<?php

namespace GravityKit\GravityExport\Save\Service;

use GFExcel\GFExcel;
use GFExcel\GFExcelOutput;
use GravityKit\GravityExport\Save\Addon\SaveAddon;

/**
 * A service that handles the rendering and storing of the files.
 *
 * @since 1.0
 */
class StorageService {
	/**
	 * Holds a reference to the produced files in this instance.
	 *
	 * @since 1.0
	 * @var string[]
	 */
	private $history = [];

	/**
	 * @inheritdoc
	 * @since 1.0
	 */
	public function getForm( string $form_id ): array {
		return \GFAPI::get_form( $form_id );
	}

	/**
	 * @inheritdoc
	 * @since 1.0
	 */
	public function renderFile( array $feed, ?array $entries = null ): string {
		$settings       = rgar( $feed, 'meta', [] );
		$form_id        = rgar( $feed, 'form_id' );
		$form           = $form_id ? \GFAPI::get_form( $form_id ) : null;
		$source_feed_id = self::getSourceFeedId( $feed );
		$file_extension = rgar( $settings, 'file_extension' );
		$hash           = md5( implode( '', [
			$form_id,
			$source_feed_id,
			$file_extension,
			serialize( $entries )
		] ) );

		// update the file name
		add_filter( 'gfexcel_renderer_filename', static function ( $original_filename ) use ( $feed, $form, $entries ) {

			$filename = SaveAddon::get_filename( $feed, $form, $entries );

			if ( ! $filename ) {
				return $original_filename;
			}

			return $filename;
		} );

		// Update the file extension.
		add_filter( 'gfexcel_file_extension', static function ( $original_file_extension ) use ( $file_extension ) {
			return $file_extension ?: $original_file_extension;
		} );

		if ( isset( $this->history[ $hash ] ) ) {
			return $this->history[ $hash ];
		}

		$renderer = GFExcel::getRenderer( $form_id );
		$output   = new GFExcelOutput( $form_id, $renderer, null, $source_feed_id );

		// When a single entry is submitted, update search criteria used when getting entries to only fetch that one entry.
		if ( $entries ) {
			add_filter( sprintf( 'gfexcel_output_search_criteria_%d_%d', $form_id, $source_feed_id ), static function ( $search_criteria ) use ( $entries ) {
				$field_filters                    = rgar( $search_criteria, 'field_filters', [] );
				$search_criteria['field_filters'] = array_merge( $field_filters, [
					[
						'key'   => 'id',
						'value' => $entries[0]['id']
					],
				] );

				return $search_criteria;
			} );
		}

		// Store the filename in the history, so we can retrieve it later.
		$this->history[ $hash ] = $output->render( true );

		return $this->history[ $hash ];
	}

	/**
	 * Removes files, and clears history.
	 *
	 * @since 1.0
	 */
	public function clearHistory(): void {
		array_map( static function ( string $file ) {
			if ( file_exists( $file ) ) {
				unlink( $file );
			}
		}, $this->history );

		// Clear history.
		$this->history = [];
	}

	/**
	 * Returns the source feed id.
	 *
	 * @param array $feed The feed object.
	 *
	 * @return int The source feed id.
	 */
	public static function getSourceFeedId( array $feed ): int {
		$settings       = rgar( $feed, 'meta', [] );
		$form_id        = (int) rgar( $feed, 'form_id' );
		$source_feed_id = (int) rgar( $settings, SaveAddon::STORAGE_SOURCE_FEED );
		if ( $source_feed_id ) {
			return $source_feed_id;
		}

		$feeds = \GFAPI::get_feeds( null, $form_id, 'gravityexport-lite', true );
		if ( is_array( $feeds ) && count( $feeds ) === 1 ) {
			$feed = reset( $feeds );
		}

		return (int) rgar( $feed, 'id' );
	}
}