<?php
/**
 * REST API endpoints for the block editor.
 *
 * @package 45Squared_AI_Image_Generator
 */

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

class Nano_Banana_Rest_API {

	const NAMESPACE = 'nano-banana/v1';

	/**
	 * Hook into WordPress.
	 */
	public function init() {
		add_action( 'rest_api_init', array( $this, 'register_routes' ) );
	}

	/**
	 * Register REST routes.
	 */
	public function register_routes() {
		register_rest_route( self::NAMESPACE, '/generate', array(
			'methods'             => 'POST',
			'callback'            => array( $this, 'generate' ),
			'permission_callback' => array( $this, 'check_edit_permission' ),
			'args'                => array(
				'prompt'       => array(
					'required'          => true,
					'type'              => 'string',
					'sanitize_callback' => 'sanitize_textarea_field',
				),
				'model'        => array(
					'type'              => 'string',
					'sanitize_callback' => 'sanitize_text_field',
					'default'           => '',
				),
				'aspect_ratio' => array(
					'type'              => 'string',
					'sanitize_callback' => 'sanitize_text_field',
					'default'           => '1:1',
				),
				'image_size'   => array(
					'type'              => 'string',
					'sanitize_callback' => 'sanitize_text_field',
					'default'           => '1K',
				),
				'count'        => array(
					'type'    => 'integer',
					'default' => 1,
					'minimum' => 1,
					'maximum' => 4,
				),
			),
		) );

		register_rest_route( self::NAMESPACE, '/save', array(
			'methods'             => 'POST',
			'callback'            => array( $this, 'save' ),
			'permission_callback' => array( $this, 'check_upload_permission' ),
			'args'                => array(
				'image_data' => array(
					'required' => true,
					'type'     => 'string',
				),
				'mime_type'  => array(
					'type'    => 'string',
					'default' => 'image/png',
				),
				'prompt'     => array(
					'type'              => 'string',
					'default'           => '',
					'sanitize_callback' => 'sanitize_textarea_field',
				),
				'model'      => array(
					'type'              => 'string',
					'default'           => '',
					'sanitize_callback' => 'sanitize_text_field',
				),
			),
		) );

		register_rest_route( self::NAMESPACE, '/edit', array(
			'methods'             => 'POST',
			'callback'            => array( $this, 'edit' ),
			'permission_callback' => array( $this, 'check_upload_permission' ),
			'args'                => array(
				'attachment_id' => array(
					'required' => true,
					'type'     => 'integer',
				),
				'prompt'        => array(
					'required'          => true,
					'type'              => 'string',
					'sanitize_callback' => 'sanitize_textarea_field',
				),
			),
		) );
	}

	/**
	 * Permission check: user can edit posts.
	 *
	 * @return bool
	 */
	public function check_edit_permission() {
		return current_user_can( 'edit_posts' );
	}

	/**
	 * Permission check: user can upload files.
	 *
	 * @return bool
	 */
	public function check_upload_permission() {
		return current_user_can( 'upload_files' );
	}

	/**
	 * Generate images.
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return WP_REST_Response|WP_Error
	 */
	public function generate( $request ) {
		$api    = new Nano_Banana_API();
		$images = $api->generate_image( $request['prompt'], array(
			'model'        => $request['model'],
			'aspect_ratio' => $request['aspect_ratio'],
			'image_size'   => $request['image_size'],
			'count'        => $request['count'],
		) );

		if ( is_wp_error( $images ) ) {
			return $images;
		}

		$results = array();
		foreach ( $images as $image ) {
			$results[] = array(
				'data'     => base64_encode( $image['data'] ), // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode
				'mimeType' => $image['mime_type'],
			);
		}

		$model = ! empty( $request['model'] ) ? $request['model'] : get_option( 'nano_banana_model' );
		Nano_Banana_History::log_generation( $request['prompt'], $model, count( $images ) );

		return rest_ensure_response( $results );
	}

	/**
	 * Save an image to the Media Library.
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return WP_REST_Response|WP_Error
	 */
	public function save( $request ) {
		$image_data = array(
			'data'      => base64_decode( $request['image_data'] ), // phpcs:ignore WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_decode
			'mime_type' => $request['mime_type'],
		);

		$api       = new Nano_Banana_API();
		$attach_id = $api->save_to_media_library( $image_data, $request['prompt'], $request['model'] );

		if ( is_wp_error( $attach_id ) ) {
			return $attach_id;
		}

		return rest_ensure_response( array(
			'attachmentId' => $attach_id,
			'url'          => wp_get_attachment_url( $attach_id ),
		) );
	}

	/**
	 * Edit an existing image.
	 *
	 * @param WP_REST_Request $request Request object.
	 * @return WP_REST_Response|WP_Error
	 */
	public function edit( $request ) {
		$attachment_id = $request['attachment_id'];

		if ( ! current_user_can( 'edit_post', $attachment_id ) ) {
			return new WP_Error( 'forbidden', __( 'You do not have permission to edit this attachment.', '45squared-ai-powered-image-generator' ), array( 'status' => 403 ) );
		}

		if ( ! wp_attachment_is_image( $attachment_id ) ) {
			return new WP_Error( 'invalid_attachment', __( 'Not a valid image attachment.', '45squared-ai-powered-image-generator' ), array( 'status' => 400 ) );
		}

		$file_path = get_attached_file( $attachment_id );
		if ( ! $file_path || ! file_exists( $file_path ) ) {
			return new WP_Error( 'file_not_found', __( 'Source image not found.', '45squared-ai-powered-image-generator' ), array( 'status' => 404 ) );
		}

		$api    = new Nano_Banana_API();
		$result = $api->edit_image( $file_path, $request['prompt'] );

		if ( is_wp_error( $result ) ) {
			return $result;
		}

		$model     = get_option( 'nano_banana_model', 'gemini-3.1-flash-image-preview' );
		$attach_id = $api->save_to_media_library( $result, $request['prompt'] . ' (edited)', $model );

		if ( is_wp_error( $attach_id ) ) {
			return $attach_id;
		}

		Nano_Banana_History::log_generation( $request['prompt'], $model, 1, 'edit' );

		return rest_ensure_response( array(
			'attachmentId' => $attach_id,
			'url'          => wp_get_attachment_url( $attach_id ),
		) );
	}
}