From ff06ea67033cd60d7cd7000dd47021b6c9fc0437 Mon Sep 17 00:00:00 2001
From: Alexander Shabunevich <loonar@gmail.com>
Date: Sun, 12 May 2024 20:11:08 +0300
Subject: [PATCH] feat: number mask

---
 packages/maska/src/mask.ts   | 10 +++++++++
 packages/maska/src/number.ts | 43 ++++++++++++++++++++++++++++++++++++
 packages/maska/src/parser.ts | 14 ++++++++++++
 3 files changed, 67 insertions(+)
 create mode 100644 packages/maska/src/number.ts

diff --git a/packages/maska/src/mask.ts b/packages/maska/src/mask.ts
index c70e68e..8738e75 100644
--- a/packages/maska/src/mask.ts
+++ b/packages/maska/src/mask.ts
@@ -1,13 +1,21 @@
 import { MaskTokens, tokens } from './tokens'
+import { processNumber } from './number'
 
 export type MaskType = string | string[] | ((input: string) => string) | null
 
+interface MaskNumber {
+  locale?: string
+  fraction?: number
+  unsigned?: boolean
+}
+
 export interface MaskOptions {
   mask?: MaskType
   tokens?: MaskTokens
   tokensReplace?: boolean
   eager?: boolean
   reversed?: boolean
+  number?: MaskNumber
 }
 
 export class Mask {
@@ -109,6 +117,8 @@ export class Mask {
   }
 
   private process (value: string, maskRaw: string | null, masked = true): string {
+    if (this.opts.number != null) return processNumber(value, masked, this.opts)
+
     if (maskRaw == null) return value
 
     const memoKey = `v=${value},mr=${maskRaw},m=${masked ? 1 : 0}`
diff --git a/packages/maska/src/number.ts b/packages/maska/src/number.ts
new file mode 100644
index 0000000..33cc6a3
--- /dev/null
+++ b/packages/maska/src/number.ts
@@ -0,0 +1,43 @@
+import { MaskOptions } from './mask'
+
+const prepare = (input: string, group: string, decimal: string): string =>
+  input.replaceAll(group, '').replace(decimal, '.').replace('..', '.').replace(/[^.\d]/g, '')
+
+const createFormatter = (min: number, max: number, opts: MaskOptions): Intl.NumberFormat =>
+  new Intl.NumberFormat(opts.number?.locale ?? 'en', {
+    minimumFractionDigits: min,
+    maximumFractionDigits: max,
+    // @ts-expect-error
+    roundingMode: 'trunc'
+  })
+
+export const processNumber = (value: string, masked = true, opts: MaskOptions): string => {
+  const sign = opts.number?.unsigned == null && value.startsWith('-') ? '-' : ''
+  const fraction = opts.number?.fraction ?? 0
+
+  let formatter = createFormatter(0, fraction, opts)
+  const parts = formatter.formatToParts(1000.12)
+  const group = parts.find((part) => part.type === 'group')?.value ?? ' '
+  const decimal = parts.find((part) => part.type === 'decimal')?.value ?? '.'
+  const float = prepare(value, group, decimal)
+
+  if (float === '' || Number.isNaN(float)) return sign
+
+  // allow zero at the end
+  const floatParts = float.split('.')
+  if (floatParts[1] != null && floatParts[1].length >= 1) {
+    const min = floatParts[1].length <= fraction ? floatParts[1].length : fraction
+    formatter = createFormatter(min, fraction, opts)
+  }
+
+  let result = formatter.format(parseFloat(float))
+
+  if (!masked) {
+    result = prepare(result, group, decimal)
+  } else if (fraction > 0 && float.endsWith('.') && !float.slice(0, -1).includes('.')) {
+    // if ends with decimal separator
+    result += decimal
+  }
+
+  return sign + result
+}
diff --git a/packages/maska/src/parser.ts b/packages/maska/src/parser.ts
index 2e3f59b..1505389 100644
--- a/packages/maska/src/parser.ts
+++ b/packages/maska/src/parser.ts
@@ -25,6 +25,20 @@ export const parseInput = (
     opts.tokens = parseTokens(input.dataset.maskaTokens)
   }
 
+  const number: MaskOptions['number'] = {}
+  if (input.dataset.maskaNumberLocale != null) {
+    number.locale = input.dataset.maskaNumberLocale
+  }
+  if (input.dataset.maskaNumberFraction != null) {
+    number.fraction = parseInt(input.dataset.maskaNumberFraction)
+  }
+  if (input.dataset.maskaNumberUnsigned != null) {
+    number.unsigned = parseBool(input.dataset.maskaNumberUnsigned)
+  }
+  if (Object.values(number).length > 0) {
+    opts.number = number
+  }
+
   return opts
 }