<?php
/**
 * View Renderer.
 *
 * Handles rendering of admin views with template system, caching, and data escaping.
 *
 * @package Accessibility_Audio_TTS_Player
 * @subpackage Admin\Views
 * @since 1.0.0
 */

namespace Accessibility_Audio_TTS\Admin;

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

/**
 * View Renderer class.
 *
 * @since 1.0.0
 */
class View_Renderer {

	/**
	 * Template cache
	 *
	 * @since 1.0.0
	 * @var array
	 */
	private static array $template_cache = array();

	/**
	 * Cache enabled flag
	 *
	 * @since 1.0.0
	 * @var bool
	 */
	private bool $cache_enabled = true;

	/**
	 * Template directories
	 *
	 * @since 1.0.0
	 * @var array
	 */
	private array $template_directories = array();

	/**
	 * Global template variables
	 *
	 * @since 1.0.0
	 * @var array
	 */
	private array $global_vars = array();

    /**
     * Constructor.
     *
     * @since 1.0.0
     * @param bool $cache_enabled Whether to enable template caching.
     */
	public function __construct( bool $cache_enabled = true ) {
		$this->cache_enabled = $cache_enabled;
		$this->setup_template_directories();
		$this->setup_global_vars();
	}

    /**
     * Render a template with data.
     *
     * @since 1.0.0
     * @param string $template_name Template name (without .php extension).
     * @param array  $data          Data to pass to template.
	 * @param bool   $return        Whether to return output instead of echoing.
     * @return string|void Template output if $return is true.
     */
    public function render( string $template_name, array $data = array(), bool $return = false ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.returnFound -- Kept for backward compatibility; not used as named argument.
		$template_path = $this->find_template( $template_name );

		if ( ! $template_path ) {
			$error_msg = sprintf( 'Template not found: %s', esc_html( $template_name ) );

			if ( $return ) {
				return $this->render_error( $error_msg );
			}

			echo wp_kses_post( $this->render_error( $error_msg ) );
			return;
		}

		$output = $this->render_template( $template_path, $data );

		if ( $return ) {
			return $output;
		}

		echo wp_kses_post( $output );
	}

    /**
     * Render template with caching.
     *
     * @since 1.0.0
     * @param string $template_path Full path to template file.
     * @param array  $data          Template data.
     * @return string Rendered output.
     */
	private function render_template( string $template_path, array $data ): string {
		$cache_key = $this->get_cache_key( $template_path, $data );

		// Check cache first.
		if ( $this->cache_enabled && isset( self::$template_cache[ $cache_key ] ) ) {
			return self::$template_cache[ $cache_key ];
		}

		// Start output buffering.
		ob_start();

		try {
			// Make data available to template.
			$template_data = $this->prepare_template_data( $data );

            // phpcs:ignore WordPress.PHP.DontExtract -- Świadomie udostępniamy przygotowane zmienne w zasięgu szablonu; EXTR_SKIP zapobiega nadpisaniu.
            extract( $template_data, EXTR_SKIP );

			// Include the template.
            // phpcs:ignore WordPressVIPMinimum.Files.IncludingFile.UsingVariable -- Ładowanie plików szablonów po weryfikacji ścieżki.
            include $template_path;

			$output = ob_get_clean();

			// Cache the output.
			if ( $this->cache_enabled ) {
				self::$template_cache[ $cache_key ] = $output;
			}

			return $output;

		} catch ( \Throwable $e ) {
			ob_end_clean();

			$error_msg = sprintf(
				'Error rendering template %s: %s',
				basename( $template_path ),
				$e->getMessage()
			);

			return $this->render_error( $error_msg );
		}
	}

    /**
     * Find template file in registered directories.
     *
     * @since 1.0.0
     * @param string $template_name Template name.
     * @return string|false Template path or false if not found.
     */
	private function find_template( string $template_name ) {
		// Add .php extension if not present.
		if ( ! str_ends_with( $template_name, '.php' ) ) {
			$template_name .= '.php';
		}

		// Search in registered directories.
		foreach ( $this->template_directories as $directory ) {
			$template_path = $directory . '/' . $template_name;

			if ( file_exists( $template_path ) && is_readable( $template_path ) ) {
				return $template_path;
			}
		}

        return false;
	}

    /**
     * Prepare template data with escaping and global variables.
     *
     * @since 1.0.0
     * @param array $data Raw template data.
     * @return array Prepared template data.
     */
	private function prepare_template_data( array $data ): array {
		// Merge with global variables.
		$template_data = array_merge( $this->global_vars, $data );

		// Add helper functions.
		$template_data['esc']              = array( $this, 'escape_data' );
		$template_data['render_partial']   = array( $this, 'render_partial' );
		$template_data['include_template'] = array( $this, 'include_template' );

		return $template_data;
	}

    /**
     * Escape data for safe output.
     *
     * @since 1.0.0
     * @param mixed  $data    Data to escape.
     * @param string $context Escaping context (html, attr, url, js, css).
     * @return mixed Escaped data.
     */
	public function escape_data( $data, string $context = 'html' ) {
		if ( is_array( $data ) ) {
			return array_map(
				function ( $item ) use ( $context ) {
					return $this->escape_data( $item, $context );
				},
				$data
			);
		}

		if ( ! is_string( $data ) ) {
			return $data;
		}

		switch ( $context ) {
			case 'attr':
				return esc_attr( $data );
			case 'url':
				return esc_url( $data );
			case 'js':
				return esc_js( $data );
            case 'css':
                return esc_attr( $data ); // WordPress doesn't have esc_css.
			case 'textarea':
				return esc_textarea( $data );
			case 'html':
			default:
				return esc_html( $data );
		}
	}

    /**
     * Render a partial template.
     *
     * @since 1.0.0
     * @param string $partial_name Partial template name.
     * @param array  $data         Data for partial.
     * @return string Rendered partial.
     */
	public function render_partial( string $partial_name, array $data = array() ): string {
		return $this->render( $partial_name, $data, true );
	}

    /**
     * Include another template within current template.
     *
     * @since 1.0.0
     * @param string $template_name Template to include.
     * @param array  $data          Additional data for included template.
     * @return void
     */
	public function include_template( string $template_name, array $data = array() ): void {
		echo wp_kses_post( $this->render( $template_name, $data, true ) );
	}

    /**
     * Add template directory.
     *
     * @since 1.0.0
     * @param string $directory Directory path.
     * @param int    $priority  Priority (lower = higher priority).
     * @return void
     */
	public function add_template_directory( string $directory, int $priority = 10 ): void {
		if ( ! is_dir( $directory ) ) {
			return;
		}

		$this->template_directories[ $priority ] = rtrim( $directory, '/' );
		ksort( $this->template_directories );
	}

    /**
     * Set global template variable.
     *
     * @since 1.0.0
     * @param string $key   Variable name.
     * @param mixed  $value Variable value.
     * @return void
     */
	public function set_global_var( string $key, $value ): void {
		$this->global_vars[ $key ] = $value;
	}

    /**
     * Set multiple global variables.
     *
     * @since 1.0.0
     * @param array $vars Variables array.
     * @return void
     */
	public function set_global_vars( array $vars ): void {
		$this->global_vars = array_merge( $this->global_vars, $vars );
	}

    /**
     * Clear template cache.
     *
     * @since 1.0.0
     * @param string|null $template_name Specific template to clear, or null for all.
     * @return void
     */
	public function clear_cache( ?string $template_name = null ): void {
        if ( null === $template_name ) {
			self::$template_cache = array();
		} else {
			$pattern = $this->get_cache_key_pattern( $template_name );

			foreach ( array_keys( self::$template_cache ) as $key ) {
				if ( str_contains( $key, $pattern ) ) {
					unset( self::$template_cache[ $key ] );
				}
			}
		}
	}

    /**
     * Enable or disable caching.
     *
     * @since 1.0.0
     * @param bool $enabled Whether to enable caching.
     * @return void
     */
	public function set_cache_enabled( bool $enabled ): void {
		$this->cache_enabled = $enabled;

		if ( ! $enabled ) {
			$this->clear_cache();
		}
	}

    /**
     * Check if template exists.
     *
     * @since 1.0.0
     * @param string $template_name Template name.
     * @return bool True if template exists.
     */
	public function template_exists( string $template_name ): bool {
        return false !== $this->find_template( $template_name );
	}

    /**
     * Get cache statistics.
     *
     * @since 1.0.0
     * @return array Cache statistics.
     */
	public function get_cache_stats(): array {
		return array(
			'enabled'          => $this->cache_enabled,
			'cached_templates' => count( self::$template_cache ),
			'memory_usage'     => $this->calculate_cache_memory_usage(),
		);
	}

    /**
     * Setup default template directories.
     *
     * @since 1.0.0
     * @return void
     */
	private function setup_template_directories(): void {
        // Plugin templates directory.
		$plugin_templates = ACCESSIBILITY_AUDIO_TTS_PLUGIN_DIR . 'admin/templates/settings';
		if ( is_dir( $plugin_templates ) ) {
			$this->add_template_directory( $plugin_templates, 10 );
		}

		// Theme override directory.
		$theme_templates = get_template_directory() . '/accessibility-audio-tts/admin';
		if ( is_dir( $theme_templates ) ) {
			$this->add_template_directory( $theme_templates, 5 );
		}

		// Child theme override directory.
		if ( is_child_theme() ) {
			$child_theme_templates = get_stylesheet_directory() . '/accessibility-audio-tts/admin';
			if ( is_dir( $child_theme_templates ) ) {
				$this->add_template_directory( $child_theme_templates, 1 );
			}
		}
	}

    /**
     * Setup global template variables.
     *
     * @since 1.0.0
     * @return void
     */
	private function setup_global_vars(): void {
		$this->global_vars = array(
			'plugin_url'     => ACCESSIBILITY_AUDIO_TTS_PLUGIN_URL,
			'plugin_path'    => ACCESSIBILITY_AUDIO_TTS_PLUGIN_DIR,
			'plugin_version' => ACCESSIBILITY_AUDIO_TTS_VERSION,
			'admin_url'      => admin_url(),
			'current_user'   => wp_get_current_user(),
			'is_admin'       => is_admin(),
			'nonce_field'    => wp_nonce_field( 'accessibility_audio_tts_admin', '_wpnonce', true, false ),
		);
	}

    /**
     * Generate cache key for template and data.
     *
     * @since 1.0.0
     * @param string $template_path Template path.
     * @param array  $data          Template data.
     * @return string Cache key.
     */
	private function get_cache_key( string $template_path, array $data ): string {
		$template_name = basename( $template_path );
		$data_json     = wp_json_encode( $data );
		if ( false === $data_json ) {
			$data_json = '';
		}
		$data_hash = md5( $data_json );
		$file_time = filemtime( $template_path );

		return sprintf( '%s_%s_%s', $template_name, $data_hash, $file_time );
	}

    /**
     * Get cache key pattern for template.
     *
     * @since 1.0.0
     * @param string $template_name Template name.
     * @return string Cache key pattern.
     */
	private function get_cache_key_pattern( string $template_name ): string {
		if ( ! str_ends_with( $template_name, '.php' ) ) {
			$template_name .= '.php';
		}

		return $template_name . '_';
	}

    /**
     * Calculate cache memory usage.
     *
     * @since 1.0.0
     * @return int Memory usage in bytes.
     */
	private function calculate_cache_memory_usage(): int {
		$total_size = 0;

		foreach ( self::$template_cache as $content ) {
			$total_size += strlen( $content );
		}

		return $total_size;
	}

    /**
     * Render error message.
     *
     * @since 1.0.0
     * @param string $message Error message.
     * @return string Error HTML.
     */
	private function render_error( string $message ): string {
        if ( defined( 'WP_DEBUG' ) && true === WP_DEBUG ) {
			return sprintf(
				'<div class="notice notice-error"><p><strong>Template Error:</strong> %s</p></div>',
				esc_html( $message )
			);
		}

		return '<!-- Template rendering error -->';
	}

    /**
     * Render JSON data safely.
     *
     * @since 1.0.0
     * @param mixed $data  Data to encode as JSON.
     * @param int   $flags JSON encoding flags.
     * @return string JSON string.
     */
	public function render_json( $data, int $flags = JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP ): string {
		return wp_json_encode( $data, $flags );
	}

    /**
     * Render inline CSS safely.
     *
     * @since 1.0.0
     * @param string $css CSS content.
     * @return string Safe CSS.
     */
	public function render_inline_css( string $css ): string {
        // Basic CSS sanitization - remove potentially dangerous content.
		$css = preg_replace( '/javascript:/i', '', $css );
		$css = preg_replace( '/expression\s*\(/i', '', $css );
		$css = preg_replace( '/import\s+/i', '', $css );

		return $css;
	}

    /**
     * Render inline JavaScript safely.
     *
     * @since 1.0.0
     * @param string $js JavaScript content.
     * @return string Safe JavaScript.
     */
	public function render_inline_js( string $js ): string {
		return esc_js( $js );
	}
}