import { FolkShape } from "./folk-shape";
import { css, html } from "./tags";

const styles = css`
	:host {
		background: white;
		border-radius: 8px;
		box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
		min-width: 360px;
		min-height: 440px;
	}

	.header {
		display: flex;
		align-items: center;
		justify-content: space-between;
		padding: 8px 12px;
		background: linear-gradient(135deg, #0891b2, #06b6d4);
		color: white;
		border-radius: 8px 8px 0 0;
		font-size: 12px;
		font-weight: 600;
		cursor: move;
	}

	.header-title {
		display: flex;
		align-items: center;
		gap: 6px;
	}

	.header-actions {
		display: flex;
		gap: 4px;
	}

	.header-actions button {
		background: transparent;
		border: none;
		color: white;
		cursor: pointer;
		padding: 2px 6px;
		border-radius: 4px;
		font-size: 14px;
	}

	.header-actions button:hover {
		background: rgba(255, 255, 255, 0.2);
	}

	.content {
		display: flex;
		flex-direction: column;
		height: calc(100% - 36px);
		overflow: hidden;
	}

	.prompt-area {
		padding: 12px;
		border-bottom: 1px solid #e2e8f0;
	}

	.prompt-input {
		width: 100%;
		padding: 10px 12px;
		border: 2px solid #e2e8f0;
		border-radius: 8px;
		font-size: 13px;
		resize: none;
		outline: none;
		font-family: inherit;
	}

	.prompt-input:focus {
		border-color: #0891b2;
	}

	.controls {
		display: flex;
		gap: 8px;
		margin-top: 8px;
	}

	.generate-btn {
		flex: 1;
		padding: 8px 16px;
		background: linear-gradient(135deg, #0891b2, #06b6d4);
		color: white;
		border: none;
		border-radius: 6px;
		font-size: 13px;
		font-weight: 600;
		cursor: pointer;
		transition: opacity 0.2s;
	}

	.generate-btn:hover {
		opacity: 0.9;
	}

	.generate-btn:disabled {
		opacity: 0.5;
		cursor: not-allowed;
	}

	.preview-area {
		flex: 1;
		display: flex;
		align-items: center;
		justify-content: center;
		padding: 12px;
		overflow: hidden;
	}

	.preview-area img {
		max-width: 100%;
		max-height: 100%;
		border-radius: 8px;
		box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
	}

	.export-row {
		display: flex;
		gap: 8px;
		padding: 8px 12px;
		border-top: 1px solid #e2e8f0;
	}

	.export-btn {
		padding: 6px 12px;
		background: #334155;
		color: white;
		border: none;
		border-radius: 6px;
		font-size: 12px;
		cursor: pointer;
		text-decoration: none;
	}

	.export-btn:hover {
		background: #475569;
	}

	.export-btn.primary {
		background: #0891b2;
	}

	.export-btn.primary:hover {
		background: #0e7490;
	}

	.placeholder {
		flex: 1;
		display: flex;
		flex-direction: column;
		align-items: center;
		justify-content: center;
		color: #94a3b8;
		text-align: center;
		gap: 8px;
	}

	.placeholder-icon {
		font-size: 48px;
		opacity: 0.5;
	}

	.loading {
		display: flex;
		flex-direction: column;
		align-items: center;
		justify-content: center;
		padding: 24px;
		gap: 12px;
	}

	.spinner {
		width: 32px;
		height: 32px;
		border: 3px solid #e2e8f0;
		border-top-color: #0891b2;
		border-radius: 50%;
		animation: spin 1s linear infinite;
	}

	@keyframes spin {
		to { transform: rotate(360deg); }
	}

	.error {
		color: #ef4444;
		padding: 12px;
		background: #fef2f2;
		border-radius: 6px;
		font-size: 13px;
		margin: 12px;
	}
`;

declare global {
	interface HTMLElementTagNameMap {
		"folk-freecad": FolkFreeCAD;
	}
}

export class FolkFreeCAD extends FolkShape {
	static override tagName = "folk-freecad";

	static {
		const sheet = new CSSStyleSheet();
		const parentRules = Array.from(FolkShape.styles.cssRules)
			.map((r) => r.cssText)
			.join("\n");
		const childRules = Array.from(styles.cssRules)
			.map((r) => r.cssText)
			.join("\n");
		sheet.replaceSync(`${parentRules}\n${childRules}`);
		this.styles = sheet;
	}

	#isLoading = false;
	#error: string | null = null;
	#previewUrl: string | null = null;
	#stepUrl: string | null = null;
	#stlUrl: string | null = null;
	#promptInput: HTMLTextAreaElement | null = null;
	#generateBtn: HTMLButtonElement | null = null;
	#previewArea: HTMLElement | null = null;
	#exportRow: HTMLElement | null = null;

	override createRenderRoot() {
		const root = super.createRenderRoot();

		const wrapper = document.createElement("div");
		wrapper.innerHTML = html`
			<div class="header">
				<span class="header-title">
					<span>📐</span>
					<span>FreeCAD</span>
				</span>
				<div class="header-actions">
					<button class="close-btn" title="Close">×</button>
				</div>
			</div>
			<div class="content">
				<div class="prompt-area">
					<textarea class="prompt-input" placeholder="Describe the parametric part to generate...\ne.g. 'Enclosure box 80x50x30mm with 3mm walls, ventilation slots, and M3 screw bosses'" rows="3"></textarea>
					<div class="controls">
						<button class="generate-btn">📐 Generate CAD</button>
					</div>
				</div>
				<div class="preview-area">
					<div class="placeholder">
						<span class="placeholder-icon">📐</span>
						<span>Describe a part and click Generate</span>
					</div>
				</div>
				<div class="export-row" style="display:none">
					<a class="export-btn primary step-dl" href="#" download>⬇️ STEP</a>
					<a class="export-btn stl-dl" href="#" download>⬇️ STL</a>
				</div>
			</div>
		`;

		const slot = root.querySelector("slot");
		const containerDiv = slot?.parentElement as HTMLElement;
		if (containerDiv) {
			containerDiv.replaceWith(wrapper);
		}

		this.#promptInput = wrapper.querySelector(".prompt-input");
		this.#generateBtn = wrapper.querySelector(".generate-btn");
		this.#previewArea = wrapper.querySelector(".preview-area");
		this.#exportRow = wrapper.querySelector(".export-row");
		const closeBtn = wrapper.querySelector(".close-btn") as HTMLButtonElement;

		this.#generateBtn?.addEventListener("click", (e) => {
			e.stopPropagation();
			this.#generate();
		});

		this.#promptInput?.addEventListener("keydown", (e) => {
			if (e.key === "Enter" && !e.shiftKey) {
				e.preventDefault();
				this.#generate();
			}
		});
		this.#promptInput?.addEventListener("pointerdown", (e) => e.stopPropagation());

		closeBtn.addEventListener("click", (e) => {
			e.stopPropagation();
			this.dispatchEvent(new CustomEvent("close"));
		});

		return root;
	}

	async #generate() {
		const prompt = this.#promptInput?.value.trim();
		if (!prompt || this.#isLoading) return;

		this.#isLoading = true;
		this.#error = null;
		if (this.#generateBtn) this.#generateBtn.disabled = true;

		if (this.#previewArea) {
			this.#previewArea.innerHTML = '<div class="loading"><div class="spinner"></div><span>Generating CAD model...</span></div>';
		}

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

			if (!res.ok) {
				const err = await res.json().catch(() => ({ error: res.statusText }));
				throw new Error(err.error || "Generation failed");
			}

			const data = await res.json();
			this.#previewUrl = data.preview_url || null;
			this.#stepUrl = data.step_url || null;
			this.#stlUrl = data.stl_url || null;

			this.#renderResult();
		} catch (err) {
			this.#error = err instanceof Error ? err.message : "Generation failed";
			if (this.#previewArea) {
				this.#previewArea.innerHTML = `<div class="error">${this.#escapeHtml(this.#error)}</div>`;
			}
		} finally {
			this.#isLoading = false;
			if (this.#generateBtn) this.#generateBtn.disabled = false;
		}
	}

	#renderResult() {
		if (this.#previewArea) {
			if (this.#previewUrl) {
				this.#previewArea.innerHTML = `<img src="${this.#escapeHtml(this.#previewUrl)}" alt="CAD Preview" />`;
			} else {
				this.#previewArea.innerHTML = '<div class="placeholder"><span class="placeholder-icon">\u2705</span><span>Model generated! Download files below.</span></div>';
			}
		}

		if (this.#exportRow && (this.#stepUrl || this.#stlUrl)) {
			this.#exportRow.style.display = "flex";
			const stepLink = this.#exportRow.querySelector(".step-dl") as HTMLAnchorElement;
			const stlLink = this.#exportRow.querySelector(".stl-dl") as HTMLAnchorElement;
			if (stepLink && this.#stepUrl) {
				stepLink.href = this.#stepUrl;
				stepLink.style.display = "";
			}
			if (stlLink && this.#stlUrl) {
				stlLink.href = this.#stlUrl;
				stlLink.style.display = "";
			}
		}
	}

	#escapeHtml(text: string): string {
		const div = document.createElement("div");
		div.textContent = text;
		return div.innerHTML;
	}

	override toJSON() {
		return {
			...super.toJSON(),
			type: "folk-freecad",
			previewUrl: this.#previewUrl,
			stepUrl: this.#stepUrl,
			stlUrl: this.#stlUrl,
		};
	}
}