import { afterAll, beforeEach, describe, expect, mock, test } from "bun:test";

const mockState = {
	warnings: [] as Array<{ message: string; data?: Record<string, unknown> }>,
};
const defaultRedis = { status: "ready" };

// Stub the full `Logger` shape — Bun's `mock.module` is process-wide, so
// later unit tests inherit this stub. Missing methods crash unrelated code.
const mockLogger = {
	debug: () => undefined,
	info: () => undefined,
	warn: (data: Record<string, unknown> | string, message?: string) => {
		if (typeof data === "string") {
			mockState.warnings.push({ message: data });
			return;
		}

		mockState.warnings.push({
			message: message || "",
			data,
		});
	},
	error: () => undefined,
	child: () => mockLogger,
};

mock.module("@/external/logtail/logtailUtils.js", () => ({
	logger: mockLogger,
}));

mock.module("@/external/redis/initUtils/redisConfig.js", () => ({
	hasRedisConfig: true,
}));
mock.module("@/external/redis/initUtils/redisClientRegistry.js", () => ({
	redis: defaultRedis,
}));
mock.module("@/external/redis/initRedis.js", () => ({
	redis: defaultRedis,
}));

import { RedisUnavailableError } from "@/external/redis/utils/errors.js";
import {
	tryRedisNx,
	tryRedisRead,
	tryRedisWrite,
} from "@/utils/cacheUtils/cacheUtils.js";

describe("cache utils", () => {
	beforeEach(() => {
		mockState.warnings = [];
	});

	test("tryRedisRead returns null and warns when Redis operation throws", async () => {
		const result = await tryRedisRead(
			async () => {
				throw new Error("boom");
			},
			{ status: "ready" } as never,
		);

		expect(result).toBeNull();
		expect(mockState.warnings).toHaveLength(1);
		expect(mockState.warnings[0]).toEqual({
			message: "[redis] operation unavailable",
			data: {
				source: "tryRedisRead:error",
				error: "boom",
			},
		});
	});

	test("tryRedisWrite throws RedisUnavailableError when Redis is not ready", async () => {
		const error = await tryRedisWrite(async () => "OK", {
			status: "connecting",
		} as never).catch((caught) => caught);

		expect(error).toBeInstanceOf(RedisUnavailableError);
		expect(error.reason).toBe("not_ready");
		expect(mockState.warnings).toHaveLength(1);
		expect(mockState.warnings[0]).toEqual({
			message: "[redis] operation unavailable",
			data: {
				source: "tryRedisWrite:not-ready",
				error: undefined,
			},
		});
	});

	test("tryRedisRead throws RedisUnavailableError when Redis command times out", async () => {
		const error = await tryRedisRead(
			async () => {
				throw new Error("Command timed out");
			},
			{ status: "ready" } as never,
		).catch((caught) => caught);

		expect(error).toBeInstanceOf(RedisUnavailableError);
		expect(error.reason).toBe("timeout");
	});

	test("tryRedisNx throws RedisUnavailableError on connection failures", async () => {
		const error = await tryRedisNx({
			operation: async () => {
				throw new Error("Connection is closed.");
			},
			redisInstance: { status: "ready" } as never,
			onRedisUnavailable: () => "fallback",
			onSuccess: () => "success",
			onKeyAlreadyExists: () => "exists",
		}).catch((caught) => caught);

		expect(error).toBeInstanceOf(RedisUnavailableError);
		expect(error.reason).toBe("connection");
	});

	test("tryRedisNx falls back and warns when Redis operation throws", async () => {
		const result = await tryRedisNx({
			operation: async () => {
				throw new Error("boom");
			},
			redisInstance: { status: "ready" } as never,
			onRedisUnavailable: () => "fallback",
			onSuccess: () => "success",
			onKeyAlreadyExists: () => "exists",
		});

		expect(result).toBe("fallback");
	});

	test("custom Redis failures do not mark default Redis unavailable", async () => {
		const result = await tryRedisRead(
			async () => {
				throw new Error("custom redis failed");
			},
			{ status: "ready" } as never,
		);

		expect(result).toBeNull();
	});

	test("Redis command errors do not mark Redis unavailable", async () => {
		await tryRedisWrite(async () => {
			throw new Error("ERR user_script:2: unexpected symbol near '#'");
		});

		expect(mockState.warnings).toHaveLength(1);
	});
});

afterAll(() => {
	mock.restore();
});