const STORAGE_KEY = "routes.links.v1";
const AUTH_SESSION_KEY = "routes.authenticated.v1";
const AUTH_SECRET = window.ROUTES_SECRET;

const authScreen = document.querySelector("#auth-screen");
const authForm = document.querySelector("#auth-form");
const authSecretInput = document.querySelector("#auth-secret");
const authMessage = document.querySelector("#auth-message");
const appShell = document.querySelector("#app-shell");
const logoutButton = document.querySelector("#logout-button");
const showFormButton = document.querySelector("#show-form-button");
const formPanel = document.querySelector("#route-editor");
const formTitle = document.querySelector("#form-title");
const form = document.querySelector("#route-form");
const idInput = document.querySelector("#route-id");
const nameInput = document.querySelector("#route-name");
const linkInput = document.querySelector("#route-link");
const dateInput = document.querySelector("#route-date");
const pictureInput = document.querySelector("#route-picture");
const descriptionInput = document.querySelector("#route-description");
const saveButton = document.querySelector("#save-button");
const cancelEditButton = document.querySelector("#cancel-edit");
const clearAllButton = document.querySelector("#clear-all");
const routeCount = document.querySelector("#route-count");
const emptyState = document.querySelector("#empty-state");
const routesList = document.querySelector("#routes-list");
const template = document.querySelector("#route-card-template");

let routes = sortRoutes(loadRoutes());

authForm.addEventListener("submit", authenticate);
logoutButton.addEventListener("click", lockApp);
showFormButton.addEventListener("click", startAddRoute);
form.addEventListener("submit", saveRoute);
cancelEditButton.addEventListener("click", resetForm);
clearAllButton?.addEventListener("click", removeAllRoutes);
routesList.addEventListener("click", handleRouteAction);
document.addEventListener("click", closeMenusOnOutsideClick);
document.addEventListener("keydown", closeMenusOnEscape);

if (sessionStorage.getItem(AUTH_SESSION_KEY) === "yes") {
  unlockApp();
} else {
  lockApp();
}

function authenticate(event) {
  event.preventDefault();
  authMessage.textContent = "";

  if (!AUTH_SECRET) {
    authMessage.textContent = "Missing config.js secret.";
    return;
  }

  if (authSecretInput.value.trim() !== AUTH_SECRET) {
    authMessage.textContent = "Wrong secret.";
    authSecretInput.select();
    return;
  }

  sessionStorage.setItem(AUTH_SESSION_KEY, "yes");
  unlockApp();
}

function unlockApp() {
  authScreen.hidden = true;
  appShell.hidden = false;
  authSecretInput.value = "";
  authMessage.textContent = "";
  renderRoutes();
}

function lockApp() {
  sessionStorage.removeItem(AUTH_SESSION_KEY);
  appShell.hidden = true;
  authScreen.hidden = false;
  resetForm();
  authSecretInput.focus();
}

function loadRoutes() {
  try {
    return JSON.parse(localStorage.getItem(STORAGE_KEY)) ?? [];
  } catch {
    return [];
  }
}

function storeRoutes() {
  localStorage.setItem(STORAGE_KEY, JSON.stringify(routes));
}

function sortRoutes(routeList) {
  return [...routeList].sort((a, b) => {
    const dateA = a.date || "0000-00-00";
    const dateB = b.date || "0000-00-00";

    if (dateA !== dateB) {
      return dateA.localeCompare(dateB);
    }

    return a.name.localeCompare(b.name, undefined, { sensitivity: "base" });
  });
}

async function saveRoute(event) {
  event.preventDefault();

  const id = idInput.value || createId();
  const existingIndex = routes.findIndex((item) => item.id === id);
  const existingRoute = routes[existingIndex];

  const route = {
    id,
    name: nameInput.value.trim(),
    link: linkInput.value.trim(),
    date: dateInput.value,
    picture: existingRoute?.picture || "",
    description: descriptionInput.value.trim(),
    updatedAt: new Date().toISOString(),
  };

  if (!route.name || !route.link) {
    return;
  }

  if (!isValidUrl(route.link)) {
    alert("Please enter a valid Google Maps link.");
    return;
  }

  if (pictureInput.files[0]) {
    try {
      route.picture = await imageFileToDataUrl(pictureInput.files[0]);
    } catch {
      alert("Could not read that picture. Please choose another image.");
      return;
    }
  }

  if (existingIndex >= 0) {
    routes[existingIndex] = route;
  } else {
    routes.unshift(route);
  }

  routes = sortRoutes(routes);
  storeRoutes();
  renderRoutes();
  resetForm();
}

function renderRoutes() {
  routesList.innerHTML = "";

  routeCount.textContent = routes.length === 1 ? "1 route saved." : `${routes.length} routes saved.`;
  emptyState.classList.toggle("hidden", routes.length > 0);
  if (clearAllButton) {
    clearAllButton.hidden = routes.length === 0;
  }

  for (const route of routes) {
    const card = template.content.firstElementChild.cloneNode(true);
    const image = card.querySelector(".route-image");
    const meta = card.querySelector(".route-meta");
    const title = card.querySelector(".route-title");
    const description = card.querySelector(".route-description");

    card.dataset.id = route.id;
    meta.textContent = route.date ? formatDate(route.date) : "";
    meta.hidden = !route.date;
    title.textContent = route.name;
    title.href = route.link;
    description.textContent = route.description;
    description.hidden = !route.description;

    if (route.picture) {
      image.hidden = false;
      image.style.backgroundImage = `url("${cssUrlEscape(route.picture)}")`;
    }

    routesList.append(card);
  }
}

function closeMenusOnOutsideClick(event) {
  if (event.target.closest(".route-menu")) {
    return;
  }

  closeRouteMenus();
}

function closeMenusOnEscape(event) {
  if (event.key === "Escape") {
    closeRouteMenus();
  }
}

function closeRouteMenus() {
  document.querySelectorAll(".route-menu[open]").forEach((menu) => menu.removeAttribute("open"));
}

function handleRouteAction(event) {
  const button = event.target.closest("button");
  if (!button) {
    return;
  }

  const card = button.closest(".route-card");
  const route = routes.find((item) => item.id === card?.dataset.id);
  if (!route) {
    return;
  }

  button.closest("details")?.removeAttribute("open");

  if (button.classList.contains("edit-route")) {
    editRoute(route);
  }

  if (button.classList.contains("remove-route")) {
    removeRoute(route.id);
  }

  if (button.classList.contains("share-route")) {
    shareRoute(route);
  }
}

function startAddRoute() {
  resetForm();
  formPanel.hidden = false;
  formTitle.textContent = "Add route";
  saveButton.textContent = "Add route";
  cancelEditButton.hidden = false;
  form.scrollIntoView({ behavior: "smooth", block: "start" });
  nameInput.focus();
}

function editRoute(route) {
  formPanel.hidden = false;
  formTitle.textContent = "Edit route";
  idInput.value = route.id;
  nameInput.value = route.name;
  linkInput.value = route.link;
  dateInput.value = route.date;
  pictureInput.value = "";
  descriptionInput.value = route.description;
  saveButton.textContent = "Save changes";
  cancelEditButton.hidden = false;
  form.scrollIntoView({ behavior: "smooth", block: "start" });
  nameInput.focus();
}

function removeRoute(id) {
  const route = routes.find((item) => item.id === id);
  if (!route || !confirm(`Remove "${route.name}"?`)) {
    return;
  }

  routes = routes.filter((item) => item.id !== id);
  storeRoutes();
  renderRoutes();
  if (idInput.value === id) {
    resetForm();
  }
}

function removeAllRoutes() {
  if (!routes.length || !confirm("Remove all saved routes?")) {
    return;
  }

  routes = [];
  storeRoutes();
  renderRoutes();
  resetForm();
}

async function shareRoute(route) {
  const shareData = {
    title: route.name,
    text: route.description || route.name,
    url: route.link,
  };

  if (navigator.share) {
    try {
      await navigator.share(shareData);
      return;
    } catch (error) {
      if (error.name === "AbortError") {
        return;
      }
    }
  }

  await navigator.clipboard.writeText(route.link);
  alert("Route link copied to clipboard.");
}

function resetForm() {
  form.reset();
  idInput.value = "";
  formTitle.textContent = "Add route";
  saveButton.textContent = "Add route";
  cancelEditButton.hidden = true;
  formPanel.hidden = true;
}

function createId() {
  return crypto.randomUUID?.() || `${Date.now()}-${Math.random().toString(16).slice(2)}`;
}

function imageFileToDataUrl(file) {
  if (!file.type.startsWith("image/")) {
    return Promise.reject(new Error("Not an image"));
  }

  return new Promise((resolve, reject) => {
    const image = new Image();
    const objectUrl = URL.createObjectURL(file);

    image.onload = () => {
      URL.revokeObjectURL(objectUrl);

      const maxSize = 1200;
      const scale = Math.min(1, maxSize / Math.max(image.width, image.height));
      const width = Math.round(image.width * scale);
      const height = Math.round(image.height * scale);
      const canvas = document.createElement("canvas");
      canvas.width = width;
      canvas.height = height;

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

      resolve(canvas.toDataURL("image/jpeg", 0.82));
    };

    image.onerror = () => {
      URL.revokeObjectURL(objectUrl);
      reject(new Error("Image load failed"));
    };

    image.src = objectUrl;
  });
}

function isValidUrl(value) {
  try {
    const url = new URL(value);
    return url.protocol === "http:" || url.protocol === "https:";
  } catch {
    return false;
  }
}

function formatDate(value) {
  return new Intl.DateTimeFormat(undefined, { dateStyle: "medium" }).format(new Date(`${value}T00:00:00`));
}

function cssUrlEscape(value) {
  return value.replaceAll("\\", "\\\\").replaceAll('"', '\\"');
}