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

const styles = css`
	:host {
		background: var(--rs-bg-surface, #fff);
		color: var(--rs-text-primary, #1e293b);
		border-radius: 8px;
		box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
		min-width: 560px;
		min-height: 480px;
	}

	.header {
		display: flex;
		align-items: center;
		justify-content: space-between;
		padding: 8px 12px;
		background: linear-gradient(135deg, #8b5cf6, #6366f1);
		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;
	}

	.toolbar-row {
		display: flex;
		align-items: center;
		gap: 6px;
		padding: 8px 12px;
		border-bottom: 1px solid var(--rs-border, rgba(255, 255, 255, 0.1));
		flex-wrap: wrap;
	}

	.tool-btn {
		width: 32px;
		height: 32px;
		display: flex;
		align-items: center;
		justify-content: center;
		border: 2px solid var(--rs-border, rgba(255, 255, 255, 0.1));
		border-radius: 6px;
		background: var(--rs-bg-surface, #1e293b);
		cursor: pointer;
		font-size: 14px;
		transition: all 0.15s;
	}

	.tool-btn:hover {
		border-color: #8b5cf6;
	}

	.tool-btn.active {
		border-color: #8b5cf6;
		background: rgba(139, 92, 246, 0.15);
	}

	.color-swatch {
		width: 24px;
		height: 24px;
		border-radius: 50%;
		border: 2px solid var(--rs-border, rgba(255, 255, 255, 0.1));
		cursor: pointer;
		transition: transform 0.1s;
	}

	.color-swatch:hover {
		transform: scale(1.2);
	}

	.color-swatch.active {
		border-color: var(--rs-text-primary, #e2e8f0);
		transform: scale(1.15);
	}

	.size-slider {
		width: 80px;
		accent-color: #8b5cf6;
	}

	.size-label {
		font-size: 11px;
		color: var(--rs-text-muted, #64748b);
		min-width: 20px;
	}

	.split-area {
		flex: 1;
		display: flex;
		overflow: hidden;
		min-height: 0;
	}

	.canvas-area {
		flex: 1;
		position: relative;
		cursor: crosshair;
		overflow: hidden;
		min-width: 0;
	}

	.canvas-area canvas {
		width: 100%;
		height: 100%;
		display: block;
	}

	.result-area {
		flex: 1;
		position: relative;
		overflow: hidden;
		display: flex;
		flex-direction: column;
		background: var(--rs-bg-muted, #f8fafc);
		border-left: 1px solid var(--rs-border, rgba(255, 255, 255, 0.1));
		min-width: 0;
	}

	.result-area iframe {
		flex: 1;
		width: 100%;
		border: none;
		background: #fff;
	}

	.result-area pre {
		flex: 1;
		margin: 0;
		padding: 10px;
		font-size: 11px;
		overflow: auto;
		background: #1e1e2e;
		color: #cdd6f4;
		white-space: pre-wrap;
		word-break: break-word;
	}

	.result-placeholder {
		display: flex;
		flex: 1;
		flex-direction: column;
		align-items: center;
		justify-content: center;
		gap: 8px;
		color: var(--rs-text-muted, #94a3b8);
		text-align: center;
		font-size: 12px;
		padding: 12px;
	}

	.result-placeholder-icon {
		font-size: 32px;
		opacity: 0.4;
	}

	.result-toolbar {
		display: flex;
		gap: 4px;
		padding: 4px 8px;
		background: var(--rs-bg-surface, #fff);
		border-bottom: 1px solid var(--rs-border, rgba(255, 255, 255, 0.1));
		font-size: 11px;
	}

	.result-toolbar button {
		padding: 3px 8px;
		border: 1px solid var(--rs-border, #e2e8f0);
		border-radius: 4px;
		background: var(--rs-bg-surface, #fff);
		cursor: pointer;
		font-size: 11px;
		color: var(--rs-text-primary, #1e293b);
	}

	.result-toolbar button:hover {
		background: var(--rs-bg-muted, #f1f5f9);
	}

	.result-toolbar button.active {
		background: #8b5cf6;
		color: white;
		border-color: #8b5cf6;
	}

	.spinner-overlay {
		position: absolute;
		inset: 0;
		display: flex;
		flex-direction: column;
		align-items: center;
		justify-content: center;
		background: rgba(255, 255, 255, 0.7);
		gap: 8px;
		z-index: 2;
	}

	.spinner {
		width: 28px;
		height: 28px;
		border: 3px solid #e2e8f0;
		border-top-color: #8b5cf6;
		border-radius: 50%;
		animation: spin 1s linear infinite;
	}

	.spinner-text {
		font-size: 11px;
		color: #64748b;
	}

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

	.prompt-bar {
		display: flex;
		gap: 6px;
		padding: 8px 12px;
		border-top: 1px solid var(--rs-border, rgba(255, 255, 255, 0.1));
		align-items: center;
	}

	.prompt-input {
		flex: 1;
		padding: 6px 10px;
		border: 2px solid var(--rs-input-border, #e2e8f0);
		border-radius: 6px;
		font-size: 12px;
		outline: none;
		font-family: inherit;
		background: var(--rs-input-bg, #fff);
		color: var(--rs-input-text, inherit);
	}

	.prompt-input:focus {
		border-color: #8b5cf6;
	}

	.generate-btn {
		padding: 6px 14px;
		background: linear-gradient(135deg, #8b5cf6, #6366f1);
		color: white;
		border: none;
		border-radius: 6px;
		font-size: 12px;
		font-weight: 600;
		cursor: pointer;
		white-space: nowrap;
		transition: opacity 0.2s;
	}

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

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

	.framework-select {
		padding: 4px 8px;
		border: 2px solid #e2e8f0;
		border-radius: 6px;
		font-size: 11px;
		background: var(--rs-bg-surface, white);
		cursor: pointer;
	}
`;

const COLORS = ["#0f172a", "#ef4444", "#f97316", "#eab308", "#22c55e", "#3b82f6", "#8b5cf6", "#ec4899", "#ffffff"];

interface Stroke {
	points: { x: number; y: number; pressure: number }[];
	color: string;
	size: number;
	tool: string;
}

declare global {
	interface HTMLElementTagNameMap {
		"folk-makereal": FolkMakereal;
	}
}

export class FolkMakereal extends FolkShape {
	static override tagName = "folk-makereal";

	static override portDescriptors = [
		{ name: "prompt", type: "text" as const, direction: "input" as const },
		{ name: "html", type: "text" as const, direction: "output" as const },
	];

	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;
	}

	#strokes: Stroke[] = [];
	#currentStroke: Stroke | null = null;
	#canvas: HTMLCanvasElement | null = null;
	#ctx: CanvasRenderingContext2D | null = null;
	#color = "#0f172a";
	#brushSize = 4;
	#tool = "pen";
	#isDrawing = false;
	#isGenerating = false;
	#framework = "html";
	#lastHtml: string | null = null;
	#showCode = false;
	#promptInput: HTMLInputElement | null = null;
	#generateBtn: HTMLButtonElement | null = null;
	#resultArea: HTMLElement | null = null;
	#resizeObserver: ResizeObserver | 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>MakeReal</span>
				</span>
				<div class="header-actions">
					<button class="close-btn" title="Close">×</button>
				</div>
			</div>
			<div class="content">
				<div class="toolbar-row">
					<button class="tool-btn active" data-tool="pen" title="Pen">✏️</button>
					<button class="tool-btn" data-tool="eraser" title="Eraser">🧹</button>
					<span style="width:1px;height:20px;background:var(--rs-border,rgba(255,255,255,0.1));margin:0 2px"></span>
					${COLORS.map((c) => `<span class="color-swatch${c === "#0f172a" ? " active" : ""}" data-color="${c}" style="background:${c}"></span>`).join("")}
					<span style="width:1px;height:20px;background:var(--rs-border,rgba(255,255,255,0.1));margin:0 2px"></span>
					<input type="range" class="size-slider" min="1" max="24" value="4" />
					<span class="size-label">4</span>
					<span style="flex:1"></span>
					<button class="tool-btn" data-tool="clear" title="Clear all">🗑️</button>
				</div>
				<div class="split-area">
					<div class="canvas-area">
						<canvas></canvas>
					</div>
					<div class="result-area">
						<div class="result-placeholder">
							<span class="result-placeholder-icon">🪄</span>
							<span>Draw a wireframe and click Make Real</span>
						</div>
					</div>
				</div>
				<div class="prompt-bar">
					<input type="text" class="prompt-input" placeholder="Describe the UI you're sketching..." />
					<select class="framework-select">
						<option value="html">HTML</option>
						<option value="tailwind">Tailwind</option>
						<option value="react">React</option>
					</select>
					<button class="generate-btn">Make Real</button>
				</div>
			</div>
		`;

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

		this.#canvas = wrapper.querySelector(".canvas-area canvas") as HTMLCanvasElement;
		this.#ctx = this.#canvas.getContext("2d");
		this.#promptInput = wrapper.querySelector(".prompt-input") as HTMLInputElement;
		this.#generateBtn = wrapper.querySelector(".generate-btn") as HTMLButtonElement;
		this.#resultArea = wrapper.querySelector(".result-area") as HTMLElement;

		const closeBtn = wrapper.querySelector(".close-btn") as HTMLButtonElement;
		const sizeSlider = wrapper.querySelector(".size-slider") as HTMLInputElement;
		const sizeLabel = wrapper.querySelector(".size-label") as HTMLElement;
		const canvasArea = wrapper.querySelector(".canvas-area") as HTMLElement;
		const frameworkSelect = wrapper.querySelector(".framework-select") as HTMLSelectElement;

		// Tool buttons
		wrapper.querySelectorAll(".tool-btn").forEach((btn) => {
			btn.addEventListener("click", (e) => {
				e.stopPropagation();
				const tool = (btn as HTMLElement).dataset.tool;
				if (tool === "clear") {
					this.#strokes = [];
					this.#redraw();
					return;
				}
				this.#tool = tool || "pen";
				wrapper.querySelectorAll(".tool-btn").forEach((b) => b.classList.remove("active"));
				if (tool !== "clear") btn.classList.add("active");
			});
		});

		// Color swatches
		wrapper.querySelectorAll(".color-swatch").forEach((swatch) => {
			swatch.addEventListener("click", (e) => {
				e.stopPropagation();
				this.#color = (swatch as HTMLElement).dataset.color || "#0f172a";
				wrapper.querySelectorAll(".color-swatch").forEach((s) => s.classList.remove("active"));
				swatch.classList.add("active");
				this.#tool = "pen";
				wrapper.querySelectorAll(".tool-btn").forEach((b) => b.classList.remove("active"));
				wrapper.querySelector('[data-tool="pen"]')?.classList.add("active");
			});
		});

		// Size slider
		sizeSlider.addEventListener("input", (e) => {
			e.stopPropagation();
			this.#brushSize = parseInt(sizeSlider.value);
			sizeLabel.textContent = sizeSlider.value;
		});
		sizeSlider.addEventListener("pointerdown", (e) => e.stopPropagation());

		// Framework select
		frameworkSelect.addEventListener("change", (e) => {
			e.stopPropagation();
			this.#framework = frameworkSelect.value;
		});
		frameworkSelect.addEventListener("pointerdown", (e) => e.stopPropagation());

		// Drawing events
		this.#canvas.addEventListener("pointerdown", (e) => {
			e.stopPropagation();
			e.preventDefault();
			this.#isDrawing = true;
			this.#canvas!.setPointerCapture(e.pointerId);
			const pos = this.#getCanvasPos(e);
			this.#currentStroke = {
				points: [{ ...pos, pressure: e.pressure || 0.5 }],
				color: this.#tool === "eraser" ? "#ffffff" : this.#color,
				size: this.#tool === "eraser" ? this.#brushSize * 3 : this.#brushSize,
				tool: this.#tool,
			};
		});

		this.#canvas.addEventListener("pointermove", (e) => {
			if (!this.#isDrawing || !this.#currentStroke) return;
			e.stopPropagation();
			const pos = this.#getCanvasPos(e);
			this.#currentStroke.points.push({ ...pos, pressure: e.pressure || 0.5 });
			this.#drawStroke(this.#currentStroke);
		});

		const endDraw = () => {
			if (!this.#isDrawing) return;
			this.#isDrawing = false;
			if (this.#currentStroke && this.#currentStroke.points.length > 0) {
				this.#strokes.push(this.#currentStroke);
			}
			this.#currentStroke = null;
		};

		this.#canvas.addEventListener("pointerup", endDraw);
		this.#canvas.addEventListener("pointerleave", endDraw);

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

		// Enter key in prompt
		this.#promptInput.addEventListener("keydown", (e) => {
			if (e.key === "Enter") {
				e.preventDefault();
				this.#generate();
			}
		});
		this.#promptInput.addEventListener("pointerdown", (e) => e.stopPropagation());

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

		// Size canvas on next frame
		requestAnimationFrame(() => {
			this.#resizeCanvas(canvasArea);
			this.#redraw();
		});

		this.#resizeObserver = new ResizeObserver(() => {
			this.#resizeCanvas(canvasArea);
			this.#redraw();
		});
		this.#resizeObserver.observe(canvasArea);

		return root;
	}

	async #generate() {
		const prompt = this.#promptInput?.value.trim() || "Convert this wireframe into a working UI";
		if (this.#isGenerating || !this.#canvas) return;

		this.#isGenerating = true;
		if (this.#generateBtn) this.#generateBtn.disabled = true;
		this.#showCode = false;
		this.#renderLoading();

		try {
			const sketchImage = this.#canvas.toDataURL("image/jpeg", 0.85);

			const response = await fetch("/api/makereal", {
				method: "POST",
				headers: { "Content-Type": "application/json" },
				body: JSON.stringify({
					sketch_image: sketchImage,
					prompt,
					framework: this.#framework,
				}),
			});

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

			const result = await response.json();
			if (!result.html) throw new Error("No HTML returned");

			this.#lastHtml = result.html;
			this.#renderResult();

			this.dispatchEvent(new CustomEvent("html-generated", {
				detail: { html: result.html, prompt },
			}));
		} catch (error) {
			const msg = error instanceof Error ? error.message : "Generation failed";
			this.#renderError(msg);
		} finally {
			this.#isGenerating = false;
			if (this.#generateBtn) this.#generateBtn.disabled = false;
		}
	}

	#renderLoading() {
		if (!this.#resultArea) return;
		this.#resultArea.innerHTML = `
			<div class="spinner-overlay">
				<div class="spinner"></div>
				<span class="spinner-text">Generating HTML...</span>
			</div>
		`;
	}

	#renderResult() {
		if (!this.#resultArea || !this.#lastHtml) return;

		const toolbar = `<div class="result-toolbar">
			<button class="view-preview-btn${!this.#showCode ? " active" : ""}">Preview</button>
			<button class="view-code-btn${this.#showCode ? " active" : ""}">Code</button>
			<button class="copy-btn">Copy HTML</button>
			<button class="open-btn">Open Tab</button>
		</div>`;

		if (this.#showCode) {
			this.#resultArea.innerHTML = `${toolbar}<pre>${this.#escapeHtml(this.#lastHtml)}</pre>`;
		} else {
			this.#resultArea.innerHTML = `${toolbar}<iframe sandbox="allow-scripts" srcdoc="${this.#escapeAttr(this.#lastHtml)}"></iframe>`;
		}

		// Wire toolbar buttons
		this.#resultArea.querySelector(".view-preview-btn")?.addEventListener("click", (e) => {
			e.stopPropagation();
			this.#showCode = false;
			this.#renderResult();
		});
		this.#resultArea.querySelector(".view-code-btn")?.addEventListener("click", (e) => {
			e.stopPropagation();
			this.#showCode = true;
			this.#renderResult();
		});
		this.#resultArea.querySelector(".copy-btn")?.addEventListener("click", (e) => {
			e.stopPropagation();
			if (this.#lastHtml) navigator.clipboard.writeText(this.#lastHtml);
		});
		this.#resultArea.querySelector(".open-btn")?.addEventListener("click", (e) => {
			e.stopPropagation();
			if (this.#lastHtml) {
				const blob = new Blob([this.#lastHtml], { type: "text/html" });
				window.open(URL.createObjectURL(blob), "_blank");
			}
		});
	}

	#renderError(msg: string) {
		if (!this.#resultArea) return;
		this.#resultArea.innerHTML = `
			<div class="result-placeholder">
				<span class="result-placeholder-icon">⚠️</span>
				<span style="color:#ef4444">${this.#escapeHtml(msg)}</span>
			</div>
		`;
	}

	#resizeCanvas(container: HTMLElement) {
		if (!this.#canvas) return;
		const rect = container.getBoundingClientRect();
		if (rect.width > 0 && rect.height > 0) {
			this.#canvas.width = rect.width * devicePixelRatio;
			this.#canvas.height = rect.height * devicePixelRatio;
			this.#canvas.style.width = rect.width + "px";
			this.#canvas.style.height = rect.height + "px";
			if (this.#ctx) {
				this.#ctx.scale(devicePixelRatio, devicePixelRatio);
			}
		}
	}

	#getCanvasPos(e: PointerEvent): { x: number; y: number } {
		const rect = this.#canvas!.getBoundingClientRect();
		return {
			x: e.clientX - rect.left,
			y: e.clientY - rect.top,
		};
	}

	#drawStroke(stroke: Stroke) {
		if (!this.#ctx || stroke.points.length < 2) return;
		const ctx = this.#ctx;

		ctx.lineCap = "round";
		ctx.lineJoin = "round";
		ctx.strokeStyle = stroke.color;

		const len = stroke.points.length;
		const p0 = stroke.points[len - 2];
		const p1 = stroke.points[len - 1];
		const pressure = (p0.pressure + p1.pressure) / 2;

		ctx.lineWidth = stroke.size * (0.5 + pressure);
		if (stroke.tool === "eraser") {
			ctx.globalCompositeOperation = "destination-out";
			ctx.lineWidth = stroke.size * 3;
		} else {
			ctx.globalCompositeOperation = "source-over";
		}

		ctx.beginPath();
		ctx.moveTo(p0.x, p0.y);
		ctx.lineTo(p1.x, p1.y);
		ctx.stroke();

		ctx.globalCompositeOperation = "source-over";
	}

	#redraw() {
		if (!this.#ctx || !this.#canvas) return;
		const ctx = this.#ctx;
		const w = this.#canvas.width / devicePixelRatio;
		const h = this.#canvas.height / devicePixelRatio;

		ctx.clearRect(0, 0, w, h);
		ctx.fillStyle = "#ffffff";
		ctx.fillRect(0, 0, w, h);

		for (const stroke of this.#strokes) {
			if (stroke.points.length < 2) continue;

			ctx.lineCap = "round";
			ctx.lineJoin = "round";
			ctx.strokeStyle = stroke.color;

			if (stroke.tool === "eraser") {
				ctx.globalCompositeOperation = "destination-out";
			} else {
				ctx.globalCompositeOperation = "source-over";
			}

			for (let i = 1; i < stroke.points.length; i++) {
				const p0 = stroke.points[i - 1];
				const p1 = stroke.points[i];
				const pressure = (p0.pressure + p1.pressure) / 2;
				ctx.lineWidth = stroke.size * (0.5 + pressure);

				ctx.beginPath();
				ctx.moveTo(p0.x, p0.y);
				ctx.lineTo(p1.x, p1.y);
				ctx.stroke();
			}
		}

		ctx.globalCompositeOperation = "source-over";
	}

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

	#escapeAttr(text: string): string {
		return text.replace(/&/g, "&amp;").replace(/"/g, "&quot;").replace(/</g, "&lt;").replace(/>/g, "&gt;");
	}

	override disconnectedCallback() {
		super.disconnectedCallback?.();
		this.#resizeObserver?.disconnect();
		this.#resizeObserver = null;
	}

	static override fromData(data: Record<string, any>): FolkMakereal {
		const shape = FolkShape.fromData(data) as FolkMakereal;
		return shape;
	}

	override toJSON() {
		return {
			...super.toJSON(),
			type: "folk-makereal",
			strokes: this.#strokes.map((s) => ({
				points: s.points,
				color: s.color,
				size: s.size,
				tool: s.tool,
			})),
			lastHtml: this.#lastHtml,
		};
	}

	override applyData(data: Record<string, any>): void {
		super.applyData(data);
		if (data.lastHtml && this.#resultArea) {
			this.#lastHtml = data.lastHtml;
			this.#renderResult();
		}
	}
}
