import { describe, it, expect, vi, beforeEach } from 'vitest';

// Mock child_process for Docker discovery
vi.mock('node:child_process', () => ({
	execFile: vi.fn()
}));

vi.mock('node:util', () => ({
	promisify: (fn: unknown) => fn
}));

// Mock appService for discoverAll
vi.mock('../appService.js', () => ({
	findAll: vi.fn()
}));

import { execFile } from 'node:child_process';
import { findAll as findAllApps } from '../appService.js';
import { discoverDocker, discoverTraefik, discoverAll } from '../discoveryService.js';

const mockExecFile = execFile as unknown as ReturnType<typeof vi.fn>;
const mockFindAllApps = findAllApps as ReturnType<typeof vi.fn>;

describe('discoveryService', () => {
	beforeEach(() => {
		vi.clearAllMocks();
	});

	describe('discoverDocker', () => {
		it('returns services from running Docker containers', async () => {
			const containers = [
				{
					Id: 'abc123',
					Names: ['/gitea'],
					Image: 'gitea/gitea:latest',
					Ports: [{ IP: '0.0.0.0', PrivatePort: 3000, PublicPort: 3000, Type: 'tcp' }],
					Labels: { 'org.opencontainers.image.description': 'Self-hosted Git' },
					State: 'running'
				}
			];

			mockExecFile.mockResolvedValue({ stdout: JSON.stringify(containers) });

			const result = await discoverDocker('/var/run/docker.sock');

			expect(result.services).toHaveLength(1);
			expect(result.services[0].name).toBe('gitea');
			expect(result.services[0].url).toBe('http://localhost:3000');
			expect(result.services[0].source).toBe('docker');
			expect(result.error).toBeUndefined();
		});

		it('extracts URL from Traefik labels in Docker containers', async () => {
			const containers = [
				{
					Id: 'def456',
					Names: ['/myapp'],
					Image: 'myapp:latest',
					Ports: [],
					Labels: {
						'traefik.http.routers.myapp.rule': 'Host(`myapp.example.com`)',
						'traefik.http.routers.myapp.entrypoints': 'websecure'
					},
					State: 'running'
				}
			];

			mockExecFile.mockResolvedValue({ stdout: JSON.stringify(containers) });

			const result = await discoverDocker('/var/run/docker.sock');

			expect(result.services).toHaveLength(1);
			expect(result.services[0].url).toBe('https://myapp.example.com');
		});

		it('skips containers without accessible URLs', async () => {
			const containers = [
				{
					Id: 'nop123',
					Names: ['/background-worker'],
					Image: 'worker:latest',
					Ports: [],
					Labels: {},
					State: 'running'
				}
			];

			mockExecFile.mockResolvedValue({ stdout: JSON.stringify(containers) });

			const result = await discoverDocker('/var/run/docker.sock');

			expect(result.services).toHaveLength(0);
		});

		it('returns error when Docker socket is inaccessible', async () => {
			mockExecFile.mockRejectedValue(new Error('connect ENOENT /var/run/docker.sock'));

			const result = await discoverDocker('/var/run/docker.sock');

			expect(result.services).toHaveLength(0);
			expect(result.error).toContain('ENOENT');
		});
	});

	describe('discoverTraefik', () => {
		// Build a Response-like object compatible with both raw fetch tests and
		// the SafeResponse wrapper used by safeFetch.
		function mockResponse(body: unknown, ok: boolean, status: number) {
			const bodyString = JSON.stringify(body);
			const bodyBytes = new TextEncoder().encode(bodyString);
			const stream = new ReadableStream<Uint8Array>({
				start(controller) {
					controller.enqueue(bodyBytes);
					controller.close();
				}
			});
			return {
				ok,
				status,
				headers: new Headers({ 'content-type': 'application/json' }),
				body: stream,
				json: () => Promise.resolve(body),
				text: () => Promise.resolve(bodyString)
			};
		}

		it('returns services from Traefik routers', async () => {
			const routers = [
				{
					name: 'myapp@docker',
					rule: 'Host(`myapp.example.com`)',
					service: 'myapp@docker',
					entryPoints: ['websecure']
				}
			];
			const services = [
				{
					name: 'myapp@docker',
					loadBalancer: { servers: [{ url: 'http://172.17.0.2:8080' }] }
				}
			];

			vi.stubGlobal(
				'fetch',
				vi.fn((url: string) => {
					if (url.includes('/api/http/routers')) {
						return Promise.resolve(mockResponse(routers, true, 200));
					}
					return Promise.resolve(mockResponse(services, true, 200));
				})
			);

			const result = await discoverTraefik('http://traefik.local:8080');

			expect(result.services).toHaveLength(1);
			expect(result.services[0].name).toBe('myapp');
			expect(result.services[0].url).toBe('https://myapp.example.com');
			expect(result.services[0].source).toBe('traefik');

			vi.unstubAllGlobals();
		});

		it('returns error on Traefik API failure', async () => {
			vi.stubGlobal(
				'fetch',
				vi.fn(() => Promise.resolve(mockResponse({}, false, 500)))
			);

			const result = await discoverTraefik('http://traefik.local:8080');

			expect(result.services).toHaveLength(0);
			expect(result.error).toContain('500');

			vi.unstubAllGlobals();
		});

		it('returns error when fetch throws', async () => {
			vi.stubGlobal(
				'fetch',
				vi.fn(() => Promise.reject(new Error('Network error')))
			);

			const result = await discoverTraefik('http://traefik.local:8080');

			expect(result.services).toHaveLength(0);
			expect(result.error).toContain('Network error');

			vi.unstubAllGlobals();
		});
	});

	describe('discoverAll', () => {
		it('marks already-registered services', async () => {
			mockExecFile.mockResolvedValue({
				stdout: JSON.stringify([
					{
						Id: 'c1',
						Names: ['/gitea'],
						Image: 'gitea/gitea',
						Ports: [{ IP: '0.0.0.0', PrivatePort: 3000, PublicPort: 3000, Type: 'tcp' }],
						Labels: {},
						State: 'running'
					}
				])
			});

			mockFindAllApps.mockResolvedValue([
				{ id: 'a1', name: 'Gitea', url: 'http://localhost:3000' }
			]);

			const result = await discoverAll({ dockerSocketPath: '/var/run/docker.sock' });

			expect(result.services).toHaveLength(1);
			expect(result.services[0].alreadyRegistered).toBe(true);
		});

		it('deduplicates by URL preferring Traefik', async () => {
			mockExecFile.mockResolvedValue({
				stdout: JSON.stringify([
					{
						Id: 'c1',
						Names: ['/app'],
						Image: 'app:latest',
						Ports: [],
						Labels: {
							'traefik.http.routers.app.rule': 'Host(`app.example.com`)'
						},
						State: 'running'
					}
				])
			});

			vi.stubGlobal(
				'fetch',
				vi.fn((url: string) => {
					if (url.includes('/api/http/routers')) {
						return Promise.resolve({
							ok: true,
							json: () =>
								Promise.resolve([
									{
										name: 'app@docker',
										rule: 'Host(`app.example.com`)',
										service: 'app@docker',
										entryPoints: ['web']
									}
								])
						});
					}
					return Promise.resolve({ ok: true, json: () => Promise.resolve([]) });
				})
			);

			mockFindAllApps.mockResolvedValue([]);

			const result = await discoverAll({
				dockerSocketPath: '/var/run/docker.sock',
				traefikApiUrl: 'http://traefik.local:8080'
			});

			// Should deduplicate: both Docker (via label) and Traefik discover http://app.example.com
			const urls = result.services.map((s) => s.url);
			const unique = new Set(urls);
			expect(urls.length).toBe(unique.size);

			vi.unstubAllGlobals();
		});

		it('returns empty when no sources configured', async () => {
			mockFindAllApps.mockResolvedValue([]);

			const result = await discoverAll({});

			expect(result.services).toHaveLength(0);
			expect(result.errors).toHaveLength(0);
		});
	});
});