<?php
namespace Rafgrid;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * CSV export / import.
 */
class Export {

	/**
	 * Export rows to CSV string.
	 *
	 * @param string $post_type Post type.
	 * @param array  $params    Same as Query::fetch, plus columns.
	 * @return string CSV.
	 */
	public static function to_csv( $post_type, $params ) {
		$params['page']     = 1;
		$params['per_page'] = min( 2000, max( 1, absint( isset( $params['per_page'] ) ? $params['per_page'] : 500 ) ) );
		$data = Query::fetch( $post_type, $params );
		$cols = Columns::get_columns( $post_type );
		$wanted = isset( $params['columns'] ) && is_array( $params['columns'] ) ? $params['columns'] : array_keys( $cols );
		$wanted = array_values( array_intersect( $wanted, array_keys( $cols ) ) );
		if ( empty( $wanted ) ) {
			$wanted = array( 'ID', 'post_title' );
		}

		$fh = fopen( 'php://temp', 'r+' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen -- In-memory php://temp stream for CSV generation; no filesystem path is involved.
		// BOM for Excel.
		fwrite( $fh, "\xEF\xBB\xBF" ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fwrite -- Writing to an in-memory php://temp stream (see above).
		$header = array();
		foreach ( $wanted as $ck ) {
			$header[] = isset( $cols[ $ck ]['label'] ) ? $cols[ $ck ]['label'] . ' [' . $ck . ']' : $ck;
		}
		fputcsv( $fh, $header );
		foreach ( $data['rows'] as $row ) {
			$line = array();
			foreach ( $wanted as $ck ) {
				$v = isset( $row[ $ck ] ) ? $row[ $ck ] : '';
				if ( is_array( $v ) && isset( $v['id'] ) ) {
					$v = $v['id'];
				} elseif ( is_array( $v ) ) {
					$v = implode( ',', $v );
				}
				$line[] = $v;
			}
			fputcsv( $fh, $line );
		}
		rewind( $fh );
		$csv = stream_get_contents( $fh );
		fclose( $fh ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose -- Closing an in-memory php://temp stream (see above).
		return $csv;
	}

	/**
	 * Parse key from a header cell like "Title [post_title]".
	 *
	 * @param string $header Header.
	 * @return string
	 */
	public static function header_to_key( $header ) {
		if ( preg_match( '/\[([^\]]+)\]\s*$/', $header, $m ) ) {
			return trim( $m[1] );
		}
		return trim( $header );
	}

	/**
	 * Import CSV string. First column must be ID or post_title for matching; v1 matches by ID only.
	 *
	 * @param string $post_type Post type.
	 * @param string $csv_text  CSV text.
	 * @return array {updated, skipped, errors}
	 */
	public static function from_csv( $post_type, $csv_text ) {
		$lines = preg_split( "/\r\n|\n|\r/", ltrim( $csv_text, "\xEF\xBB\xBF" ) );
		$lines = array_values( array_filter( $lines, function ( $l ) { return '' !== trim( $l ); } ) );
		if ( count( $lines ) < 2 ) {
			return array( 'updated' => 0, 'skipped' => 0, 'errors' => array( __( 'Empty CSV.', 'rafgrid' ) ) );
		}
		$header = str_getcsv( array_shift( $lines ) );
		$keys   = array_map( array( __CLASS__, 'header_to_key' ), $header );
		$cols   = Columns::get_columns( $post_type );

		$updated = 0;
		$skipped = 0;
		$errors  = array();
		foreach ( $lines as $i => $line ) {
			$cells = str_getcsv( $line );
			$row   = array();
			foreach ( $keys as $idx => $k ) {
				$row[ $k ] = isset( $cells[ $idx ] ) ? $cells[ $idx ] : '';
			}
			if ( empty( $row['ID'] ) || ! get_post( absint( $row['ID'] ) ) ) {
				++$skipped;
				continue;
			}
			$id = absint( $row['ID'] );
			foreach ( $row as $k => $v ) {
				if ( 'ID' === $k || '_edit_link' === $k || '_view_link' === $k ) {
					continue;
				}
				if ( ! isset( $cols[ $k ] ) && ! str_starts_with( $k, 'meta:' ) && ! str_starts_with( $k, 'tax:' ) ) {
					continue;
				}
				if ( isset( $cols[ $k ] ) && empty( $cols[ $k ]['editable'] ) ) {
					continue;
				}
				$res = Saving::save_cell( $id, $k, $v );
				if ( is_wp_error( $res ) ) {
					/* translators: 1: CSV row number, 2: column key, 3: error message */
					$errors[] = sprintf( __( 'Row %1$d, column %2$s: %3$s', 'rafgrid' ), $i + 2, $k, $res->get_error_message() );
				}
			}
			++$updated;
		}
		return array(
			'updated' => $updated,
			'skipped' => $skipped,
			'errors'  => array_slice( $errors, 0, 20 ),
		);
	}

	/**
	 * Minimal XLSX export (inline strings, no external library).
	 * Returns binary string or empty string when ZipArchive is missing.
	 *
	 * @param string $post_type Post type.
	 * @param array  $params    Query params.
	 * @return string
	 */
	public static function to_xlsx( $post_type, $params ) {
		if ( ! class_exists( 'ZipArchive' ) ) {
			return '';
		}
		$params['page']     = 1;
		$params['per_page'] = min( 2000, max( 1, absint( isset( $params['per_page'] ) ? $params['per_page'] : 500 ) ) );
		$data = Query::fetch( $post_type, $params );
		$cols = Columns::get_columns( $post_type );
		$wanted = isset( $params['columns'] ) && is_array( $params['columns'] ) ? $params['columns'] : array_keys( $cols );
		$wanted = array_values( array_intersect( $wanted, array_keys( $cols ) ) );
		if ( empty( $wanted ) ) {
			$wanted = array( 'ID', 'post_title' );
		}
		$rows_xml = '';
		$r = 1;
		$header = array();
		foreach ( $wanted as $ck ) {
			$header[] = isset( $cols[ $ck ]['label'] ) ? $cols[ $ck ]['label'] . ' [' . $ck . ']' : $ck;
		}
		$rows_xml .= self::xlsx_row( $header, $r++ );
		foreach ( $data['rows'] as $row ) {
			$line = array();
			foreach ( $wanted as $ck ) {
				$v = isset( $row[ $ck ] ) ? $row[ $ck ] : '';
				if ( is_array( $v ) && isset( $v['id'] ) ) {
					$v = $v['id'];
				} elseif ( is_array( $v ) ) {
					$v = implode( ',', $v );
				}
				$line[] = (string) $v;
			}
			$rows_xml .= self::xlsx_row( $line, $r++ );
		}
		$sheet = '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>' .
			'<worksheet xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main"><sheetData>' . $rows_xml . '</sheetData></worksheet>';
		$tmp = wp_tempnam( 'rafgrid-xlsx' );
		$zip = new \ZipArchive();
		if ( true !== $zip->open( $tmp, \ZipArchive::OVERWRITE ) ) {
			return '';
		}
		$zip->addFromString( '[Content_Types].xml', '<?xml version="1.0" encoding="UTF-8" standalone="yes"?><Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types"><Default Extension="rels" ContentType="application/vnd.openxmlformats-package.relationships+xml"/><Default Extension="xml" ContentType="application/xml"/><Override PartName="/xl/workbook.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet.main+xml"/><Override PartName="/xl/worksheets/sheet1.xml" ContentType="application/vnd.openxmlformats-officedocument.spreadsheetml.worksheet+xml"/></Types>' );
		$zip->addFromString( '_rels/.rels', '<?xml version="1.0" encoding="UTF-8" standalone="yes"?><Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"><Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/officeDocument" Target="xl/workbook.xml"/></Relationships>' );
		$zip->addFromString( 'xl/workbook.xml', '<?xml version="1.0" encoding="UTF-8" standalone="yes"?><workbook xmlns="http://schemas.openxmlformats.org/spreadsheetml/2006/main" xmlns:r="http://schemas.openxmlformats.org/officeDocument/2006/relationships"><sheets><sheet name="Sheet" sheetId="1" r:id="rId1"/></sheets></workbook>' );
		$zip->addFromString( 'xl/_rels/workbook.xml.rels', '<?xml version="1.0" encoding="UTF-8" standalone="yes"?><Relationships xmlns="http://schemas.openxmlformats.org/package/2006/relationships"><Relationship Id="rId1" Type="http://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="worksheets/sheet1.xml"/></Relationships>' );
		$zip->addFromString( 'xl/worksheets/sheet1.xml', $sheet );
		$zip->close();
		$bin = file_get_contents( $tmp ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_get_contents
		wp_delete_file( $tmp );
		return $bin ? $bin : '';
	}

	private static function xlsx_row( $cells, $r ) {
		$out = '<row r="' . $r . '">';
		$c = 1;
		foreach ( $cells as $v ) {
			$ref = self::xlsx_col( $c++ ) . $r;
			$out .= '<c r="' . $ref . '" t="inlineStr"><is><t>' . esc_xml( (string) $v ) . '</t></is></c>';
		}
		return $out . '</row>';
	}

	private static function xlsx_col( $n ) {
		$s = '';
		while ( $n > 0 ) {
			$m = ( $n - 1 ) % 26;
			$s = chr( 65 + $m ) . $s;
			$n = intdiv( $n - 1, 26 );
		}
		return $s;
	}


	/**
	 * Convert XLSX binary (first sheet) to CSV text for the CSV importer.
	 *
	 * @param string $bin XLSX binary.
	 * @return string CSV text (empty on failure).
	 */
	public static function xlsx_to_csv( $bin ) {
		if ( ! class_exists( 'ZipArchive' ) ) {
			return '';
		}
		$tmp = wp_tempnam( 'rafgrid-xlsx-in' );
		file_put_contents( $tmp, $bin ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_put_contents
		$zip = new \ZipArchive();
		if ( true !== $zip->open( $tmp ) ) {
			wp_delete_file( $tmp );
			return '';
		}
		$shared = array();
		$ss = $zip->getFromName( 'xl/sharedStrings.xml' );
		if ( false !== $ss ) {
			$xml = simplexml_load_string( $ss );
			if ( $xml ) {
				foreach ( $xml->si as $si ) {
					$shared[] = (string) $si->t;
				}
			}
		}
		$sheet = $zip->getFromName( 'xl/worksheets/sheet1.xml' );
		$zip->close();
		wp_delete_file( $tmp );
		if ( false === $sheet ) {
			return '';
		}
		$xml = simplexml_load_string( $sheet );
		if ( ! $xml || ! isset( $xml->sheetData ) ) {
			return '';
		}
		$fh = fopen( 'php://temp', 'r+' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fopen -- In-memory php://temp stream for CSV conversion; no filesystem path is involved.
		foreach ( $xml->sheetData->row as $row ) {
			$cells = array();
			foreach ( $row->c as $c ) {
				$type = (string) ( $c['t'] ?? '' );
				if ( 'inlineStr' === $type ) {
					$cells[] = (string) $c->is->t;
				} elseif ( 's' === $type ) {
					$cells[] = $shared[ (int) $c->v ] ?? '';
				} else {
					$cells[] = (string) $c->v;
				}
			}
			fputcsv( $fh, $cells );
		}
		rewind( $fh );
		$csv = stream_get_contents( $fh );
		fclose( $fh ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose -- Closing an in-memory php://temp stream (see above).
		return $csv ? $csv : '';
	}

}