<?php
/**
 * Entry CSV export and scheduled auto-delete (entry automation).
 *
 * @package PhemightForms
 */

namespace PhemightForms;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Handles CSV export downloads and the daily cleanup cron event.
 */
class Export {

	const CRON_HOOK = 'phemightforms_daily_cleanup';

	/**
	 * Register hooks.
	 */
	public function __construct() {
		add_action( 'admin_post_phemightforms_export', [ $this, 'export_csv' ] );
		add_action( self::CRON_HOOK, [ $this, 'cleanup' ] );
	}

	/**
	 * Stream a CSV of entries for download.
	 */
	public function export_csv() {
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'Permission denied.', 'phemightforms' ) );
		}

		check_admin_referer( 'phemightforms_export' );

		global $wpdb;

		$table   = Install::entries_table();
		$form_id = isset( $_GET['form'] ) ? absint( wp_unslash( $_GET['form'] ) ) : 0;

		if ( $form_id ) {
			$rows = $wpdb->get_results( $wpdb->prepare( "SELECT * FROM {$table} WHERE form_id = %d ORDER BY created_at DESC", $form_id ) ); // phpcs:ignore WordPress.DB
		} else {
			$rows = $wpdb->get_results( "SELECT * FROM {$table} ORDER BY created_at DESC" ); // phpcs:ignore WordPress.DB
		}

		// Collect the union of all field labels for the header row.
		$labels = [];
		$parsed = [];
		foreach ( $rows as $row ) {
			$data       = json_decode( $row->fields, true );
			$data       = is_array( $data ) ? $data : [];
			$parsed[]   = [ 'row' => $row, 'data' => $data ];
			foreach ( $data as $field ) {
				$label = isset( $field['label'] ) ? $field['label'] : '';
				if ( '' !== $label && ! in_array( $label, $labels, true ) ) {
					$labels[] = $label;
				}
			}
		}

		$filename = 'phemightforms-entries-' . gmdate( 'Y-m-d' ) . '.csv';

		nocache_headers();
		header( 'Content-Type: text/csv; charset=utf-8' );
		header( 'Content-Disposition: attachment; filename=' . $filename );

		$out = fopen( 'php://output', 'w' );

		fputcsv( $out, array_merge( [ __( 'ID', 'phemightforms' ), __( 'Date', 'phemightforms' ) ], $labels ) );

		foreach ( $parsed as $item ) {
			$values = [ $item['row']->id, $item['row']->created_at ];

			// Map this entry's values onto the shared label columns.
			$by_label = [];
			foreach ( $item['data'] as $field ) {
				if ( isset( $field['label'] ) ) {
					$by_label[ $field['label'] ] = isset( $field['value'] ) ? $field['value'] : '';
				}
			}

			foreach ( $labels as $label ) {
				$values[] = isset( $by_label[ $label ] ) ? $by_label[ $label ] : '';
			}

			fputcsv( $out, $values );
		}

		fclose( $out ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose
		exit;
	}

	/**
	 * Delete entries older than the configured retention window.
	 */
	public function cleanup() {
		$days = (int) Plugin::get_option( 'entry_retention_days', 0 );

		if ( $days <= 0 ) {
			return;
		}

		global $wpdb;

		$table  = Install::entries_table();
		$cutoff = gmdate( 'Y-m-d H:i:s', time() - ( $days * DAY_IN_SECONDS ) );

		$wpdb->query( $wpdb->prepare( "DELETE FROM {$table} WHERE created_at < %s", $cutoff ) ); // phpcs:ignore WordPress.DB
	}

	/**
	 * Build a nonce-protected export URL.
	 *
	 * @param int $form_id Optional form filter.
	 * @return string
	 */
	public static function export_url( $form_id = 0 ) {
		return wp_nonce_url(
			add_query_arg(
				array_filter(
					[
						'action' => 'phemightforms_export',
						'form'   => $form_id,
					]
				),
				admin_url( 'admin-post.php' )
			),
			'phemightforms_export'
		);
	}
}