Refactor GRN configuration page layout

distribution_fe/lib/api/sys-config.ts

@@ -22,3 +22,53 @@ export const sysConfig = {
   set: (key: string, value: string, userId?: string | null) =>
     api.put<SysConfigResponse>(`/sys-config/${key}`, { value, userId }).then(r => r.data),
 }
+
+// ─── GRN tax settings (must match Distribution.Features.SysConfig.SysConfigService) ──────────
+
+export type TaxMode = 'Disabled' | 'Optional' | 'Mandatory'
+
+export const GRN_TAX_KEYS = {
+  vatMode: 'Grn.Tax.Vat.Mode',
+  vatRate: 'Grn.Tax.Vat.DefaultRate',
+  nbtMode: 'Grn.Tax.Nbt.Mode',
+  nbtRate: 'Grn.Tax.Nbt.DefaultRate',
+} as const
+
+export interface GrnTaxSettings {
+  vatMode: TaxMode
+  vatDefaultRate: number
+  nbtMode: TaxMode
+  nbtDefaultRate: number
+}
+
+const TAX_MODES: TaxMode[] = ['Disabled', 'Optional', 'Mandatory']
+
+/** Unconfigured, VAT is Optional (as GRNs behaved before the setting existed) and NBT is off. */
+export const DEFAULT_GRN_TAX_SETTINGS: GrnTaxSettings = {
+  vatMode: 'Optional',
+  vatDefaultRate: 0,
+  nbtMode: 'Disabled',
+  nbtDefaultRate: 0,
+}
+
+export function parseGrnTaxSettings(byKey: Record<string, string>): GrnTaxSettings {
+  const mode = (raw: string | undefined, fallback: TaxMode): TaxMode =>
+    TAX_MODES.includes(raw as TaxMode) ? (raw as TaxMode) : fallback
+  const rate = (raw: string | undefined) => {
+    const n = Number(raw)
+    return raw !== undefined && Number.isFinite(n) && n >= 0 && n <= 100 ? n : 0
+  }
+  return {
+    vatMode: mode(byKey[GRN_TAX_KEYS.vatMode], DEFAULT_GRN_TAX_SETTINGS.vatMode),
+    vatDefaultRate: rate(byKey[GRN_TAX_KEYS.vatRate]),
+    nbtMode: mode(byKey[GRN_TAX_KEYS.nbtMode], DEFAULT_GRN_TAX_SETTINGS.nbtMode),
+    nbtDefaultRate: rate(byKey[GRN_TAX_KEYS.nbtRate]),
+  }
+}
+
+export const grnTaxSettings = {
+  get: () =>
+    sysConfig
+      .getAll()
+      .then(all => parseGrnTaxSettings(Object.fromEntries(all.map(c => [c.key, c.value])))),
+}