<?php
/**
 * Thumbnail Generator Class
 *
 * Generates featured images from content images
 *
 * @package AI_Thumbnails_Maker
 * @since 1.0.0
 */

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

/**
 * Thumbnail Generator class
 */
class AITM_Thumbnail_Generator {

	/**
	 * Plugin settings
	 *
	 * @var array
	 */
	private $settings;

	/**
	 * Image finder instance
	 *
	 * @var AITM_Content_Image_Finder
	 */
	private $image_finder;

	/**
	 * AI generator instance
	 *
	 * @var AITM_AI_Image_Generator
	 */
	private $ai_generator;

	/**
	 * Constructor
	 *
	 * @param array $settings Plugin settings.
	 */
	public function __construct( $settings = array() ) {
		$this->settings = $settings;

		$generation_method = $settings['generation_method'] ?? 'first_content_image';

		if ( $generation_method === 'ai_generation' ) {
			require_once AITM_PLUGIN_DIR . '/includes/class-ai-image-generator.php';
			try {
				$this->ai_generator = new AITM_AI_Image_Generator( $settings );
			} catch ( Exception $e ) {
				// If AI generator fails to initialize, fall back to content image finder
				$min_width          = $settings['min_image_width'] ?? 0;
				$min_height         = $settings['min_image_height'] ?? 0;
				$this->image_finder = new AITM_Content_Image_Finder( $min_width, $min_height );
			}
		} else {
			$min_width          = $settings['min_image_width'] ?? 0;
			$min_height         = $settings['min_image_height'] ?? 0;
			$this->image_finder = new AITM_Content_Image_Finder( $min_width, $min_height );
		}
	}

	/**
	 * Generate thumbnail for post
	 *
	 * @param int $post_id Post ID.
	 * @return array Result data.
	 */
	public function generate_for_post( $post_id ) {
		$post = get_post( $post_id );

		if ( ! $post ) {
			return array(
				'success'    => false,
				'message'    => __( 'Post not found', 'ai-thumbnails-maker' ),
				'post_id'    => $post_id,
				'post_title' => '',
			);
		}

		// Check if post already has thumbnail
		$overwrite_existing = $this->settings['overwrite_existing'] ?? false;
		if ( ! $overwrite_existing && has_post_thumbnail( $post_id ) ) {
			return array(
				'success'    => false,
				'message'    => __( 'Post already has thumbnail', 'ai-thumbnails-maker' ),
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
			);
		}

		// Choose generation method
		$generation_method = $this->settings['generation_method'] ?? 'first_content_image';

		switch ( $generation_method ) {
			case 'ai_generation':
				if ( isset( $this->ai_generator ) ) {
					return $this->generate_with_ai( $post_id, $post );
				}
				break;

			case 'generate_from_title':
				return $this->generate_from_title( $post_id, $post );

			case 'search_or_generate':
				$result = $this->generate_from_content( $post_id, $post );
				if ( ! $result['success'] ) {
					return $this->generate_from_title( $post_id, $post );
				}
				return $result;

			case 'use_default_image':
				$result = $this->generate_from_content( $post_id, $post );
				if ( ! $result['success'] ) {
					return $this->use_default_image( $post_id, $post );
				}
				return $result;
		}

		// Fallback to default method
		return $this->generate_from_content( $post_id, $post );
	}

	/**
	 * Generate thumbnail from content image
	 *
	 * @param int     $post_id Post ID.
	 * @param WP_Post $post Post object.
	 * @return array Result data.
	 */
	private function generate_from_content( $post_id, $post ) {
		// Find image in content
		$image = $this->image_finder->find_first_image( $post_id );

		if ( ! $image ) {
			$this->add_to_log(
				array(
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'success'    => false,
					'message'    => __( 'No suitable image found in content', 'ai-thumbnails-maker' ),
					'type'       => 'first_content_image',
					'image_size' => '',
				)
			);

			return array(
				'success'    => false,
				'message'    => __( 'No suitable image found in content', 'ai-thumbnails-maker' ),
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'type'       => 'first_content_image',
			);
		}

		// Get attachment ID
		$attachment_id = $this->image_finder->get_thumbnail_id( $image );

		if ( ! $attachment_id ) {
			$this->add_to_log(
				array(
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'success'    => false,
					'message'    => __( 'Image not found in media library', 'ai-thumbnails-maker' ),
					'type'       => 'first_content_image',
					'image_size' => '',
				)
			);

			return array(
				'success'    => false,
				'message'    => __( 'Image not found in media library', 'ai-thumbnails-maker' ),
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'type'       => 'first_content_image',
			);
		}

		// Check image size requirements
		if ( ! $this->image_finder->check_image_size( $attachment_id ) ) {
			$this->add_to_log(
				array(
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'success'    => false,
					'message'    => __( 'Image does not meet size requirements', 'ai-thumbnails-maker' ),
					'type'       => 'first_content_image',
					'image_size' => '',
				)
			);

			return array(
				'success'    => false,
				'message'    => __( 'Image does not meet size requirements', 'ai-thumbnails-maker' ),
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'type'       => 'first_content_image',
			);
		}

		// Set as featured image
		// If overwrite_existing is enabled, delete current thumbnail first
		if ( $overwrite_existing && has_post_thumbnail( $post_id ) ) {
			delete_post_thumbnail( $post_id );
		}
		
		$result = set_post_thumbnail( $post_id, $attachment_id );

		if ( $result || get_post_thumbnail_id( $post_id ) == $attachment_id ) {
			$metadata   = wp_get_attachment_metadata( $attachment_id );
			$image_size = '';
			
			if ( isset( $metadata['width'], $metadata['height'] ) ) {
				$width  = $metadata['width'];
				$height = $metadata['height'];
				
				// Get file size
				$file_path = get_attached_file( $attachment_id );
				$file_size = '';
				if ( $file_path && file_exists( $file_path ) ) {
					$size_bytes = filesize( $file_path );
					$file_size  = size_format( $size_bytes, 2 );
				}
				
				$image_size = $width . 'x' . $height;
				if ( $file_size ) {
					$image_size .= ' (' . $file_size . ')';
				}
			}

			$thumbnail_url = wp_get_attachment_image_url( $attachment_id, 'thumbnail' );

			$this->add_to_log(
				array(
					'post_id'       => $post_id,
					'post_title'    => $post->post_title,
					'success'       => true,
					'message'       => __( 'Thumbnail generated successfully', 'ai-thumbnails-maker' ),
					'type'          => 'first_content_image',
					'image_size'    => $image_size,
					'thumbnail_url' => $thumbnail_url,
					'thumbnail_id'  => $attachment_id,
				)
			);

			return array(
				'success'       => true,
				'message'       => __( 'Thumbnail generated successfully', 'ai-thumbnails-maker' ),
				'post_id'       => $post_id,
				'post_title'    => $post->post_title,
				'thumbnail_url' => $thumbnail_url,
				'thumbnail_id'  => $attachment_id,
				'image_size'    => $image_size,
				'type'          => 'first_content_image',
			);
		}

		$this->add_to_log(
			array(
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'success'    => false,
				'message'    => __( 'Failed to set thumbnail', 'ai-thumbnails-maker' ),
				'type'       => 'first_content_image',
				'image_size' => '',
			)
		);

		return array(
			'success'    => false,
			'message'    => __( 'Failed to set thumbnail', 'ai-thumbnails-maker' ),
			'post_id'    => $post_id,
			'post_title' => $post->post_title,
			'type'       => 'first_content_image',
		);
	}

	/**
	 * Generate thumbnail using AI
	 *
	 * @param int     $post_id Post ID.
	 * @param WP_Post $post Post object.
	 * @return array Result data.
	 */
	private function generate_with_ai( $post_id, $post ) {
		try {
			$attachment_id = $this->ai_generator->generate_for_post( $post_id );

			if ( ! $attachment_id ) {
				$this->add_to_log(
					array(
						'post_id'    => $post_id,
						'post_title' => $post->post_title,
						'success'    => false,
						'message'    => __( 'Failed to generate AI image', 'ai-thumbnails-maker' ),
						'type'       => 'ai_generation',
						'image_size' => '',
					)
				);
				return array(
					'success'    => false,
					'message'    => __( 'Failed to generate AI image', 'ai-thumbnails-maker' ),
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'type'       => 'ai_generation',
				);
			}

			// Get image metadata
			$metadata   = wp_get_attachment_metadata( $attachment_id );
			$image_size = '';
			if ( isset( $metadata['width'], $metadata['height'] ) ) {
				$width  = $metadata['width'];
				$height = $metadata['height'];

				// Get file size
				$file_path = get_attached_file( $attachment_id );
				$file_size = '';
				if ( $file_path && file_exists( $file_path ) ) {
					$size_bytes = filesize( $file_path );
					$file_size  = size_format( $size_bytes, 2 );
				}

				$image_size = $width . 'x' . $height;
				if ( $file_size ) {
					$image_size .= ' (' . $file_size . ')';
				}
			}

			// Set thumbnail
			$overwrite_existing = $this->settings['overwrite_existing'] ?? false;
			if ( $overwrite_existing && has_post_thumbnail( $post_id ) ) {
				delete_post_thumbnail( $post_id );
			}

			$result = set_post_thumbnail( $post_id, $attachment_id );

			if ( $result || get_post_thumbnail_id( $post_id ) == $attachment_id ) {
				$thumbnail_url = wp_get_attachment_image_url( $attachment_id, 'thumbnail' );

				$this->add_to_log(
					array(
						'post_id'       => $post_id,
						'post_title'    => $post->post_title,
						'success'       => true,
						'message'       => __( 'AI image generated successfully', 'ai-thumbnails-maker' ),
						'type'          => 'ai_generation',
						'image_size'    => $image_size,
						'thumbnail_url' => $thumbnail_url,
						'thumbnail_id'  => $attachment_id,
					)
				);

				return array(
					'success'       => true,
					'message'       => __( 'AI image generated successfully', 'ai-thumbnails-maker' ),
					'post_id'       => $post_id,
					'post_title'    => $post->post_title,
					'thumbnail_url' => $thumbnail_url,
					'thumbnail_id'  => $attachment_id,
					'image_size'    => $image_size,
					'type'          => 'ai_generation',
				);
			} else {
				$this->add_to_log(
					array(
						'post_id'    => $post_id,
						'post_title' => $post->post_title,
						'success'    => false,
						'message'    => __( 'Failed to set thumbnail', 'ai-thumbnails-maker' ),
						'type'       => 'ai_generation',
						'image_size' => '',
					)
				);

				return array(
					'success'    => false,
					'message'    => __( 'Failed to set thumbnail', 'ai-thumbnails-maker' ),
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'type'       => 'ai_generation',
				);
			}
		} catch ( Exception $e ) {
			$this->add_to_log(
				array(
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'success'    => false,
					'message'    => $e->getMessage(),
					'type'       => 'ai_generation',
					'image_size' => '',
				)
			);

			return array(
				'success'    => false,
				'message'    => $e->getMessage(),
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'type'       => 'ai_generation',
			);
		}
	}

	/**
	 * Add entry to generation log
	 *
	 * @param array $log_entry Log entry data.
	 */
	private function add_to_log( $log_entry ) {
		// Get log from separate option for better reliability
		$log = get_option( 'aitm_generation_log', array() );

		// Add timestamp
		$log_entry['timestamp'] = current_time( 'mysql' );

		// Add to the beginning of array
		array_unshift( $log, $log_entry );

		// Limit log size to 100 entries
		$log = array_slice( $log, 0, 100 );

		// Save updated log to separate option
		update_option( 'aitm_generation_log', $log, false );
	}

	/**
	 * Generate thumbnail from title
	 *
	 * @param int     $post_id Post ID.
	 * @param WP_Post $post Post object.
	 * @return array Result data.
	 */
	private function generate_from_title( $post_id, $post ) {
		require_once AITM_PLUGIN_DIR . '/includes/class-title-image-generator.php';

		try {
			$title_generator = new AITM_Title_Image_Generator( $this->settings );
			$attachment_id   = $title_generator->generate_for_post( $post_id );

			if ( ! $attachment_id ) {
				$this->add_to_log(
					array(
						'post_id'    => $post_id,
						'post_title' => $post->post_title,
						'success'    => false,
						'message'    => __( 'Failed to generate title image', 'ai-thumbnails-maker' ),
						'type'       => 'generate_from_title',
						'image_size' => '',
					)
				);

				return array(
					'success'    => false,
					'message'    => __( 'Failed to generate title image', 'ai-thumbnails-maker' ),
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'type'       => 'generate_from_title',
				);
			}

			// Get image metadata
			$metadata   = wp_get_attachment_metadata( $attachment_id );
			$image_size = '';
			if ( isset( $metadata['width'], $metadata['height'] ) ) {
				$width  = $metadata['width'];
				$height = $metadata['height'];

				// Get file size
				$file_path = get_attached_file( $attachment_id );
				$file_size = '';
				if ( $file_path && file_exists( $file_path ) ) {
					$size_bytes = filesize( $file_path );
					$file_size  = size_format( $size_bytes, 2 );
				}

				$image_size = $width . 'x' . $height;
				if ( $file_size ) {
					$image_size .= ' (' . $file_size . ')';
				}
			}

			// Set thumbnail
			$overwrite_existing = $this->settings['overwrite_existing'] ?? false;
			if ( $overwrite_existing && has_post_thumbnail( $post_id ) ) {
				delete_post_thumbnail( $post_id );
			}

			$result = set_post_thumbnail( $post_id, $attachment_id );

			if ( $result || get_post_thumbnail_id( $post_id ) == $attachment_id ) {
				$thumbnail_url = wp_get_attachment_image_url( $attachment_id, 'thumbnail' );

				$this->add_to_log(
					array(
						'post_id'       => $post_id,
						'post_title'    => $post->post_title,
						'success'       => true,
						'message'       => __( 'Title image generated successfully', 'ai-thumbnails-maker' ),
						'type'          => 'generate_from_title',
						'image_size'    => $image_size,
						'thumbnail_url' => $thumbnail_url,
						'thumbnail_id'  => $attachment_id,
					)
				);

				return array(
					'success'       => true,
					'message'       => __( 'Title image generated successfully', 'ai-thumbnails-maker' ),
					'post_id'       => $post_id,
					'post_title'    => $post->post_title,
					'thumbnail_url' => $thumbnail_url,
					'thumbnail_id'  => $attachment_id,
					'image_size'    => $image_size,
					'type'          => 'generate_from_title',
				);
			}

			$this->add_to_log(
				array(
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'success'    => false,
					'message'    => __( 'Failed to set thumbnail', 'ai-thumbnails-maker' ),
					'type'       => 'generate_from_title',
					'image_size' => '',
				)
			);

			return array(
				'success'    => false,
				'message'    => __( 'Failed to set thumbnail', 'ai-thumbnails-maker' ),
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'type'       => 'generate_from_title',
			);
		} catch ( Exception $e ) {
			$this->add_to_log(
				array(
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'success'    => false,
					'message'    => $e->getMessage(),
					'type'       => 'generate_from_title',
					'image_size' => '',
				)
			);

			return array(
				'success'    => false,
				'message'    => $e->getMessage(),
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'type'       => 'generate_from_title',
			);
		}
	}

	/**
	 * Use default image as thumbnail
	 *
	 * @param int     $post_id Post ID.
	 * @param WP_Post $post Post object.
	 * @return array Result data.
	 */
	private function use_default_image( $post_id, $post ) {
		$default_image_id = $this->settings['default_image_id'] ?? 0;

		if ( ! $default_image_id || ! wp_attachment_is_image( $default_image_id ) ) {
			$this->add_to_log(
				array(
					'post_id'    => $post_id,
					'post_title' => $post->post_title,
					'success'    => false,
					'message'    => __( 'No default image configured or image not found', 'ai-thumbnails-maker' ),
					'type'       => 'use_default_image',
					'image_size' => '',
				)
			);

			return array(
				'success'    => false,
				'message'    => __( 'No default image configured or image not found', 'ai-thumbnails-maker' ),
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'type'       => 'use_default_image',
			);
		}

		// Get image metadata
		$metadata   = wp_get_attachment_metadata( $default_image_id );
		$image_size = '';
		if ( isset( $metadata['width'], $metadata['height'] ) ) {
			$width  = $metadata['width'];
			$height = $metadata['height'];

			// Get file size
			$file_path = get_attached_file( $default_image_id );
			$file_size = '';
			if ( $file_path && file_exists( $file_path ) ) {
				$size_bytes = filesize( $file_path );
				$file_size  = size_format( $size_bytes, 2 );
			}

			$image_size = $width . 'x' . $height;
			if ( $file_size ) {
				$image_size .= ' (' . $file_size . ')';
			}
		}

		// Set thumbnail
		$overwrite_existing = $this->settings['overwrite_existing'] ?? false;
		if ( $overwrite_existing && has_post_thumbnail( $post_id ) ) {
			delete_post_thumbnail( $post_id );
		}

		$result = set_post_thumbnail( $post_id, $default_image_id );

		if ( $result || get_post_thumbnail_id( $post_id ) == $default_image_id ) {
			$thumbnail_url = wp_get_attachment_image_url( $default_image_id, 'thumbnail' );

			$this->add_to_log(
				array(
					'post_id'       => $post_id,
					'post_title'    => $post->post_title,
					'success'       => true,
					'message'       => __( 'Default image set successfully', 'ai-thumbnails-maker' ),
					'type'          => 'use_default_image',
					'image_size'    => $image_size,
					'thumbnail_url' => $thumbnail_url,
					'thumbnail_id'  => $default_image_id,
				)
			);

			return array(
				'success'       => true,
				'message'       => __( 'Default image set successfully', 'ai-thumbnails-maker' ),
				'post_id'       => $post_id,
				'post_title'    => $post->post_title,
				'thumbnail_url' => $thumbnail_url,
				'thumbnail_id'  => $default_image_id,
				'image_size'    => $image_size,
				'type'          => 'use_default_image',
			);
		}

		$this->add_to_log(
			array(
				'post_id'    => $post_id,
				'post_title' => $post->post_title,
				'success'    => false,
				'message'    => __( 'Failed to set default image', 'ai-thumbnails-maker' ),
				'type'       => 'use_default_image',
				'image_size' => '',
			)
		);

		return array(
			'success'    => false,
			'message'    => __( 'Failed to set default image', 'ai-thumbnails-maker' ),
			'post_id'    => $post_id,
			'post_title' => $post->post_title,
			'type'       => 'use_default_image',
		);
	}

	/**
	 * Get statistics
	 *
	 * @param string $post_type Post type.
	 * @return array Statistics data.
	 */
	public function get_statistics( $post_type = 'post' ) {
		// Посты с превью
		$with_thumbnail = new WP_Query(
			array(
				'post_type'      => $post_type,
				'post_status'    => 'publish',
				'posts_per_page' => -1,
				'fields'         => 'ids',
				'meta_query'     => array(
					array(
						'key'     => '_thumbnail_id',
						'compare' => 'EXISTS',
					),
				),
			)
		);

		// Посты без превью
		$without_thumbnail = new WP_Query(
			array(
				'post_type'      => $post_type,
				'post_status'    => 'publish',
				'posts_per_page' => -1,
				'fields'         => 'ids',
				'meta_query'     => array(
					array(
						'key'     => '_thumbnail_id',
						'compare' => 'NOT EXISTS',
					),
				),
			)
		);

		$with_count    = $with_thumbnail->found_posts;
		$without_count = $without_thumbnail->found_posts;
		$total         = $with_count + $without_count;
		$percentage    = $total > 0 ? round( ( $with_count / $total ) * 100 ) : 0;

		return array(
			'with_thumbnail'    => $with_count,
			'without_thumbnail' => $without_count,
			'total'             => $total,
			'percentage'        => $percentage,
		);
	}
}