// Who may move the active chain, and when.
//
// wallet_switchEthereumChain used to be answered for any origin at all, with
// no connection check and no prompt, so a page the user had never connected
// to could clear the [TESTNET] banner under someone who believed they were
// on Sepolia (https://git.eeqj.de/sneak/AutistMask/issues/308). Gated on the
// connection, a connected site could still move the wallet between mainnet and
// Sepolia without asking. Only the user switches the network: a connected
// site's request opens a prompt, and nothing changes unless the user approves
// it there (https://git.eeqj.de/sneak/AutistMask/issues/408).
//
// Every refusal is asserted as a refusal to ACT — the stored record unmoved
// and no chainChanged broadcast — because an error code alone would not
// distinguish a refusal from a switch that happened and then reported a
// failure.
//
// The endpoint half of #308 lives in tests/networkEndpoints.test.js, which
// covers the popup's chain switch; this file covers the background's, which
// goes through storage rather than the shared state singleton. The last block
// covers what the background tells open tabs when the user switches the
// network in Settings.

const { networkById } = require("../src/shared/networks");
const { makeStorageStub } = require("./support/storageStub");

const ADDRESS = "0x66133E8ea0f5D1d612D2502a968757D1048c214a";

// The site the persisted state has connected, and one it has never heard of.
const CONNECTED_ORIGIN = "https://dapp.example";
const STRANGER_ORIGIN = "https://stranger.example";

const EXT_URL = "chrome-extension://autistmask/";

const MAINNET = networkById("mainnet");
const SEPOLIA = networkById("sepolia");

// The user's own node, so a switch that happens is visible as the loss of it.
const CUSTOM_RPC = "http://127.0.0.1:8545";

// A balance a switch would clear, so a switch that happens is visible here too.
function walletFixture() {
    return [
        {
            name: "Wallet 1",
            type: "hd",
            addresses: [
                { address: ADDRESS, balance: "1.5", tokenBalances: [] },
            ],
        },
    ];
}

// Let the handler's promise chain run to the next suspension point. The gate
// reads storage before it answers, so the response is several awaits deep.
async function settle() {
    for (let i = 0; i < 50; i++) await Promise.resolve();
}

afterEach(() => {
    delete global.chrome;
});

// Load the background worker against stubbed browser APIs, with the real
// chain-switch and persistence modules behind it, and return the handles to
// drive it.
function loadBackground() {
    jest.resetModules();

    jest.doMock("../src/shared/balances", () => ({
        getProvider: () => ({}),
        refreshBalances: jest.fn(async () => {}),
    }));
    jest.doMock("../src/shared/phishingDomains", () => ({
        isPhishingDomain: () => false,
    }));
    jest.doMock("../src/shared/alarms", () => ({
        BALANCE_REFRESH_ALARM: "balance",
        BALANCE_REFRESH_PERIOD_MINUTES: 1,
        ensureRecurringAlarms: jest.fn(async () => {}),
        registerAlarmHandlers: jest.fn(),
    }));

    // Storage is the only wallet state there is. The background reads and
    // writes it per call — it holds no in-memory copy and cannot reach the
    // shared singleton — so a switch that happened is visible here as a
    // written record, and one that did not is visible as its absence.
    const persisted = {
        networkId: "mainnet",
        rpcUrl: CUSTOM_RPC,
        blockscoutUrl: MAINNET.defaultBlockscoutUrl,
        networkEndpoints: {},
        wallets: walletFixture(),
        lastBalanceRefresh: 1,
        tokenHolderCache: {},
        fraudContracts: [],
        activeAddress: ADDRESS,
        allowedSites: { [ADDRESS]: [CONNECTED_ORIGIN] },
        deniedSites: {},
    };
    const storage = makeStorageStub({ autistmask: persisted });

    let messageListener = null;
    let connectListener = null;
    let windowRemovedListener = null;
    // The URL of every approval window the background opened. The approval id
    // is in it, and that is how the popup learns which approval it answers.
    const opened = [];
    // Every message the background pushed at a content script. chainChanged
    // is what tells a page the wallet moved, so a switch is visible here as
    // well as in the state.
    const toTabs = [];

    global.chrome = {
        storage,
        runtime: {
            getURL: (path) => EXT_URL + path,
            onMessage: {
                addListener: (fn) => {
                    messageListener = fn;
                },
            },
            onConnect: {
                addListener: (fn) => {
                    connectListener = fn;
                },
            },
            lastError: null,
        },
        windows: {
            getLastFocused: (cb) => cb(null),
            create: (options, cb) => {
                opened.push(options.url);
                cb({ id: opened.length });
            },
            remove: (id, cb) => {
                if (cb) cb();
            },
            onRemoved: {
                addListener: (fn) => {
                    windowRemovedListener = fn;
                },
            },
        },
        tabs: {
            query: (queryInfo, cb) => cb([{ id: 1 }]),
            sendMessage: (tabId, message, cb) => {
                toTabs.push(message);
                if (cb) cb();
            },
        },
        action: { setPopup: () => {} },
    };

    require("../src/background/index");

    // A page's request. Its answer is read with result(), which is null for as
    // long as the request is waiting on the user.
    async function switchChain(chainId, origin) {
        let result = null;
        messageListener(
            {
                type: "AUTISTMASK_RPC",
                method: "wallet_switchEthereumChain",
                params: [{ chainId }],
            },
            { origin },
            (r) => {
                result = r;
            },
        );
        await settle();
        return { result: () => result };
    }

    function promptId() {
        return new URL(opened[opened.length - 1]).searchParams.get("approval");
    }

    // What the popup is told to show for the prompt.
    function describePrompt() {
        let reply = null;
        messageListener(
            { type: "AUTISTMASK_GET_APPROVAL", id: promptId() },
            { url: EXT_URL + "src/popup/index.html" },
            (r) => {
                reply = r;
            },
        );
        return reply;
    }

    // The user's answer, as the popup sends it: on the port named for the
    // approval, from the extension's own page, and then the window closes.
    async function answerPrompt(approved) {
        const onMessage = [];
        const onDisconnect = [];
        const port = {
            name: "approval:" + promptId(),
            sender: { url: EXT_URL + "src/popup/index.html" },
            onMessage: { addListener: (fn) => onMessage.push(fn) },
            onDisconnect: { addListener: (fn) => onDisconnect.push(fn) },
        };
        connectListener(port);
        for (const fn of onMessage) {
            fn(
                {
                    type: "AUTISTMASK_APPROVAL_DECISION",
                    approved,
                    remember: false,
                },
                port,
            );
        }
        for (const fn of onDisconnect) fn(port);
        await settle();
    }

    // The user closes the prompt window without answering it.
    async function closePrompt() {
        windowRemovedListener(opened.length);
        await settle();
    }

    return {
        switchChain,
        describePrompt,
        answerPrompt,
        closePrompt,
        opened,
        // A message to the background from `sender`, and its answer.
        send: (msg, sender) => {
            let reply = null;
            messageListener(msg, sender, (r) => {
                reply = r;
            });
            return reply;
        },
        walletState: () => storage.read("autistmask"),
        chainChangedEvents: () =>
            toTabs.filter((m) => m.eventName === "chainChanged"),
    };
}

const USER_REJECTED = { code: 4001, message: "User rejected the request." };

describe("wallet_switchEthereumChain is gated on the connection", () => {
    test("an origin the wallet was never connected to is refused with 4100", async () => {
        const bg = loadBackground();
        const before = bg.walletState();

        const request = await bg.switchChain(SEPOLIA.chainId, STRANGER_ORIGIN);

        expect(request.result().error).toEqual({
            code: 4100,
            message: "Unauthorized",
        });
        expect(request.result().result).toBeUndefined();
        // The refusal has to be a refusal to ACT, not just an error string:
        // the wallet is still on mainnet, still on the user's own node, and
        // no page was told the chain moved. Nor was the user asked.
        expect(bg.walletState()).toEqual(before);
        expect(bg.chainChangedEvents()).toEqual([]);
        expect(bg.opened).toEqual([]);
    });

    test("an unconnected origin is refused even for the chain already active", async () => {
        const bg = loadBackground();

        const request = await bg.switchChain(MAINNET.chainId, STRANGER_ORIGIN);

        expect(request.result().error).toEqual({
            code: 4100,
            message: "Unauthorized",
        });
    });

    test("an unconnected origin is refused before the unsupported-chain answer", async () => {
        const bg = loadBackground();

        const request = await bg.switchChain("0x89", STRANGER_ORIGIN);

        expect(request.result().error.code).toBe(4100);
    });
});

describe("only the user switches the network", () => {
    test("a connected site's request changes nothing while the prompt is open", async () => {
        const bg = loadBackground();
        const before = bg.walletState();

        const request = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);

        // Waiting on the user, with one prompt on screen naming the site and
        // both networks.
        expect(request.result()).toBeNull();
        expect(bg.opened).toHaveLength(1);
        expect(bg.describePrompt()).toMatchObject({
            origin: CONNECTED_ORIGIN,
            type: "network",
            currentNetworkId: "mainnet",
            requestedNetworkId: "sepolia",
        });

        // The network, the endpoints and the balances are as they were, and
        // no page was told otherwise.
        expect(bg.walletState()).toEqual(before);
        expect(bg.chainChangedEvents()).toEqual([]);
    });

    test("approving the prompt switches the network", async () => {
        const bg = loadBackground();

        const request = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
        await bg.answerPrompt(true);

        expect(request.result()).toEqual({ result: null });
        const after = bg.walletState();
        expect(after.networkId).toBe("sepolia");
        expect(after.rpcUrl).toBe(SEPOLIA.defaultRpcUrl);
        expect(after.wallets[0].addresses[0].balance).toBe("0");
        expect(bg.chainChangedEvents()).toEqual([
            {
                type: "AUTISTMASK_EVENT",
                eventName: "chainChanged",
                data: SEPOLIA.chainId,
            },
        ]);
    });

    test("rejecting the prompt changes nothing and answers 4001", async () => {
        const bg = loadBackground();
        const before = bg.walletState();

        const request = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
        await bg.answerPrompt(false);

        expect(request.result()).toEqual({ error: USER_REJECTED });
        expect(bg.walletState()).toEqual(before);
        expect(bg.chainChangedEvents()).toEqual([]);
    });

    test("closing the prompt without answering changes nothing and answers 4001", async () => {
        const bg = loadBackground();
        const before = bg.walletState();

        const request = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
        await bg.closePrompt();

        expect(request.result()).toEqual({ error: USER_REJECTED });
        expect(bg.walletState()).toEqual(before);
        expect(bg.chainChangedEvents()).toEqual([]);
    });

    test("a request for the chain already active opens no prompt", async () => {
        const bg = loadBackground();
        const before = bg.walletState();

        const request = await bg.switchChain(MAINNET.chainId, CONNECTED_ORIGIN);

        expect(request.result()).toEqual({ result: null });
        expect(bg.opened).toEqual([]);
        expect(bg.walletState()).toEqual(before);
        expect(bg.chainChangedEvents()).toEqual([]);
    });

    test("a second request while the prompt is open is refused with -32002", async () => {
        const bg = loadBackground();

        const first = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
        const second = await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);

        expect(second.result().error.code).toBe(-32002);
        expect(bg.opened).toHaveLength(1);

        // The first prompt still decides.
        await bg.answerPrompt(true);
        expect(first.result()).toEqual({ result: null });
        expect(bg.walletState().networkId).toBe("sepolia");
    });

    test("a request for an unsupported chain still gets 4902 and no prompt", async () => {
        const bg = loadBackground();

        const request = await bg.switchChain("0x89", CONNECTED_ORIGIN);

        expect(request.result().error.code).toBe(4902);
        expect(bg.opened).toEqual([]);
        expect(bg.walletState().networkId).toBe("mainnet");
    });

    test("an approved switch keeps the user's endpoint", async () => {
        const bg = loadBackground();

        await bg.switchChain(SEPOLIA.chainId, CONNECTED_ORIGIN);
        await bg.answerPrompt(true);
        expect(bg.walletState().rpcUrl).toBe(SEPOLIA.defaultRpcUrl);

        await bg.switchChain(MAINNET.chainId, CONNECTED_ORIGIN);
        await bg.answerPrompt(true);
        expect(bg.walletState().rpcUrl).toBe(CUSTOM_RPC);
    });
});

// Switching the network in Settings tells open pages, as an approved site
// request does (https://git.eeqj.de/sneak/AutistMask/issues/500). These drive
// the real Settings view over the background's storage, with what it sends
// delivered to the background from the extension's own page.
describe("switching the network in Settings tells every open tab", () => {
    const POPUP = { url: EXT_URL + "src/popup/index.html" };

    // A stand-in for one DOM node: enough of an element for init() to set
    // properties on it and hang listeners off it.
    function fakeElement() {
        return {
            value: "",
            checked: false,
            textContent: "",
            style: {},
            dataset: {},
            classList: { add() {}, remove() {} },
            listeners: {},
            addEventListener(event, handler) {
                this.listeners[event] = handler;
            },
            querySelectorAll: () => [],
        };
    }

    // Settings, opened the way the popup opens it. Returns its network
    // selector.
    async function openSettings(bg) {
        const elements = {};
        const element = (id) => (elements[id] ||= fakeElement());
        jest.doMock("../src/popup/views/helpers", () => ({
            $: element,
            showView: () => {},
            updateDebugBanner: () => {},
            showFlash: () => {},
            escapeHtml: (s) => s,
            flashCopyFeedback: () => {},
            goBack: () => {},
            pushCurrentView: () => {},
            onViewLeave: () => {},
            VIEWS: [],
        }));
        global.chrome.runtime.sendMessage = (msg) => {
            bg.send(msg, POPUP);
        };
        await require("../src/shared/state").loadState();
        require("../src/popup/views/settings").init({
            pageClosed: new AbortController().signal,
        });
        const select = element("settings-network");
        select.value = "mainnet";
        return select;
    }

    // The user picks `networkId` in the selector.
    async function choose(select, networkId) {
        select.value = networkId;
        await select.listeners.change();
        await settle();
    }

    afterEach(() => {
        jest.dontMock("../src/popup/views/helpers");
    });

    test("switching to the other network sends chainChanged once, with its chain id", async () => {
        const bg = loadBackground();
        const select = await openSettings(bg);

        await choose(select, "sepolia");

        expect(bg.walletState().networkId).toBe("sepolia");
        expect(bg.chainChangedEvents()).toEqual([
            {
                type: "AUTISTMASK_EVENT",
                eventName: "chainChanged",
                data: SEPOLIA.chainId,
            },
        ]);
    });

    test("choosing the network already active changes nothing and sends nothing", async () => {
        const bg = loadBackground();
        const select = await openSettings(bg);
        const before = bg.walletState();

        await choose(select, "mainnet");

        expect(bg.walletState()).toEqual(before);
        expect(bg.chainChangedEvents()).toEqual([]);
    });

    test("a page cannot make the background send chainChanged", async () => {
        const bg = loadBackground();

        const reply = bg.send(
            { type: "AUTISTMASK_NETWORK_CHANGED", chainId: SEPOLIA.chainId },
            { url: CONNECTED_ORIGIN + "/" },
        );
        await settle();

        expect(reply).toEqual({ error: "Unauthorized sender" });
        expect(bg.chainChangedEvents()).toEqual([]);
    });
});