<?php
/**
 * Settings → Vimine: the confidential client (id + secret), the API and app URLs, the permissions requested, and how the
 * enrolment form looks on the site (empty: from the theme — Vimine_Appearance).
 * The secret never leaves the server: it is used only in the code exchange, the refresh and client_credentials.
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

final class Vimine_Settings {

    public const OPTION = 'vimine_settings';

    public static function init(): void {
        add_action( 'admin_menu', [ __CLASS__, 'menu' ] );
        add_action( 'admin_init', [ __CLASS__, 'register' ] );
    }

    /** @return array{client_id:string,client_secret:string,api_url:string,app_url:string,scopes:string,callback_path:string,enroll_scheme:string,enroll_accent:string,enroll_background:string,enroll_font:string} */
    public static function get(): array {
        $defaults = [
            'client_id'         => '',
            'client_secret'     => '',
            'api_url'           => 'https://api.vimine.network',
            'app_url'           => 'https://app.vimine.network',
            'scopes'            => 'profile:read membership:read',
            'callback_path'     => 'vimine-callback',
            'enroll_scheme'     => '',
            'enroll_accent'     => '',
            'enroll_background' => '',
            'enroll_font'       => '',
        ];
        $saved = get_option( self::OPTION, [] );
        return array_merge( $defaults, is_array( $saved ) ? $saved : [] );
    }

    public static function configured(): bool {
        $s = self::get();
        return '' !== $s['client_id'] && '' !== $s['client_secret'];
    }

    /** The redirect URI registered on the Vimine client (must match exactly). */
    public static function redirect_uri(): string {
        return home_url( '/' . ltrim( self::get()['callback_path'], '/' ) . '/' );
    }

    public static function menu(): void {
        add_options_page( 'Vimine', 'Vimine', 'manage_options', 'vimine', [ __CLASS__, 'page' ] );
    }

    public static function register(): void {
        register_setting( 'vimine', self::OPTION, [ 'sanitize_callback' => [ __CLASS__, 'sanitize' ] ] );
    }

    /** @param mixed $input */
    public static function sanitize( $input ): array {
        $input   = is_array( $input ) ? $input : [];
        $current = self::get();
        $text    = static fn( string $key ): string => isset( $input[ $key ] ) && is_string( $input[ $key ] ) ? $input[ $key ] : '';
        $out     = [];
        $out['client_id']     = sanitize_text_field( $text( 'client_id' ) );
        $secret               = sanitize_text_field( $text( 'client_secret' ) );
        $out['client_secret'] = '' === $secret ? $current['client_secret'] : $secret; // an empty field keeps the stored secret
        $out['api_url']       = self::url( $text( 'api_url' ), $current['api_url'] );
        $out['app_url']       = self::url( $text( 'app_url' ), $current['app_url'] );
        $out['scopes']        = sanitize_text_field( '' !== $text( 'scopes' ) ? $text( 'scopes' ) : $current['scopes'] );
        $out['callback_path'] = sanitize_title( '' !== $text( 'callback_path' ) ? $text( 'callback_path' ) : $current['callback_path'] ) ?: 'vimine-callback';

        // The enrolment form's look: empty, or Automatic, is the theme's.
        $out['enroll_scheme']     = Vimine_Appearance::scheme( $text( 'enroll_scheme' ) );
        $out['enroll_accent']     = self::colour( $text( 'enroll_accent' ), false, $current['enroll_accent'] );
        $out['enroll_background'] = self::colour( $text( 'enroll_background' ), true, $current['enroll_background'] );
        $out['enroll_font']       = Vimine_Appearance::font( $text( 'enroll_font' ) );
        return $out;
    }

    /** A colour of the enrolment form: empty is the theme's; anything but a colour keeps the stored value, with a notice. */
    private static function colour( string $raw, bool $transparent, string $current ): string {
        if ( '' === trim( $raw ) ) {
            return '';
        }
        $colour = Vimine_Appearance::colour( $raw, $transparent );
        if ( '' === $colour ) {
            if ( ! in_array( 'vimine_colour', array_column( get_settings_errors( self::OPTION ), 'code' ), true ) ) { // one notice for both fields
                add_settings_error( self::OPTION, 'vimine_colour', __( 'Vimine: a colour is a hex code, such as #1e3a5f; the background can also be transparent. The previous value was kept.', 'vimine' ) );
            }
            return $current;
        }
        return $colour;
    }

    /**
     * The `<option>`s of a select, `$selected` marked.
     *
     * @param array<string,string> $choices value → label
     */
    private static function options( array $choices, string $selected ): void {
        foreach ( $choices as $value => $label ) {
            echo '<option value="' . esc_attr( (string) $value ) . '"' . selected( (string) $value, $selected, false ) . '>' . esc_html( $label ) . '</option>';
        }
    }

    /**
     * An API or app URL: https, since the secret and the members' tokens travel to it — plain http only on a site
     * whose environment type is local or development (a Vimine running on the developer's machine). Anything else
     * keeps the stored value, with a notice on the settings page.
     */
    private static function url( string $raw, string $current ): string {
        $url = untrailingslashit( esc_url_raw( trim( $raw ), [ 'https', 'http' ] ) );
        if ( '' === $url ) {
            return $current;
        }
        if ( 'https' !== wp_parse_url( $url, PHP_URL_SCHEME ) && ! in_array( wp_get_environment_type(), [ 'local', 'development' ], true ) ) {
            add_settings_error( self::OPTION, 'vimine_https', __( 'Vimine: the API and app URLs must start with https://. The previous value was kept.', 'vimine' ) );
            return $current;
        }
        return $url;
    }

    public static function page(): void {
        if ( ! current_user_can( 'manage_options' ) ) {
            return;
        }
        $s     = self::get();
        $theme = Vimine_Appearance::theme();
        // What Automatic comes to on this site, in its option's label.
        $automatic = static fn( string $what ): string => sprintf(
            /* translators: %s: what Automatic comes to on this site, e.g. Light, or the name of a typeface */
            __( 'Automatic (%s)', 'vimine' ),
            $what
        );
        $faces = [
            'vimine' => __( 'Vimine’s own', 'vimine' ),
            'system' => __( 'System', 'vimine' ),
        ] + Vimine_Appearance::FACES;
        ?>
        <div class="wrap">
            <h1>Vimine</h1>
            <p><?php echo wp_kses( __( 'Register a <strong>confidential</strong> client in your association’s Developers console on Vimine and enter its credentials here.', 'vimine' ), [ 'strong' => [] ] ); ?></p>
            <p><?php esc_html_e( 'Redirect URI to register:', 'vimine' ); ?> <code><?php echo esc_html( self::redirect_uri() ); ?></code></p>
            <form method="post" action="options.php">
                <?php settings_fields( 'vimine' ); ?>
                <table class="form-table" role="presentation">
                    <tr><th scope="row"><label for="vimine-client-id"><?php esc_html_e( 'Client ID', 'vimine' ); ?></label></th><td><input id="vimine-client-id" class="regular-text code" type="text" name="<?php echo esc_attr( self::OPTION ); ?>[client_id]" value="<?php echo esc_attr( $s['client_id'] ); ?>" placeholder="vmc_…"></td></tr>
                    <tr><th scope="row"><label for="vimine-client-secret"><?php esc_html_e( 'Client secret', 'vimine' ); ?></label></th><td><input id="vimine-client-secret" class="regular-text code" type="password" name="<?php echo esc_attr( self::OPTION ); ?>[client_secret]" value="" placeholder="<?php echo esc_attr( '' !== $s['client_secret'] ? '•••••••• ' . __( '(saved)', 'vimine' ) : 'vms_…' ); ?>" autocomplete="new-password" aria-describedby="vimine-client-secret-help"><p class="description" id="vimine-client-secret-help"><?php esc_html_e( 'Leave empty to keep the saved secret.', 'vimine' ); ?></p></td></tr>
                    <tr><th scope="row"><label for="vimine-scopes"><?php esc_html_e( 'Permissions', 'vimine' ); ?></label></th><td><input id="vimine-scopes" class="large-text code" type="text" name="<?php echo esc_attr( self::OPTION ); ?>[scopes]" value="<?php echo esc_attr( $s['scopes'] ); ?>" aria-describedby="vimine-scopes-help"><p class="description" id="vimine-scopes-help"><?php esc_html_e( 'Separated by spaces, for example:', 'vimine' ); ?> <code>profile:read membership:read events:read</code></p></td></tr>
                    <tr><th scope="row"><label for="vimine-callback"><?php esc_html_e( 'Callback path', 'vimine' ); ?></label></th><td><input id="vimine-callback" class="regular-text code" type="text" name="<?php echo esc_attr( self::OPTION ); ?>[callback_path]" value="<?php echo esc_attr( $s['callback_path'] ); ?>" aria-describedby="vimine-callback-help"><p class="description" id="vimine-callback-help"><?php esc_html_e( 'Where Vimine sends members back after signing in: the redirect URI above follows it.', 'vimine' ); ?></p></td></tr>
                    <tr><th scope="row"><label for="vimine-api-url"><?php esc_html_e( 'API URL', 'vimine' ); ?></label></th><td><input id="vimine-api-url" class="regular-text code" type="url" name="<?php echo esc_attr( self::OPTION ); ?>[api_url]" value="<?php echo esc_attr( $s['api_url'] ); ?>"></td></tr>
                    <tr><th scope="row"><label for="vimine-app-url"><?php esc_html_e( 'App URL', 'vimine' ); ?></label></th><td><input id="vimine-app-url" class="regular-text code" type="url" name="<?php echo esc_attr( self::OPTION ); ?>[app_url]" value="<?php echo esc_attr( $s['app_url'] ); ?>"></td></tr>
                </table>
                <h2><?php esc_html_e( 'Enrolment form', 'vimine' ); ?></h2>
                <p><?php esc_html_e( 'Automatic and empty fields follow your theme. Each block or shortcode can set its own.', 'vimine' ); ?></p>
                <table class="form-table" role="presentation">
                    <tr><th scope="row"><label for="vimine-enroll-scheme"><?php esc_html_e( 'Colour scheme', 'vimine' ); ?></label></th><td><select id="vimine-enroll-scheme" name="<?php echo esc_attr( self::OPTION ); ?>[enroll_scheme]"><?php self::options( [ '' => $automatic( 'dark' === Vimine_Appearance::scheme_for( $s['enroll_background'] ) ? __( 'Dark', 'vimine' ) : __( 'Light', 'vimine' ) ), 'light' => __( 'Light', 'vimine' ), 'dark' => __( 'Dark', 'vimine' ) ], $s['enroll_scheme'] ); ?></select></td></tr>
                    <tr><th scope="row"><label for="vimine-enroll-accent"><?php esc_html_e( 'Accent colour', 'vimine' ); ?></label></th><td><input id="vimine-enroll-accent" class="regular-text code" type="text" name="<?php echo esc_attr( self::OPTION ); ?>[enroll_accent]" value="<?php echo esc_attr( $s['enroll_accent'] ); ?>" placeholder="<?php echo esc_attr( '' !== $theme['accent'] ? $theme['accent'] : '#rrggbb' ); ?>"></td></tr>
                    <tr><th scope="row"><label for="vimine-enroll-background"><?php esc_html_e( 'Background', 'vimine' ); ?></label></th><td><input id="vimine-enroll-background" class="regular-text code" type="text" name="<?php echo esc_attr( self::OPTION ); ?>[enroll_background]" value="<?php echo esc_attr( $s['enroll_background'] ); ?>" placeholder="<?php echo esc_attr( '' !== $theme['background'] ? $theme['background'] : '#rrggbb' ); ?>" aria-describedby="vimine-enroll-background-help"><p class="description" id="vimine-enroll-background-help"><?php echo wp_kses( __( 'A colour, or <code>transparent</code> to let the page show through.', 'vimine' ), [ 'code' => [] ] ); ?></p></td></tr>
                    <tr><th scope="row"><label for="vimine-enroll-font"><?php esc_html_e( 'Typeface', 'vimine' ); ?></label></th><td><select id="vimine-enroll-font" name="<?php echo esc_attr( self::OPTION ); ?>[enroll_font]"><?php self::options( [ '' => $automatic( $faces[ '' !== $theme['font'] ? $theme['font'] : 'vimine' ] ) ] + $faces, $s['enroll_font'] ); ?></select></td></tr>
                </table>
                <?php submit_button(); ?>
            </form>
            <h2><?php esc_html_e( 'Usage', 'vimine' ); ?></h2>
            <ul>
                <li><code>[vimine_signin]</code> — <?php esc_html_e( 'the “Sign in with Vimine” button, and “Sign out” once the member is signed in. Attributes:', 'vimine' ); ?> <code>label</code>, <code>label_signed_in</code>, <code>return_to</code>, <code>scope</code>.</li>
                <li><code>[vimine_card]</code> — <?php esc_html_e( 'the signed-in member’s card, an image with the QR code.', 'vimine' ); ?></li>
                <li><code>[vimine_events slug="…"]</code> — <?php esc_html_e( 'the association’s events, with the places left. Attributes:', 'vimine' ); ?> <code>filter</code> (upcoming, past, cancelled, all), <code>limit</code>.</li>
                <li><code>[vimine_enroll slug="…"]</code> — <?php esc_html_e( 'the association’s enrolment form. Attributes:', 'vimine' ); ?> <code>height</code>, <code>lang</code>, <code>scheme</code>, <code>accent</code>, <code>background</code>, <code>font</code>.</li>
                <li><?php esc_html_e( 'The same four are blocks in the editor, under Widgets.', 'vimine' ); ?></li>
            </ul>
        </div>
        <?php
    }
}