import { describe, expect, it } from "vitest";
import { initialTreatmentValues } from "@/app/(app)/treatments/new/treatment-form-values";
import { applyPrefill, formatPrefillDate } from "./prefill";
import type { TreatmentPrefill } from "./types";

const prefill: TreatmentPrefill = {
  sourceTreatmentId: "t-1",
  sourceDate: "2026-08-12T00:00:00.000Z",
  product: "Oxuvar",
  activeIngredient: "Oxalsäure",
  withdrawalPeriodDays: 0,
  supplier: "Imkereibedarf Muster",
  purchaseProof: "Rechnung 4711",
  prescribingVet: "Dr. Biene",
};

describe("applyPrefill", () => {
  it("fills empty fields only", () => {
    const values = { ...initialTreatmentValues("c-1"), activeIngredient: "Ameisensäure" };

    const result = applyPrefill(values, prefill);

    expect(result.values.activeIngredient).toBe("Ameisensäure");
    expect(result.values.supplier).toBe("Imkereibedarf Muster");
    expect(result.filled).not.toContain("activeIngredient");
    expect(result.filled).toEqual([
      "withdrawalPeriodDays",
      "supplier",
      "purchaseProof",
      "prescribingVet",
    ]);
    expect(values.supplier).toBe("");
  });

  it('fills withdrawalPeriodDays 0 as "0"', () => {
    const result = applyPrefill(initialTreatmentValues("c-1"), prefill);

    expect(result.values.withdrawalPeriodDays).toBe("0");
    expect(result.filled).toContain("withdrawalPeriodDays");
  });

  it("does not fill null values", () => {
    const result = applyPrefill(initialTreatmentValues("c-1"), {
      ...prefill,
      activeIngredient: null,
      withdrawalPeriodDays: null,
      supplier: null,
    });

    expect(result.values.activeIngredient).toBe("");
    expect(result.values.withdrawalPeriodDays).toBe("");
    expect(result.filled).toEqual(["purchaseProof", "prescribingVet"]);
  });

  it("treats whitespace-only values as empty", () => {
    const values = { ...initialTreatmentValues("c-1"), supplier: "   " };

    expect(applyPrefill(values, prefill).filled).toContain("supplier");
  });
});

describe("formatPrefillDate", () => {
  it("writes the calendar day as TT.MM.JJJJ without a time zone shift", () => {
    expect(formatPrefillDate("2026-08-12T00:00:00.000Z")).toBe("12.08.2026");
  });
});