import {
	type Component,
	type KeyId,
	matchesKey,
	replaceTabs,
	sliceWithWidth,
	truncateToWidth,
	visibleWidth,
} from "@oh-my-pi/pi-tui";
import { sanitizeText } from "@oh-my-pi/pi-utils";
import { type ThemeColor, theme } from "../modes/theme/theme";

/** Distinct states of a realtime call connection. */
export type LivePhase = "connecting" | "listening" | "working" | "speaking" | "muted" | "error";
/** Configuration callbacks for user interactions in the visualizer. */
export interface LiveVisualizerOptions {
	onStop(): void;
	onToggleMute(): void;
	/** Configured `app.live.toggle` chords that also end the call (Ctrl+L by default). */
	stopKeys?: readonly KeyId[];
}

function normalizeTranscript(text: string): string {
	return replaceTabs(sanitizeText(text)).replace(/\s+/g, " ").trim();
}

function truncateFromStart(text: string, width: number): string {
	if (width <= 0) return "";
	const textWidth = visibleWidth(text);
	if (textWidth <= width) return text;
	if (width === 1) return "…";
	return `…${sliceWithWidth(text, textWidth - width + 1, width - 1, true).text}`;
}

/** A compact, fixed-height terminal component for displaying a realtime call. */
export class LiveVisualizer implements Component {
	readonly wantsKeyRelease = false;

	readonly #options: LiveVisualizerOptions;

	#phase: LivePhase = "connecting";
	#inputLevel = 0;
	#displayLevel = 0;
	#frame = 0;
	#userTranscript = "";

	#cache:
		| {
				width: number;
				phase: LivePhase;
				displayLevel: number;
				frame: number;
				userTranscript: string;
				lines: readonly string[];
		  }
		| undefined;

	constructor(options: LiveVisualizerOptions) {
		this.#options = options;
	}

	/** Updates the current call phase. */
	setPhase(phase: LivePhase): void {
		if (this.#phase !== phase) {
			this.#phase = phase;
			this.invalidate();
		}
	}

	/** Updates the microphone volume level (0..1). */
	setInputLevel(level: number): void {
		const next = Number.isFinite(level) ? Math.min(1, Math.max(0, level)) : 0;
		if (this.#inputLevel === next) return;
		this.#inputLevel = next;
		if (next > this.#displayLevel) this.#displayLevel = next;
		this.invalidate();
	}

	/** Advances the spectrum animation and its peak decay. */
	setFrame(frame: number): void {
		const nextLevel = Math.max(this.#inputLevel, this.#displayLevel * 0.84);
		if (this.#frame !== frame || this.#displayLevel !== nextLevel) {
			this.#frame = frame;
			this.#displayLevel = nextLevel;
			this.invalidate();
		}
	}

	/** Updates the user's streaming voice transcript. */
	setTranscript(text: string): void {
		const normalized = normalizeTranscript(text);
		if (this.#userTranscript === normalized) return;
		this.#userTranscript = normalized;
		this.invalidate();
	}

	/** Clears the user's voice transcript row. */
	clearTranscript(): void {
		if (!this.#userTranscript) return;
		this.#userTranscript = "";
		this.invalidate();
	}

	/** Processes user keypresses. */
	handleInput(data: string): void {
		if (
			matchesKey(data, "escape") ||
			matchesKey(data, "ctrl+c") ||
			this.#options.stopKeys?.some(key => matchesKey(data, key))
		) {
			this.#options.onStop();
		} else if (matchesKey(data, "space")) {
			this.#options.onToggleMute();
		}
	}

	/** Clears the render cache. */
	invalidate(): void {
		this.#cache = undefined;
	}

	/** Renders the microphone spectrum into a compact fixed-height panel. */
	render(width: number): readonly string[] {
		if (
			this.#cache &&
			this.#cache.width === width &&
			this.#cache.phase === this.#phase &&
			this.#cache.displayLevel === this.#displayLevel &&
			this.#cache.frame === this.#frame &&
			this.#cache.userTranscript === this.#userTranscript
		) {
			return this.#cache.lines;
		}

		const lines = this.#renderLines(width);
		this.#cache = {
			width,
			phase: this.#phase,
			displayLevel: this.#displayLevel,
			frame: this.#frame,
			userTranscript: this.#userTranscript,
			lines,
		};
		return lines;
	}

	#renderLines(maxWidth: number): readonly string[] {
		const width = Math.max(2, maxWidth);
		const innerWidth = width - 2;
		const border = (content: string): string =>
			theme.fg("border", "│") + content + (width > 1 ? theme.fg("border", "│") : "");
		const top = theme.fg("border", `┌${"─".repeat(innerWidth)}${width > 1 ? "┐" : ""}`);
		const spectrumColor: ThemeColor = this.#phase === "muted" ? "dim" : this.#phase === "error" ? "error" : "success";
		const spectrum = this.#generateSpectrum(innerWidth, 2);
		const spectrumRows = spectrum.map(row => border(theme.fg(spectrumColor, row)));
		const transcript = this.#renderTranscript(this.#userTranscript, innerWidth, border);
		return [top, ...spectrumRows, transcript, this.#renderFooter(width, innerWidth)];
	}

	#renderTranscript(transcript: string, innerWidth: number, border: (content: string) => string): string {
		const content = truncateFromStart(transcript, innerWidth);
		const padding = " ".repeat(Math.max(0, innerWidth - visibleWidth(content)));
		return border(theme.fg("accent", content) + padding);
	}

	#renderFooter(width: number, innerWidth: number): string {
		const spinners = ["⠋", "⠙", "⠹", "⠸", "⠼", "⠴", "⠦", "⠧", "⠇", "⠏"];
		const staticIcons: Record<LivePhase, string> = {
			connecting: "○",
			listening: "●",
			working: "○",
			speaking: "»",
			muted: "×",
			error: "!",
		};
		const icon = this.#phase === "working" ? spinners[this.#frame % spinners.length] : staticIcons[this.#phase];
		const phaseColors: Record<LivePhase, ThemeColor> = {
			connecting: "dim",
			listening: "success",
			working: "warning",
			speaking: "accent",
			muted: "dim",
			error: "error",
		};
		const status = `${icon} ${this.#phase}`;
		const fullLabel = ` ${status} · space mute · esc end `;
		const shortLabel = ` ${status} `;
		const label =
			innerWidth >= visibleWidth(fullLabel) + 1
				? fullLabel
				: innerWidth >= visibleWidth(shortLabel) + 1
					? shortLabel
					: "";
		if (!label) {
			return theme.fg("border", `└${"─".repeat(innerWidth)}${width > 1 ? "┘" : ""}`);
		}
		const remaining = Math.max(0, innerWidth - visibleWidth(label) - 1);
		return (
			theme.fg("border", "└─") +
			theme.fg(phaseColors[this.#phase], truncateToWidth(label, innerWidth - 1)) +
			theme.fg("border", `${"─".repeat(remaining)}${width > 1 ? "┘" : ""}`)
		);
	}

	#generateSpectrum(width: number, rows: number): string[] {
		const blocks = [" ", "▁", "▂", "▃", "▄", "▅", "▆", "▇", "█"];
		const output = Array.from({ length: rows }, () => "");
		const energy = this.#phase === "muted" ? 0 : Math.min(1, Math.sqrt(this.#displayLevel * 5));
		const maxHeight = rows * (blocks.length - 1);
		for (let column = 0; column < width; column += 1) {
			const carrier = 0.5 + 0.5 * Math.sin(this.#frame * 0.43 + column * 0.71);
			const shimmer = 0.5 + 0.5 * Math.sin(this.#frame * 0.19 - column * 1.17);
			const height = Math.round(energy * (0.3 + carrier * 0.5 + shimmer * 0.2) * maxHeight);
			for (let row = 0; row < rows; row += 1) {
				const units = Math.max(0, Math.min(blocks.length - 1, height - (rows - row - 1) * 8));
				output[row] += blocks[units];
			}
		}
		return output;
	}
}