// A popup save reads the stored record, merges this page's changes into it
// and writes it back. The background's write of a network the user approved
// used to be able to land between that read and that write, and the popup's
// write then put the old network back
// (https://git.eeqj.de/sneak/AutistMask/issues/641). Every write of the record
// now holds one lock from its read to its write.
//
// The popup and the background run here as the real modules over one shared
// storage stub, and share the lock the way the extension's pages and its
// background share the browser's (tests/support/navigatorLocks.js).

const { makeStorageStub } = require("./support/storageStub");

function loadContexts(storage) {
    jest.resetModules();
    globalThis.chrome = { storage: { local: storage.local } };
    return {
        popup: require("../src/shared/state"),
        background: require("../src/background/state"),
        applyChainSwitchFields: require("../src/shared/chainSwitchFields")
            .applyChainSwitchFields,
    };
}

// Lets every pending promise callback run, and then some.
function nextMacrotask() {
    return new Promise((resolve) => setImmediate(resolve));
}

afterEach(() => {
    delete globalThis.chrome;
    jest.restoreAllMocks();
});

test("a network the background switches to during a popup save stays stored", async () => {
    const storage = makeStorageStub({ autistmask: { networkId: "sepolia" } });
    const { popup, background, applyChainSwitchFields } = loadContexts(storage);
    await popup.loadState();

    // The popup navigates, so its save has a change of its own to write.
    popup.state.currentView = "settings";

    // The popup's save has read the record and is about to write it back when
    // the user's approval of a site's switch to mainnet reaches the
    // background. Without the lock the background's whole update runs before
    // the next macrotask; with it, the update waits for the popup's write.
    let backgroundSwitch;
    const realSet = storage.local.set.getMockImplementation();
    storage.local.set.mockImplementationOnce(async (items) => {
        backgroundSwitch = background.updateState((fresh) =>
            applyChainSwitchFields(fresh, "mainnet"),
        );
        await nextMacrotask();
        return realSet(items);
    });

    await popup.saveState();
    await backgroundSwitch;

    const stored = storage.read("autistmask");
    expect(stored.networkId).toBe("mainnet");
    expect(stored.currentView).toBe("settings");
});

test("a save that fails holding the lock lets it go", async () => {
    jest.spyOn(console, "error").mockImplementation(() => {});
    const storage = makeStorageStub({ autistmask: { networkId: "sepolia" } });
    const { popup, background, applyChainSwitchFields } = loadContexts(storage);
    await popup.loadState();

    storage.local.set.mockRejectedValueOnce(new Error("quota exceeded"));
    await expect(popup.saveState()).rejects.toThrow("quota exceeded");

    await background.updateState((fresh) =>
        applyChainSwitchFields(fresh, "mainnet"),
    );
    expect(storage.read("autistmask").networkId).toBe("mainnet");
});