound = "1";

    btn.addEventListener("click", (ev) => {
      ev.preventDefault();
      if (btn.disabled) return;

      const card = btn.closest(".book-card");
      const bookIdx = card?.dataset.bookIdx;

      console.log(">>> START clicked:", bookIdx);
      if (!bookIdx) {
        console.error(">>> ERROR: bookIdx missing on .book-card dataset");
        return;
      }

      startBook(bookIdx);
    });
  });

  // ABORT BUTTONS
  document.querySelectorAll(".book-card .icon-abort").forEach((btn) => {
    if (btn.dataset.bound === "1") return;
    btn.dataset.bound = "1";

    btn.addEventListener("click", (ev) => {
      ev.preventDefault();
      if (btn.disabled) return;

      const card = btn.closest(".book-card");
      const bookIdx = card?.dataset.bookIdx;

      console.log(">>> ABORT clicked:", bookIdx);
      if (!bookIdx) {
        console.error(">>> ERROR: bookIdx missing on .book-card dataset");
        return;
      }

      abortBookAjax(bookIdx);
    });
  });
}

/* ---------------------------------------------------------
   AJAX START
   --------------------------------------------------------- */
function startBook(bookIdx) {
  console.log(">>> startBook():", bookIdx);

  fetch("/start", {
    method: "POST",
    headers: { "Content-Type": "application/x-www-form-urlencoded" },
    body: `book_idx=${bookIdx}`, // backend expects field name book_idx
  })
    .then(async (r) => {
      console.log(">>> /start status:", r.status);

      let data = null;
      try {
        data = await r.json();
      } catch (e) {}

      console.log(">>> /start response:", data);
      refreshBookCards();
      refreshBook(bookIdx);
    })
    .catch((err) => console.error("Start failed:", err));
}

/* ---------------------------------------------------------
   AJAX ABORT
   --------------------------------------------------------- */
function abortBookAjax(bookIdx) {
  if (!confirm(`Abort tasks for book ${bookIdx}?`)) return;

  console.log(">>> abortBookAjax():", bookIdx);

  fetch(`/abort/${bookIdx}`, { method: "POST" })
    .then(async (r) => {
      let data = null;
      try {
        data = await r.json();
      } catch (e) {}
      console.log(">>> /abort response:", data);

      refreshBookCards();
      refreshBook(bookIdx);
    })
    .catch((err) => console.error("Abort failed:", err));
}

/* ---------------------------------------------------------
   Refresh all book-cards (status, classes, buttons)
   --------------------------------------------------------- */
async function refreshBookCards() {
  const books = await apiGet("/api/books");
  if (!books) return;

  document.querySelectorAll(".book-card").forEach((card) => {
    const idx = card.dataset.bookIdx;
    const info = books.find((b) => b.book_idx === idx);
    if (!info) return;

    // Status CSS
    card.className = `book-card ${info.status}`;

    // Button states
    const startBtn = card.querySelector(".icon-start");
    const abortBtn = card.querySelector(".icon-abort");

    if (startBtn) startBtn.disabled = info.status !== "registered";
    if (abortBtn)
      abortBtn.disabled = ![
        "processing",
        "downloading",
        "parsing",
        "audio",
      ].includes(info.status);
  });

  bindBookCardButtons();
}