import { invoke as tauriInvoke } from "@tauri-apps/api/core";
import { listen } from "@tauri-apps/api/event";

export type RecordingStatus = "idle" | "recording";

export interface AppSettings {
	transcription: {
		mode: "localFirst" | "apiOnly";
		modelId: string;
		language: string | null;
		openaiCompatible: {
			endpoint: string;
			apiKeyConfigured: boolean;
			model: string;
		};
	};
	insertion: {
		method: "clipboardPaste" | "keyTyping" | "manualCopy";
		restoreClipboard: boolean;
		waylandManualFallback: boolean;
	};
	storage: {
		keepAudio: boolean;
		audioFormat: "wav" | "ogg" | "mp3";
	};
}

export interface ModelWithStatus {
	model: {
		id: string;
		displayName: string;
		repository: string;
		filename: string;
		quantization: string;
		sizeBytes: number;
		downloadUrl?: string;
		languages: string[];
		recommendedForSimplePc: boolean;
	};
	status: "notInstalled" | "ready" | { error: string };
	localPath?: string | null;
}

export interface TranscriptionAttempt {
	stage: string;
	audioPath: string;
	audioSizeBytes: number;
	sidecar: string;
	model: string;
	exitCode: number | null;
	stdoutTail: string;
	stderrTail: string;
	error: string | null;
}

export interface TranscriptDraft {
	text: string;
	lastMessage: string | null;
	lastAttempt?: TranscriptionAttempt;
}

export interface AppSnapshot {
	settings: AppSettings;
	recordingStatus: RecordingStatus;
	transcript: TranscriptDraft;
	models: ModelWithStatus[];
}

export interface NativeClient {
	invoke<T>(command: string, args?: Record<string, unknown>): Promise<T>;
}

const fallbackSnapshot: AppSnapshot = {
	recordingStatus: "idle",
	transcript: {
		text: "",
		lastMessage:
			"Modo pré-visualização: comandos nativos disponíveis dentro do Tauri.",
	},
	settings: {
		transcription: {
			mode: "localFirst",
			modelId: "parakeet-tdt-0.6b-v3-q8_0",
			language: null,
			openaiCompatible: {
				endpoint: "https://api.openai.com/v1/audio/transcriptions",
				apiKeyConfigured: false,
				model: "whisper-1",
			},
		},
		insertion: {
			method: "clipboardPaste",
			restoreClipboard: true,
			waylandManualFallback: true,
		},
		storage: {
			keepAudio: false,
			audioFormat: "wav",
		},
	},
	models: [
		{
			model: {
				id: "parakeet-tdt-0.6b-v3-q8_0",
				displayName: "Parakeet TDT 0.6B v3 Q8",
				repository: "cstr/parakeet-tdt-0.6b-v3-GGUF",
				filename: "parakeet-tdt-0.6b-v3-q8_0.gguf",
				quantization: "Q8_0",
				sizeBytes: 745_121_600,
				languages: ["pt", "en", "es", "fr", "de"],
				recommendedForSimplePc: true,
			},
			status: "notInstalled",
		},
	],
};

function createNativeClient(): NativeClient {
	return {
		invoke: <T>(command: string, args?: Record<string, unknown>) =>
			tauriInvoke<T>(command, args),
	};
}

function element<K extends keyof HTMLElementTagNameMap>(
	tag: K,
	className?: string,
	text?: string,
): HTMLElementTagNameMap[K] {
	const node = document.createElement(tag);
	if (className) node.className = className;
	if (text !== undefined) node.textContent = text;
	return node;
}

function formatBytes(bytes: number): string {
	if (bytes < 1024) return `${bytes} B`;
	if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
	return `${(bytes / 1024 / 1024).toFixed(2)} MB`;
}

function formatAttempt(attempt: TranscriptionAttempt): string {
	const lines = [
		`stage: ${attempt.stage}`,
		`audio: ${attempt.audioPath} (${formatBytes(attempt.audioSizeBytes)})`,
		`sidecar: ${attempt.sidecar}`,
		`model: ${attempt.model}`,
		`exitCode: ${attempt.exitCode ?? "n/a"}`,
		`error: ${attempt.error ?? "—"}`,
		`stdout:`,
		attempt.stdoutTail || "(vazio)",
		`stderr:`,
		attempt.stderrTail || "(vazio)",
	];
	return lines.join("\n");
}

function modelStatusLabel(status: ModelWithStatus["status"]): string {
	if (status === "ready") return "pronto";
	if (status === "notInstalled") return "não instalado";
	return status.error;
}

async function safeSnapshot(client: NativeClient): Promise<AppSnapshot> {
	try {
		return await client.invoke<AppSnapshot>("get_app_snapshot");
	} catch {
		return fallbackSnapshot;
	}
}

export function createTranscriptionApp(
	mount: HTMLElement,
	client: NativeClient = createNativeClient(),
): void {
	mount.textContent = "";

	let snapshot = fallbackSnapshot;

	const shell = element("section", "modal-shell");
	shell.setAttribute("aria-labelledby", "app-title");

	const topbar = element("header", "topbar");
	const titleGroup = element("div", "title-group");
	const eyebrow = element("p", "eyebrow", "Transcript Desktop");
	const title = element("h1", undefined, "Transcrição");
	title.id = "app-title";
	const subtitle = element("p", "subtitle");
	titleGroup.append(eyebrow, title, subtitle);

	const status = element("span", "status-pill");
	topbar.append(titleGroup, status);

	const editorLabel = element("label", "editor-label", "Texto transcrito");
	editorLabel.setAttribute("for", "transcript-editor");

	const editor = element(
		"textarea",
		"transcript-editor",
	) as HTMLTextAreaElement;
	editor.id = "transcript-editor";
	editor.placeholder =
		"A transcrição aparecerá aqui para revisão antes da inserção.";
	editor.rows = 10;

	const message = element("p", "message");
	message.setAttribute("role", "status");

	const actions = element("div", "actions");
	const recordButton = element(
		"button",
		"primary-button",
		"Iniciar gravação",
	) as HTMLButtonElement;
	const continueButton = element(
		"button",
		"secondary-button",
		"+ Continuar",
	) as HTMLButtonElement;
	const copyButton = element(
		"button",
		"secondary-button",
		"Copiar",
	) as HTMLButtonElement;
	const insertButton = element(
		"button",
		"secondary-button",
		"Inserir no app",
	) as HTMLButtonElement;
	const saveButton = element(
		"button",
		"ghost-button",
		"Salvar texto",
	) as HTMLButtonElement;
	actions.append(
		recordButton,
		continueButton,
		copyButton,
		insertButton,
		saveButton,
	);

	const modelPanel = element("aside", "model-panel");
	const modelTitle = element("h2", undefined, "Modelo offline");
	const modelDetails = element("p");
	const modelStatus = element("p", "model-status");
	const downloadModelButton = element(
		"button",
		"ghost-button",
		"Baixar modelo",
	) as HTMLButtonElement;
	modelPanel.append(modelTitle, modelDetails, modelStatus, downloadModelButton);

	const diagnostics = element("details", "diagnostics");
	const diagnosticsSummary = element(
		"summary",
		"diagnostics-summary",
		"Detalhes técnicos",
	);
	const diagnosticsBody = element("pre", "diagnostics-body");
	diagnostics.append(diagnosticsSummary, diagnosticsBody);
	diagnostics.open = false;

	shell.append(topbar, editorLabel, editor, message, actions, modelPanel, diagnostics);
	mount.append(shell);

	const render = (next: AppSnapshot): void => {
		snapshot = next;
		const isRecording = snapshot.recordingStatus === "recording";
		status.textContent = isRecording ? "Gravando" : "Pronto";
		status.dataset.state = snapshot.recordingStatus;
		subtitle.textContent = `${snapshot.settings.transcription.mode === "localFirst" ? "Offline primeiro" : "API"} · idioma ${snapshot.settings.transcription.language ?? "automático"}`;
		editor.value = snapshot.transcript.text;
		message.textContent =
			snapshot.transcript.lastMessage ?? "Revise o texto antes de inserir.";
		recordButton.textContent = isRecording
			? "Parar e transcrever"
			: "Iniciar gravação";

		const firstModelStatus = snapshot.models[0];
		const firstModel = firstModelStatus?.model;
		modelDetails.textContent = firstModel
			? `${firstModel.displayName} · ${firstModel.quantization} · ${formatBytes(firstModel.sizeBytes)} · ${firstModel.repository}`
			: "Nenhum modelo offline homologado encontrado.";
		modelStatus.textContent = firstModelStatus
			? `Status: ${modelStatusLabel(firstModelStatus.status)}`
			: "Status: indisponível";
		downloadModelButton.disabled = firstModelStatus?.status === "ready";
		downloadModelButton.textContent =
			firstModelStatus?.status === "ready" ? "Modelo pronto" : "Baixar modelo";

		const attempt = snapshot.transcript.lastAttempt;
		if (attempt) {
			diagnostics.open = true;
			diagnosticsBody.textContent = formatAttempt(attempt);
		} else {
			diagnosticsBody.textContent = "Nenhuma tentativa registrada ainda.";
		}
	};

	const refresh = async (): Promise<void> => {
		render(await safeSnapshot(client));
	};

	const showError = (error: unknown): void => {
		message.textContent =
			error instanceof Error ? error.message : String(error);
	};

	const toggleRecording = async (): Promise<void> => {
		const command =
			snapshot.recordingStatus === "recording"
				? "stop_recording_and_transcribe"
				: "start_recording";
		render(await client.invoke<AppSnapshot>(command));
	};

	recordButton.addEventListener("click", () => {
		void toggleRecording().catch(showError);
	});

	downloadModelButton.addEventListener("click", () => {
		downloadModelButton.disabled = true;
		downloadModelButton.textContent = "Baixando...";
		message.textContent = "Baixando modelo offline. Isso pode demorar.";
		void client
			.invoke("download_default_model_command")
			.then(refresh)
			.catch((error) => {
				downloadModelButton.disabled = false;
				downloadModelButton.textContent = "Baixar modelo";
				showError(error);
			});
	});

	continueButton.addEventListener("click", () => {
		void client
			.invoke<AppSnapshot>("start_recording")
			.then(render)
			.catch(showError);
	});

	copyButton.addEventListener("click", () => {
		void navigator.clipboard
			.writeText(editor.value)
			.then(() => {
				message.textContent = "Texto copiado para a área de transferência.";
			})
			.catch(() => {
				message.textContent =
					"Não foi possível copiar automaticamente. Selecione o texto manualmente.";
			});
	});

	insertButton.addEventListener("click", () => {
		void client
			.invoke<{ message: string }>("request_insert_text", {
				text: editor.value,
			})
			.then((result) => {
				message.textContent = result.message;
			})
			.catch(showError);
	});

	saveButton.addEventListener("click", () => {
		const blob = new Blob([editor.value], { type: "text/plain;charset=utf-8" });
		const url = URL.createObjectURL(blob);
		const link = document.createElement("a");
		link.href = url;
		link.download = "transcricao.txt";
		link.click();
		URL.revokeObjectURL(url);
		message.textContent = "Arquivo de texto preparado para download.";
	});

	void listen("transcript://toggle-recording", () => {
		void toggleRecording().catch(showError);
	}).catch(() => {
		// Browser preview and tests do not expose the Tauri event bridge.
	});

	void refresh();
}