const state = {
  authenticated: false,
  folders: [],
  photos: [],
  selectedFolderId: 1,
};

const pages = document.querySelectorAll("[data-page]");
const routeLinks = document.querySelectorAll("[data-route]");
const loginOpenButton = document.querySelector("#loginOpenButton");
const logoutButton = document.querySelector("#logoutButton");
const loginDialog = document.querySelector("#loginDialog");
const loginForm = document.querySelector("#loginForm");
const loginCancelButton = document.querySelector("#loginCancelButton");
const passwordInput = document.querySelector("#passwordInput");
const loginMessage = document.querySelector("#loginMessage");
const ownerPanels = document.querySelectorAll(".owner-panel");

const profileForm = document.querySelector("#profileForm");
const nameInput = document.querySelector("#nameInput");
const bioInput = document.querySelector("#bioInput");
const avatarInput = document.querySelector("#avatarInput");
const profileName = document.querySelector("#profileName");
const profileBio = document.querySelector("#profileBio");
const avatarPreview = document.querySelector("#avatarPreview");

const folderForm = document.querySelector("#folderForm");
const folderNameInput = document.querySelector("#folderNameInput");
const folderTabs = document.querySelector("#folderTabs");
const uploadFolderSelect = document.querySelector("#uploadFolderSelect");

const galleryForm = document.querySelector("#galleryForm");
const galleryInput = document.querySelector("#galleryInput");
const galleryGrid = document.querySelector("#galleryGrid");
const homeGalleryGrid = document.querySelector("#homeGalleryGrid");
const galleryStatus = document.querySelector("#galleryStatus");
const imageDialog = document.querySelector("#imageDialog");
const imagePreview = document.querySelector("#imagePreview");
const imageCloseButton = document.querySelector("#imageCloseButton");

const diaryForm = document.querySelector("#diaryForm");
const titleInput = document.querySelector("#diaryTitle");
const textInput = document.querySelector("#diaryText");
const diaryImageInput = document.querySelector("#diaryImageInput");
const diaryList = document.querySelector("#diaryList");

async function api(path, options = {}) {
  const response = await fetch(path, {
    headers: {
      "Content-Type": "application/json",
      ...(options.headers || {}),
    },
    credentials: "same-origin",
    ...options,
  });

  const data = await response.json().catch(() => ({}));
  if (!response.ok) {
    throw new Error(data.error || "请求失败");
  }
  return data;
}

function showPage(route) {
  const nextRoute = route || "home";
  pages.forEach((page) => {
    page.classList.toggle("active", page.dataset.page === nextRoute);
  });
  routeLinks.forEach((link) => {
    link.classList.toggle("active", link.dataset.route === nextRoute);
  });
}

function syncRoute() {
  const route = (location.hash || "#home").replace("#", "");
  showPage(["home", "gallery", "diary"].includes(route) ? route : "home");
}

function updateAuthUi() {
  ownerPanels.forEach((panel) => panel.classList.toggle("hidden", !state.authenticated));
  loginOpenButton.classList.toggle("hidden", state.authenticated);
  logoutButton.classList.toggle("hidden", !state.authenticated);

  document.querySelectorAll(".delete-button").forEach((button) => {
    button.classList.toggle("hidden", !state.authenticated);
  });
}

function dataUrlBytes(dataUrl) {
  const base64 = dataUrl.split(",")[1] || "";
  return Math.ceil((base64.length * 3) / 4);
}

function drawImageToDataUrl(image, maxSize, quality) {
  const scale = Math.min(1, maxSize / Math.max(image.width, image.height));
  const canvas = document.createElement("canvas");
  canvas.width = Math.max(1, Math.round(image.width * scale));
  canvas.height = Math.max(1, Math.round(image.height * scale));

  const context = canvas.getContext("2d");
  context.fillStyle = "#fff8fc";
  context.fillRect(0, 0, canvas.width, canvas.height);
  context.drawImage(image, 0, 0, canvas.width, canvas.height);

  return canvas.toDataURL("image/jpeg", quality);
}

function readImage(file, options = {}) {
  const maxSize = options.maxSize || 900;
  const quality = options.quality || 0.78;
  const maxBytes = options.maxBytes || 120000;

  return new Promise((resolve, reject) => {
    const reader = new FileReader();
    reader.onload = () => {
      const image = new Image();
      image.onload = () => {
        const sizes = [maxSize, 640, 520, 420, 320, 240, 180].filter((size) => size <= maxSize);
        const qualities = [quality, 0.62, 0.5, 0.42, 0.34, 0.28];
        let bestImage = drawImageToDataUrl(image, sizes[0], qualities[0]);

        for (const size of sizes) {
          for (const nextQuality of qualities) {
            bestImage = drawImageToDataUrl(image, size, nextQuality);
            if (dataUrlBytes(bestImage) <= maxBytes) {
              resolve(bestImage);
              return;
            }
          }
        }

        resolve(bestImage);
      };
      image.onerror = () => reject(new Error("图片读取失败"));
      image.src = reader.result;
    };
    reader.onerror = () => reject(reader.error);
    reader.readAsDataURL(file);
  });
}

async function loadSession() {
  const data = await api("/api/session");
  state.authenticated = data.authenticated;
  updateAuthUi();
}

async function loadProfile() {
  const profile = await api("/api/profile");
  const name = profile.name || "CICI";

  profileName.textContent = `你好，我是 ${name}`;
  profileBio.textContent = profile.bio || "";
  nameInput.value = name;
  bioInput.value = profile.bio || "";

  if (profile.avatar) {
    avatarPreview.innerHTML = "";
    const image = document.createElement("img");
    image.src = profile.avatar;
    image.alt = `${name} 的头像`;
    avatarPreview.append(image);
  } else {
    avatarPreview.innerHTML = "<span>C</span>";
  }
}

function openImagePreview(src, alt = "相册大图") {
  imagePreview.src = src;
  imagePreview.alt = alt;
  imageDialog.showModal();
}

function createPhotoCard(photo) {
  const figure = document.createElement("figure");
  figure.className = "photo-card uploaded-photo";

  const previewButton = document.createElement("button");
  previewButton.className = "photo-preview-button";
  previewButton.type = "button";
  previewButton.setAttribute("aria-label", "查看大图");

  const image = document.createElement("img");
  image.src = photo.src;
  image.alt = photo.name || "CICI 的照片";

  previewButton.append(image);
  previewButton.addEventListener("click", () => openImagePreview(photo.src, photo.name || "相册大图"));

  const deleteButton = document.createElement("button");
  deleteButton.className = "delete-button";
  deleteButton.type = "button";
  deleteButton.textContent = "删除";
  deleteButton.addEventListener("click", async () => {
    await api(`/api/photos/${photo.id}`, { method: "DELETE" });
    await loadGallery();
    updateAuthUi();
  });

  figure.append(previewButton, deleteButton);
  return figure;
}

function renderSampleGallery(target) {
  target.innerHTML = `
    <figure class="photo-card"><div class="photo-illustration night"></div><figcaption>我的酷酷自拍</figcaption></figure>
    <figure class="photo-card"><div class="photo-illustration doodle"></div><figcaption>甜酷手账</figcaption></figure>
    <figure class="photo-card"><div class="photo-illustration stage"></div><figcaption>闪亮表演视频</figcaption></figure>
  `;
}

function renderEmptyFolder(target) {
  target.innerHTML = "";
  const empty = document.createElement("div");
  empty.className = "empty-gallery";
  empty.textContent = "这个文件夹还没有照片。";
  target.append(empty);
}

function renderPhotoGrid(target, photos, options = {}) {
  target.innerHTML = "";
  const visiblePhotos = typeof options.limit === "number" ? photos.slice(0, options.limit) : photos;

  if (visiblePhotos.length === 0) {
    if (options.showSamples) {
      renderSampleGallery(target);
    } else {
      renderEmptyFolder(target);
    }
    return;
  }

  visiblePhotos.forEach((photo) => {
    target.append(createPhotoCard(photo));
  });
}

function renderFolders() {
  folderTabs.innerHTML = "";
  uploadFolderSelect.innerHTML = "";

  state.folders.forEach((folder) => {
    const tab = document.createElement("button");
    tab.className = "folder-tab";
    tab.type = "button";
    tab.classList.toggle("active", folder.id === state.selectedFolderId);
    tab.textContent = `${folder.name} (${folder.photo_count})`;
    tab.addEventListener("click", () => {
      state.selectedFolderId = folder.id;
      renderFolders();
      renderSelectedFolderPhotos();
    });

    if (state.authenticated && folder.id !== 1) {
      const renameButton = document.createElement("span");
      renameButton.className = "folder-action";
      renameButton.textContent = "重命名";
      renameButton.addEventListener("click", async (event) => {
        event.stopPropagation();
        const nextName = window.prompt("请输入新的文件夹名称", folder.name);
        if (!nextName || nextName.trim() === folder.name) {
          return;
        }
        await api(`/api/folders/${folder.id}`, {
          method: "PUT",
          body: JSON.stringify({ name: nextName.trim() }),
        });
        await loadGallery();
      });

      const deleteButton = document.createElement("span");
      deleteButton.className = "folder-action folder-delete";
      deleteButton.textContent = "删除";
      deleteButton.addEventListener("click", async (event) => {
        event.stopPropagation();
        await api(`/api/folders/${folder.id}`, { method: "DELETE" });
        state.selectedFolderId = 1;
        await loadGallery();
      });
      tab.append(renameButton);
      tab.append(deleteButton);
    }

    folderTabs.append(tab);

    const option = document.createElement("option");
    option.value = folder.id;
    option.textContent = folder.name;
    option.selected = folder.id === state.selectedFolderId;
    uploadFolderSelect.append(option);
  });
}

function renderSelectedFolderPhotos() {
  const photos = state.photos.filter((photo) => photo.folder_id === state.selectedFolderId);
  renderPhotoGrid(galleryGrid, photos);
  updateAuthUi();
}

async function loadGallery() {
  const [foldersData, photosData] = await Promise.all([api("/api/folders"), api("/api/photos")]);
  state.folders = foldersData.folders;
  state.photos = photosData.photos;

  if (!state.folders.some((folder) => folder.id === state.selectedFolderId)) {
    state.selectedFolderId = state.folders[0]?.id || 1;
  }

  renderFolders();
  renderSelectedFolderPhotos();
  renderPhotoGrid(homeGalleryGrid, state.photos, { limit: 3, showSamples: true });
  updateAuthUi();
}

async function loadDiary() {
  const data = await api("/api/diary");
  diaryList.innerHTML = "";

  if (data.entries.length === 0) {
    const empty = document.createElement("div");
    empty.className = "empty-diary";
    empty.textContent = "还没有日记。";
    diaryList.append(empty);
    return;
  }

  data.entries.forEach((entry) => {
    const item = document.createElement("article");
    item.className = "diary-entry";

    const time = document.createElement("time");
    time.textContent = entry.created_at;

    const title = document.createElement("h3");
    title.textContent = entry.title;

    const text = document.createElement("p");
    text.textContent = entry.text;

    item.append(time, title);

    if (entry.image) {
      const imageButton = document.createElement("button");
      imageButton.className = "diary-image-button";
      imageButton.type = "button";
      imageButton.setAttribute("aria-label", "查看日记图片");

      const image = document.createElement("img");
      image.src = entry.image;
      image.alt = entry.title || "日记图片";
      imageButton.append(image);
      imageButton.addEventListener("click", () => openImagePreview(entry.image, entry.title || "日记图片"));
      item.append(imageButton);
    }

    if (entry.text) {
      item.append(text);
    }

    const deleteButton = document.createElement("button");
    deleteButton.className = "delete-button";
    deleteButton.type = "button";
    deleteButton.textContent = "删除";
    deleteButton.addEventListener("click", async () => {
      await api(`/api/diary/${entry.id}`, { method: "DELETE" });
      await loadDiary();
      updateAuthUi();
    });

    item.append(deleteButton);
    diaryList.append(item);
  });

  updateAuthUi();
}

profileForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  let avatar = null;
  if (avatarInput.files[0]) {
    avatar = await readImage(avatarInput.files[0], {
      maxSize: 360,
      quality: 0.72,
      maxBytes: 80000,
    });
  }

  await api("/api/profile", {
    method: "PUT",
    body: JSON.stringify({
      name: nameInput.value.trim() || "CICI",
      bio: bioInput.value.trim(),
      avatar,
    }),
  });

  avatarInput.value = "";
  await loadProfile();
});

folderForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  const name = folderNameInput.value.trim();
  if (!name) {
    folderNameInput.focus();
    return;
  }

  const folder = await api("/api/folders", {
    method: "POST",
    body: JSON.stringify({ name }),
  });
  state.selectedFolderId = folder.id;
  folderForm.reset();
  await loadGallery();
});

galleryForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  const files = Array.from(galleryInput.files).slice(0, 12);
  if (files.length === 0) {
    galleryInput.focus();
    return;
  }

  galleryStatus.textContent = "正在自动缩小照片，请稍等一下...";
  const photos = await Promise.all(
    files.map(async (file) => ({
      name: file.name.replace(/\.[^.]+$/, ""),
      src: await readImage(file, {
        maxSize: 520,
        quality: 0.68,
        maxBytes: 90000,
      }),
    })),
  );

  const folderId = Number(uploadFolderSelect.value) || state.selectedFolderId || 1;
  await api("/api/photos", {
    method: "POST",
    body: JSON.stringify({ folder_id: folderId, photos }),
  });

  state.selectedFolderId = folderId;
  galleryInput.value = "";
  galleryStatus.textContent = `已上传 ${photos.length} 张照片。`;
  await loadGallery();
});

diaryForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  const text = textInput.value.trim();
  let image = "";

  if (diaryImageInput.files[0]) {
    image = await readImage(diaryImageInput.files[0], {
      maxSize: 620,
      quality: 0.72,
      maxBytes: 120000,
    });
  }

  if (!text && !image) {
    textInput.focus();
    return;
  }

  await api("/api/diary", {
    method: "POST",
    body: JSON.stringify({
      title: titleInput.value.trim() || "今天的小日记",
      text,
      image,
    }),
  });

  diaryForm.reset();
  await loadDiary();
});

loginOpenButton.addEventListener("click", () => {
  loginMessage.textContent = "";
  passwordInput.value = "";
  loginDialog.showModal();
  passwordInput.focus();
});

loginCancelButton.addEventListener("click", () => {
  loginDialog.close();
});

loginForm.addEventListener("submit", async (event) => {
  event.preventDefault();

  try {
    await api("/api/login", {
      method: "POST",
      body: JSON.stringify({ password: passwordInput.value }),
    });
    loginDialog.close();
    await loadSession();
    await Promise.all([loadProfile(), loadGallery(), loadDiary()]);
  } catch (error) {
    loginMessage.textContent = error.message;
  }
});

logoutButton.addEventListener("click", async () => {
  await api("/api/logout", { method: "POST", body: "{}" });
  await loadSession();
  await loadGallery();
});

imageCloseButton.addEventListener("click", () => {
  imageDialog.close();
});

imageDialog.addEventListener("click", (event) => {
  if (event.target === imageDialog) {
    imageDialog.close();
  }
});

window.addEventListener("hashchange", syncRoute);

async function start() {
  syncRoute();
  await loadSession();
  await Promise.all([loadProfile(), loadGallery(), loadDiary()]);
}

start().catch((error) => {
  console.error(error);
});