<?php

namespace AdPresso\Modules\Tracking;

use AdPresso\Entities\Ad;
use AdPresso\Entities\Group;
use WP_Error;

defined( 'ABSPATH' ) || exit;

/**
 * Generates dummy tracking data for testing.
 */
class TrackingDataGenerator {

	/**
	 * Generates and stores dummy tracking data for the existing placement assignments.
	 *
	 * @param array $args {
	 *     Optional.
	 *
	 *     @type int   $days_back               Number of days to generate data for. Default 30.
	 *     @type int   $avg_impressions_per_day Average impressions per assignment and day. Default 1000.
	 *     @type float $avg_ctr_percent         Average click-through rate in percent. Default 2.5.
	 *     @type bool  $include_active_view     Whether to generate Active View (Pro) data. Default true.
	 *     @type float $avg_viewability_percent Average viewability rate in percent. Default 70.
	 * }
	 *
	 * @return true|WP_Error
	 */
	public static function generate_data( array $args = [] ): bool|WP_Error {
		global $wpdb;

		$config = wp_parse_args( $args, [
			'days_back'             => 30,
			'avg_impressions_per_day' => 1000,
			'avg_ctr_percent'       => 2.5,
			'include_active_view'   => true,
			'avg_viewability_percent' => 70.0,
		] );

		$combinations = [];
		$placement_repo = adpresso_get_placement_repository();
		$all_placements = $placement_repo->get_all();

		if ( empty( $all_placements ) ) {
			return new WP_Error( 'no_placements', 'Keine Placements gefunden, für die Daten generiert werden könnten.' );
		}

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

			if ( $item instanceof Ad ) {
				$combinations[] = [
					'placement_id' => $placement->get_id(),
					'group_id'     => 0,
					'ad_id'        => $item->get_id(),
				];
			} elseif ( $item instanceof Group ) {
				$ad_data = $item->get_raw_ad_data(); // [ ad_id => weight ]
				foreach ( array_keys( $ad_data ) as $ad_id ) {
					$combinations[] = [
						'placement_id' => $placement->get_id(),
						'group_id'     => $item->get_id(),
						'ad_id'        => $ad_id,
					];
				}
			}
		}

		if ( empty( $combinations ) ) {
			return new WP_Error( 'no_combinations', 'Keine gültigen Anzeigen-Zuweisungen gefunden.' );
		}

		$stats_table = $wpdb->prefix . 'adpresso_stats';
		$sql_values = [];
		$date_format = 'Y-m-d';
		// Site-local days, like the tracking writes.
		$today                 = new \DateTimeImmutable( current_time( 'Y-m-d' ), new \DateTimeZone( 'UTC' ) );
		$variation_impressions = (int) $config['avg_impressions_per_day'] * 0.05;

		for ( $i = 0; $i < $config['days_back']; $i++ ) {
			$stat_date = $today->modify( "-$i days" )->format( $date_format );

			foreach ( $combinations as $combo ) {
				$impressions = max( 0, (int) $config['avg_impressions_per_day'] + wp_rand( $variation_impressions * -1, $variation_impressions ) );
				// A low CTR plus negative jitter must not produce negative clicks.
				$clicks = max( 0, (int) ( $impressions * ( ( $config['avg_ctr_percent'] + wp_rand( -100, 100 ) / 100 ) / 100 ) ) );

				$impressions_av = 0;
				if ( $config['include_active_view'] ) {
					$impressions_av = max( 0, (int) ( $impressions * ( ( $config['avg_viewability_percent'] + wp_rand( -10, 10 ) ) / 100 ) ) );
				}

				$sql_values[] = $wpdb->prepare(
					'(%s, %d, %d, %d, %d, %d, %d)',
					$stat_date,
					$combo['placement_id'],
					$combo['group_id'],
					$combo['ad_id'],
					$impressions,
					$clicks,
					$impressions_av
				);
			}
		}

		if ( empty( $sql_values ) ) {
			return true;
		}

		// Adds to rows that already exist for a day.
		$query = "INSERT INTO {$stats_table} (stat_date, placement_id, group_id, ad_id, impressions, clicks, impressions_av)
                  VALUES " . implode( ',', $sql_values ) . "
                  ON DUPLICATE KEY UPDATE
                  impressions = impressions + VALUES(impressions),
                  clicks = clicks + VALUES(clicks),
                  impressions_av = impressions_av + VALUES(impressions_av)";

		// phpcs:ignore WordPress.DB.PreparedSQL.NotPrepared -- values prepared individually above.
		$result = $wpdb->query( $query );

		return $result !== false;
	}
}