From 2513e711b12a9dce3577019e69e8a6c75c302a8b Mon Sep 17 00:00:00 2001
From: Madeorsk <madeorsk@protonmail.com>
Date: Sat, 27 Jul 2024 13:45:25 +0200
Subject: [PATCH] Add multi-columns rows sorting with customizable comparison
 function for each column.

---
 src/Smartable/AsyncManager.tsx |  6 +--
 src/Smartable/Column.tsx       |  9 ++++-
 src/Smartable/Instance.tsx     | 71 ++++++++++++++++++++++++++++++----
 3 files changed, 75 insertions(+), 11 deletions(-)

diff --git a/src/Smartable/AsyncManager.tsx b/src/Smartable/AsyncManager.tsx
index d6b3311..947a5fb 100644
--- a/src/Smartable/AsyncManager.tsx
+++ b/src/Smartable/AsyncManager.tsx
@@ -1,6 +1,6 @@
-import React, {startTransition, useEffect, useRef, useState} from "react";
+import React, { useEffect, useRef, useState} from "react";
 import {ColumnKey} from "./Column";
-import {normalizeRowDefinition, RowCells, RowData, RowDefinition} from "./Row";
+import {normalizeRowDefinition, RowData, RowDefinition} from "./Row";
 import {CellDefinition} from "./Cell";
 import {SmartableData} from "./Smartable";
 import {Modify, Promisable} from "@kernelui/core";
@@ -84,7 +84,7 @@ class AsyncManager<CK extends ColumnKey>
 	 */
 	protected promisedRowsCells: Partial<Record<CK, Promised<CellDefinition>>>[] = [];
 
-	
+
 	/**
 	 * Rows data.
 	 * @protected
diff --git a/src/Smartable/Column.tsx b/src/Smartable/Column.tsx
index 3634b50..d1ba4fc 100644
--- a/src/Smartable/Column.tsx
+++ b/src/Smartable/Column.tsx
@@ -25,7 +25,7 @@ export function createColumns<K extends ColumnKey>(...columns: [K, Column][]): C
 /**
  * Smartable column definition.
  */
-export interface Column
+export interface Column<T = any>
 {
 	/**
 	 * Column title element.
@@ -36,6 +36,13 @@ export interface Column
 	 * Column cell default element.
 	 */
 	cellElement?: React.ReactElement;
+
+	/**
+	 * Cells data comparison in the column.
+	 * @param a First data to compare.
+	 * @param b Second data to compare.
+	 */
+	compare?: (a: T, b: T) => number;
 }
 
 /**
diff --git a/src/Smartable/Instance.tsx b/src/Smartable/Instance.tsx
index 1562454..949aa7c 100644
--- a/src/Smartable/Instance.tsx
+++ b/src/Smartable/Instance.tsx
@@ -1,8 +1,8 @@
-import React from "react";
-import {AutoColumnContextProvider, ColumnHeading, ColumnKey, Columns} from "./Column";
+import React, {useMemo} from "react";
+import {AutoColumnContextProvider, ColumnHeading, ColumnKey, Columns, SortState, SortType} from "./Column";
 import {SmartableProperties, useTable} from "./Smartable";
 import {RowInstance, RowLoader} from "./Row";
-import {useAsyncManager} from "./AsyncManager";
+import {CurrentRowData, useAsyncManager} from "./AsyncManager";
 
 /**
  * Smartable instance component properties.
@@ -53,14 +53,19 @@ export function ColumnsHeadings<CK extends ColumnKey>({columns}: {columns: Colum
 export function TableBody<CK extends ColumnKey>()
 {
 	// Get data from table.
-	const {data} = useTable();
+	const {data, columns, columnsSortState} = useTable<CK>();
 
 	// Get current data state from the async table value.
-	const {currentDataState} = useAsyncManager(data);
+	const {currentDataState} = useAsyncManager<CK>(data);
+
+	// Memorize sorted rows.
+	const sortedRows = useMemo(() => (
+		sortRows<CK>(currentDataState.rows, columns, columnsSortState)
+	), [currentDataState.rows, columns, columnsSortState]);
 
 	return (
-		Array.isArray(currentDataState?.rows) ? (
-			currentDataState.rows.map((rowData, index) => (
+		sortedRows ? (
+			sortedRows.map((rowData, index) => (
 				// Rendering each row from its definition.
 				<RowInstance row={rowData} />
 			))
@@ -69,3 +74,55 @@ export function TableBody<CK extends ColumnKey>()
 		)
 	);
 }
+
+/**
+ * Sort the given rows from the columns sort state.
+ * @param rows Rows to sort.
+ * @param columns Columns definition.
+ * @param columnsSortState Columns current sort state.
+ */
+export function sortRows<CK extends ColumnKey>(rows: CurrentRowData<CK>[], columns: Columns<CK>, columnsSortState: Record<CK, SortState>): CurrentRowData<CK>[]
+{
+	// Normalize value to undefined when rows are not loaded.
+	if (!Array.isArray(rows)) return undefined;
+
+	// Get the sort column states following their priority order.
+	const orderedSortColumns = (Object.entries(columnsSortState) as [CK, SortState][]).sort((a, b) => (
+		a[1].order - b[1].order
+	));
+
+	// Sort the given rows.
+	return rows.toSorted((a, b) => {
+		for (const [columnKey, columnSort] of orderedSortColumns)
+		{
+			// Get the current comparison result for the given cells' data.
+			const comparison =
+				(columnSort.type == SortType.DESC ? 1 : -1) *
+				(columns[columnKey]?.compare ?? genericCompare)(a.cells[columnKey]?.data, b.cells[columnKey]?.data);
+
+			if (comparison != 0)
+				// If an order can be determined from the current comparison, returning it.
+				return comparison;
+		}
+
+		// The comparisons always returned 0.
+		return 0;
+	});
+}
+
+/**
+ * Generic comparison function for table data.
+ * @param a First data to compare.
+ * @param b Second data to compare.
+ */
+export function genericCompare(a: any, b: any): number
+{
+	if (typeof a == "number" && typeof a == typeof b)
+	{ // Compare numbers.
+		return b - a;
+	}
+	else
+	{ // Compare data as strings.
+		return String(b).localeCompare(String(a));
+	}
+}