import { describe, expect, it } from "vitest";
import { resolveRate, type RateLike } from "../../app/services/rates.server";
import { formatPriceLabel } from "../../app/lib/currency";

function zoneRate(overrides: Partial<RateLike> = {}): RateLike {
  return {
    id: "rate_1",
    method: "LOCAL_DELIVERY",
    zoneId: "zone_1",
    name: "Zone A",
    priceCents: 500,
    keyedBy: "zone",
    minDistanceKm: null,
    maxDistanceKm: null,
    ...overrides,
  };
}

describe("resolveRate", () => {
  it("matches a zone-keyed rate by exact zoneId", () => {
    const rates = [zoneRate({ id: "a", zoneId: "zone_1" }), zoneRate({ id: "b", zoneId: "zone_2" })];
    const result = resolveRate(rates, { method: "LOCAL_DELIVERY", zoneId: "zone_1" });
    expect(result?.id).toBe("a");
  });

  it("returns null when no zone matches", () => {
    const rates = [zoneRate({ zoneId: "zone_1" })];
    expect(resolveRate(rates, { method: "LOCAL_DELIVERY", zoneId: "zone_9" })).toBeNull();
  });

  it("does not match a different method", () => {
    const rates = [zoneRate({ method: "PICKUP", zoneId: "zone_1" })];
    expect(resolveRate(rates, { method: "LOCAL_DELIVERY", zoneId: "zone_1" })).toBeNull();
  });

  it("matches a distance-keyed rate within its band", () => {
    const rates = [
      zoneRate({ id: "near", keyedBy: "distance", zoneId: null, minDistanceKm: 0, maxDistanceKm: 5, priceCents: 300 }),
      zoneRate({ id: "far", keyedBy: "distance", zoneId: null, minDistanceKm: 5, maxDistanceKm: 15, priceCents: 700 }),
    ];
    expect(resolveRate(rates, { method: "LOCAL_DELIVERY", distanceKm: 3 })?.id).toBe("near");
    expect(resolveRate(rates, { method: "LOCAL_DELIVERY", distanceKm: 10 })?.id).toBe("far");
  });

  it("treats an unbounded minDistanceKm as 0 and unbounded maxDistanceKm as infinite", () => {
    const rates = [zoneRate({ id: "flat", keyedBy: "distance", zoneId: null, minDistanceKm: null, maxDistanceKm: null })];
    expect(resolveRate(rates, { method: "LOCAL_DELIVERY", distanceKm: 999 })?.id).toBe("flat");
  });

  it("excludes the upper bound of a distance band (half-open interval)", () => {
    const rates = [
      zoneRate({ id: "near", keyedBy: "distance", zoneId: null, minDistanceKm: 0, maxDistanceKm: 5 }),
      zoneRate({ id: "far", keyedBy: "distance", zoneId: null, minDistanceKm: 5, maxDistanceKm: 15 }),
    ];
    expect(resolveRate(rates, { method: "LOCAL_DELIVERY", distanceKm: 5 })?.id).toBe("far");
  });

  it("returns the cheapest match when multiple rates overlap", () => {
    const rates = [
      zoneRate({ id: "expensive", zoneId: "zone_1", priceCents: 900 }),
      zoneRate({ id: "cheap", zoneId: "zone_1", priceCents: 400 }),
    ];
    expect(resolveRate(rates, { method: "LOCAL_DELIVERY", zoneId: "zone_1" })?.id).toBe("cheap");
  });

  it("returns null for an empty rate list", () => {
    expect(resolveRate([], { method: "LOCAL_DELIVERY", zoneId: "zone_1" })).toBeNull();
  });
});

describe("formatPriceLabel", () => {
  it("formats cents as a dollar amount with 2 decimals", () => {
    expect(formatPriceLabel(500)).toBe("$5.00");
    expect(formatPriceLabel(1999)).toBe("$19.99");
    expect(formatPriceLabel(0)).toBe("$0.00");
  });
});