describe("WhatsAppThrottle", () => {
    let WhatsAppThrottle: typeof import("../WhatsAppThrottle.js").WhatsAppThrottleClass;

    beforeAll(async () => {
        const mod = await import("../WhatsAppThrottle.js");
        WhatsAppThrottle = mod.WhatsAppThrottleClass;
    });

    beforeEach(() => {
        jest.restoreAllMocks();
    });

    it("allows first send for a company immediately", () => {
        const throttle = new WhatsAppThrottle(8000);
        expect(throttle.canSend("company-1")).toBe(true);
    });

    it("blocks send within minimum interval", () => {
        const throttle = new WhatsAppThrottle(8000);
        throttle.recordSent("company-1");

        jest.useFakeTimers();
        jest.setSystemTime(new Date("2026-07-21T12:00:03.000Z")); // 3s later

        expect(throttle.canSend("company-1")).toBe(false);

        jest.useRealTimers();
    });

    it("allows send after maximum possible interval (base + jitter)", () => {
        const throttle = new WhatsAppThrottle(8000);
        const now = new Date("2026-07-21T12:00:00.000Z");
        jest.useFakeTimers();
        jest.setSystemTime(now);

        throttle.recordSent("company-1");

        // After 16s (max = 8s base + 8s jitter), should always be allowed
        jest.setSystemTime(new Date("2026-07-21T12:00:16.000Z"));

        expect(throttle.canSend("company-1")).toBe(true);

        jest.useRealTimers();
    });

    it("tracks companies independently", () => {
        const throttle = new WhatsAppThrottle(8000);
        const now = new Date("2026-07-21T12:00:00.000Z");
        jest.useFakeTimers();
        jest.setSystemTime(now);

        throttle.recordSent("company-1");

        // company-2 should still be allowed
        expect(throttle.canSend("company-2")).toBe(true);

        jest.useRealTimers();
    });

    it("applies jitter to minimum interval", () => {
        const throttle = new WhatsAppThrottle(8000);
        const now = new Date("2026-07-21T12:00:00.000Z");
        jest.useFakeTimers();
        jest.setSystemTime(now);

        throttle.recordSent("company-1");

        // At exactly 8s (base interval), it should still be blocked due to jitter
        jest.setSystemTime(new Date("2026-07-21T12:00:08.000Z"));
        expect(throttle.canSend("company-1")).toBe(false);

        // At 16s (max interval = base + jitter), it should be allowed
        jest.setSystemTime(new Date("2026-07-21T12:00:16.000Z"));
        expect(throttle.canSend("company-1")).toBe(true);

        jest.useRealTimers();
    });

    it("uses default interval of 8000ms when not specified", () => {
        const throttle = new WhatsAppThrottle();
        const now = new Date("2026-07-21T12:00:00.000Z");
        jest.useFakeTimers();
        jest.setSystemTime(now);

        throttle.recordSent("company-1");

        // 7s should be blocked
        jest.setSystemTime(new Date("2026-07-21T12:00:07.000Z"));
        expect(throttle.canSend("company-1")).toBe(false);

        jest.useRealTimers();
    });
});