/**
 * Tests for the client session lifecycle: `toJSON`, `fromJSON`, `logout`, and
 * the CLI's `loadSession`, which reads the saved session file back into a
 * client.
 */

import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import sodium from "libsodium-wrappers-sumo";
import { afterAll, beforeAll, describe, expect, it } from "vitest";
import { init, toBase64 } from "../../src/crypto/index.js";
import { Client, type ClientSnapshot } from "../../src/client.js";
import { loadSession } from "../../src/cli-session.js";

const validSnapshot = (): ClientSnapshot => {
    const kp = sodium.crypto_box_keypair();
    return {
        email: "user@example.com",
        userID: 42,
        token: "test-token",
        masterKey: toBase64(sodium.crypto_secretbox_keygen()),
        secretKey: toBase64(kp.privateKey),
        publicKey: toBase64(kp.publicKey),
    };
};

// The client's key buffers are private; the tests read them to prove that
// logout wipes them.
const keyBuffers = (client: Client): Uint8Array[] => [
    client["masterKey"],
    client["secretKey"],
    client["publicKey"],
];

beforeAll(async () => {
    await init();
});

describe("Client.toJSON", () => {
    it("round-trips through fromJSON unchanged", () => {
        const snapshot = validSnapshot();
        expect(Client.fromJSON(snapshot).toJSON()).toEqual(snapshot);
    });

    it("throws instead of emitting a snapshot without a token", () => {
        const client = Client.fromJSON(validSnapshot());
        client.getApiClient().clearAuthToken();
        expect(() => client.toJSON()).toThrow(/no auth token/);
    });
});

describe("Client.fromJSON", () => {
    const shortKey = toBase64(new Uint8Array(16));

    it.each([
        ["email", undefined],
        ["email", 7],
        ["email", ""],
        ["token", undefined],
        ["token", null],
        ["token", ""],
        ["userID", undefined],
        ["userID", "42"],
        ["userID", 4.2],
        ["masterKey", undefined],
        ["masterKey", 7],
        ["masterKey", "not base64!"],
        ["masterKey", shortKey],
        ["secretKey", undefined],
        ["secretKey", "not base64!"],
        ["secretKey", shortKey],
        ["publicKey", undefined],
        ["publicKey", "not base64!"],
        ["publicKey", shortKey],
    ])("rejects %s = %j, naming the field", (field, value) => {
        const snapshot: Record<string, unknown> = { ...validSnapshot() };
        snapshot[field] = value;
        expect(() => Client.fromJSON(snapshot)).toThrow(
            new RegExp(`^Invalid session data: ${field} `),
        );
    });

    it.each([null, "a string", 42])("rejects a non-object %j", (value) => {
        expect(() => Client.fromJSON(value)).toThrow(
            /^Invalid session data: not a JSON object/,
        );
    });
});

describe("Client.logout", () => {
    it("zeroes the key buffers and clears the token", () => {
        const client = Client.fromJSON(validSnapshot());
        const api = client.getApiClient();
        const keys = keyBuffers(client);

        client.logout();

        for (const key of keys) {
            expect(key.length).toBe(32);
            expect(key.every((b) => b === 0)).toBe(true);
        }
        expect(api.getAuthToken()).toBeUndefined();
    });

    it("makes every later operation throw", async () => {
        const client = Client.fromJSON(validSnapshot());
        client.logout();

        expect(() => client.whoami()).toThrow(/logged out/);
        expect(() => client.toJSON()).toThrow(/logged out/);
        expect(() => client.getApiClient()).toThrow(/logged out/);
        expect(() => client.contentSource()).toThrow(/logged out/);
        await expect(client.listCollections()).rejects.toThrow(/logged out/);
        await expect(client.collectionsSince({ sinceTime: 0 })).rejects.toThrow(
            /logged out/,
        );
        await expect(
            client.filesSince({
                collectionID: 1,
                collectionKey: new Uint8Array(32),
                sinceTime: 0,
            }),
        ).rejects.toThrow(/logged out/);
        await expect(
            client.fetchMLData({ fileIDs: [1], fileKeys: new Map() }),
        ).rejects.toThrow(/logged out/);
    });

    it("stops a listing in flight from decrypting with the zeroed keys", async () => {
        // The server answers only after the client has logged out. If the
        // listing went on to decrypt this row with all-zero keys it would fail
        // with a decryption error, not the logged-out one.
        const row = {
            id: 1,
            owner: { id: 42 },
            encryptedKey: toBase64(new Uint8Array(48)),
            keyDecryptionNonce: toBase64(new Uint8Array(24)),
            updationTime: 1,
        };
        const client: Client = Client.fromJSON(validSnapshot(), {
            fetch: async () => {
                client.logout();
                return new Response(JSON.stringify({ collections: [row] }), {
                    status: 200,
                    headers: { "content-type": "application/json" },
                });
            },
        });

        await expect(client.listCollections()).rejects.toThrow(/logged out/);
    });
});

describe("loadSession", () => {
    let dir: string;

    beforeAll(() => {
        dir = mkdtempSync(join(tmpdir(), "quak-session-test-"));
    });

    afterAll(() => {
        rmSync(dir, { recursive: true, force: true });
    });

    it("returns null when there is no session file", () => {
        expect(loadSession(join(dir, "missing.json"))).toBeNull();
    });

    it("restores a client from a valid session file", () => {
        const path = join(dir, "valid.json");
        writeFileSync(path, JSON.stringify(validSnapshot()));
        expect(loadSession(path)!.whoami()).toEqual({
            email: "user@example.com",
            userID: 42,
        });
    });

    it("says the file is corrupt when it is not JSON", () => {
        const path = join(dir, "truncated.json");
        writeFileSync(path, '{"email": "user@exa');
        expect(() => loadSession(path)).toThrow(
            `Session file ${path} is corrupt`,
        );
    });

    it("says the file is corrupt and names the bad field", () => {
        const path = join(dir, "bad-key.json");
        writeFileSync(
            path,
            JSON.stringify({ ...validSnapshot(), secretKey: "AAAA" }),
        );
        expect(() => loadSession(path)).toThrow(
            new RegExp(`^Session file ${path} is corrupt: .*secretKey`),
        );
    });
});