// composables/useWikiTree.ts
export interface WikiPageItem {
    id: string
    parentId: string | null
    title: string
    isFolder: boolean
    sortOrder: number
    entityType?: string | null
    children?: WikiPageItem[]
}

export const useWikiTree = () => {
    const { $api } = useNuxtApp()

    // State
    const items = useState<WikiPageItem[]>('wiki-items', () => [])
    const isLoading = useState<boolean>('wiki-loading', () => false)
    const isSidebarOpen = useState<boolean>('wiki-sidebar-open', () => true)

    // --- Computed: Tree Logic ---
    const tree = computed(() => {
        const rawItems = items.value || []
        if (!rawItems.length) return []

        const roots: WikiPageItem[] = []
        const lookup: Record<string, WikiPageItem> = {}

        // Clone & Init
        rawItems.forEach(item => {
            lookup[item.id] = { ...item, children: [] }
        })

        // Build Tree
        rawItems.forEach(item => {
            const node = lookup[item.id]
            if (item.parentId && lookup[item.parentId]) {
                lookup[item.parentId].children?.push(node)
            } else {
                roots.push(node)
            }
        })

        // Sort: Folders first, then Alphabet
        const sortNodes = (nodes: WikiPageItem[]) => {
            nodes.sort((a, b) => {
                if (a.isFolder !== b.isFolder) return a.isFolder ? -1 : 1
                return a.title.localeCompare(b.title)
            })
            nodes.forEach(n => {
                if (n.children?.length) sortNodes(n.children)
            })
        }

        sortNodes(roots)
        return roots
    })

    // --- Actions ---

    const loadTree = async () => {
        isLoading.value = true
        try {
            const data = await $api<WikiPageItem[]>('/api/wiki/tree', { method: 'GET' })
            items.value = data
        } catch (e) { console.error(e) }
        finally { isLoading.value = false }
    }

    // Zentralisierte Erstellen-Funktion
    const createItem = async (title: string, parentId: string | null, isFolder: boolean) => {
        try {
            const newItem = await $api('/api/wiki', {
                method: 'POST',
                body: { title, parentId, isFolder }
            })
            await loadTree() // Neu laden
            return newItem
        } catch (e) {
            alert('Fehler beim Erstellen')
            return null
        }
    }

    // Löschen Funktion
    const deleteItem = async (id: string) => {
        if (!confirm('Wirklich löschen? Alle Unterseiten werden ebenfalls gelöscht.')) return
        try {
            await $api(`/api/wiki/${id}`, { method: 'DELETE' })
            await loadTree()
            return true
        } catch (e) {
            alert('Fehler beim Löschen')
            return false
        }
    }

    return {
        tree, items, isLoading, isSidebarOpen,
        loadTree, createItem, deleteItem
    }
}