import { describe, expect, it, jest } from "@jest/globals";
import { DockerProvider } from "../../../../src/service/network/DockerProvider.ts";
import { testStatusProviderContract } from "../../../helpers/statusProviderContract.ts";
import { createMockLogger } from "../../../helpers/createMockLogger.ts";
import { NETWORK_ERROR } from "../../../../src/types/network.ts";
import { AppError } from "../../../../src/utils/AppError.ts";
import type { Monitor } from "../../../../src/domain/monitors/monitor.type.ts";

// ── Fixtures ─────────────────────────────────────────────────────────────────

const PRIVATE_KEY = "-----BEGIN OPENSSH PRIVATE KEY-----\nfake\n-----END OPENSSH PRIVATE KEY-----";

const makeMonitor = (overrides?: Partial<Monitor>): Monitor =>
	({
		id: "mon-1",
		teamId: "team-1",
		type: "docker",
		url: "unix:///var/run/docker.sock",
		...overrides,
	}) as Monitor;

const makeContainer = (overrides?: Record<string, any>) => ({
	Id: "abc123def456abc123def456abc123def456abc123def456abc123def456abcd",
	Names: ["/my-container"],
	Image: "nginx:latest",
	State: "running",
	Status: "Up 3 hours (healthy)",
	...overrides,
});

const makeInspect = (overrides?: Record<string, any>) => ({
	RestartCount: 2,
	State: { StartedAt: "2026-08-28T10:00:00.000Z", Health: { Status: "healthy" } },
	...overrides,
});

// cpuDelta 200M over systemDelta 1000M on 4 cpus → 80%; memory 300MiB raw - 100MiB page cache = 200MiB of 1GiB → 19.53125%
const makeStats = (overrides?: Record<string, any>) => ({
	cpu_stats: {
		cpu_usage: { total_usage: 400_000_000 },
		system_cpu_usage: 2_000_000_000,
		online_cpus: 4,
	},
	precpu_stats: {
		cpu_usage: { total_usage: 200_000_000 },
		system_cpu_usage: 1_000_000_000,
	},
	memory_stats: {
		usage: 300 * 1024 * 1024,
		limit: 1024 * 1024 * 1024,
		stats: { inactive_file: 100 * 1024 * 1024 },
	},
	...overrides,
});

const setup = (overrides: Partial<{ ping: any; listContainers: any; getContainer: any; inspect: any; stats: any }> = {}) => {
	const inspect = overrides.inspect ?? jest.fn().mockResolvedValue(makeInspect());
	const stats = overrides.stats ?? jest.fn().mockResolvedValue(makeStats());
	const getContainer = overrides.getContainer ?? jest.fn().mockReturnValue({ inspect, stats });
	const instance = {
		ping: overrides.ping ?? jest.fn().mockResolvedValue("OK"),
		listContainers: overrides.listContainers ?? jest.fn().mockResolvedValue([makeContainer()]),
		getContainer,
	};
	const DockerLib = jest.fn().mockReturnValue(instance) as any;
	const logger = createMockLogger();
	const provider = new DockerProvider(logger as any, DockerLib);
	return { provider, logger, DockerLib, ping: instance.ping, listContainers: instance.listContainers, getContainer, inspect, stats };
};

// ── Contract ─────────────────────────────────────────────────────────────────

testStatusProviderContract("DockerProvider", {
	create: () => setup().provider,
	supportedType: "docker",
	unsupportedType: "http",
	makeMonitor: () => makeMonitor(),
});

// ── Tests ────────────────────────────────────────────────────────────────────

describe("DockerProvider", () => {
	// ── Host url parsing ─────────────────────────────────────────────────

	describe("host url parsing", () => {
		it("parses unix:// urls into socketPath", async () => {
			const { provider, DockerLib } = setup();

			await provider.handle(makeMonitor({ url: "unix:///run/docker.sock" }));

			expect(DockerLib).toHaveBeenCalledWith({ socketPath: "/run/docker.sock" });
		});

		it("parses bare absolute paths into socketPath", async () => {
			const { provider, DockerLib } = setup();

			await provider.handle(makeMonitor({ url: "/var/run/docker.sock" }));

			expect(DockerLib).toHaveBeenCalledWith({ socketPath: "/var/run/docker.sock" });
		});

		it("trims surrounding whitespace", async () => {
			const { provider, DockerLib } = setup();

			await provider.handle(makeMonitor({ url: "  /var/run/docker.sock  " }));

			expect(DockerLib).toHaveBeenCalledWith({ socketPath: "/var/run/docker.sock" });
		});

		it("parses ssh urls with a private key, defaulting to port 22", async () => {
			const { provider, DockerLib } = setup();

			await provider.handle(makeMonitor({ url: "ssh://deploy@prod-swarm-01.internal", sshPrivateKey: PRIVATE_KEY }));

			expect(DockerLib).toHaveBeenCalledWith({
				protocol: "ssh",
				host: "prod-swarm-01.internal",
				port: 22,
				username: "deploy",
				sshOptions: { privateKey: PRIVATE_KEY },
			});
		});

		it("parses an explicit ssh port", async () => {
			const { provider, DockerLib } = setup();

			await provider.handle(makeMonitor({ url: "ssh://deploy@host:2222", sshPrivateKey: PRIVATE_KEY }));

			expect(DockerLib).toHaveBeenCalledWith(expect.objectContaining({ port: 2222 }));
		});
	});

	// ── Fail-loudly url validation ───────────────────────────────────────

	describe("invalid host urls", () => {
		const invalidUrls: [label: string, url: string, message: string][] = [
			["empty url", "", "Docker host URL is required"],
			["unix:// with an empty path", "unix://", "Invalid Docker host URL"],
			["unix:// with a relative path", "unix://run/docker.sock", "Invalid Docker host URL"],
			["garbage", "not-a-url", "Invalid Docker host URL"],
			["a container name (old semantics)", "my-container", "Invalid Docker host URL"],
			["tcp engine urls (unsupported)", "tcp://host:2375", "Invalid Docker host URL"],
			["https engine urls (unsupported)", "https://host", "Invalid Docker host URL"],
			["ssh without a user", "ssh://host", "SSH Docker host URL requires a user: ssh://user@host"],
		];

		it.each(invalidUrls)("throws AppError for %s and never constructs a client", async (_label, url, message) => {
			const { provider, DockerLib } = setup();

			await expect(provider.handle(makeMonitor({ url }))).rejects.toThrow(message);
			expect(DockerLib).not.toHaveBeenCalled();
		});

		it("throws AppError for an ssh url with no private key", async () => {
			const { provider, DockerLib } = setup();

			await expect(provider.handle(makeMonitor({ url: "ssh://deploy@host", sshPrivateKey: undefined }))).rejects.toThrow(
				"SSH Docker host requires a private key"
			);
			expect(DockerLib).not.toHaveBeenCalled();
		});

		it("preserves the toDockerOptions AppError through handle's catch", async () => {
			const { provider } = setup();

			await expect(provider.handle(makeMonitor({ url: "not-a-url" }))).rejects.toMatchObject({
				service: "DockerProvider",
				method: "toDockerOptions",
				status: 422,
			});
			await expect(provider.handle(makeMonitor({ url: "not-a-url" }))).rejects.toBeInstanceOf(AppError);
		});
	});

	// ── Host reachability ────────────────────────────────────────────────

	describe("host reachability", () => {
		it("returns a down check with NETWORK_ERROR when ping rejects with a plain Error", async () => {
			const { provider, listContainers } = setup({ ping: jest.fn().mockRejectedValue(new Error("ECONNREFUSED")) });

			const result = await provider.handle(makeMonitor());

			expect(result.status).toBe(false);
			expect(result.code).toBe(NETWORK_ERROR);
			expect(result.message).toBe("ECONNREFUSED");
			expect(result.payload).toBeNull();
			expect(listContainers).not.toHaveBeenCalled();
		});

		it("uses the DockerError statusCode and json message when ping rejects with one", async () => {
			const dockerErr = Object.assign(new Error("base"), { statusCode: 500, json: { message: "engine exploded" } });
			const { provider } = setup({ ping: jest.fn().mockRejectedValue(dockerErr) });

			const result = await provider.handle(makeMonitor());

			expect(result.code).toBe(500);
			expect(result.message).toBe("engine exploded");
		});

		it("falls back to the DockerError reason when json has no message", async () => {
			const dockerErr = Object.assign(new Error("base"), { statusCode: 500, reason: "server error", json: {} });
			const { provider } = setup({ ping: jest.fn().mockRejectedValue(dockerErr) });

			const result = await provider.handle(makeMonitor());

			expect(result.message).toBe("server error");
		});

		it("uses the default message when ping rejects with a non-Error", async () => {
			const { provider } = setup({ ping: jest.fn().mockRejectedValue("nope") });

			const result = await provider.handle(makeMonitor());

			expect(result.status).toBe(false);
			expect(result.message).toBe("Docker host is unreachable");
		});
	});

	// ── Happy path ───────────────────────────────────────────────────────

	describe("container payload", () => {
		it("returns an up check with enriched containers and summary counts", async () => {
			const { provider } = setup();

			const result = await provider.handle(makeMonitor());

			expect(result.status).toBe(true);
			expect(result.code).toBe(200);
			expect(result.message).toBe("Docker host is reachable");
			expect(result.payload?.summary).toEqual({ total: 1, running: 1, stopped: 0, unhealthy: 0 });
			expect(result.payload?.containers[0]).toEqual(
				expect.objectContaining({
					id: makeContainer().Id,
					name: "my-container",
					image: "nginx:latest",
					state: "running",
					status: "Up 3 hours (healthy)",
					health: "healthy",
					restartCount: 2,
					startedAt: "2026-08-28T10:00:00.000Z",
				})
			);
		});

		it("counts running, stopped, and unhealthy states in the summary", async () => {
			const containers = [
				makeContainer({ Id: "a".repeat(64) }),
				makeContainer({ Id: "b".repeat(64), State: "exited" }),
				makeContainer({ Id: "c".repeat(64), State: "dead" }),
				makeContainer({ Id: "d".repeat(64), State: "paused" }),
			];
			const inspect = jest.fn().mockResolvedValue(makeInspect({ State: { Health: { Status: "unhealthy" } } }));
			const { provider } = setup({ listContainers: jest.fn().mockResolvedValue(containers), inspect });

			const result = await provider.handle(makeMonitor());

			expect(result.payload?.summary).toEqual({ total: 4, running: 1, stopped: 2, unhealthy: 4 });
		});

		it("falls back to a truncated id when a container has no name", async () => {
			const container = makeContainer({ Names: [] });
			const { provider } = setup({ listContainers: jest.fn().mockResolvedValue([container]) });

			const result = await provider.handle(makeMonitor());

			expect(result.payload?.containers[0]?.name).toBe(container.Id.slice(0, 12));
		});

		it("clamps unknown container states and health statuses", async () => {
			const container = makeContainer({ State: "warp-speed" });
			const inspect = jest.fn().mockResolvedValue(makeInspect({ State: { Health: { Status: "confused" } } }));
			const { provider } = setup({ listContainers: jest.fn().mockResolvedValue([container]), inspect });

			const result = await provider.handle(makeMonitor());

			expect(result.payload?.containers[0]?.state).toBe("created");
			expect(result.payload?.containers[0]?.health).toBe("none");
		});
	});

	// ── Enrichment fault isolation ───────────────────────────────────────

	describe("enrichment fault isolation", () => {
		it("keeps the container and the up status when inspect rejects", async () => {
			const inspect = jest.fn().mockRejectedValue(new Error("inspect failed"));
			const { provider, logger } = setup({ inspect });

			const result = await provider.handle(makeMonitor());

			expect(result.status).toBe(true);
			expect(result.payload?.containers).toHaveLength(1);
			expect(result.payload?.containers[0]).toEqual(expect.objectContaining({ health: "none" }));
			expect(result.payload?.containers[0]?.restartCount).toBeUndefined();
			expect(logger.warn).toHaveBeenCalledWith(expect.objectContaining({ message: expect.stringContaining("Failed to inspect") }));
		});

		it("keeps the container without metrics when stats rejects", async () => {
			const stats = jest.fn().mockRejectedValue(new Error("stats failed"));
			const { provider } = setup({ stats });

			const result = await provider.handle(makeMonitor());

			expect(result.status).toBe(true);
			expect(result.payload?.containers[0]?.cpuPct).toBeUndefined();
			expect(result.payload?.containers[0]?.memoryUsedBytes).toBeUndefined();
		});

		it("only requests stats for running containers", async () => {
			const containers = [makeContainer({ Id: "a".repeat(64) }), makeContainer({ Id: "b".repeat(64), State: "exited" })];
			const { provider, stats } = setup({ listContainers: jest.fn().mockResolvedValue(containers) });

			await provider.handle(makeMonitor());

			expect(stats).toHaveBeenCalledTimes(1);
		});
	});

	// ── Metric math ──────────────────────────────────────────────────────

	describe("metric math", () => {
		it("computes cpu and memory percentages from cgroup v2 stats", async () => {
			const { provider } = setup();

			const result = await provider.handle(makeMonitor());
			const container = result.payload?.containers[0];

			expect(container?.cpuPct).toBeCloseTo(0.8);
			expect(container?.memoryUsedBytes).toBe(200 * 1024 * 1024);
			expect(container?.memoryLimitBytes).toBe(1024 * 1024 * 1024);
			expect(container?.memoryPct).toBeCloseTo(0.1953125);
		});

		it("falls back to the cgroup v1 cache field for page cache", async () => {
			const stats = jest
				.fn()
				.mockResolvedValue(makeStats({ memory_stats: { usage: 300 * 1024 * 1024, limit: 1024 * 1024 * 1024, stats: { cache: 50 * 1024 * 1024 } } }));
			const { provider } = setup({ stats });

			const result = await provider.handle(makeMonitor());

			expect(result.payload?.containers[0]?.memoryUsedBytes).toBe(250 * 1024 * 1024);
		});

		it("derives cpu count from percpu_usage when online_cpus is absent", async () => {
			const stats = jest.fn().mockResolvedValue(
				makeStats({
					cpu_stats: { cpu_usage: { total_usage: 400_000_000, percpu_usage: [1, 2] }, system_cpu_usage: 2_000_000_000 },
				})
			);
			const { provider } = setup({ stats });

			const result = await provider.handle(makeMonitor());

			expect(result.payload?.containers[0]?.cpuPct).toBeCloseTo(0.4);
		});

		it("returns 0 cpu when the system delta is not positive", async () => {
			const stats = jest
				.fn()
				.mockResolvedValue(makeStats({ precpu_stats: { cpu_usage: { total_usage: 200_000_000 }, system_cpu_usage: 2_000_000_000 } }));
			const { provider } = setup({ stats });

			const result = await provider.handle(makeMonitor());

			expect(result.payload?.containers[0]?.cpuPct).toBe(0);
		});

		it("returns 0 memory percent when there is no limit", async () => {
			const stats = jest.fn().mockResolvedValue(makeStats({ memory_stats: { usage: 300 * 1024 * 1024, limit: 0, stats: {} } }));
			const { provider } = setup({ stats });

			const result = await provider.handle(makeMonitor());

			expect(result.payload?.containers[0]?.memoryPct).toBe(0);
		});
	});

	// ── Outer error handling ─────────────────────────────────────────────

	describe("outer error handling", () => {
		it("throws AppError when listContainers rejects after a successful ping", async () => {
			const { provider } = setup({ listContainers: jest.fn().mockRejectedValue(new Error("Docker daemon unavailable")) });

			await expect(provider.handle(makeMonitor())).rejects.toThrow("Docker daemon unavailable");
		});

		it("throws AppError with the default message for non-Error thrown values", async () => {
			const { provider } = setup({ listContainers: jest.fn().mockRejectedValue(null) });

			await expect(provider.handle(makeMonitor())).rejects.toThrow("Error performing Docker request");
		});
	});
});