<?php
/**
 * Import and export of forms (JSON) and entries (CSV or JSON).
 *
 * JSON file:
 *   { "bylt_forms": 1, "version": "…", "forms": [ { "ref", "name", "fields", "settings" } ],
 *     "entries": [ { "form", "status", "email", "data", "created_gmt", "page_url", "product_id" } ] }
 * "form" on an entry is the "ref" of its form in the same file.
 *
 * @package BYLTCommerce
 */

defined( 'ABSPATH' ) || exit;

class Bylt_Forms_IO {

	/* ---------------------------------------------------------------------
	 * Export
	 * ------------------------------------------------------------------- */

	/** @param int[] $form_ids Empty = all forms. */
	public static function export_json( array $form_ids = array(), $with_entries = false, array $entry_args = array() ) {
		$forms = $form_ids ? array_filter( array_map( array( 'Bylt_Forms_Store', 'get' ), $form_ids ) ) : Bylt_Forms_Store::all();
		$out   = array(
			'bylt_forms' => 1,
			'version'    => defined( 'BYLT_VERSION' ) ? BYLT_VERSION : '',
			'site'       => home_url(),
			'exported'   => gmdate( 'c' ),
			'forms'      => array(),
			'entries'    => array(),
		);
		foreach ( $forms as $f ) {
			$out['forms'][] = array(
				'ref'      => $f['id'],
				'name'     => $f['name'],
				'fields'   => $f['fields'],
				'settings' => array_diff_key( $f['settings'], array( 'page_id' => 1 ) ), // Page ids don't carry across sites.
			);
			if ( $with_entries ) {
				$page = 1;
				do {
					$res = Bylt_Forms_Store::entries( array_merge( $entry_args, array( 'form_id' => $f['id'], 'page' => $page++, 'per_page' => 500 ) ) );
					foreach ( $res['items'] as $e ) {
						$out['entries'][] = array(
							'form'        => $f['id'],
							'status'      => $e['status'],
							'email'       => $e['email'],
							'data'        => array_diff_key( $e['data'], array( '_files' => 1 ) ), // Uploaded files stay on this site.
							'created_gmt' => $e['created_gmt'],
							'page_url'    => $e['page_url'],
							'product_id'  => $e['product_id'],
						);
					}
				} while ( 500 === count( $res['items'] ) );
			}
		}
		if ( ! $with_entries ) {
			unset( $out['entries'] );
		}
		return wp_json_encode( $out, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );
	}

	/** CSV of one form's entries: Entry ID, Submitted, Status, each field, Page, Product ID. */
	public static function export_csv( $form_id, array $entry_args = array(), $handle = null ) {
		$form = Bylt_Forms_Store::get( $form_id );
		if ( ! $form ) {
			return '';
		}
		$own = null === $handle;
		$h   = $own ? fopen( 'php://temp', 'w+' ) : $handle; // phpcs:ignore WordPress.WP.AlternativeFunctions
		$keys = array();
		$head = array( 'Entry ID', 'Submitted', 'Status' );
		foreach ( $form['fields'] as $f ) {
			if ( 'html' !== $f['type'] ) {
				$keys[] = $f['key'];
				$head[] = $f['label'];
			}
		}
		// Keys from removed fields that still appear in entries.
		$extra = array();
		$rows  = array();
		$page  = 1;
		do {
			$res = Bylt_Forms_Store::entries( array_merge( $entry_args, array( 'form_id' => $form_id, 'page' => $page++, 'per_page' => 500 ) ) );
			foreach ( $res['items'] as $e ) {
				foreach ( array_keys( $e['data'] ) as $k ) {
					if ( '_' !== substr( (string) $k, 0, 1 ) && ! in_array( $k, $keys, true ) && ! in_array( $k, $extra, true ) ) {
						$extra[] = $k;
					}
				}
				$rows[] = $e;
			}
		} while ( 500 === count( $res['items'] ) );
		$head = array_merge( $head, $extra, array( 'Page', 'Product ID' ) );
		fputcsv( $h, self::safe_row( $head ) );
		foreach ( $rows as $e ) {
			$line = array( $e['id'], get_date_from_gmt( $e['created_gmt'], 'Y-m-d H:i:s' ), $e['status'] );
			foreach ( array_merge( $keys, $extra ) as $k ) {
				$line[] = isset( $e['data'][ $k ] ) ? Bylt_Forms_Mailer::text( $e['data'][ $k ] ) : '';
			}
			$line[] = $e['page_url'];
			$line[] = $e['product_id'] ? $e['product_id'] : '';
			fputcsv( $h, self::safe_row( $line ) );
		}
		if ( ! $own ) {
			return '';
		}
		rewind( $h );
		$csv = stream_get_contents( $h );
		fclose( $h ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		return $csv;
	}

	/** Stop spreadsheet apps running a submitted value as a formula. */
	private static function safe_row( array $row ) {
		return array_map(
			function ( $v ) {
				$v = (string) $v;
				return '' !== $v && in_array( $v[0], array( '=', '+', '-', '@', "\t", "\r" ), true ) && ! is_numeric( $v ) ? "'" . $v : $v;
			},
			$row
		);
	}

	/* ---------------------------------------------------------------------
	 * Import
	 * ------------------------------------------------------------------- */

	private static function form_by_name( $name ) {
		foreach ( Bylt_Forms_Store::all() as $f ) {
			if ( 0 === strcasecmp( $f['name'], $name ) ) {
				return $f;
			}
		}
		return null;
	}

	private static function entry_exists( $form_id, $created, $email, array $data ) {
		global $wpdb;
		$t = Bylt_Forms_Store::table();
		return (bool) $wpdb->get_var( $wpdb->prepare( "SELECT id FROM {$t} WHERE form_id = %d AND created_gmt = %s AND email = %s AND data = %s LIMIT 1", $form_id, $created, $email, wp_json_encode( $data ) ) ); // phpcs:ignore WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.DirectDatabaseQuery
	}

	/**
	 * Import a BYLTCommerce forms JSON file.
	 *
	 * @param string $mode 'merge' (a form with the same name is reused, entries go into it) or 'copy' (always add new forms).
	 * @return array{forms_added: int, forms_reused: int, entries: int, skipped: int}|WP_Error
	 */
	public static function import_json( $json, $mode = 'merge' ) {
		$in = json_decode( (string) $json, true );
		if ( ! is_array( $in ) || empty( $in['bylt_forms'] ) || ! isset( $in['forms'] ) || ! is_array( $in['forms'] ) ) {
			return new WP_Error( 'bylt_forms_file', __( 'That isn\'t a BYLTCommerce forms export file.', 'byltcommerce-toolkit' ) );
		}
		$report = array( 'forms_added' => 0, 'forms_reused' => 0, 'entries' => 0, 'skipped' => 0 );
		$map    = array();
		foreach ( $in['forms'] as $f ) {
			if ( ! is_array( $f ) || empty( $f['name'] ) ) {
				continue;
			}
			$existing = 'merge' === $mode ? self::form_by_name( $f['name'] ) : null;
			if ( $existing ) {
				$id = $existing['id'];
				++$report['forms_reused'];
			} else {
				$name = $f['name'];
				if ( 'copy' === $mode && self::form_by_name( $name ) ) {
					/* translators: %s: form name */
					$name = sprintf( __( '%s (imported)', 'byltcommerce-toolkit' ), $name );
				}
				$id = Bylt_Forms_Store::save(
					array(
						'name'     => $name,
						'fields'   => isset( $f['fields'] ) ? (array) $f['fields'] : array(),
						'settings' => isset( $f['settings'] ) ? (array) $f['settings'] : array(),
					)
				);
				++$report['forms_added'];
			}
			if ( isset( $f['ref'] ) ) {
				$map[ (string) $f['ref'] ] = $id;
			}
		}
		foreach ( isset( $in['entries'] ) && is_array( $in['entries'] ) ? $in['entries'] : array() as $e ) {
			$ref = isset( $e['form'] ) ? (string) $e['form'] : '';
			if ( ! isset( $map[ $ref ] ) || ! isset( $e['data'] ) || ! is_array( $e['data'] ) ) {
				++$report['skipped'];
				continue;
			}
			$data    = self::clean_data( $e['data'] );
			$created = isset( $e['created_gmt'] ) && preg_match( '/^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}$/', $e['created_gmt'] ) ? $e['created_gmt'] : gmdate( 'Y-m-d H:i:s' );
			$email   = isset( $e['email'] ) ? sanitize_email( $e['email'] ) : '';
			if ( self::entry_exists( $map[ $ref ], $created, $email, $data ) ) {
				++$report['skipped'];
				continue;
			}
			Bylt_Forms_Store::add_entry(
				array(
					'form_id'     => $map[ $ref ],
					'status'      => isset( $e['status'] ) ? $e['status'] : 'read',
					'email'       => $email,
					'data'        => $data,
					'created_gmt' => $created,
					'page_url'    => isset( $e['page_url'] ) ? $e['page_url'] : '',
					'product_id'  => isset( $e['product_id'] ) ? (int) $e['product_id'] : 0,
				)
			);
			++$report['entries'];
		}
		return $report;
	}

	private static function clean_data( array $data ) {
		$out = array();
		foreach ( $data as $k => $v ) {
			$k = sanitize_key( $k );
			if ( '' === $k ) {
				continue;
			}
			$out[ $k ] = is_array( $v ) ? array_values( array_map( 'sanitize_text_field', $v ) ) : sanitize_textarea_field( (string) $v );
		}
		return $out;
	}

	/**
	 * Import entries from a CSV into a form. Columns are matched to fields by key or label;
	 * "Submitted" (site time) and "Status" are used when present; other columns are ignored.
	 *
	 * @return array{entries: int, skipped: int, matched: string[]}|WP_Error
	 */
	public static function import_csv( $form_id, $path ) {
		$form = Bylt_Forms_Store::get( $form_id );
		if ( ! $form ) {
			return new WP_Error( 'bylt_forms_form', __( 'Choose the form to import into.', 'byltcommerce-toolkit' ) );
		}
		$h = fopen( $path, 'r' ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		if ( ! $h ) {
			return new WP_Error( 'bylt_forms_file', __( 'Couldn\'t read the file.', 'byltcommerce-toolkit' ) );
		}
		$head = fgetcsv( $h );
		if ( ! $head ) {
			fclose( $h ); // phpcs:ignore WordPress.WP.AlternativeFunctions
			return new WP_Error( 'bylt_forms_file', __( 'The file is empty.', 'byltcommerce-toolkit' ) );
		}
		$head[0] = preg_replace( '/^\xEF\xBB\xBF/', '', (string) $head[0] ); // Excel's BOM.
		$cols    = array();
		$fields  = array();
		foreach ( $form['fields'] as $f ) {
			if ( 'html' !== $f['type'] ) {
				$fields[ $f['key'] ] = $f;
			}
		}
		$matched = array();
		foreach ( $head as $i => $label ) {
			$l = strtolower( trim( (string) $label ) );
			if ( in_array( $l, array( 'submitted', 'date', 'created_gmt' ), true ) ) {
				$cols[ $i ] = '_date';
				continue;
			}
			if ( 'status' === $l ) {
				$cols[ $i ] = '_status';
				continue;
			}
			foreach ( $fields as $k => $f ) {
				if ( strtolower( $k ) === $l || strtolower( $f['label'] ) === $l ) {
					$cols[ $i ] = $k;
					$matched[]  = $f['label'];
					break;
				}
			}
		}
		if ( ! $matched ) {
			fclose( $h ); // phpcs:ignore WordPress.WP.AlternativeFunctions
			return new WP_Error( 'bylt_forms_cols', __( 'None of the column headings match this form\'s fields (use the field labels or keys).', 'byltcommerce-toolkit' ) );
		}
		$report = array( 'entries' => 0, 'skipped' => 0, 'matched' => $matched );
		while ( false !== ( $row = fgetcsv( $h ) ) ) { // phpcs:ignore WordPress.CodeAnalysis.AssignmentInCondition
			if ( ! array_filter( $row, 'bylt_filled' ) ) {
				continue;
			}
			$data    = array();
			$created = gmdate( 'Y-m-d H:i:s' );
			$status  = 'read';
			foreach ( $cols as $i => $k ) {
				$v = isset( $row[ $i ] ) ? (string) $row[ $i ] : '';
				$v = "'" === substr( $v, 0, 1 ) && strlen( $v ) > 1 && in_array( $v[1], array( '=', '+', '-', '@' ), true ) ? substr( $v, 1 ) : $v; // Undo our formula guard.
				if ( '_date' === $k ) {
					$t       = strtotime( $v );
					$created = $t ? get_gmt_from_date( gmdate( 'Y-m-d H:i:s', $t ) ) : $created;
				} elseif ( '_status' === $k ) {
					$status = in_array( $v, Bylt_Forms_Store::STATUSES, true ) ? $v : 'read';
				} elseif ( 'checkboxes' === $fields[ $k ]['type'] ) {
					$data[ $k ] = '' === $v ? array() : array_map( 'trim', explode( ',', $v ) );
				} else {
					$data[ $k ] = $v;
				}
			}
			$data  = self::clean_data( $data );
			$email = Bylt_Forms_Render::first_email( $form, $data );
			if ( self::entry_exists( $form['id'], $created, $email, $data ) ) {
				++$report['skipped'];
				continue;
			}
			Bylt_Forms_Store::add_entry(
				array(
					'form_id'     => $form['id'],
					'status'      => $status,
					'email'       => $email,
					'data'        => $data,
					'created_gmt' => $created,
				)
			);
			++$report['entries'];
		}
		fclose( $h ); // phpcs:ignore WordPress.WP.AlternativeFunctions
		return $report;
	}
}