74 lines
2.5 KiB
Swift
74 lines
2.5 KiB
Swift
//
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// MastodonMetricFormatter.swift
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// Mastodon
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//
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// Created by MainasuK Cirno on 2021-4-2.
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//
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import Foundation
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enum DecimalUnit: Int {
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case one = 1
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case ten = 10
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case hundred = 100
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case thousand = 1_000
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case million = 1_000_000
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case billion = 1_000_000_000
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case trillion = 1_000_000_000_000
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var asInt: Int {
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self.rawValue
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}
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var asDouble: Double {
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Double(self.rawValue)
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}
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}
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public final class MastodonMetricFormatter: Formatter {
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private let ten_thousands = DecimalUnit.thousand.asInt * 10
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private let ten_millions = DecimalUnit.million.asInt * 10
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public func string(from number: Int) -> String? {
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let isPositive = number >= 0
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let symbol = isPositive ? "" : "-"
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let numberFormatter = NumberFormatter()
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let value = abs(number)
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let metric: String
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switch value {
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case 0 ..< DecimalUnit.thousand.asInt: // 0 ~ 1K
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numberFormatter.maximumFractionDigits = 0
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let string = numberFormatter.string(from: NSNumber(value: value)) ?? String(value)
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metric = string
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case DecimalUnit.thousand.asInt ..< DecimalUnit.million.asInt: // 1K ~ 1M
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numberFormatter.maximumFractionDigits = value < ten_thousands ? 1 : 0
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let string = numberFormatter.string(from: NSNumber(value: Double(value) / DecimalUnit.thousand.asDouble)) ??
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String(value / DecimalUnit.thousand.asInt)
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metric = string + "K"
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case DecimalUnit.million.asInt ..< DecimalUnit.billion.asInt: // 1M ~ 1B
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numberFormatter.maximumFractionDigits = value < ten_millions ? 1 : 0
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let string = numberFormatter.string(from: NSNumber(value: Double(value) / DecimalUnit.million.asDouble)) ??
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String(value / DecimalUnit.million.asInt)
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metric = string + "M"
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case DecimalUnit.billion.asInt ..< DecimalUnit.trillion.asInt: // 1B ~ 1T
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numberFormatter.maximumFractionDigits = 0
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let string = numberFormatter.string(from: NSNumber(value: Double(value) / DecimalUnit.billion.asDouble)) ??
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String(value / DecimalUnit.billion.asInt)
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metric = string + "B"
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default: // > 1T
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numberFormatter.maximumFractionDigits = 0
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let string = numberFormatter.string(from: NSNumber(value: Double(value) / DecimalUnit.trillion.asDouble)) ??
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String(value / DecimalUnit.trillion.asInt)
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metric = string + "T"
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}
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return symbol + metric
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}
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}
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