<?php
/**
 * Settings page (Settings → Adara Translate).
 *
 * @package AdaraTranslate
 */

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

final class Adara_Translate_Settings {

	public const OPTION_KEY = 'adara_translate_settings';
	public const ALLOWED_ENGINES = [ 'deepl', 'google', 'microsoft', 'gpt', 'gemini' ];
	public const DEFAULT_ENDPOINT = 'https://www.adaratranslate.com/api/translation/translate';

	private static ?self $instance = null;

	public static function instance() : self {
		if ( null === self::$instance ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	private function __construct() {
		add_action( 'admin_menu', [ $this, 'register_menu' ] );
		add_action( 'admin_init', [ $this, 'register_settings' ] );
	}

	public static function get_api_key() : string {
		$opts = get_option( self::OPTION_KEY, [] );
		return isset( $opts['api_key'] ) ? (string) $opts['api_key'] : '';
	}

	public static function get_engine() : string {
		$opts   = get_option( self::OPTION_KEY, [] );
		$engine = isset( $opts['engine'] ) ? (string) $opts['engine'] : 'deepl';
		return in_array( $engine, self::ALLOWED_ENGINES, true ) ? $engine : 'deepl';
	}

	public static function get_endpoint() : string {
		if ( ! self::is_endpoint_override_allowed() ) {
			return self::DEFAULT_ENDPOINT;
		}
		$opts     = get_option( self::OPTION_KEY, [] );
		$endpoint = isset( $opts['endpoint'] ) && '' !== $opts['endpoint']
			? (string) $opts['endpoint']
			: self::DEFAULT_ENDPOINT;
		if ( ! self::is_valid_endpoint( $endpoint ) ) {
			return self::DEFAULT_ENDPOINT;
		}
		return $endpoint;
	}

	public static function is_endpoint_override_allowed() : bool {
		if ( defined( 'ADARA_TRANSLATE_ALLOW_ENDPOINT_OVERRIDE' ) && ADARA_TRANSLATE_ALLOW_ENDPOINT_OVERRIDE ) {
			return true;
		}
		return defined( 'WP_DEBUG' ) && WP_DEBUG;
	}

	private static function is_valid_endpoint( string $url ) : bool {
		$parts = wp_parse_url( $url );
		if ( ! is_array( $parts ) || empty( $parts['scheme'] ) || empty( $parts['host'] ) ) {
			return false;
		}
		$scheme = strtolower( (string) $parts['scheme'] );
		if ( 'https' === $scheme ) {
			return true;
		}
		if ( 'http' === $scheme ) {
			$host = strtolower( (string) $parts['host'] );
			return in_array( $host, [ 'localhost', '127.0.0.1', '[::1]' ], true );
		}
		return false;
	}

	public static function is_configured() : bool {
		return '' !== self::get_api_key();
	}

	public function register_menu() : void {
		add_options_page(
			__( 'Adara Translate', 'adara-translate' ),
			__( 'Adara Translate', 'adara-translate' ),
			'manage_options',
			'adara-translate',
			[ $this, 'render_page' ]
		);
	}

	public function register_settings() : void {
		register_setting(
			'adara_translate_group',
			self::OPTION_KEY,
			[
				'type'              => 'array',
				'sanitize_callback' => [ $this, 'sanitize' ],
				'default'           => [],
			]
		);
	}

	public function sanitize( $input ) : array {
		$clean            = [];
		$clean['api_key'] = isset( $input['api_key'] ) ? sanitize_text_field( $input['api_key'] ) : '';
		$clean['engine']  = isset( $input['engine'] )  ? sanitize_key( $input['engine'] )         : 'deepl';
		if ( ! in_array( $clean['engine'], self::ALLOWED_ENGINES, true ) ) {
			$clean['engine'] = 'deepl';
		}

		$endpoint_input = isset( $input['endpoint'] ) ? trim( (string) $input['endpoint'] ) : '';
		if ( '' === $endpoint_input ) {
			$clean['endpoint'] = '';
		} elseif ( ! self::is_endpoint_override_allowed() ) {
			$clean['endpoint'] = '';
			add_settings_error(
				self::OPTION_KEY,
				'adara_endpoint_override_disabled',
				__( 'Custom API endpoint overrides are disabled. Define ADARA_TRANSLATE_ALLOW_ENDPOINT_OVERRIDE in wp-config.php to enable for development.', 'adara-translate' )
			);
		} else {
			$sanitized = esc_url_raw( $endpoint_input );
			if ( '' === $sanitized || ! self::is_valid_endpoint( $sanitized ) ) {
				$clean['endpoint'] = '';
				add_settings_error(
					self::OPTION_KEY,
					'adara_endpoint_invalid',
					__( 'API endpoint must be an HTTPS URL (or http://localhost for local dev).', 'adara-translate' )
				);
			} else {
				$clean['endpoint'] = $sanitized;
			}
		}

		return $clean;
	}

	public function render_page() : void {
		if ( ! current_user_can( 'manage_options' ) ) {
			return;
		}

		$opts     = get_option( self::OPTION_KEY, [] );
		$api_key  = isset( $opts['api_key'] )  ? (string) $opts['api_key']  : '';
		$engine   = isset( $opts['engine'] )   ? (string) $opts['engine']   : 'deepl';
		$endpoint = isset( $opts['endpoint'] ) ? (string) $opts['endpoint'] : self::DEFAULT_ENDPOINT;
		?>
		<div class="wrap">
			<h1><?php esc_html_e( 'Adara Translate', 'adara-translate' ); ?></h1>
			<form method="post" action="options.php">
				<?php settings_fields( 'adara_translate_group' ); ?>
				<table class="form-table" role="presentation">
					<tr>
						<th scope="row"><label for="adara-api-key"><?php esc_html_e( 'API key', 'adara-translate' ); ?></label></th>
						<td>
							<input id="adara-api-key" type="password" class="regular-text" autocomplete="off"
								name="<?php echo esc_attr( self::OPTION_KEY ); ?>[api_key]"
								value="<?php echo esc_attr( $api_key ); ?>" />
							<p class="description">
								<?php
								printf(
									/* translators: %s: link to Adara dashboard */
									esc_html__( 'Create an API key in your %s.', 'adara-translate' ),
									'<a href="https://www.adaratranslate.com/dashboard/api-keys" target="_blank" rel="noopener">' . esc_html__( 'Adara dashboard', 'adara-translate' ) . '</a>'
								);
								?>
							</p>
						</td>
					</tr>
					<tr>
						<th scope="row"><label for="adara-engine"><?php esc_html_e( 'Default engine', 'adara-translate' ); ?></label></th>
						<td>
							<select id="adara-engine" name="<?php echo esc_attr( self::OPTION_KEY ); ?>[engine]">
								<?php foreach ( self::ALLOWED_ENGINES as $value ) : ?>
									<option value="<?php echo esc_attr( $value ); ?>" <?php selected( $engine, $value ); ?>>
										<?php echo esc_html( $value ); ?>
									</option>
								<?php endforeach; ?>
							</select>
						</td>
					</tr>
					<?php if ( self::is_endpoint_override_allowed() ) : ?>
						<tr>
							<th scope="row"><label for="adara-endpoint"><?php esc_html_e( 'API endpoint', 'adara-translate' ); ?></label></th>
							<td>
								<input id="adara-endpoint" type="url" class="regular-text code"
									name="<?php echo esc_attr( self::OPTION_KEY ); ?>[endpoint]"
									value="<?php echo esc_attr( $endpoint ); ?>"
									placeholder="<?php echo esc_attr( self::DEFAULT_ENDPOINT ); ?>" />
								<p class="description">
									<?php esc_html_e( 'Override for self-hosted Adara or local dev. Must be HTTPS, or http://localhost. Leave blank to use the default.', 'adara-translate' ); ?>
								</p>
							</td>
						</tr>
					<?php endif; ?>
				</table>
				<?php submit_button(); ?>
			</form>
		</div>
		<?php
	}
}