import type { IActivityHandler } from "@vertigis/workflow";

/** An interface that defines the inputs of the activity. */
interface Base64ToFileInputs {
    /**
     * @displayName base64
     * @description Base4 string content.
     * @required
     */
    base64: string;
}

/** An interface that defines the outputs of the activity. */
interface Base64ToFileOutputs {
    /**
     * @description the result Blob
     */
    blob: Blob;
}


function base64toFile(base64String: string) {
    const binaryData = atob(base64String.replace(/-/g, "+").replace(/_/g, "/"));

    // Create a new array buffer to hold the binary data
    const arrayBuffer = new ArrayBuffer(binaryData.length);

    // Create a new unit8 array to view the array buffer
    const uint8Array = new Uint8Array(arrayBuffer);

    // Fill the uint8 array with the binary data
    for (let i = 0; i < binaryData.length; i++) {
        uint8Array[i] = binaryData.charCodeAt(i);
    }

    // Create a Blob object from the array buffer
    const blob = new Blob([uint8Array], { type: 'application/octet-stream' });


    return blob
}


/**
 * @displayName Base64 To File
 * @category EBTA Utilities
 * @description Convert Base64 To File Ver02
 */
export default class Base64ToFileActivity implements IActivityHandler {
    /** Perform the execution logic of the activity. */
    execute(inputs: Base64ToFileInputs): Base64ToFileOutputs {
        return {
            blob: base64toFile(inputs.base64)
        };
    }
}