import type { Topic } from "~~/types";

export const useTopics = async () => {
    const appState = useAppState()
    const fetchingTopics = ref(false);
    const topics: Ref<any[] | null> = useState('topics', () => null);

    /**
     * Compute topics for the currently active agent
     */
    const topicsForActiveAgent = computed(() => {
        if (topics.value === null || !appState.activeAgentId.value) return [];
        return topics.value.filter(topic => topic.agentId === appState.activeAgentId.value);
    });

    const activeTopic = computed(() => {
        if (topicsForActiveAgent.value.length === 0) return;
        if (!appState.activeTopicId.value) return;

        const topic = topicsForActiveAgent.value.find(topic => topic.id === appState.activeTopicId.value);
        return topic;
    });

    const refreshTopics = async () => {
        if (fetchingTopics.value) return;
        fetchingTopics.value = true;

        try {
            const { data, error } = await useFetch('/api/topics');
            if (error.value) throw error;
            topics.value = data.value!;
        } finally {
            fetchingTopics.value = false;
        }
    }

    if (topics.value === null) await refreshTopics();

    const createTopic = async (name: string, agentId: string) => {
        const res = await fetch('/api/topics', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/json'
            },
            body: JSON.stringify({ name, agentId })
        })

        if (!res.ok) {
            throw new Error('Failed to create topic')
        }

        const newTopic = await res.json()
        if (topics.value === null) topics.value = []
        topics.value.push(newTopic)
        return newTopic
    }

    return { createTopic, activeTopic, topics, topicsForActiveAgent, fetchingTopics, refreshTopics }
}