<?php

namespace AdPresso\Core\Rest;

use AdPresso\Entities\Group;
use AdPresso\Infrastructure\SvgLoader;
use WP_Error;
use WP_REST_Request;
use WP_REST_Response;
use WP_REST_Server;

defined( 'ABSPATH' ) || exit;

/**
 * REST API Controller for handling entity assignments.
 */
class AssignmentController {

	protected string $namespace = 'adpresso/v1';
	protected string $rest_base = 'assignments';

	/**
	 * Register the hook for REST API routes.
	 *
	 * @return void
	 */
	public function hooks(): void {
		add_action( 'rest_api_init', [ $this, 'register_routes' ] );
	}

	/**
	 * Register the REST API routes.
	 *
	 * @return void
	 */
	public function register_routes(): void {
		// Endpoint for getting initial data for a specific ad
		register_rest_route( $this->namespace, '/' . $this->rest_base . '/ad/(?P<ad_id>[\d]+)', [
			[
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => [ $this, 'get_ad_assignments' ],
				'permission_callback' => [ $this, 'get_ad_assignments_permission_check' ],
				'args'                => [
					'ad_id' => [
						'validate_callback' => function( $param ) {
							return is_numeric( $param );
						},
						'required'          => true,
					],
				],
			],
		] );

		register_rest_route( $this->namespace, '/' . $this->rest_base . '/group/(?P<group_id>[\d]+)', [
			[
				'methods'             => WP_REST_Server::READABLE,
				'callback'            => [ $this, 'get_group_assignments' ],
				'permission_callback' => [ $this, 'get_group_assignments_permission_check' ],
				'args'                => [
					'group_id' => [
						'validate_callback' => function( $param ) {
							return is_numeric( $param );
						},
						'required'          => true,
					],
				],
			],
		] );
	}

	/**
	 * Permission check for the ad assignments endpoint.
	 *
	 * @param WP_REST_Request $request
	 *
	 * @return bool|WP_Error
	 */
	public function get_ad_assignments_permission_check( WP_REST_Request $request ): bool|WP_Error {
		$ad_id = (int) $request->get_param( 'ad_id' );
		// A new (unsaved) ad has no post yet - fall back to the type-level capability.
		$allowed = 0 === $ad_id ? current_user_can( adpresso_get_capability( 'edit_ad' ) ) : current_user_can( 'edit_post', $ad_id );
		if ( ! $allowed ) {
			return new WP_Error( 'rest_forbidden', __( 'Sorry, you are not allowed to view these assignments.', 'adpresso' ), [ 'status' => 403 ] );
		}

		return true;
	}

	/**
	 * Callback function to get all assignment data for a single ad.
	 *
	 * @param WP_REST_Request $request
	 *
	 * @return WP_REST_Response
	 */
	public function get_ad_assignments( WP_REST_Request $request ): WP_REST_Response {
		$ad_id = (int) $request->get_param( 'ad_id' );

		$group_repository     = adpresso_get_group_repository();
		$placement_repository = adpresso_get_placement_repository();

		// Get all available groups
		$all_groups = $group_repository->get_all();

		// Placements per group, from the same placement list the target column needs anyway (no extra queries).
		$placements             = $placement_repository->get_all( [ 'any' ], false );
		$group_placement_counts = [];
		foreach ( $placements as $placement ) {
			$item = $placement->get_item();
			if ( $item instanceof Group ) {
				$group_placement_counts[ $item->get_id() ] = ( $group_placement_counts[ $item->get_id() ] ?? 0 ) + 1;
			}
		}

		// Get the IDs of groups this ad is assigned to
		$assigned_group_ids = [];
		if ( $ad_id > 0 ) {
			$assigned_group_ids = $group_repository->find_by_contained_ad( $ad_id, [ 'publish', 'draft' ], false, true );
		}

		// Prepare the group array for the response, adding the 'is_assigned_to_ad' flag.
		$groups_response = [];
		foreach ( $all_groups as $group ) {
			$groups_response[] = [
				'id'                => $group->get_id(),
				'title'             => $group->get_title(),
				'placement_count'   => $group_placement_counts[ $group->get_id() ] ?? 0,
				'is_assigned_to_ad' => in_array( $group->get_id(), $assigned_group_ids, true ),
				'image'             => SvgLoader::get( ADPRESSO_ABSPATH . $group->get_image(), [ 'class' => 'adpresso-icon-main' ] ),
			];
		}

		// Sort the groups: assigned groups first, then alphabetically by title
		usort( $groups_response, function( $a, $b ) {
			if ( $a['is_assigned_to_ad'] !== $b['is_assigned_to_ad'] ) {
				return $b['is_assigned_to_ad'] <=> $a['is_assigned_to_ad']; // true (1) comes before false (0)
			}

			return strcasecmp( $a['title'], $b['title'] ); // Secondary sort by title
		} );

		// Get the placement IDs for the singular ad context
		$start                  = microtime( true );
		$assigned_placement_ids = [];
		if ( $ad_id > 0 ) {
			$assigned_placement_ids = $placement_repository->get_by_using_item( $ad_id, 'ad', [ 'any' ], false, true );
		}
		$placements_response = [];

		foreach ( $placements as $placement ) {
			$placement_id          = $placement->get_id();
			$item                  = $placement->get_item();
			$placements_response[] = [
				'id'         => $placement_id,
				'title'      => $placement->get_title(),
				'type_label' => $placement->get_type_object() ? $placement->get_type_object()->get_title() : $placement->get_type(),
				'item_id'    => $item ? $item->get_id() : 0,
				'image'      => $placement->get_image(),
			];
		}
		$end = microtime( true );
		usort( $placements_response, function( $a, $b ) use ( $assigned_placement_ids ) {
			$a_is_assigned = in_array( $a['id'], $assigned_placement_ids, true );
			$b_is_assigned = in_array( $b['id'], $assigned_placement_ids, true );

			if ( $a_is_assigned !== $b_is_assigned ) {
				return $b_is_assigned <=> $a_is_assigned; // true (1) comes befor false (0)
			}

			return strcasecmp( $a['title'], $b['title'] ); // Second sorting for the title.
		} );

		$response_data = [
			'groups'                  => $groups_response,
			'placements'              => $placements_response,
			'singular_ad_assignments' => [
				'placement_ids' => $assigned_placement_ids,
				// The "single" icon of the group list for the "Singular ad" card.
				'image'         => SvgLoader::get( ADPRESSO_ABSPATH . 'admin/assets/img/groups/ap-ui-grp-single.svg', [ 'class' => 'adpresso-icon-main' ] ),
			],
			'total_time'              => ( $end - $start ) * 1000 . 'ms',
		];

		return new WP_REST_Response( $response_data, 200 );
	}

	/**
	 * Permission check for the Group-Assignments endpoint.
	 *
	 * @param WP_REST_Request $request
	 *
	 * @return bool|WP_Error
	 */
	public function get_group_assignments_permission_check( WP_REST_Request $request ): bool|WP_Error {
		$group_id = (int) $request->get_param( 'group_id' );
		if ( ! current_user_can( 'edit_post', $group_id ) ) {
			return new WP_Error( 'rest_forbidden', __( 'Sorry, you are not allowed to view these assignments.', 'adpresso' ), [ 'status' => 403 ] );
		}

		return true;
	}

	/**
	 * Callback function to get all assignment data for a single group.
	 *
	 * @param WP_REST_Request $request
	 *
	 * @return WP_REST_Response
	 */
	public function get_group_assignments( WP_REST_Request $request ): WP_REST_Response {
		$group_id = (int) $request->get_param( 'group_id' );

		$placement_repository = adpresso_get_placement_repository();

		$placements             = $placement_repository->get_all( [ 'any' ], false );
		$placements_response    = [];
		$assigned_placement_ids = $placement_repository->get_by_using_item( $group_id, 'group', [ 'any' ], false, true );

		foreach ( $placements as $placement ) {
			$item = $placement->get_item();

			$placements_response[] = [
				'id'         => $placement->get_id(),
				'title'      => $placement->get_title(),
				'type_label' => $placement->get_type_object() ? $placement->get_type_object()->get_title() : $placement->get_type(),
				'item_id'    => $item ? $item->get_id() : 0, // Important for the replacement logic
				'image'      => $placement->get_image(),
			];
		}

		// sort the placements: assigned first, then alphabetically by title
		usort( $placements_response, function( $a, $b ) use ( $assigned_placement_ids ) {
			$a_is_assigned = in_array( $a['id'], $assigned_placement_ids, true );
			$b_is_assigned = in_array( $b['id'], $assigned_placement_ids, true );

			if ( $a_is_assigned !== $b_is_assigned ) {
				return $b_is_assigned <=> $a_is_assigned; // true (1) comes before false (0)
			}

			return strcasecmp( $a['title'], $b['title'] ); // Second sorting for the title.
		} );

		$response_data = [
			'placements'             => $placements_response,
			'assigned_placement_ids' => $assigned_placement_ids,
		];

		return new WP_REST_Response( $response_data, 200 );
	}
}