<?php

namespace Quiztech\AssessmentPlatform\Admin;

/**
 * Handles the Quiztech plugin settings page in WP Admin.
 */
class SettingsPage {

    /**
     * Option group name.
     * @var string
     */
    private $option_group = 'quiztech_settings';

    /**
     * Option name in wp_options table.
     * @var string
     */
    private $option_name = 'quiztech_settings';

    /**
     * Settings page slug.
     * @var string
     */
    private $page_slug = 'quiztech-settings-page';

    /**
     * Register hooks for the settings page.
     */
    public function register_hooks() {
        add_action( 'admin_menu', [ $this, 'add_admin_page' ] );
        add_action( 'admin_init', [ $this, 'register_settings' ] );
        add_action( 'wp_ajax_quiztech_send_test_email', [ $this, 'handle_send_test_email_ajax' ] );
    }

    /**
     * Adds the submenu page under the main Settings menu.
     */
    public function add_admin_page() {
        add_options_page(
            __( 'Quiztech Settings', 'quiztech' ), // Page Title
            __( 'Quiztech', 'quiztech' ),          // Menu Title
            'manage_options',                      // Capability Required
            $this->page_slug,                      // Menu Slug
            [ $this, 'render_settings_page' ]      // Callback function to render the page
        );
    }

    /**
     * Registers settings, sections, and fields using the Settings API.
     */
    public function register_settings() {
        register_setting(
            $this->option_group,                // Option group
            $this->option_name,                 // Option name
            [ $this, 'sanitize_settings' ]      // Sanitization callback
        );

        // Stripe Section
        add_settings_section(
            'quiztech_stripe_section',          // Section ID
            __( 'Stripe API Keys', 'quiztech' ), // Section Title
            '__return_false',                   // Section callback (optional description)
            $this->page_slug                    // Page slug where section appears
        );

        // Stripe Public Key Field
        add_settings_field(
            'quiztech_stripe_public_key',       // Field ID
            __( 'Stripe Public Key', 'quiztech' ), // Field Title
            [ $this, 'render_text_field' ],     // Field render callback
            $this->page_slug,                   // Page slug
            'quiztech_stripe_section',          // Section ID
            [                                   // Arguments for callback
                'id' => 'quiztech_stripe_public_key',
                'option_name' => $this->option_name,
                'key' => 'stripe_public_key',
                'description' => __( 'Enter your Stripe publishable API key.', 'quiztech' )
            ]
        );

        // Stripe Secret Key Field
        add_settings_field(
            'quiztech_stripe_secret_key',       // Field ID
            __( 'Stripe Secret Key', 'quiztech' ), // Field Title
            [ $this, 'render_text_field' ],     // Field render callback
            $this->page_slug,                   // Page slug
            'quiztech_stripe_section',          // Section ID
            [                                   // Arguments for callback
                'id' => 'quiztech_stripe_secret_key',
                'option_name' => $this->option_name,
                'key' => 'stripe_secret_key',
                'type' => 'password', // Mask the input
                'description' => __( 'Enter your Stripe secret API key. This is kept confidential.', 'quiztech' )
            ]
        );


        // --- SMTP Section ---
        add_settings_section(
            'quiztech_smtp_section',            // Section ID
            __( 'SMTP Settings', 'quiztech' ),   // Section Title
            [ $this, 'render_smtp_section_description' ], // Section callback for description
            $this->page_slug                      // Page slug where section appears
        );

        // SMTP Enabled Field (Checkbox)
        add_settings_field(
            'quiztech_smtp_enabled',
            __( 'Enable SMTP', 'quiztech' ),
            [ $this, 'render_checkbox_field' ], // New callback needed
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_enabled',
                'option_name' => $this->option_name,
                'key' => 'smtp_enabled',
                'description' => __( 'Enable sending emails via a custom SMTP server instead of the default WordPress mail function.', 'quiztech' )
            ]
        );

        // SMTP Host Field
        add_settings_field(
            'quiztech_smtp_host',
            __( 'SMTP Host', 'quiztech' ),
            [ $this, 'render_text_field' ],
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_host',
                'option_name' => $this->option_name,
                'key' => 'smtp_host',
                'description' => __( 'e.g., smtp.example.com', 'quiztech' )
            ]
        );

        // SMTP Port Field
        add_settings_field(
            'quiztech_smtp_port',
            __( 'SMTP Port', 'quiztech' ),
            [ $this, 'render_text_field' ], // Use text field, sanitize as number later
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_port',
                'option_name' => $this->option_name,
                'key' => 'smtp_port',
                'type' => 'number',
                'description' => __( 'e.g., 587 (TLS) or 465 (SSL)', 'quiztech' )
            ]
        );

        // SMTP Encryption Field (Select)
        add_settings_field(
            'quiztech_smtp_encryption',
            __( 'Encryption', 'quiztech' ),
            [ $this, 'render_select_field' ], // New callback needed
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_encryption',
                'option_name' => $this->option_name,
                'key' => 'smtp_encryption',
                'options' => [
                    '' => __( 'None', 'quiztech' ),
                    'ssl' => __( 'SSL', 'quiztech' ),
                    'tls' => __( 'TLS', 'quiztech' ),
                ],
                'description' => __( 'Select the encryption method.', 'quiztech' )
            ]
        );

        // SMTP Auth Field (Checkbox)
        add_settings_field(
            'quiztech_smtp_auth',
            __( 'Use Authentication', 'quiztech' ),
            [ $this, 'render_checkbox_field' ], // Reuse callback
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_auth',
                'option_name' => $this->option_name,
                'key' => 'smtp_auth',
                'description' => __( 'Enable if your SMTP server requires a username and password.', 'quiztech' )
            ]
        );

        // SMTP Username Field
        add_settings_field(
            'quiztech_smtp_username',
            __( 'SMTP Username', 'quiztech' ),
            [ $this, 'render_text_field' ],
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_username',
                'option_name' => $this->option_name,
                'key' => 'smtp_username',
                'description' => __( 'The username for SMTP authentication.', 'quiztech' )
            ]
        );

        // SMTP Password Field
        add_settings_field(
            'quiztech_smtp_password',
            __( 'SMTP Password', 'quiztech' ),
            [ $this, 'render_text_field' ],
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_password',
                'option_name' => $this->option_name,
                'key' => 'smtp_password',
                'type' => 'password',
                'description' => __( 'The password for SMTP authentication. Stored as plain text in the database.', 'quiztech' )
            ]
        );

        // SMTP From Address Field
        add_settings_field(
            'quiztech_smtp_from_address',
            __( 'From Email Address', 'quiztech' ),
            [ $this, 'render_text_field' ],
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_from_address',
                'option_name' => $this->option_name,
                'key' => 'smtp_from_address',
                'type' => 'email',
                'description' => __( 'The email address emails will be sent from.', 'quiztech' )
            ]
        );

        // SMTP From Name Field
        add_settings_field(
            'quiztech_smtp_from_name',
            __( 'From Name', 'quiztech' ),
            [ $this, 'render_text_field' ],
            $this->page_slug,
            'quiztech_smtp_section',
            [
                'id' => 'quiztech_smtp_from_name',
                'option_name' => $this->option_name,
                'key' => 'smtp_from_name',
                'description' => __( 'The name emails will be sent from.', 'quiztech' )
            ]
        );

        // Future settings sections/fields (e.g., email, defaults) should be registered here.
    } // End register_settings()

    /**
     * Renders the main settings page container and form.
     */
    public function render_settings_page() {
        ?>
        <div class="wrap">
            <h1><?php echo esc_html( get_admin_page_title() ); ?></h1>
            <form action="options.php" method="post">
                <?php
                // Output security fields for the registered setting group
                settings_fields( $this->option_group );

                // Output setting sections and their fields
                do_settings_sections( $this->page_slug );

                // Output save settings button
                submit_button( __( 'Save Settings', 'quiztech' ) );
                ?>

                <hr />
                <h2><?php esc_html_e( 'Test SMTP Settings', 'quiztech' ); ?></h2>
                <p><?php esc_html_e( 'Click the button below to send a test email to the site administrator', 'quiztech' ); ?> (<?php echo esc_html( get_option('admin_email') ); ?>) <?php esc_html_e( 'using the currently saved settings.', 'quiztech' ); ?></p>
                <button type="button" id="quiztech-test-email-button" class="button">
                    <?php esc_html_e( 'Send Test Email', 'quiztech' ); ?>
                </button>
                <span id="quiztech-test-email-status" style="margin-left: 10px;"></span>

                <script type="text/javascript">
                    jQuery(document).ready(function($) {
                        $('#quiztech-test-email-button').on('click', function() {
                            var button = $(this);
                            var statusSpan = $('#quiztech-test-email-status');

                            statusSpan.text('<?php echo esc_js( __( 'Sending...', 'quiztech' ) ); ?>').css('color', '');
                            button.prop('disabled', true);

                            $.post(ajaxurl, {
                                action: 'quiztech_send_test_email',
                                _ajax_nonce: '<?php echo wp_create_nonce( 'quiztech_test_email_nonce' ); ?>'
                            }, function(response) {
                                if (response.success) {
                                    statusSpan.text('<?php echo esc_js( __( 'Test email sent successfully!', 'quiztech' ) ); ?>').css('color', 'green');
                                } else {
                                    var errorMsg = response.data && response.data.message ? response.data.message : '<?php echo esc_js( __( 'An unknown error occurred.', 'quiztech' ) ); ?>';
                                    statusSpan.text('<?php echo esc_js( __( 'Error:', 'quiztech' ) ); ?> ' + errorMsg).css('color', 'red');
                                }
                                button.prop('disabled', false);
                            }).fail(function() {
                                statusSpan.text('<?php echo esc_js( __( 'AJAX request failed.', 'quiztech' ) ); ?>').css('color', 'red');
                                button.prop('disabled', false);
                            });
                        });
                    });
                </script>
            </form>
        </div>
        <?php
    }

    /**
     * Renders a standard text input field for a setting.
     * Expects args: 'id', 'option_name', 'key', 'description' (optional), 'type' (optional, default 'text')
     *
     * @param array $args Arguments passed from add_settings_field.
     */
    public function render_text_field( $args ) {
        $options = get_option( $args['option_name'], [] ); // Get all settings or default to empty array
        $value = isset( $options[ $args['key'] ] ) ? $options[ $args['key'] ] : '';
        $type = isset( $args['type'] ) ? $args['type'] : 'text';
        ?>
        <input
            type="<?php echo esc_attr( $type ); ?>"
            id="<?php echo esc_attr( $args['id'] ); ?>"
            name="<?php echo esc_attr( $args['option_name'] . '[' . $args['key'] . ']' ); ?>"
            value="<?php echo esc_attr( $value ); ?>"
            class="regular-text"
        />
        <?php if ( isset( $args['description'] ) ) : ?>
            <p class="description"><?php echo esc_html( $args['description'] ); ?></p>
        <?php endif; ?>
        <?php
    }


    /**
     * Renders the description for the SMTP settings section.
     */
    public function render_smtp_section_description() {
        echo '<p>' . esc_html__( 'Configure your SMTP server details for reliable email sending. If disabled, WordPress will use the default PHP mail function.', 'quiztech' ) . '</p>';
    }

    /**
     * Renders a checkbox input field for a setting.
     * Expects args: 'id', 'option_name', 'key', 'description' (optional)
     *
     * @param array $args Arguments passed from add_settings_field.
     */
    public function render_checkbox_field( $args ) {
        $options = get_option( $args['option_name'], [] );
        $checked = isset( $options[ $args['key'] ] ) && $options[ $args['key'] ] ? 'checked' : '';
        ?>
        <input
            type="checkbox"
            id="<?php echo esc_attr( $args['id'] ); ?>"
            name="<?php echo esc_attr( $args['option_name'] . '[' . $args['key'] . ']' ); ?>"
            value="1" <?php // Value is 1 when checked ?>
            <?php echo esc_attr( $checked ); ?>
        />
        <?php if ( isset( $args['description'] ) ) : ?>
            <label for="<?php echo esc_attr( $args['id'] ); ?>"> <?php echo esc_html( $args['description'] ); ?></label>
        <?php endif; ?>
        <?php
    }

    /**
     * Renders a select dropdown field for a setting.
     * Expects args: 'id', 'option_name', 'key', 'options' (array of value => label), 'description' (optional)
     *
     * @param array $args Arguments passed from add_settings_field.
     */
    public function render_select_field( $args ) {
        $options = get_option( $args['option_name'], [] );
        $value = isset( $options[ $args['key'] ] ) ? $options[ $args['key'] ] : '';
        ?>
        <select
            id="<?php echo esc_attr( $args['id'] ); ?>"
            name="<?php echo esc_attr( $args['option_name'] . '[' . $args['key'] . ']' ); ?>"
        >
            <?php foreach ( $args['options'] as $option_value => $option_label ) : ?>
                <option value="<?php echo esc_attr( $option_value ); ?>" <?php selected( $value, $option_value ); ?>>
                    <?php echo esc_html( $option_label ); ?>
                </option>
            <?php endforeach; ?>
        </select>
        <?php if ( isset( $args['description'] ) ) : ?>
            <p class="description"><?php echo esc_html( $args['description'] ); ?></p>
        <?php endif; ?>
        <?php
    }

    /**
     * Sanitizes the settings array before saving.
     *
     * @param array $input The raw input array from the form.
     * @return array The sanitized array.
     */
    public function sanitize_settings( $input ) {
        $sanitized_input = [];

        if ( isset( $input['stripe_public_key'] ) ) {
            // Basic sanitization, might need stricter validation (e.g., regex for pk_live_/pk_test_)
            $sanitized_input['stripe_public_key'] = sanitize_text_field( $input['stripe_public_key'] );
        }
        if ( isset( $input['stripe_secret_key'] ) ) {
             // Basic sanitization, might need stricter validation (e.g., regex for sk_live_/sk_test_)
            $sanitized_input['stripe_secret_key'] = sanitize_text_field( $input['stripe_secret_key'] );

        // Sanitize SMTP settings
        $smtp_fields = [
            'smtp_host' => 'sanitize_text_field',
            'smtp_port' => 'absint', // Sanitize as integer
            'smtp_encryption' => 'sanitize_key', // 'ssl', 'tls', or ''
            'smtp_username' => 'sanitize_text_field',
            'smtp_password' => 'sanitize_text_field', // Keep as text, WP handles display
            'smtp_from_address' => 'sanitize_email',
            'smtp_from_name' => 'sanitize_text_field',
        ];

        foreach ( $smtp_fields as $key => $sanitize_callback ) {
            if ( isset( $input[ $key ] ) ) {
                $sanitized_input[ $key ] = call_user_func( $sanitize_callback, $input[ $key ] );
            }
        }

        // Checkboxes (only save if present and value is '1')
        $checkbox_fields = [ 'smtp_enabled', 'smtp_auth' ];
        foreach ( $checkbox_fields as $key ) {
            $sanitized_input[ $key ] = ( isset( $input[ $key ] ) && $input[ $key ] === '1' ) ? 1 : 0;
        }

        // Validate encryption value
        if ( ! in_array( $sanitized_input['smtp_encryption'], [ '', 'ssl', 'tls' ], true ) ) {
            $sanitized_input['smtp_encryption'] = ''; // Default to none if invalid
        }

        // Future settings added should have their sanitization logic implemented here.

        return $sanitized_input;
    }


    /**
     * Handles the AJAX request to send a test email.
     */
    public function handle_send_test_email_ajax() {
        check_ajax_referer( 'quiztech_test_email_nonce', '_ajax_nonce' );

        if ( ! current_user_can( 'manage_options' ) ) {
            wp_send_json_error( [ 'message' => __( 'Permission denied.', 'quiztech' ) ], 403 );
        }

        $admin_email = get_option( 'admin_email' );
        if ( ! is_email( $admin_email ) ) {
            wp_send_json_error( [ 'message' => __( 'Invalid site administrator email address.', 'quiztech' ) ] );
        }

        $subject = __( 'Quiztech SMTP Test Email', 'quiztech' );
        $message = __( 'This is a test email sent from the Quiztech plugin settings page to verify your SMTP configuration.', 'quiztech' );
        $headers = []; // Can add headers if needed, e.g., Content-Type

        // Temporarily hook into phpmailer to capture errors
        $error_message = '';
        add_action( 'wp_mail_failed', function ( $wp_error ) use ( &$error_message ) {
            if ( is_wp_error( $wp_error ) ) {
                $error_message = $wp_error->get_error_message();
            }
        }, 10, 1 );

        $sent = wp_mail( $admin_email, $subject, $message, $headers );

        // Remove the temporary hook
        // Note: Removing anonymous functions requires more complex handling (e.g., storing the closure in a property).
        // For simplicity in this test function, we'll leave it, but be aware it persists for the request.
        // A better approach for production code might involve a dedicated class or named function.
        // remove_action( 'wp_mail_failed', $this->capture_wp_mail_error_closure ); // Example if stored

        if ( $sent ) {
            wp_send_json_success();
        } else {
            $error_to_send = ! empty( $error_message ) ? $error_message : __( 'The email could not be sent. Check your SMTP settings and server logs.', 'quiztech' );
            wp_send_json_error( [ 'message' => $error_to_send ] );
        }
    }
}