import { compatGlobal } from "@vrtmrz/livesync-commonlib/compat/common/coreEnvFunctions";
import { reactive, reactiveSource } from "octagonal-wheels/dataobject/reactive";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";

import {
    STATUS_COUNTER_INACTIVE_LINGER_MS,
    createChunkFetchCounterLabel,
    createMinimumVisibleActivityCount,
    createPaddedCounterLabel,
} from "./StatusBarDisplay.ts";

describe("createMinimumVisibleActivityCount", () => {
    beforeEach(() => {
        vi.useFakeTimers();
        vi.setSystemTime(new Date("2026-07-16T00:00:00Z"));
    });

    afterEach(() => {
        vi.useRealTimers();
    });

    it("keeps a short activity visible for the configured minimum lifetime", () => {
        const source = reactiveSource(0);
        const display = createMinimumVisibleActivityCount(source, 150);
        const rendered = reactive(() => `active:${display.value}`);

        expect(rendered.value).toBe("active:0");
        source.value = 1;
        expect(rendered.value).toBe("active:1");
        vi.advanceTimersByTime(50);
        source.value = 0;

        expect(display.value).toBe(1);
        vi.advanceTimersByTime(99);
        expect(display.value).toBe(1);
        vi.advanceTimersByTime(1);
        expect(display.value).toBe(0);
        expect(rendered.value).toBe("active:0");

        display.dispose();
    });

    it("updates overlapping activity and starts a new minimum lifetime after becoming idle", () => {
        const source = reactiveSource(0);
        const display = createMinimumVisibleActivityCount(source, 150);

        source.value = 1;
        vi.advanceTimersByTime(25);
        source.value = 2;
        expect(display.value).toBe(2);
        source.value = 0;

        vi.advanceTimersByTime(50);
        source.value = 1;
        expect(display.value).toBe(1);

        vi.advanceTimersByTime(75);
        source.value = 0;
        expect(display.value).toBe(0);

        source.value = 3;
        source.value = 0;
        expect(display.value).toBe(3);
        vi.advanceTimersByTime(150);
        expect(display.value).toBe(0);

        display.dispose();
    });

    it("cancels pending work and stops observing its source when disposed", () => {
        const source = reactiveSource(0);
        const display = createMinimumVisibleActivityCount(source, 150);

        source.value = 1;
        source.value = 0;
        display.dispose();
        vi.advanceTimersByTime(150);
        source.value = 2;

        expect(display.value).toBe(1);
    });
});

describe("createPaddedCounterLabel", () => {
    beforeEach(() => {
        vi.useFakeTimers();
    });

    afterEach(() => {
        vi.useRealTimers();
    });

    it("keeps the widest counter label until its inactive linger period ends", () => {
        const source = reactiveSource(0);
        const display = createPaddedCounterLabel(source, "📥");

        expect(display.value).toBe("");
        source.value = 9;
        expect(display.value).toBe(" 📥\u20079");
        source.value = 123;
        expect(display.value).toBe(" 📥\u2007123");
        source.value = 0;
        expect(display.value).toBe(" 📥\u2007\u2007\u20070");

        vi.advanceTimersByTime(STATUS_COUNTER_INACTIVE_LINGER_MS - 1);
        expect(display.value).toBe(" 📥\u2007\u2007\u20070");
        vi.advanceTimersByTime(1);
        expect(display.value).toBe("");

        source.value = 7;
        expect(display.value).toBe(" 📥\u20077");
        display.dispose();
    });

    it("exposes the numeric value while retaining zero through the existing linger", () => {
        const source = reactiveSource(0);
        const display = createPaddedCounterLabel(source, "📥");

        expect(display.count.value).toBeUndefined();
        source.value = 9;
        expect(display.count.value).toBe(9);
        source.value = 0;
        expect(display.count.value).toBe(0);

        vi.advanceTimersByTime(STATUS_COUNTER_INACTIVE_LINGER_MS - 1);
        expect(display.count.value).toBe(0);
        vi.advanceTimersByTime(1);
        expect(display.count.value).toBeUndefined();

        display.dispose();
    });

    it("cancels the pending clear when counter activity resumes", () => {
        const source = reactiveSource(0);
        const display = createPaddedCounterLabel(source, "📄");

        source.value = 1;
        source.value = 0;
        vi.advanceTimersByTime(1_000);
        source.value = 2;
        vi.advanceTimersByTime(STATUS_COUNTER_INACTIVE_LINGER_MS);

        expect(display.value).toBe(" 📄\u20072");
        display.dispose();
    });

    it("cancels its inactive timer and source subscription when disposed", () => {
        const source = reactiveSource(0);
        const display = createPaddedCounterLabel(source, "📄");

        source.value = 4;
        source.value = 0;
        display.dispose();
        vi.advanceTimersByTime(STATUS_COUNTER_INACTIVE_LINGER_MS);
        source.value = 5;

        expect(display.value).toBe(" 📄\u20070");
    });
});

describe("createChunkFetchCounterLabel", () => {
    beforeEach(() => {
        vi.useFakeTimers();
    });

    afterEach(() => {
        vi.useRealTimers();
    });

    it("keeps initial and retry counts separate across an unchanged-total handoff", () => {
        const counts = reactiveSource({ initial: 2, retrying: 5 });
        const display = createChunkFetchCounterLabel(counts);
        const withoutPadding = () => display.value.replace(/\u2007/g, "");
        const transitionSnapshots: string[] = [];
        const observeTransitions = () => transitionSnapshots.push(withoutPadding());

        expect(withoutPadding()).toBe(" 🛄2 🔁5");

        display.onChanged(observeTransitions);
        counts.value = { initial: 0, retrying: 7 };
        expect(withoutPadding()).toBe(" 🛄0 🔁7");
        expect(transitionSnapshots).toEqual([" 🛄0 🔁7"]);
        display.offChanged(observeTransitions);
        vi.advanceTimersByTime(STATUS_COUNTER_INACTIVE_LINGER_MS - 1);
        expect(withoutPadding()).toBe(" 🛄0 🔁7");
        vi.advanceTimersByTime(1);
        expect(withoutPadding()).toBe(" 🔁7");

        counts.value = { initial: 0, retrying: 0 };
        expect(withoutPadding()).toBe(" 🔁0");
        display.dispose();
        vi.advanceTimersByTime(STATUS_COUNTER_INACTIVE_LINGER_MS);
        counts.value = { initial: 1, retrying: 0 };

        expect(withoutPadding()).toBe(" 🔁0");
    });
});

describe("status timeout ownership", () => {
    beforeEach(() => {
        vi.useFakeTimers();
        vi.setSystemTime(new Date("2026-10-24T00:00:00Z"));
    });

    afterEach(() => {
        vi.restoreAllMocks();
        vi.useRealTimers();
    });

    it("counts the minimum lifetime from construction when activity is already visible", () => {
        const source = reactiveSource(2);
        const display = createMinimumVisibleActivityCount(source, 150);
        vi.advanceTimersByTime(40);
        source.value = 0;

        vi.advanceTimersByTime(109);
        expect(display.value).toBe(2);
        vi.advanceTimersByTime(1);
        expect(display.value).toBe(0);
        display.dispose();
    });

    it("hides immediately for a non-positive minimum lifetime and clamps negative activity", () => {
        const source = reactiveSource(-2);
        const display = createMinimumVisibleActivityCount(source, -10);
        expect(display.value).toBe(0);
        source.value = 1;
        source.value = -2;

        expect(display.value).toBe(0);
        expect(vi.getTimerCount()).toBe(0);
        display.dispose();
    });

    it("keeps a zero-duration counter clear asynchronous", () => {
        const source = reactiveSource(0);
        const display = createPaddedCounterLabel(source, "A", 0);
        source.value = 1;
        source.value = 0;

        expect(display.value).toBe(" A\u20070");
        vi.advanceTimersByTime(0);
        expect(display.value).toBe("");
        display.dispose();
    });

    it.each(["activity", "label"] as const)(
        "retains timer receivers, zero handles, and idempotent disposal for %s",
        (kind) => {
            const source = reactiveSource(0);
            const offChanged = vi.spyOn(source, "offChanged");
            const setTimer = vi.spyOn(compatGlobal as Window, "setTimeout").mockReturnValue(0);
            const clearTimer = vi.spyOn(compatGlobal as Window, "clearTimeout").mockImplementation(() => {});
            const display =
                kind === "activity"
                    ? createMinimumVisibleActivityCount(source, 150)
                    : createPaddedCounterLabel(source, "A", 150);

            source.value = 1;
            source.value = 0;
            expect(setTimer).toHaveBeenCalledTimes(1);
            expect(setTimer.mock.contexts[0]).toBe(compatGlobal);
            expect(setTimer.mock.calls[0][1]).toBe(150);
            source.value = 2;
            expect(clearTimer).toHaveBeenCalledExactlyOnceWith(0);
            source.value = 0;
            display.dispose();
            display.dispose();
            source.value = 3;

            expect(setTimer).toHaveBeenCalledTimes(2);
            expect(clearTimer).toHaveBeenCalledTimes(2);
            expect(clearTimer.mock.calls).toEqual([[0], [0]]);
            expect(clearTimer.mock.contexts).toEqual([compatGlobal, compatGlobal]);
            expect(offChanged).toHaveBeenCalledTimes(1);
        }
    );

    it("keeps pending clears independent between display instances", () => {
        const firstSource = reactiveSource(0);
        const secondSource = reactiveSource(0);
        const first = createPaddedCounterLabel(firstSource, "A", 100);
        const second = createPaddedCounterLabel(secondSource, "B", 100);
        firstSource.value = 1;
        firstSource.value = 0;
        secondSource.value = 1;
        secondSource.value = 0;
        expect(vi.getTimerCount()).toBe(2);

        first.dispose();
        expect(vi.getTimerCount()).toBe(1);
        vi.advanceTimersByTime(100);
        expect(first.value).toBe(" A\u20070");
        expect(second.value).toBe("");
        second.dispose();
        expect(vi.getTimerCount()).toBe(0);
    });

    it("disposes both child timers and its source subscription for chunk counts", () => {
        const source = reactiveSource({ initial: 2, retrying: 3 });
        const offChanged = vi.spyOn(source, "offChanged");
        const display = createChunkFetchCounterLabel(source);
        source.value = { initial: 0, retrying: 0 };
        const lastLabel = display.value;
        expect(vi.getTimerCount()).toBe(2);

        display.dispose();
        display.dispose();
        expect(vi.getTimerCount()).toBe(0);
        vi.advanceTimersByTime(STATUS_COUNTER_INACTIVE_LINGER_MS);
        source.value = { initial: 4, retrying: 5 };
        expect(display.value).toBe(lastLabel);
        expect(offChanged).toHaveBeenCalledTimes(1);
    });
});