/**
 * Validates the email input and handles error display.
 * 
 * @returns True if the email is valid, otherwise false.
 */
const accessibleDocsFormValidation = (): boolean => {
    // Email validation regex
    const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
    const emailInput = document.querySelector<HTMLInputElement>('.js-accessible-docs-email');
    const errorElement = document.querySelector<HTMLElement>('.js-accessible-docs-popup-error');

    if (!emailInput || !errorElement) {
        console.warn('Email input or error element is not found.');
        return false;
    }

    if (!emailInput || !emailRegex.test(emailInput.value.trim())) {
        errorElement.style.display = 'block';
        return false;
    }

    // If valid, hide the error
    errorElement.style.display = 'none';
    return true;
};

/**
 * Sends a request for accessible documents.
 * 
 * @param {string} email - The email address of the requester.
 * @param {string} href - The URL of the document being requested.
 * @returns {Promise<string>} A promise that resolves to:
 *   - `error` if the request fails.
 *   - `in-process` if the file request is being processed.
 *   - `completed` if the file request is successful.
 */
const sendAccessibleDocsRequest = async (email: string, href: string): Promise<string> => {
    try {
        const formData = new FormData();
        formData.append('action', 'accessible_docs_request');
        // @ts-ignore
        formData.append('nonce', accessible_docs_object.nonce);
        formData.append('email', email);
        formData.append('url', href);

        // @ts-ignore
        const response = await fetch(accessible_docs_object.ajax_url, {
            method: 'POST',
            body: formData
        });               

        if (!response.ok) {
            accessibleDocsUpdatePopupStatus('error');
            throw new Error(`Response status: ${response.status}`);
        }

        const result = await response.json();

        if (!result.success) {
            accessibleDocsUpdatePopupStatus('error');
            throw new Error(`Error: ${result.data.error}`);
        } 
        
        if (result.data.status) {
            return result.data.status;
        }

        return 'success'; // Ensure a return value for all cases

    } catch (error) {
        accessibleDocsUpdatePopupStatus('error');
        throw new Error(`Error: ${error}`);
    }
};

/**
 * Updates the status of the accessible documents popup.
 * 
 * @param {string} status - The status to be added as a CSS class. Allowed values: 'success', 'error', 'in_process'.
 */
const accessibleDocsUpdatePopupStatus = (status?: string): void => {
    const loader = document.querySelector<HTMLElement>('.js-accessible-docs-popup-loader');

    if (!status) {
        throw new Error('Status parameter is required.');
    }

    const popup = document.querySelector<HTMLElement>('.js-accessible-docs-popup');

    if (!popup) {
        throw new Error('Accessible docs popup element not found.');
    }

    // Only add the class if it's not already present
    if (!popup.classList.contains(status)) {
        popup.classList.add(status);
    }

    if (loader) {
        loader.classList.remove('active');
    }
};

/**
 * Handles the submit button logic for the accessible docs popup form.
 */
const handleSubmitAccessibleDocs = async () => {
    const emailInput = document.querySelector<HTMLInputElement>('.js-accessible-docs-email');
    const linkElement = document.querySelector<HTMLAnchorElement>('.js-accessible-docs-link');
    const loader = document.querySelector<HTMLElement>('.js-accessible-docs-popup-loader');

    // Validate the email and handle error display
    const isValid = accessibleDocsFormValidation();

    if ( isValid && emailInput && linkElement ) {
        const email = emailInput.value.trim();
        const href = linkElement.href;

        if (loader) {
            loader.classList.add('active');
        }

        const requestStatus = await sendAccessibleDocsRequest(email, href);

        if (requestStatus) {
            accessibleDocsUpdatePopupStatus(requestStatus);
        }

        if (loader) {
            loader.classList.remove('active');
        }
    }
    
}

export default handleSubmitAccessibleDocs;