import { calculate as calculateHashes } from "../hashes.js";

export function HashesManager( wire ) {
    return {

        /**
         * Wire variable instance.
         */
        $wire: wire,

        /**
         * If a file hash is currently calculated or not.
         * @type {boolean}
         */
        isCalculating: false,

        /**
         * An error on hash calculation.
         * @type {any|null}
         */
        error: null,

        async handleSubmitFile(){

            if( this.isCalculating === true ) // Calculation already done for another file.
                return;

            this.error = null; // Reset.
            const FILE = await this.openFileInput();

            if( !FILE )
                return; // No file sent.

            this.isCalculating = true;

            try {
                const RESULT = await calculateHashes(FILE);
                await this.$wire.addHash(RESULT.filename, RESULT.crc32, RESULT.sha1); // Send a signal to livewire.
            } catch(err) {
                this.error = err.message;
            } finally {
                this.isCalculating = false;
            }
        },

        /**
         * Open a specific file.
         * @returns {Promise<unknown>}
         */
        async openFileInput(){
            return new Promise(resolve => {
                const input = document.createElement("input");
                input.type = "file";
                input.onchange = () => resolve(input.files[0] ?? null );
                input.oncancel = () => resolve(null);
                input.click();
            });
        }
    }
}