import { useCallback, useEffect, useState } from "react";
import {
	listTerminalSessions,
	createTerminalSession,
	closeTerminalSession,
	resetTerminalSession,
	renameTerminalSession,
	type TerminalSession,
} from "../api/terminal";

export interface UseTerminalSessionsResult {
	sessions: TerminalSession[];
	activeSessionId: string | null;
	setActiveSessionId: (id: string) => void;
	createSession: (name?: string) => Promise<TerminalSession | null>;
	closeSession: (sessionId: string) => Promise<void>;
	renameSession: (sessionId: string, name: string) => Promise<void>;
	resetSession: (sessionId: string) => Promise<void>;
	loading: boolean;
	error: string | null;
}

export function useTerminalSessions(
	instanceId: string,
): UseTerminalSessionsResult {
	const [sessions, setSessions] = useState<TerminalSession[]>([]);
	const [activeSessionId, setActiveSessionId] = useState<string | null>(null);
	const [loading, setLoading] = useState(true);
	const [error, setError] = useState<string | null>(null);

	const loadSessions = useCallback(async () => {
		setLoading(true);
		setError(null);
		try {
			const sess = await listTerminalSessions(instanceId);
			setSessions(sess);
			if (sess.length > 0 && !activeSessionId) {
				setActiveSessionId(sess[0].id);
			}
		} catch (err) {
			setError(err instanceof Error ? err.message : "Failed to load sessions");
		} finally {
			setLoading(false);
		}
	}, [instanceId, activeSessionId]);

	const createSession = useCallback(
		async (name?: string) => {
			setError(null);
			try {
				const newSession = await createTerminalSession(instanceId, name);
				const session: TerminalSession = {
					id: newSession.id,
					name: newSession.name,
					status: newSession.status,
					has_websockets: false,
					created_at: newSession.created_at,
					last_activity_at: null,
				};
				setSessions((prev) => [...prev, session]);
				setActiveSessionId(session.id);
				return session;
			} catch (err) {
				const msg =
					err instanceof Error ? err.message : "Failed to create session";
				setError(msg);
				return null;
			}
		},
		[instanceId],
	);

	const closeSession = useCallback(
		async (sessionId: string) => {
			setError(null);
			try {
				await closeTerminalSession(instanceId, sessionId);
				setSessions((prev) => {
					const filtered = prev.filter((s) => s.id !== sessionId);
					if (activeSessionId === sessionId && filtered.length > 0) {
						setActiveSessionId(filtered[0].id);
					} else if (filtered.length === 0) {
						setActiveSessionId(null);
					}
					return filtered;
				});
			} catch (err) {
				setError(
					err instanceof Error ? err.message : "Failed to close session",
				);
			}
		},
		[instanceId, activeSessionId],
	);

	const renameSession = useCallback(
		async (sessionId: string, name: string) => {
			setError(null);
			try {
				await renameTerminalSession(instanceId, sessionId, name);
				setSessions((prev) =>
					prev.map((s) => (s.id === sessionId ? { ...s, name } : s)),
				);
			} catch (err) {
				setError(
					err instanceof Error ? err.message : "Failed to rename session",
				);
			}
		},
		[instanceId],
	);

	const resetSession = useCallback(
		async (sessionId: string) => {
			setError(null);
			try {
				await resetTerminalSession(instanceId, sessionId);
				// Refetch to get updated session info
				await loadSessions();
			} catch (err) {
				setError(
					err instanceof Error ? err.message : "Failed to reset session",
				);
			}
		},
		[instanceId, loadSessions],
	);

	// Initial load
	useEffect(() => {
		void loadSessions();
	}, [loadSessions]);

	return {
		sessions,
		activeSessionId,
		setActiveSessionId,
		createSession,
		closeSession,
		renameSession,
		resetSession,
		loading,
		error,
	};
}