first commit

src/widgets/currency-converter/model/tiers.ts

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+export interface Tier {
+  min: number
+  max: number
+  pct: number
+}
+
+export const TIERS: readonly Tier[] = [
+  { min: 5_000, max: 30_000, pct: 8 },
+  { min: 30_000, max: 100_000, pct: 6 },
+  { min: 100_000, max: 600_000, pct: 4 },
+] as const
+
+export const TIER_MIN = TIERS[0].min
+export const TIER_MAX = TIERS[TIERS.length - 1].max
+
+export function findTier(amount: number): Pick<Tier, 'pct'> {
+  const match = TIERS.find((t) => amount >= t.min && amount <= t.max)
+  if (match) return match
+  if (amount > TIER_MAX) return { pct: TIERS[TIERS.length - 1].pct }
+  return { pct: TIERS[0].pct }
+}
+
+export function progressPercent(amount: number): number {
+  if (amount <= TIER_MIN) return 0
+  if (amount >= TIER_MAX) return 100
+  return ((amount - TIER_MIN) / (TIER_MAX - TIER_MIN)) * 100
+}