<?php
/**
 * Settings — single option, schema in defaults().
 *
 * @package H4B\ImageOptim
 */

namespace H4B\ImageOptim;

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

final class Settings {

	public const OPTION_KEY = 'h4b_image_optim_settings';

	public static function register(): void {
		// No admin UI in v0.1 — settings read-only via WP-CLI for now.
	}

	public static function defaults(): array {
		return [
			// Quality
			'jpeg_quality'             => 85,
			'png_quality_min'          => 70,
			'png_quality_max'          => 90,
			'jpeg_chroma_subsampling'  => '4:4:4',  // preserve edges; the fix for the Smush bug
			'preserve_icc_profile'     => true,     // CRITICAL — the bug fix
			'strip_gps_exif'           => true,
			'strip_camera_exif'        => false,    // keep camera info for art provenance

			// Format generation
			'generate_webp'            => true,
			'generate_avif'            => true,     // design decision 1: on by default everywhere
			'webp_quality'             => 90,    // matches source JPG luminance for B&W ink on white
			'avif_quality'             => 65,       // ≈ JPEG q=85 visually
			'avif_speed'               => 6,        // 0-10; 6 is balanced
			'avif_async'               => true,     // background WP-Cron so upload UI is responsive

			// Behaviour
			'optimise_on_upload'       => true,
			'backup_originals'         => true,     // design decision 4: always
			'backup_prune_days'        => 90,       // 0 = keep forever
			'resize_max_width'         => 2560,
			'resize_max_height'        => 2560,
			'skip_already_processed'   => true,
			'min_optimise_bytes'       => 20480,    // skip files < 20KB (thumbnails)

			// Serving
			'rewrite_content_images'   => true,     // Picture tag rewriting
			'use_htaccess_fallback'    => true,     // .htaccess content negotiation

			// Bulk
			'bulk_batch_size'          => 10,
			'bulk_pause_seconds'       => 1,

			// Exclusions
			'exclude_mime_types'       => [ 'image/svg+xml', 'image/x-icon', 'image/gif' ],
			'exclude_paths_regex'      => '',
		];
	}

	public static function install_defaults(): void {
		$existing = get_option( self::OPTION_KEY );
		if ( false === $existing ) {
			add_option( self::OPTION_KEY, self::defaults(), '', false );
			return;
		}
		// Merge new keys without clobbering user changes
		$merged = array_replace( self::defaults(), is_array( $existing ) ? $existing : [] );
		update_option( self::OPTION_KEY, $merged, false );
	}

	public static function get( string $key, mixed $default = null ): mixed {
		$settings = get_option( self::OPTION_KEY, self::defaults() );
		return $settings[ $key ] ?? $default;
	}

	public static function set( string $key, mixed $value ): void {
		$settings = get_option( self::OPTION_KEY, self::defaults() );
		$settings[ $key ] = $value;
		update_option( self::OPTION_KEY, $settings, false );
	}

	public static function all(): array {
		return get_option( self::OPTION_KEY, self::defaults() );
	}
}