/**
 * <folk-splat-viewer> — Gaussian splat gallery + 3D viewer web component.
 *
 * Gallery mode: card grid of splats with upload form.
 * Viewer mode: full-viewport Three.js + GaussianSplats3D renderer.
 *
 * Three.js and GaussianSplats3D are loaded via CDN importmap (not bundled).
 */

interface SplatItem {
  id: string;
  slug: string;
  title: string;
  description?: string;
  file_format: string;
  file_size_bytes: number;
  view_count: number;
  contributor_name?: string;
  created_at: string;
}

export class FolkSplatViewer extends HTMLElement {
  private _mode: "gallery" | "viewer" = "gallery";
  private _splats: SplatItem[] = [];
  private _spaceSlug = "demo";
  private _splatUrl = "";
  private _splatTitle = "";
  private _splatDesc = "";
  private _viewer: any = null;

  static get observedAttributes() {
    return ["mode", "splat-url", "splat-title", "splat-desc", "space-slug"];
  }

  set splats(val: SplatItem[]) {
    this._splats = val;
    if (this._mode === "gallery") this.renderGallery();
  }

  set spaceSlug(val: string) {
    this._spaceSlug = val;
  }

  connectedCallback() {
    this._mode = (this.getAttribute("mode") as "gallery" | "viewer") || "gallery";
    this._splatUrl = this.getAttribute("splat-url") || "";
    this._splatTitle = this.getAttribute("splat-title") || "";
    this._splatDesc = this.getAttribute("splat-desc") || "";
    this._spaceSlug = this.getAttribute("space-slug") || "demo";

    if (this._mode === "viewer") {
      this.renderViewer();
    } else {
      this.renderGallery();
    }
  }

  disconnectedCallback() {
    if (this._viewer) {
      try { this._viewer.dispose(); } catch {}
      this._viewer = null;
    }
  }

  attributeChangedCallback(name: string, _old: string, val: string) {
    if (name === "mode") this._mode = val as "gallery" | "viewer";
    if (name === "splat-url") this._splatUrl = val;
    if (name === "splat-title") this._splatTitle = val;
    if (name === "splat-desc") this._splatDesc = val;
    if (name === "space-slug") this._spaceSlug = val;
  }

  // ── Gallery ──

  private renderGallery() {
    const cards = this._splats.map((s) => `
      <a class="splat-card" href="/${this._spaceSlug}/splat/view/${s.slug}">
        <div class="splat-card__preview">
          <span>🔮</span>
        </div>
        <div class="splat-card__body">
          <div class="splat-card__title">${esc(s.title)}</div>
          <div class="splat-card__meta">
            <span class="splat-badge splat-badge--${s.file_format}">${s.file_format}</span>
            <span>${formatSize(s.file_size_bytes)}</span>
            <span>${s.view_count} views</span>
          </div>
        </div>
      </a>
    `).join("");

    const empty = this._splats.length === 0 ? `
      <div class="splat-empty">
        <div class="splat-empty__icon">🔮</div>
        <h3>No splats yet</h3>
        <p>Upload a .ply, .splat, or .spz file to get started</p>
      </div>
    ` : "";

    this.innerHTML = `
      <div class="splat-gallery">
        <h1>rSplat</h1>
        <p class="splat-gallery__subtitle">3D Gaussian Splat Gallery</p>
        ${empty}
        <div class="splat-grid">${cards}</div>
        <div class="splat-upload" id="splat-drop">
          <div class="splat-upload__icon">📤</div>
          <p class="splat-upload__text">
            Drag &amp; drop a <strong>.ply</strong>, <strong>.splat</strong>, or <strong>.spz</strong> file here
            <br>or <strong id="splat-browse">browse</strong> to upload
          </p>
          <input type="file" id="splat-file" accept=".ply,.splat,.spz" hidden>
          <div class="splat-upload__form" id="splat-form">
            <input type="text" id="splat-title-input" placeholder="Title (required)" required>
            <textarea id="splat-desc-input" placeholder="Description (optional)" rows="2"></textarea>
            <input type="text" id="splat-tags-input" placeholder="Tags (comma-separated)">
            <button class="splat-upload__btn" id="splat-submit" disabled>Upload Splat</button>
            <div class="splat-upload__status" id="splat-status"></div>
          </div>
        </div>
      </div>
    `;

    this.setupUploadHandlers();
  }

  private setupUploadHandlers() {
    const drop = this.querySelector("#splat-drop") as HTMLElement;
    const fileInput = this.querySelector("#splat-file") as HTMLInputElement;
    const browse = this.querySelector("#splat-browse") as HTMLElement;
    const form = this.querySelector("#splat-form") as HTMLElement;
    const titleInput = this.querySelector("#splat-title-input") as HTMLInputElement;
    const descInput = this.querySelector("#splat-desc-input") as HTMLTextAreaElement;
    const tagsInput = this.querySelector("#splat-tags-input") as HTMLInputElement;
    const submitBtn = this.querySelector("#splat-submit") as HTMLButtonElement;
    const status = this.querySelector("#splat-status") as HTMLElement;

    if (!drop || !fileInput) return;

    let selectedFile: File | null = null;

    browse?.addEventListener("click", () => fileInput.click());

    fileInput.addEventListener("change", () => {
      if (fileInput.files?.[0]) {
        selectedFile = fileInput.files[0];
        form.classList.add("active");
        // Auto-populate title from filename
        const name = selectedFile.name.replace(/\.(ply|splat|spz)$/i, "");
        titleInput.value = name.replace(/[-_]/g, " ");
        titleInput.dispatchEvent(new Event("input"));
      }
    });

    drop.addEventListener("dragover", (e) => {
      e.preventDefault();
      drop.classList.add("splat-upload--dragover");
    });

    drop.addEventListener("dragleave", () => {
      drop.classList.remove("splat-upload--dragover");
    });

    drop.addEventListener("drop", (e) => {
      e.preventDefault();
      drop.classList.remove("splat-upload--dragover");
      const file = e.dataTransfer?.files[0];
      if (file && /\.(ply|splat|spz)$/i.test(file.name)) {
        selectedFile = file;
        form.classList.add("active");
        const name = file.name.replace(/\.(ply|splat|spz)$/i, "");
        titleInput.value = name.replace(/[-_]/g, " ");
        titleInput.dispatchEvent(new Event("input"));
      }
    });

    titleInput?.addEventListener("input", () => {
      submitBtn.disabled = !titleInput.value.trim() || !selectedFile;
    });

    submitBtn?.addEventListener("click", async () => {
      if (!selectedFile || !titleInput.value.trim()) return;

      submitBtn.disabled = true;
      status.textContent = "Uploading...";

      const formData = new FormData();
      formData.append("file", selectedFile);
      formData.append("title", titleInput.value.trim());
      formData.append("description", descInput.value.trim());
      formData.append("tags", tagsInput.value.trim());

      try {
        const token = localStorage.getItem("encryptid_token") || "";
        const res = await fetch(`/${this._spaceSlug}/splat/api/splats`, {
          method: "POST",
          headers: token ? { Authorization: `Bearer ${token}` } : {},
          body: formData,
        });

        if (res.status === 402) {
          status.textContent = "Payment required for upload (x402)";
          submitBtn.disabled = false;
          return;
        }

        if (res.status === 401) {
          status.textContent = "Sign in with rStack Identity to upload";
          submitBtn.disabled = false;
          return;
        }

        if (!res.ok) {
          const err = await res.json().catch(() => ({ error: "Upload failed" }));
          status.textContent = (err as any).error || "Upload failed";
          submitBtn.disabled = false;
          return;
        }

        const splat = await res.json() as SplatItem;
        status.textContent = "Uploaded!";
        // Navigate to viewer
        setTimeout(() => {
          window.location.href = `/${this._spaceSlug}/splat/view/${splat.slug}`;
        }, 500);
      } catch (e) {
        status.textContent = "Network error";
        submitBtn.disabled = false;
      }
    });
  }

  // ── Viewer ──

  private renderViewer() {
    this.innerHTML = `
      <div class="splat-viewer">
        <div class="splat-loading" id="splat-loading">
          <div class="splat-loading__spinner"></div>
          <div class="splat-loading__text">Loading splat...</div>
        </div>
        <div class="splat-viewer__controls">
          <a class="splat-viewer__back" href="/${this._spaceSlug}/splat">← Gallery</a>
        </div>
        ${this._splatTitle ? `
          <div class="splat-viewer__info">
            <p class="splat-viewer__title">${esc(this._splatTitle)}</p>
            ${this._splatDesc ? `<p class="splat-viewer__desc">${esc(this._splatDesc)}</p>` : ""}
          </div>
        ` : ""}
        <div id="splat-container" class="splat-viewer__canvas"></div>
      </div>
    `;

    this.initThreeViewer();
  }

  private async initThreeViewer() {
    const container = this.querySelector("#splat-container") as HTMLElement;
    const loading = this.querySelector("#splat-loading") as HTMLElement;

    if (!container || !this._splatUrl) return;

    try {
      // Dynamic import from CDN (via importmap)
      const THREE = await import("three");
      const GaussianSplats3D = await import("@mkkellogg/gaussian-splats-3d");

      const viewer = new GaussianSplats3D.Viewer({
        cameraUp: [0, -1, 0],
        initialCameraPosition: [1, 0.5, 1],
        initialCameraLookAt: [0, 0, 0],
        rootElement: container,
        sharedMemoryForWorkers: false,
      });

      this._viewer = viewer;

      await viewer.addSplatScene(this._splatUrl, {
        showLoadingUI: false,
        progressiveLoad: true,
      });

      viewer.start();

      if (loading) {
        loading.classList.add("hidden");
      }
    } catch (e) {
      console.error("[rSplat] Viewer init error:", e);
      if (loading) {
        const text = loading.querySelector(".splat-loading__text");
        if (text) text.textContent = `Error loading splat: ${(e as Error).message}`;
        const spinner = loading.querySelector(".splat-loading__spinner") as HTMLElement;
        if (spinner) spinner.style.display = "none";
      }
    }
  }
}

// ── Helpers ──

function esc(s: string): string {
  return s.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/"/g, "&quot;");
}

function formatSize(bytes: number): string {
  if (bytes < 1024) return `${bytes} B`;
  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
  return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
}

customElements.define("folk-splat-viewer", FolkSplatViewer);