import { computeLayout } from "./layout.js";
import { RepoRenderer } from "./renderer.js";

const landing = document.getElementById("landing");
const loading = document.getElementById("loading");
const loadingText = document.getElementById("loading-text");
const viewport = document.getElementById("viewport");
const controlsHint = document.getElementById("controls-hint");
const gitUrlInput = document.getElementById("git-url");
const btnClone = document.getElementById("btn-clone");
const dropZone = document.getElementById("drop-zone");
const fileInput = document.getElementById("file-input");
const historyEl = document.getElementById("history");
const historyList = document.getElementById("history-list");

function showLoading(msg) {
  landing.style.display = "none";
  loading.classList.add("active");
  loadingText.textContent = msg;
}

function showVisualization() {
  loading.classList.remove("active");
  viewport.classList.add("active");
  controlsHint.classList.add("active");
}

function showError(msg) {
  loading.classList.remove("active");
  landing.style.display = "";
  alert(msg);
}

async function visualize(tree, repoName, cacheKey) {
  showLoading("Building layout...");

  // Wait for fonts to load so canvas renders them correctly
  await document.fonts.ready;
  await new Promise((r) => setTimeout(r, 50));

  const { leaves, totalWidth, totalHeight } = computeLayout(tree);

  if (leaves.length === 0) {
    showError("No source files found in repository.");
    return;
  }

  showLoading(`Rendering ${leaves.length} files...`);
  await new Promise((r) => setTimeout(r, 50));

  showVisualization();
  document.getElementById("osd-info").classList.add("active");
  const renderer = new RepoRenderer(viewport, repoName || tree.name, cacheKey);
  await renderer.load(leaves, totalWidth, totalHeight);
}

// --- History ---
async function loadHistory() {
  try {
    const res = await fetch("/api/repos");
    if (!res.ok) return;
    const repos = await res.json();
    if (repos.length === 0) return;

    historyEl.classList.add("has-items");
    historyList.innerHTML = "";

    for (const repo of repos) {
      const item = document.createElement("div");
      item.className = "history-item";
      item.innerHTML = `
        <span class="name">${escapeHtml(repo.name)}</span>
        <span class="meta">${repo.file_count} files</span>
      `;
      item.addEventListener("click", () => loadCachedRepo(repo.cache_key, repo.name));
      historyList.appendChild(item);
    }
  } catch {
    // ignore
  }
}

async function loadCachedRepo(key, name) {
  showLoading(`Loading ${name}...`);
  try {
    const res = await fetch(`/api/repos/${key}`);
    if (!res.ok) throw new Error("Cache expired");
    const { cache_key, tree } = await res.json();
    await visualize(tree, name, cache_key);
  } catch (err) {
    showError(err.message);
  }
}

function escapeHtml(s) {
  const div = document.createElement("div");
  div.textContent = s;
  return div.innerHTML;
}

// Load history on page load
loadHistory();

// --- Git clone ---
btnClone.addEventListener("click", async () => {
  const url = gitUrlInput.value.trim();
  if (!url) return;

  btnClone.disabled = true;
  showLoading("Cloning repository...");

  try {
    const res = await fetch("/api/scan-git", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ url }),
    });

    if (!res.ok) {
      const err = await res.json();
      throw new Error(err.error || "Clone failed");
    }

    const { cache_key, tree } = await res.json();
    await visualize(tree, undefined, cache_key);
  } catch (err) {
    showError(err.message);
  } finally {
    btnClone.disabled = false;
  }
});

gitUrlInput.addEventListener("keydown", (e) => {
  if (e.key === "Enter") btnClone.click();
});

// --- Zip upload ---
dropZone.addEventListener("click", () => fileInput.click());

dropZone.addEventListener("dragover", (e) => {
  e.preventDefault();
  dropZone.classList.add("dragover");
});

dropZone.addEventListener("dragleave", () => {
  dropZone.classList.remove("dragover");
});

dropZone.addEventListener("drop", (e) => {
  e.preventDefault();
  dropZone.classList.remove("dragover");
  const file = e.dataTransfer.files[0];
  if (file) uploadZip(file);
});

fileInput.addEventListener("change", () => {
  if (fileInput.files[0]) uploadZip(fileInput.files[0]);
});

async function uploadZip(file) {
  showLoading("Uploading and scanning zip...");

  try {
    const form = new FormData();
    form.append("file", file);

    const res = await fetch("/api/scan-zip", {
      method: "POST",
      body: form,
    });

    if (!res.ok) {
      const err = await res.json();
      throw new Error(err.error || "Upload failed");
    }

    const { cache_key, tree } = await res.json();
    await visualize(tree, undefined, cache_key);
  } catch (err) {
    showError(err.message);
  }
}