From 941dc3700ecc717c9a998661f05d972bcf34cf32 Mon Sep 17 00:00:00 2001
From: Alice Gaudon <alice@gaudon.pro>
Date: Mon, 8 Nov 2021 00:25:28 +0100
Subject: [PATCH] Add FileSize helper class

---
 src/common/FileSize.ts | 48 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)
 create mode 100644 src/common/FileSize.ts

diff --git a/src/common/FileSize.ts b/src/common/FileSize.ts
new file mode 100644
index 0000000..6ea0036
--- /dev/null
+++ b/src/common/FileSize.ts
@@ -0,0 +1,48 @@
+export class FileSizeUnit {
+    public constructor(
+        public readonly bytes: number,
+        public readonly longName: string,
+        public readonly shortName: string,
+        public readonly divisible: boolean = true,
+    ) {
+    }
+}
+
+export class FileSize {
+    public static readonly UNITS: Record<string, FileSizeUnit> = {
+        B: new FileSizeUnit(1, 'byte', 'B', false),
+        KB: new FileSizeUnit(1000, 'kilobyte', 'kB'),
+        MB: new FileSizeUnit(1000 * 1000, 'megabyte', 'MB'),
+        GB: new FileSizeUnit(1000 * 1000 * 1000, 'gigabyte', 'GB'),
+        TB: new FileSizeUnit(1000 * 1000 * 1000 * 1000, 'terabyte', 'TB'),
+    };
+
+    public static humanizeFileSize(
+        size: number,
+        short: boolean = false,
+        skipOneUnitNumber: boolean = false,
+        units: FileSizeUnit[] = [
+            this.UNITS.B,
+            this.UNITS.KB,
+            this.UNITS.MB,
+            this.UNITS.GB,
+            this.UNITS.TB,
+        ],
+    ): string {
+        for (let i = units.length - 1; i > 0; i--) {
+            const fileSizeUnit = units[i - 1];
+            if (size >= fileSizeUnit.bytes && size < units[i].bytes) {
+                const amount = size / fileSizeUnit.bytes;
+                const unit = short ?
+                    fileSizeUnit.shortName :
+                    ' ' + fileSizeUnit.longName + (amount > 1 ? 's' : '');
+                const strAmount = fileSizeUnit.divisible ?
+                    amount.toFixed(1) :
+                    Math.floor(amount);
+                return (amount > 1 || !skipOneUnitNumber ? strAmount : '') + unit;
+            }
+        }
+
+        return '0';
+    }
+}