import { describe, expect, test } from "bun:test";

import { defineFlags } from "./define-flags";
import { resolveAllFlags, resolveFlag } from "./resolve-flags";

const testFlags = defineFlags({
  TEST_FLAG: {
    description: "Test flag",
    defaults: {
      development: true,
      staging: true,
      preview: true,
      production: false,
    },
  },
  SECOND_FLAG: {
    description: "Second test flag",
    defaults: {
      development: false,
      production: true,
    },
  },
});

describe("resolveFlag", () => {
  test("uses declared environment defaults and falls back to production", () => {
    expect(
      resolveFlag(testFlags, "TEST_FLAG", { env: { NODE_ENV: "development" } })
    ).toBe(true);
    expect(
      resolveFlag(testFlags, "TEST_FLAG", { env: { NODE_ENV: "staging" } })
    ).toBe(true);
    expect(
      resolveFlag(testFlags, "TEST_FLAG", { env: { NODE_ENV: "preview" } })
    ).toBe(true);
    expect(
      resolveFlag(testFlags, "TEST_FLAG", { env: { NODE_ENV: "test" } })
    ).toBe(false);
    expect(resolveFlag(testFlags, "TEST_FLAG", { env: {} })).toBe(false);
  });

  test("uses valid FLAG overrides before defaults", () => {
    expect(
      resolveFlag(testFlags, "TEST_FLAG", {
        env: { FLAG_TEST_FLAG: "TrUe", NODE_ENV: "production" },
      })
    ).toBe(true);
    expect(
      resolveFlag(testFlags, "TEST_FLAG", {
        env: { FLAG_TEST_FLAG: "FALSE", NODE_ENV: "development" },
      })
    ).toBe(false);
  });

  test("requires exact FLAG env var keys", () => {
    expect(
      resolveFlag(testFlags, "TEST_FLAG", {
        env: { flag_test_flag: "true", NODE_ENV: "production" },
      })
    ).toBe(false);
  });

  test("falls back to defaults and warns once for invalid overrides", () => {
    const warnings: string[] = [];
    const warn = (message: string) => warnings.push(message);
    const env = { FLAG_TEST_FLAG: "yes", NODE_ENV: "development" };

    expect(resolveFlag(testFlags, "TEST_FLAG", { env, warn })).toBe(true);
    expect(resolveFlag(testFlags, "TEST_FLAG", { env, warn })).toBe(true);
    expect(warnings).toHaveLength(1);
    expect(warnings[0]).toContain("FLAG_TEST_FLAG");
  });

  test("resolves all flags into a boolean snapshot", () => {
    expect(
      resolveAllFlags(testFlags, {
        env: { FLAG_TEST_FLAG: "true", NODE_ENV: "production" },
      })
    ).toEqual({
      TEST_FLAG: true,
      SECOND_FLAG: true,
    });
  });
});