import { describe, it, expect } from "vitest";
import { validatePinForm, pinActionLabel, type PinFormState } from "./pinForm";

function form(overrides: Partial<PinFormState> = {}): PinFormState {
  return {
    intent: "set",
    hasPin: false,
    currentPin: "",
    newPin: "",
    confirmPin: "",
    ...overrides,
  };
}

describe("validatePinForm", () => {
  it("accepts a well-formed new PIN", () => {
    expect(validatePinForm(form({ newPin: "1234", confirmPin: "1234" }))).toBeNull();
  });

  it("requires the current PIN whenever one is set", () => {
    expect(
      validatePinForm(form({ intent: "change", hasPin: true, newPin: "5678", confirmPin: "5678" })),
    ).toBe("Enter your current PIN.");
  });

  it("does not ask for a current PIN when none is set", () => {
    expect(validatePinForm(form({ hasPin: false, newPin: "1234", confirmPin: "1234" }))).toBeNull();
  });

  it("rejects non-digits", () => {
    expect(validatePinForm(form({ newPin: "12a4", confirmPin: "12a4" }))).toBe(
      "A PIN can only contain digits.",
    );
  });

  it("enforces the length range at both ends", () => {
    expect(validatePinForm(form({ newPin: "123", confirmPin: "123" }))).toBe(
      "A PIN must be 4–8 digits.",
    );
    expect(validatePinForm(form({ newPin: "123456789", confirmPin: "123456789" }))).toBe(
      "A PIN must be 4–8 digits.",
    );
  });

  it("catches a mistyped confirmation", () => {
    expect(validatePinForm(form({ newPin: "1234", confirmPin: "1235" }))).toBe(
      "The two PINs do not match.",
    );
  });

  it("asks for confirmation before comparing", () => {
    expect(validatePinForm(form({ newPin: "1234", confirmPin: "" }))).toBe("Confirm your new PIN.");
  });

  it("rejects a change that changes nothing", () => {
    expect(
      validatePinForm(
        form({
          intent: "change",
          hasPin: true,
          currentPin: "1234",
          newPin: "1234",
          confirmPin: "1234",
        }),
      ),
    ).toBe("The new PIN is the same as the current one.");
  });

  it("needs only the current PIN to turn one off", () => {
    expect(validatePinForm(form({ intent: "clear", hasPin: true, currentPin: "1234" }))).toBeNull();
  });

  it("will not turn off a PIN without the current one", () => {
    expect(validatePinForm(form({ intent: "clear", hasPin: true, currentPin: "" }))).toBe(
      "Enter your current PIN.",
    );
  });

  it("reports one problem at a time, most blocking first", () => {
    // Both the current PIN is missing *and* the new one is too short; the
    // current-PIN prompt is the one that comes back.
    expect(
      validatePinForm(form({ intent: "change", hasPin: true, newPin: "1", confirmPin: "2" })),
    ).toBe("Enter your current PIN.");
  });
});

describe("pinActionLabel", () => {
  it("names each intent", () => {
    expect(pinActionLabel("set")).toBe("Set PIN");
    expect(pinActionLabel("change")).toBe("Change PIN");
    expect(pinActionLabel("clear")).toBe("Turn off PIN");
  });
});