<?php

namespace Classifai\Features;

use Classifai\Providers\Azure\ComputerVision;
use Classifai\Providers\OpenAI\ChatGPT;
use Classifai\Providers\Localhost\OllamaMultimodal as OllamaMM;
use Classifai\Services\ImageProcessing;
use WP_REST_Server;
use WP_REST_Request;
use WP_Error;
use DOMDocument;

use function Classifai\get_asset_info;
use function Classifai\clean_input;

/**
 * Class ImageTextExtraction
 */
class ImageTextExtraction extends Feature {
	/**
	 * ID of the current feature.
	 *
	 * @var string
	 */
	const ID = 'feature_image_to_text_generator';

	/**
	 * Prompt for extracting text.
	 *
	 * @var string
	 */
	public $prompt = 'You are an assistant that extracts text from images. You will be provided with an image and will return whatever text is in the image. Return only the text, nothing else. If there is no text present, return the word none.';

	/**
	 * Constructor.
	 */
	public function __construct() {
		$this->label = __( 'Image Text Extraction', 'classifai' );

		// Contains all providers that are registered to the service.
		$this->provider_instances = $this->get_provider_instances( ImageProcessing::get_service_providers() );

		// Contains just the providers this feature supports.
		$this->supported_providers = [
			ComputerVision::ID => __( 'Microsoft Azure AI Vision', 'classifai' ),
			ChatGPT::ID        => __( 'OpenAI ChatGPT', 'classifai' ),
			OllamaMM::ID       => __( 'Ollama', 'classifai' ),
		];
	}

	/**
	 * Set up necessary hooks.
	 *
	 * We utilize this so we can register the REST route.
	 */
	public function setup() {
		parent::setup();
		add_action( 'rest_api_init', [ $this, 'register_endpoints' ] );
	}

	/**
	 * Returns the settings for the feature.
	 *
	 * @param string $index The index of the setting to return.
	 * @return array|mixed
	 */
	public function get_settings( $index = false ) {
		$settings = parent::get_settings( $index );

		// Keep using the original prompt from the codebase to allow updates.
		if ( $settings && ! empty( $settings[ ChatGPT::ID ]['prompt'] ) ) {
			foreach ( $settings[ ChatGPT::ID ]['prompt'] as $key => $prompt ) {
				if ( 1 === intval( $prompt['original'] ) ) {
					$settings[ ChatGPT::ID ]['prompt'][ $key ]['prompt'] = $this->prompt;
					break;
				}
			}
		}

		if ( $settings && ! empty( $settings[ OllamaMM::ID ]['prompt'] ) ) {
			foreach ( $settings[ OllamaMM::ID ]['prompt'] as $key => $prompt ) {
				if ( 1 === intval( $prompt['original'] ) ) {
					$settings[ OllamaMM::ID ]['prompt'][ $key ]['prompt'] = $this->prompt;
					break;
				}
			}
		}

		return $settings;
	}

	/**
	 * Set up necessary hooks.
	 */
	public function feature_setup() {
		add_action( 'rest_api_init', [ $this, 'add_ocr_data_to_api_response' ] );
		add_action( 'enqueue_block_editor_assets', [ $this, 'enqueue_editor_assets' ] );
		add_action( 'add_meta_boxes_attachment', [ $this, 'setup_attachment_meta_box' ] );
		add_action( 'edit_attachment', [ $this, 'maybe_rescan_image' ] );

		add_filter( 'the_content', [ $this, 'add_ocr_aria_describedby' ] );
		add_filter( 'attachment_fields_to_edit', [ $this, 'add_rescan_button_to_media_modal' ], 10, 2 );
		add_filter( 'wp_generate_attachment_metadata', [ $this, 'generate_ocr_text' ], 9, 2 );
	}

	/**
	 * Register any needed endpoints.
	 */
	public function register_endpoints() {
		register_rest_route(
			'classifai/v1',
			'ocr/(?P<id>\d+)',
			[
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => [ $this, 'rest_endpoint_callback' ],
				'args'                => [
					'id' => [
						'required'          => true,
						'type'              => 'integer',
						'sanitize_callback' => 'absint',
						'description'       => esc_html__( 'Image ID to read text from.', 'classifai' ),
					],
				],
				'permission_callback' => [ $this, 'image_text_extractor_permissions_check' ],
			]
		);
	}

	/**
	 * Check if a given request has access to generate OCR.
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return bool|WP_Error
	 */
	public function image_text_extractor_permissions_check( WP_REST_Request $request ) {
		$attachment_id = $request->get_param( 'id' );
		$post_type     = get_post_type_object( 'attachment' );

		// Ensure attachments are allowed in REST endpoints.
		if ( empty( $post_type ) || empty( $post_type->show_in_rest ) ) {
			return false;
		}

		// Ensure we have a logged in user that can upload and change files.
		if ( empty( $attachment_id ) || ! current_user_can( 'edit_post', $attachment_id ) || ! current_user_can( 'upload_files' ) ) {
			return false;
		}

		if ( ! $this->is_feature_enabled() ) {
			return new WP_Error( 'not_enabled', esc_html__( 'Scan image for text is disabled. Please check your settings.', 'classifai' ) );
		}

		return true;
	}

	/**
	 * Generic request handler for all our custom routes.
	 *
	 * @param WP_REST_Request $request The full request object.
	 * @return \WP_REST_Response
	 */
	public function rest_endpoint_callback( WP_REST_Request $request ) {
		$route = $request->get_route();

		if ( strpos( $route, '/classifai/v1/ocr' ) === 0 ) {
			$result = $this->run( $request->get_param( 'id' ), 'ocr' );

			if ( $result && ! is_wp_error( $result ) ) {
				$this->save( $result, $request->get_param( 'id' ) );
			}

			return rest_ensure_response( $result );
		}

		return parent::rest_endpoint_callback( $request );
	}

	/**
	 * Generate the tags for the image being uploaded.
	 *
	 * @param array $metadata      The metadata for the image.
	 * @param int   $attachment_id Post ID for the attachment.
	 * @return array
	 */
	public function generate_ocr_text( array $metadata, int $attachment_id ): array {
		if (
			! $this->is_feature_enabled() ||
			'automatic' !== $this->get_processing_mode()
		) {
			return $metadata;
		}

		$result = $this->run( $attachment_id, 'ocr' );

		if ( $result && ! is_wp_error( $result ) ) {
			$this->save( $result, $attachment_id );
		}

		return $metadata;
	}

	/**
	 * Save the OCR text.
	 *
	 * @param string $result The result to save.
	 * @param int    $attachment_id The attachment ID.
	 */
	public function save( string $result, int $attachment_id ) {
		$content = get_the_content( null, false, $attachment_id );

		$post_args = [
			'ID'           => $attachment_id,
			'post_content' => sanitize_text_field( $result ),
		];

		/**
		 * Filter the post arguments before saving the text to post_content.
		 *
		 * This enables text to be stored in a different post or post meta field,
		 * or do other post data setting based on scan results.
		 *
		 * @since 1.6.0
		 * @hook classifai_ocr_text_post_args
		 *
		 * @param array  $post_args      Array of post data for the attachment post update. Defaults to `ID` and `post_content`.
		 * @param int    $attachment_id ID of the attachment post.
		 * @param string $result        The full scan results from the API.
		 *
		 * @return array The filtered post arguments.
		 */
		$post_args = apply_filters( 'classifai_ocr_text_post_args', $post_args, $attachment_id, $result );

		if ( $content !== $result ) {
			wp_update_post( $post_args );
		}
	}

	/**
	 * Include classifai_computer_vision_ocr in API response.
	 */
	public function add_ocr_data_to_api_response() {
		register_rest_field(
			'attachment',
			'classifai_has_ocr',
			[
				'get_callback' => function ( $params ) {
					return ! empty( get_post_meta( $params['id'], 'classifai_computer_vision_ocr', true ) );
				},
				'schema'       => [
					'type'    => 'boolean',
					'context' => [ 'view' ],
				],
			]
		);
	}

	/**
	 * Enqueue the editor scripts.
	 */
	public function enqueue_editor_assets() {
		wp_enqueue_script(
			'classifai-plugin-editor-ocr-js',
			CLASSIFAI_PLUGIN_URL . 'dist/classifai-plugin-editor-ocr.js',
			array_merge( get_asset_info( 'classifai-plugin-editor-ocr', 'dependencies' ), array( 'lodash' ) ),
			get_asset_info( 'classifai-plugin-editor-ocr', 'version' ),
			true
		);
	}

	/**
	 * Adds a meta box for rescanning options if the settings are configured.
	 *
	 * @param \WP_Post $post The post object.
	 */
	public function setup_attachment_meta_box( \WP_Post $post ) {
		global $wp_meta_boxes;

		if ( ! wp_attachment_is_image( $post ) || ! $this->is_feature_enabled() ) {
			return;
		}

		// Add our content to the metabox.
		add_action( 'classifai_render_attachment_metabox', [ $this, 'attachment_data_meta_box_content' ] );

		// If the metabox was already registered, don't add it again.
		if ( isset( $wp_meta_boxes['attachment']['side']['high']['classifai_image_processing'] ) ) {
			return;
		}

		// Register the metabox if needed.
		add_meta_box(
			'classifai_image_processing',
			__( 'ClassifAI Image Processing', 'classifai' ),
			[ $this, 'attachment_data_meta_box' ],
			'attachment',
			'side',
			'high'
		);
	}

	/**
	 * Render the meta box.
	 *
	 * @param \WP_Post $post The post object.
	 */
	public function attachment_data_meta_box( \WP_Post $post ) {
		/**
		 * Allows more fields to be rendered in attachment metabox.
		 *
		 * @since 3.0.0
		 * @hook classifai_render_attachment_metabox
		 *
		 * @param \WP_Post $post The post object.
		 * @param object   $this The Provider object.
		 */
		do_action( 'classifai_render_attachment_metabox', $post, $this );
	}

	/**
	 * Display meta data.
	 *
	 * @param \WP_Post $post The post object.
	 */
	public function attachment_data_meta_box_content( \WP_Post $post ) {
		$ocr = get_post_meta( $post->ID, 'classifai_computer_vision_ocr', true ) ? __( 'Rescan for text', 'classifai' ) : __( 'Scan image for text', 'classifai' );
		?>

		<?php if ( $this->is_feature_enabled() ) : ?>
			<div class="misc-pub-section">
				<label for="rescan-ocr">
					<input type="checkbox" value="yes" id="rescan-ocr" name="rescan-ocr"/>
					<?php echo esc_html( $ocr ); ?>
				</label>
			</div>
			<?php
		endif;
	}

	/**
	 * Determine if we need to rescan the image.
	 *
	 * @param int $attachment_id Attachment ID.
	 */
	public function maybe_rescan_image( int $attachment_id ) {
		if ( clean_input( 'rescan-ocr' ) ) {
			$result = $this->run( $attachment_id, 'ocr' );

			if ( $result && ! is_wp_error( $result ) ) {
				// Ensure we don't re-run this when the attachment is updated.
				remove_action( 'edit_attachment', [ $this, 'maybe_rescan_image' ] );
				$this->save( $result, $attachment_id );
			}
		}
	}

	/**
	 * Filter the post content to inject aria-describedby attribute.
	 *
	 * @param string $content Post content.
	 * @return string
	 */
	public function add_ocr_aria_describedby( string $content ): string {
		$modified = false;

		if ( ! is_singular() || empty( $content ) ) {
			return $content;
		}

		$dom = new DOMDocument();

		// Suppress warnings generated by loadHTML.
		$errors = libxml_use_internal_errors( true );
		$dom->loadHTML(
			sprintf(
				'<!DOCTYPE html><html><head><meta charset="%s"></head><body>%s</body></html>',
				esc_attr( get_bloginfo( 'charset' ) ),
				$content
			)
		);
		libxml_use_internal_errors( $errors );

		foreach ( $dom->getElementsByTagName( 'img' ) as $image ) {
			foreach ( $image->attributes as $attribute ) {
				if ( 'aria-describedby' === $attribute->name ) {
					break;
				}

				if ( 'class' !== $attribute->name ) {
					continue;
				}

				$image_id            = preg_match( '~wp-image-\K\d+~', $image->getAttribute( 'class' ), $out ) ? $out[0] : 0;
				$ocr_scanned_text_id = "classifai-ocr-$image_id";
				$ocr_scanned_text    = $dom->getElementById( $ocr_scanned_text_id );

				if ( ! empty( $ocr_scanned_text ) ) {
					$image->setAttribute( 'aria-describedby', $ocr_scanned_text_id );
					$modified = true;
				}
			}
		}

		if ( $modified ) {
			$body = $dom->getElementsByTagName( 'body' )->item( 0 );
			return trim( $dom->saveHTML( $body ) );
		}

		return $content;
	}

	/**
	 * Adds the rescan buttons to the media modal.
	 *
	 * @param array         $form_fields Array of fields
	 * @param \WP_Post|null $post        Post object for the attachment being viewed.
	 * @return array
	 */
	public function add_rescan_button_to_media_modal( array $form_fields, ?\WP_Post $post ): array {
		if ( null === $post || ! $this->is_feature_enabled() || ! wp_attachment_is_image( $post ) ) {
			return $form_fields;
		}

		$ocr_text = empty( get_post_meta( $post->ID, 'classifai_computer_vision_ocr', true ) ) ? __( 'Scan', 'classifai' ) : __( 'Rescan', 'classifai' );

		$form_fields['rescan_ocr'] = [
			'label'        => __( 'Scan image for text', 'classifai' ),
			'input'        => 'html',
			'show_in_edit' => false,
			'html'         => '<button class="button secondary" id="classifai-rescan-ocr" data-id="' . esc_attr( absint( $post->ID ) ) . '">' . esc_html( $ocr_text ) . '</button><span class="spinner" style="display:none;float:none;"></span><span class="error" style="display:none;color:#bc0b0b;padding:5px;"></span>',
		];

		return $form_fields;
	}

	/**
	 * Get the description for the enable field.
	 *
	 * @return string
	 */
	public function get_enable_description(): string {
		return esc_html__( 'OCR detects text in images (e.g., handwritten notes) and saves that as content with the image.', 'classifai' );
	}

	/**
	 * Returns the default settings for the feature.
	 *
	 * @return array
	 */
	public function get_feature_default_settings(): array {
		return [
			'processing_mode' => 'automatic',
			'provider'        => ComputerVision::ID,
		];
	}

	/**
	 * Sanitizes the default feature settings.
	 *
	 * @param array $new_settings Settings being saved.
	 * @return array
	 */
	public function sanitize_default_feature_settings( array $new_settings ): array {
		$settings = $this->get_settings();

		$new_settings['processing_mode'] = sanitize_text_field( $new_settings['processing_mode'] ?? $settings['processing_mode'] );

		return $new_settings;
	}

	/**
	 * Return the processing mode for the feature.
	 *
	 * @return string
	 */
	public function get_processing_mode(): string {
		$settings = $this->get_settings();
		$value    = $settings['processing_mode'] ?? 'automatic';

		return $value;
	}

	/**
	 * Generates feature setting data required for migration from
	 * ClassifAI < 3.0.0 to 3.0.0
	 *
	 * @return array
	 */
	public function migrate_settings() {
		$old_settings = get_option( 'classifai_computer_vision', array() );
		$new_settings = $this->get_default_settings();

		$new_settings['provider'] = 'ms_computer_vision';

		if ( isset( $old_settings['enable_smart_cropping'] ) ) {
			$new_settings['status'] = $old_settings['enable_smart_cropping'];
		}

		if ( isset( $old_settings['url'] ) ) {
			$new_settings['ms_computer_vision']['endpoint_url'] = $old_settings['url'];
		}

		if ( isset( $old_settings['api_key'] ) ) {
			$new_settings['ms_computer_vision']['api_key'] = $old_settings['api_key'];
		}

		if ( isset( $old_settings['authenticated'] ) ) {
			$new_settings['ms_computer_vision']['authenticated'] = $old_settings['authenticated'];
		}

		if ( isset( $old_settings['ocr_roles'] ) ) {
			$new_settings['roles'] = $old_settings['ocr_roles'];
		}

		if ( isset( $old_settings['ocr_users'] ) ) {
			$new_settings['users'] = $old_settings['ocr_users'];
		}

		if ( isset( $old_settings['ocr_user_based_opt_out'] ) ) {
			$new_settings['user_based_opt_out'] = $old_settings['ocr_user_based_opt_out'];
		}

		return $new_settings;
	}
}
