<?php
/**
 * Hooks into the WP upload pipeline.
 *
 * Important: we hook into wp_generate_attachment_metadata so we run AFTER
 * WP-core generates all the size variants. We then optimise each variant in
 * place. This keeps WP's metadata structure intact.
 *
 * @package H4B\ImageOptim
 */

namespace H4B\ImageOptim;

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

final class Uploader_Hook {

	public static function register(): void {
		add_filter( 'wp_generate_attachment_metadata', [ self::class, 'on_metadata' ], 10, 2 );
	}

	/**
	 * @param array $metadata     The freshly-generated _wp_attachment_metadata array.
	 * @param int   $attachment_id Post ID of the attachment.
	 */
	public static function on_metadata( $metadata, $attachment_id ): array {
		$metadata = is_array( $metadata ) ? $metadata : [];

		if ( ! Settings::get( 'optimise_on_upload', true ) ) {
			return $metadata;
		}
		if ( Attachment_Meta::is_processed( (int) $attachment_id )
			&& Settings::get( 'skip_already_processed', true ) ) {
			return $metadata;
		}

		$uploads = wp_get_upload_dir();
		$basedir = trailingslashit( $uploads['basedir'] );

		// File path of the original full-size image
		$relative = $metadata['file'] ?? get_post_meta( $attachment_id, '_wp_attached_file', true );
		if ( ! $relative ) {
			return $metadata;
		}
		$full_path = $basedir . $relative;
		if ( ! is_readable( $full_path ) ) {
			return $metadata;
		}

		// Optimise the full file
		self::process_single( (int) $attachment_id, 'full', $full_path );

		// Optimise every generated size
		$dir = dirname( $full_path );
		foreach ( ( $metadata['sizes'] ?? [] ) as $size_key => $size_data ) {
			if ( empty( $size_data['file'] ) ) {
				continue;
			}
			$size_path = trailingslashit( $dir ) . $size_data['file'];
			if ( ! is_readable( $size_path ) ) {
				continue;
			}
			self::process_single( (int) $attachment_id, (string) $size_key, $size_path );
			// Refresh filesize in metadata after re-encode
			clearstatcache( true, $size_path );
			$metadata['sizes'][ $size_key ]['filesize'] = filesize( $size_path );
		}

		// Refresh full filesize too
		clearstatcache( true, $full_path );
		$metadata['filesize'] = filesize( $full_path );

		return $metadata;
	}

	private static function process_single( int $attachment_id, string $size_key, string $path ): void {
		$opt = Optimizer::optimise( $path );

		// Generate WebP/AVIF siblings regardless of whether Optimizer touched
		// the source JPEG (e.g. it might have skipped tiny thumbnails).
		// Sibling generation is still valuable for those.
		$webp_stats = [ 'status' => 'skipped' ];
		$avif_stats = [ 'status' => 'skipped' ];
		$generate_siblings = in_array( $opt['status'], [ 'done', 'skipped' ], true );

		if ( $generate_siblings && Settings::get( 'generate_webp', true ) ) {
			$webp_stats = Format_Generator::make_webp( $path );
		}
		if ( $generate_siblings && Settings::get( 'generate_avif', true ) ) {
			$avif_stats = Format_Generator::make_avif( $path );
			if ( $avif_stats['status'] === 'queued' ) {
				Attachment_Meta::mark_avif_pending( $attachment_id, $size_key );
			}
		}

		Attachment_Meta::record_size( $attachment_id, $size_key, [
			'status'        => $opt['status'],
			'before'        => $opt['before'],
			'after'         => $opt['after'],
			'percent'       => $opt['percent'],
			'icc_preserved' => $opt['icc_preserved'] ?? false,
			'tool_chain'    => $opt['tool_chain'] ?? [],
			'webp'          => $webp_stats['status'] === 'done' ? $webp_stats['size'] : null,
			'avif'          => $avif_stats['status'] === 'done' ? $avif_stats['size'] : null,
			'avif_status'   => $avif_stats['status'],
			'backup'        => $opt['backup_path'] ?? null,
			'error'         => $opt['error'] ?? null,
		] );
	}
}