package com.sshmanager.service;

import com.sshmanager.dto.ConnectionStatusCheckRequest;
import com.sshmanager.dto.ConnectionStatusResponseDto;
import com.sshmanager.entity.Connection;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;

import java.util.Arrays;
import java.util.Collections;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.Mockito.doAnswer;
import static org.mockito.Mockito.when;

@ExtendWith(MockitoExtension.class)
class ConnectionStatusServiceTest {

    @Mock
    private ConnectionService connectionService;

    @Mock
    private TcpProbe tcpProbe;

    private ConnectionStatusService connectionStatusService;

    @BeforeEach
    void setUp() {
        connectionStatusService = new ConnectionStatusService(connectionService, tcpProbe);
    }

    @Test
    void checkStatusesRejectsEmptyConnectionIds() {
        ConnectionStatusCheckRequest request = new ConnectionStatusCheckRequest();
        IllegalArgumentException error = assertThrows(
            IllegalArgumentException.class,
            () -> connectionStatusService.checkStatuses(1L, request)
        );
        assertEquals("At least one connection is required", error.getMessage());
    }

    @Test
    void checkStatusesMarksReachableAsOnline() throws Exception {
        Connection conn = new Connection();
        conn.setId(1L);
        conn.setUserId(99L);
        conn.setName("reachable-host");
        conn.setHost("10.0.0.1");
        conn.setPort(22);

        when(connectionService.getConnectionForSsh(1L, 99L)).thenReturn(conn);

        ConnectionStatusCheckRequest request = new ConnectionStatusCheckRequest();
        request.setConnectionIds(Arrays.asList(1L));

        ConnectionStatusResponseDto response = connectionStatusService.checkStatuses(99L, request);

        assertEquals(1, response.getTotal());
        assertEquals(1, response.getOnlineCount());
        assertEquals(0, response.getOfflineCount());
        assertEquals("online", response.getResults().get(0).getStatus());
        assertEquals("TCP port reachable", response.getResults().get(0).getMessage());
    }

    @Test
    void checkStatusesMarksUnreachableAsOffline() throws Exception {
        Connection conn = new Connection();
        conn.setId(2L);
        conn.setUserId(99L);
        conn.setName("unreachable-host");
        conn.setHost("10.0.0.2");
        conn.setPort(22);

        when(connectionService.getConnectionForSsh(2L, 99L)).thenReturn(conn);
        doAnswer(invocation -> { throw new RuntimeException("Connection refused"); })
            .when(tcpProbe).checkReachable(conn, 5);

        ConnectionStatusCheckRequest request = new ConnectionStatusCheckRequest();
        request.setConnectionIds(Arrays.asList(2L));

        ConnectionStatusResponseDto response = connectionStatusService.checkStatuses(99L, request);

        assertEquals(1, response.getTotal());
        assertEquals(0, response.getOnlineCount());
        assertEquals(1, response.getOfflineCount());
        assertEquals("offline", response.getResults().get(0).getStatus());
    }

    @Test
    void checkStatusesAggregatesMixedResults() throws Exception {
        Connection online = new Connection();
        online.setId(10L);
        online.setUserId(99L);
        online.setName("server-a");
        online.setHost("10.0.0.1");
        online.setPort(22);

        Connection offline = new Connection();
        offline.setId(20L);
        offline.setUserId(99L);
        offline.setName("server-b");
        offline.setHost("10.0.0.2");
        offline.setPort(22);

        when(connectionService.getConnectionForSsh(10L, 99L)).thenReturn(online);
        when(connectionService.getConnectionForSsh(20L, 99L)).thenReturn(offline);
        // Answer with argument matching based on connection ID
        doAnswer(invocation -> {
            Connection c = invocation.getArgument(0);
            if (c.getId() == 20L) throw new RuntimeException("Connection refused");
            return null;
        }).when(tcpProbe).checkReachable(any(Connection.class), anyInt());

        ConnectionStatusCheckRequest request = new ConnectionStatusCheckRequest();
        request.setConnectionIds(Arrays.asList(10L, 20L));

        ConnectionStatusResponseDto response = connectionStatusService.checkStatuses(99L, request);

        assertEquals(2, response.getTotal());
        assertEquals(1, response.getOnlineCount());
        assertEquals(1, response.getOfflineCount());
    }

    @Test
    void checkStatusesHandlesAllOfflineGracefully() throws Exception {
        Connection conn = new Connection();
        conn.setId(99L);
        conn.setUserId(99L);
        conn.setName("fail-host");
        conn.setHost("10.0.0.1");
        conn.setPort(22);

        when(connectionService.getConnectionForSsh(99L, 99L)).thenReturn(conn);
        doAnswer(invocation -> { throw new RuntimeException("timeout"); })
            .when(tcpProbe).checkReachable(conn, 5);

        ConnectionStatusCheckRequest request = new ConnectionStatusCheckRequest();
        request.setConnectionIds(Collections.singletonList(99L));

        ConnectionStatusResponseDto response = connectionStatusService.checkStatuses(99L, request);

        assertEquals(1, response.getTotal());
        assertEquals(0, response.getOnlineCount());
        assertEquals(1, response.getOfflineCount());
    }
}