// ESLint flat config. Static analysis for make check; formatting stays with
// prettier (script/fmt-check), so nothing here touches style.
//
// The sources are CommonJS and are bundled per entrypoint by build.js, so the
// globals differ by tree and are declared per tree below. Getting that wrong in
// either direction defeats the point: too few globals buries a real no-undef in
// false positives, too many hides the next unimported identifier.

const js = require("@eslint/js");
const globals = require("globals");

// The extension APIs. MV3 Chrome exposes `chrome`; Firefox exposes both, and
// the code feature-detects between them.
const extensionGlobals = {
    chrome: "readonly",
    browser: "readonly",
};

const commonjs = {
    ecmaVersion: 2024,
    sourceType: "commonjs",
};

module.exports = [
    {
        ignores: [
            "dist/",
            "node_modules/",
            // Emitted by build.js, not authored here.
            "src/popup/styles/",
        ],
    },

    js.configs.recommended,

    {
        rules: {
            // The two rules this config exists for. Both are already
            // error-level in the recommended set; restated so a future
            // recommended-set change cannot silently downgrade them.
            "no-undef": "error",
            // `_`-prefixed arguments are the deliberate "present for the
            // interface, unused here" marker: the popup views share one
            // init(ctx) signature and three of the eight do not read ctx.
            // An unused catch binding is written `catch {`, which the repo
            // already does, so caught errors stay checked.
            "no-unused-vars": ["error", { argsIgnorePattern: "^_" }],

            // Off: it flags `password = null` and `decryptedSecret = null` in
            // approval.js and confirmTx.js, which are the best-effort wipes of
            // decrypted key material after use. The assignments are dead by
            // construction — that is the point of them — and satisfying the
            // rule would mean deleting the wipes.
            "no-useless-assignment": "off",

            // Off: it requires every rethrow to carry `{ cause }`. That is a
            // change to what the wallet's error paths actually throw, which is
            // not this config's business; adopting it is its own decision.
            "preserve-caught-error": "off",
        },
    },

    // Popup and content scripts: page/window context.
    {
        files: ["src/popup/**/*.js", "src/content/**/*.js"],
        languageOptions: {
            ...commonjs,
            globals: { ...globals.browser, ...extensionGlobals },
        },
    },

    // MV3 background: a service worker, with no window and no document.
    {
        files: ["src/background/**/*.js"],
        languageOptions: {
            ...commonjs,
            globals: { ...globals.serviceworker, ...extensionGlobals },
        },
    },

    // src/shared is bundled into both, so it may only use what both provide:
    // the service worker globals are the intersection, plus the extension APIs.
    {
        files: ["src/shared/**/*.js"],
        languageOptions: {
            ...commonjs,
            globals: { ...globals.serviceworker, ...extensionGlobals },
        },
    },

    // src/shared/ens.js is the documented exception to the line above: its own
    // header says POPUP ONLY, it caches in localStorage, and only popup views
    // require it. Linting it as a service worker would be wrong about the file.
    {
        files: ["src/shared/ens.js"],
        languageOptions: {
            ...commonjs,
            globals: { ...globals.browser, ...extensionGlobals },
        },
    },

    // Unit tests: jest on node.
    {
        files: ["tests/**/*.test.js"],
        languageOptions: {
            ...commonjs,
            globals: { ...globals.node, ...globals.jest },
        },
    },

    // The build script is a plain node program.
    {
        files: ["build.js"],
        languageOptions: {
            ...commonjs,
            globals: { ...globals.node },
        },
    },

    // The e2e harnesses are node programs that also carry, inline, the
    // callbacks they ship into the browser via page.evaluate — so both
    // contexts really are present in the same file and both sets of globals
    // are in scope somewhere in it.
    {
        files: ["tests/e2e/**/*.js"],
        languageOptions: {
            ...commonjs,
            globals: {
                ...globals.node,
                ...globals.browser,
                ...extensionGlobals,
            },
        },
    },

    // This config file itself.
    {
        files: ["eslint.config.js"],
        languageOptions: {
            ...commonjs,
            globals: { ...globals.node },
        },
    },
];