import { onMounted, readonly, ref } from "vue";

import type { BrowsableFilesSourcePlugin, FilterFileSourcesOptions } from "@/api/remoteFiles";
import { useFileSourcesStore } from "@/stores/fileSourcesStore";
import { USER_FILE_PREFIX } from "@/utils/url";

/**
 * Composable for accessing and working with file sources.
 *
 * @param options - The options to filter the file sources.
 */
export function useFileSources(options: FilterFileSourcesOptions = {}) {
    const fileSourcesStore = useFileSourcesStore();

    const isLoading = ref(true);
    const hasWritable = ref(false);
    const fileSources = ref<BrowsableFilesSourcePlugin[]>([]);

    onMounted(async () => {
        fileSources.value = await fileSourcesStore.getFileSources(options);
        hasWritable.value = fileSources.value.some((fs) => fs.writable);
        isLoading.value = false;
    });

    function getFileSourceById(id: string) {
        return fileSources.value.find((fs) => fs.id === id);
    }

    function getFileSourcesByType(type: string) {
        return fileSources.value.filter((fs) => fs.type === type);
    }

    function isPrivateFileSource(fs: BrowsableFilesSourcePlugin) {
        return fs.uri_root.startsWith(USER_FILE_PREFIX);
    }

    function getFileSourceByUri(uri: string) {
        const sourceId = getFileSourceIdFromUri(uri);
        let matchedFileSource = getFileSourceById(sourceId);
        if (matchedFileSource) {
            return matchedFileSource;
        }

        // Match by URI root if the source ID is not found.
        matchedFileSource = fileSources.value.find((fs) => uri.startsWith(fs.uri_root));
        return matchedFileSource;
    }

    function getFileSourceIdFromUri(uri: string) {
        const sourceId = uri.split("://")[1]?.split("/")[0] ?? "";
        return sourceId;
    }

    function supportsFeature(uri: string | null | undefined, feature: "pagination" | "search" | "sorting"): boolean {
        if (!uri) {
            return false;
        }
        const fileSource = getFileSourceByUri(uri);
        return Boolean(fileSource?.supports?.[feature]);
    }

    function supportsPagination(uri: string | null | undefined): boolean {
        return supportsFeature(uri, "pagination");
    }

    function supportsSearch(uri: string | null | undefined): boolean {
        return supportsFeature(uri, "search");
    }

    function supportsSorting(uri: string | null | undefined): boolean {
        return supportsFeature(uri, "sorting");
    }

    return {
        /**
         * The list of available file sources from the server.
         */
        fileSources: readonly(fileSources),
        /**
         * Whether the file sources are being loaded from the server.
         */
        isLoading: readonly(isLoading),
        /**
         * Whether the user can write files to any of the available file sources.
         */
        hasWritable: readonly(hasWritable),
        /**
         * Get the file source with the given ID.
         *
         * @param id - The ID of the file source to get.
         * @returns The file source with the given ID, if found.
         */
        getFileSourceById,
        /**
         * Get the file source that matches the given URI.
         *
         * @param uri - The URI to match.
         * @returns The file source that matches the given URI, if found.
         */
        getFileSourceByUri,
        /**
         * Get the file sources that match the given type.
         *
         * @param type - The type to match.
         * @returns The file sources that match the given type.
         */
        getFileSourcesByType,
        /**
         * Check if the given file source is a private file source provided by the user.
         *
         * @param fs - The file source to check.
         * @returns Whether the file source is a private file source.
         */
        isPrivateFileSource,
        /**
         * Check if the file source at the given URI supports pagination.
         *
         * @param uri - The URI of the file source.
         * @returns Whether the file source supports pagination.
         */
        supportsPagination,
        /**
         * Check if the file source at the given URI supports search.
         *
         * @param uri - The URI of the file source.
         * @returns Whether the file source supports search.
         */
        supportsSearch,
        /**
         * Check if the file source at the given URI supports sorting.
         *
         * @param uri - The URI of the file source.
         * @returns Whether the file source supports sorting.
         */
        supportsSorting,
    };
}