useConversation.ts

import { useCallback, useEffect, useRef, useState } from "react";
import {
	conversationApi,
	sessionApi,
	speechToText,
	textToSpeechUrl,
} from "@/lib/api";
import type { VoiceAnalysisResult } from "@/lib/audio/voiceAnalysis";
import type { ConversationSession, Message } from "@/types/api";
import { useLipSync } from "./useLipSync";

interface UseConversationOptions {
	systemPrompt?: string;
	onAudioReady?: (audioUrl: string) => void;
	onLipSyncUpdate?: (value: number) => void;
	ttsVoiceId?: string;
	onEmotionUpdate?: (
		emotion: "neutral" | "happy" | "sad" | "surprised" | "angry" | "bashful",
	) => void;
	avatarId?: string; // persona id
}

interface ConversationState {
	session: ConversationSession | null;
	messages: Message[];
	isProcessing: boolean;
	error: Error | null;
	currentAudioUrl: string | null;
}

export function useConversation(options: UseConversationOptions) {
	const {
		systemPrompt,
		onAudioReady,
		onLipSyncUpdate,
		ttsVoiceId,
		onEmotionUpdate,
		avatarId,
	} = options;

	const [state, setState] = useState<ConversationState>({
		session: null,
		messages: [],
		isProcessing: false,
		error: null,
		currentAudioUrl: null,
	});

	const audioRef = useRef<HTMLAudioElement | null>(null);

	// リップシンクを統合
	const lipSyncValue = useLipSync(audioRef.current);

	// セッションを開始
	const startSession = useCallback(async () => {
		try {
			setState((prev) => ({ ...prev, isProcessing: true, error: null }));

			// localStorageから既存のuserIdを取得
			let existingUserId: string | null = null;
			if (typeof window !== "undefined") {
				existingUserId = localStorage.getItem("conversationUserId");
				console.log("Existing user ID from localStorage:", existingUserId);
			}

			// 既存のuserIdがあればそれを使用、なければバックエンドで新規作成
			const session = await sessionApi.createSession(
				existingUserId || undefined,
			);

			// userIdをlocalStorageに保存して永続化
			if (session.userId && typeof window !== "undefined") {
				localStorage.setItem("conversationUserId", session.userId);
				console.log("User ID saved to localStorage:", session.userId);
			}

			setState((prev) => ({
				...prev,
				session,
				isProcessing: false,
			}));
			return session;
		} catch (error) {
			const err = error instanceof Error ? error : new Error("Unknown error");
			setState((prev) => ({
				...prev,
				error: err,
				isProcessing: false,
			}));
			throw err;
		}
	}, []);

	// セッションを終了
	const endSession = useCallback(async () => {
		if (!state.session) return;

		try {
			setState((prev) => ({ ...prev, isProcessing: true }));
			await sessionApi.finishSession(state.session.id);
			setState((prev) => ({
				...prev,
				isProcessing: false,
			}));
		} catch (error) {
			const err = error instanceof Error ? error : new Error("Unknown error");
			setState((prev) => ({
				...prev,
				error: err,
				isProcessing: false,
			}));
		}
	}, [state.session]);

	// リップシンク値を親コンポーネントに通知
	useEffect(() => {
		if (onLipSyncUpdate) {
			onLipSyncUpdate(lipSyncValue);
		}
	}, [lipSyncValue, onLipSyncUpdate]);

	// 音声を送信して応答を取得（STT → AI → TTS）
	const sendAudio = useCallback(
		async (
			audioBlob: Blob,
			_voiceAnalysis?: VoiceAnalysisResult | null,
		): Promise<Message | null> => {
			if (!state.session) {
				throw new Error("No active session");
			}

			try {
				setState((prev) => ({ ...prev, isProcessing: true, error: null }));

				// 1. STT: 音声をテキストに変換
				const audioFile = new File([audioBlob], "recording.webm", {
					type: audioBlob.type,
				});
				const sttResult = await speechToText({
					audio: audioFile,
				});

				console.log("STT Result:", sttResult.text);

				// Unsupported language プレースホルダーを検出したらAI呼び出しをスキップ
				if (sttResult.text === "[UNSUPPORTED_LANGUAGE]") {
					const unsupportedErr = new Error(
						"日本語または英語で話してください (Detected unsupported language).",
					);
					setState((prev) => ({
						...prev,
						error: unsupportedErr,
						isProcessing: false,
					}));
					return null;
				}

				// 2. AI: テキストから応答を生成
				const relationshipStage =
					state.messages.length < 7
						? "shy"
						: state.messages.length < 15
							? "friendly"
							: "open";
				const aiResponse = await conversationApi.generateResponse({
					sessionId: state.session.id,
					userMessage: sttResult.text,
					systemPrompt,
					avatarId,
					relationshipStage,
				});

				console.log(
					"AI Response:",
					aiResponse.response,
					"Emotion:",
					aiResponse.emotion,
				);

				// Emotion update to UI
				if (onEmotionUpdate) {
					onEmotionUpdate(aiResponse.emotion);
				}

				// メッセージを状態に追加
				setState((prev) => ({
					...prev,
					messages: [
						...prev.messages,
						aiResponse.userMessage,
						aiResponse.assistantMessage,
					],
				}));

				// 3. TTS: AIの応答を音声に変換
				console.log("Starting TTS for text:", aiResponse.response);
				const audioUrl = await textToSpeechUrl({
					text: aiResponse.response,
					voiceId: ttsVoiceId,
				});

				console.log("TTS Audio URL created:", audioUrl);

				// 音声を再生
				const audio = new Audio(audioUrl);
				audioRef.current = audio;

				// 音量を確認（デフォルトは1.0）
				audio.volume = 1.0;
				console.log("Audio volume set to:", audio.volume);

				console.log("Audio element created, waiting for playback...");

				try {
					await audio.play();
					console.log("Audio playback started successfully");
				} catch (err) {
					console.error("Audio playback failed (autoplay?)", err);
					setState((prev) => ({
						...prev,
						error: new Error(
							"Audio playback failed. Please interact with the page (e.g., click somewhere) and try again.",
						),
					}));
				}

				setState((prev) => ({
					...prev,
					currentAudioUrl: audioUrl,
					isProcessing: false,
				}));

				onAudioReady?.(audioUrl);

				return aiResponse.assistantMessage;
			} catch (error) {
				const err = error instanceof Error ? error : new Error("Unknown error");
				console.error("Conversation error:", err);
				setState((prev) => ({
					...prev,
					error: err,
					isProcessing: false,
				}));
				return null;
			}
		},
		[
			state.session,
			systemPrompt,
			ttsVoiceId,
			onAudioReady,
			onEmotionUpdate,
			avatarId,
			state.messages.length,
		],
	);

	// クリーンアップ
	useEffect(() => {
		return () => {
			if (audioRef.current) {
				audioRef.current.pause();
				audioRef.current = null;
			}
		};
	}, []);

	return {
		session: state.session,
		messages: state.messages,
		isProcessing: state.isProcessing,
		error: state.error,
		currentAudioUrl: state.currentAudioUrl,
		startSession,
		endSession,
		sendAudio,
	};
}