import { attempt } from "~~/types/result";
import * as schema from '~~/drizzle/schema';

export type ResourceFile = typeof schema.files.$inferSelect;

export type ResourceCategory = 'all' | 'documents' | 'images' | 'audio' | 'videos';

const categoryMimeMap: Record<ResourceCategory, (mime: string) => boolean> = {
    all: () => true,
    documents: (mime) =>
        mime === 'application/pdf' ||
        mime.startsWith('text/') ||
        mime.includes('document') ||
        mime.includes('spreadsheet') ||
        mime.includes('presentation'),
    images: (mime) => mime.startsWith('image/'),
    audio: (mime) => mime.startsWith('audio/'),
    videos: (mime) => mime.startsWith('video/'),
};

export const useResources = async () => {
    const files = useState<ResourceFile[]>('resources:files', () => []);
    const loaded = useState('resources:loaded', () => false);
    const selectedIds = useState<Set<string>>('resources:selected', () => new Set());
    const category = useState<ResourceCategory>('resources:category', () => 'all');

    const { refresh } = await useFetch<ResourceFile[]>('/api/files', {
        key: 'resources_files_request',
        immediate: !loaded.value,
        onRequest() {
            loaded.value = true;
        },
        onResponse({ response }) {
            if (response.ok) {
                files.value = response._data ?? [];
            }
        },
    });

    const filteredFiles = computed(() => {
        const filter = categoryMimeMap[category.value];
        return files.value.filter(f => filter(f.mimeType));
    });

    const setCategory = (cat: ResourceCategory) => {
        category.value = cat;
        clearSelection();
    };

    const categoryCount = (cat: ResourceCategory): number => {
        const filter = categoryMimeMap[cat];
        return files.value.filter(f => filter(f.mimeType)).length;
    };

    const toggleSelect = (id: string) => {
        const next = new Set(selectedIds.value);
        if (next.has(id)) {
            next.delete(id);
        } else {
            next.add(id);
        }
        selectedIds.value = next;
    };

    const selectAll = () => {
        selectedIds.value = new Set(filteredFiles.value.map(f => f.id));
    };

    const clearSelection = () => {
        selectedIds.value = new Set();
    };

    const isAllSelected = computed(() =>
        filteredFiles.value.length > 0 && selectedIds.value.size === filteredFiles.value.length
    );

    const hasSelection = computed(() => selectedIds.value.size > 0);

    const selectedCount = computed(() => selectedIds.value.size);

    const deleteFile = async (id: string) => {
        const file = files.value.find(f => f.id === id);
        if (!file) return;

        const res = await attempt($fetch(`/api/file/${id}`, {
            method: 'DELETE',
            onRequest() {
                files.value = files.value.filter(f => f.id !== id);
                const next = new Set(selectedIds.value);
                next.delete(id);
                selectedIds.value = next;
            },
            onRequestError() {
                files.value = [...files.value, file].sort(
                    (a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime()
                );
            },
            onResponseError() {
                files.value = [...files.value, file].sort(
                    (a, b) => new Date(b.createdAt).getTime() - new Date(a.createdAt).getTime()
                );
            },
        }));

        return res;
    };

    const deleteSelected = async () => {
        const ids = Array.from(selectedIds.value);
        clearSelection();

        const results = await Promise.allSettled(
            ids.map(id => deleteFile(id))
        );

        await refresh();
        return results;
    };

    const copyLink = async (file: ResourceFile) => {
        const url = file.url;
        await navigator.clipboard.writeText(url);
    };

    const downloadFile = (file: ResourceFile) => {
        const url = file.url;
        const a = document.createElement('a');
        a.href = url;
        a.download = file.name;
        document.body.appendChild(a);
        a.click();
        document.body.removeChild(a);
    };

    const getFileIcon = (mimeType: string): string => {
        if (mimeType.startsWith('image/')) return 'i-mynaui-image';
        if (mimeType === 'application/pdf') return 'i-tabler-file-type-pdf';
        if (mimeType.startsWith('text/')) return 'i-mynaui-file-text';
        if (mimeType.startsWith('video/')) return 'i-mynaui-video';
        if (mimeType.startsWith('audio/')) return 'i-mynaui-music';
        return 'i-mynaui-file-text';
    };

    const isImage = (mimeType: string): boolean => mimeType.startsWith('image/');

    const formatSize = (bytes: number): string => {
        if (bytes === 0) return '-';
        const units = ['B', 'KB', 'MB', 'GB'];
        const i = Math.floor(Math.log(bytes) / Math.log(1024));
        const size = bytes / Math.pow(1024, i);
        return `${size.toFixed(i === 0 ? 0 : 1)} ${units[i]}`;
    };

    const formatDate = (date: Date | string): string => {
        const d = new Date(date);
        return d.toLocaleDateString('en-US', {
            month: 'short',
            day: 'numeric',
            year: 'numeric',
        });
    };

    return {
        files,
        filteredFiles,
        selectedIds,
        selectedCount,
        hasSelection,
        isAllSelected,
        category,
        setCategory,
        categoryCount,
        toggleSelect,
        selectAll,
        clearSelection,
        deleteFile,
        deleteSelected,
        copyLink,
        downloadFile,
        getFileIcon,
        isImage,
        formatSize,
        formatDate,
        refresh,
    };
};