import transaction from custom delimiter-separated values file

src/core/timezone.ts

@@ -1,4 +1,4 @@
-import type { TypeAndName } from './base.ts';
+import type { NameValue, TypeAndName } from './base.ts';
 
 export interface TimezoneInfo {
     readonly displayName: string;
@@ -13,6 +13,77 @@ export interface LocalizedTimezoneInfo {
     readonly displayNameWithUtcOffset: string;
 }
 
+export class KnownDateTimezoneFormat implements NameValue {
+    private static readonly allInstances: KnownDateTimezoneFormat[] = [];
+    private static readonly allInstancesByValue: Record<string, KnownDateTimezoneFormat> = {};
+
+    public static readonly HHColonMM = new KnownDateTimezoneFormat('±HH:mm', 'Z', /^[+-]?([0-1][0-9]|2[0-3]):[0-5][0-9]$/);
+    public static readonly HHMM = new KnownDateTimezoneFormat('±HHmm', 'ZZ', /^[+-]?([0-1][0-9]|2[0-3])[0-5][0-9]$/);
+
+    public readonly name: string;
+    public readonly value: string;
+    private readonly regex: RegExp;
+
+    private constructor(name: string, value: string, regex: RegExp) {
+        this.name = name;
+        this.value = value;
+        this.regex = regex;
+
+        KnownDateTimezoneFormat.allInstances.push(this);
+        KnownDateTimezoneFormat.allInstancesByValue[value] = this;
+    }
+
+    public isValid(dateTime: string): boolean {
+        return this.regex.test(dateTime);
+    }
+
+    public static values(): KnownDateTimezoneFormat[] {
+        return KnownDateTimezoneFormat.allInstances;
+    }
+
+    public static valueOf(value: string): KnownDateTimezoneFormat | undefined {
+        return KnownDateTimezoneFormat.allInstancesByValue[value];
+    }
+
+    public static detect(dateTime: string): KnownDateTimezoneFormat[] | undefined {
+        const result: KnownDateTimezoneFormat[] = [];
+
+        for (const format of KnownDateTimezoneFormat.allInstances) {
+            if (format.isValid(dateTime)) {
+                result.push(format);
+            }
+        }
+
+        return result.length > 0 ? result : undefined;
+    }
+
+    public static detectMany(dateTimes: string[]): KnownDateTimezoneFormat[] | undefined {
+        const detectedCounts: Record<string, number> = {};
+
+        for (const dateTime of dateTimes) {
+            const detectedFormats = KnownDateTimezoneFormat.detect(dateTime);
+
+            if (detectedFormats) {
+                for (const format of detectedFormats) {
+                    detectedCounts[format.value] = (detectedCounts[format.value] || 0) + 1;
+                }
+            } else {
+                return undefined;
+            }
+        }
+
+        const result: KnownDateTimezoneFormat[] = [];
+
+        for (const format of KnownDateTimezoneFormat.allInstances) {
+            if (detectedCounts[format.value] === dateTimes.length) {
+                result.push(format);
+            }
+        }
+
+        return result.length > 0 ? result : undefined;
+    }
+}
+
 export class TimezoneTypeForStatistics implements TypeAndName {
     public static readonly ApplicationTimezone = new TimezoneTypeForStatistics(0, 'Application Timezone');
     public static readonly TransactionTimezone = new TimezoneTypeForStatistics(1, 'Transaction Timezone');