package com.reportdist.service;

import com.reportdist.dto.ProjectRequest;
import com.reportdist.dto.ProjectResponse;
import com.reportdist.entity.Project;
import com.reportdist.repository.ProjectRepository;
import com.reportdist.repository.ReportRepository;
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.time.LocalDateTime;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import static org.junit.jupiter.api.Assertions.*;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.Mockito.*;

@ExtendWith(MockitoExtension.class)
class ProjectServiceTest {

    @Mock
    private ProjectRepository projectRepository;

    @Mock
    private ReportRepository reportRepository;

    private ProjectService projectService;

    @BeforeEach
    void setUp() {
        projectService = new ProjectService(projectRepository, reportRepository);
    }

    // ==================== createProject Tests ====================

    @Test
    void createProject_shouldCreateAndReturnProject() {
        // Given
        ProjectRequest request = new ProjectRequest("Test Project", "Test Description");
        Project savedProject = new Project(1L, "Test Project", "Test Description", LocalDateTime.now());

        when(projectRepository.save(any(Project.class))).thenReturn(savedProject);

        // When
        ProjectResponse response = projectService.createProject(request);

        // Then
        assertNotNull(response);
        assertEquals(1L, response.getId());
        assertEquals("Test Project", response.getName());
        assertEquals("Test Description", response.getDescription());
        verify(projectRepository, times(1)).save(any(Project.class));
    }

    @Test
    void createProject_shouldHandleDuplicateName() {
        // Given - Note: The service doesn't explicitly handle duplicates,
        // but we test the normal flow still works
        ProjectRequest request = new ProjectRequest("Duplicate Project", "Description");
        Project savedProject = new Project(2L, "Duplicate Project", "Description", LocalDateTime.now());

        when(projectRepository.save(any(Project.class))).thenReturn(savedProject);

        // When
        ProjectResponse response = projectService.createProject(request);

        // Then
        assertNotNull(response);
        assertEquals("Duplicate Project", response.getName());
        verify(projectRepository, times(1)).save(any(Project.class));
    }

    // ==================== getAllProjects Tests ====================

    @Test
    void getAllProjects_shouldReturnEmptyList() {
        // Given
        when(projectRepository.findAll()).thenReturn(Collections.emptyList());

        // When
        List<ProjectResponse> result = projectService.getAllProjects();

        // Then
        assertNotNull(result);
        assertTrue(result.isEmpty());
    }

    @Test
    void getAllProjects_shouldReturnSingleProject() {
        // Given
        Project project = new Project(1L, "Single Project", "Description", LocalDateTime.now());
        when(projectRepository.findAll()).thenReturn(Collections.singletonList(project));

        // When
        List<ProjectResponse> result = projectService.getAllProjects();

        // Then
        assertNotNull(result);
        assertEquals(1, result.size());
        assertEquals("Single Project", result.get(0).getName());
    }

    @Test
    void getAllProjects_shouldReturnMultipleProjects() {
        // Given
        Project project1 = new Project(1L, "Project One", "Description 1", LocalDateTime.now());
        Project project2 = new Project(2L, "Project Two", "Description 2", LocalDateTime.now());
        Project project3 = new Project(3L, "Project Three", "Description 3", LocalDateTime.now());
        when(projectRepository.findAll()).thenReturn(Arrays.asList(project1, project2, project3));

        // When
        List<ProjectResponse> result = projectService.getAllProjects();

        // Then
        assertNotNull(result);
        assertEquals(3, result.size());
        assertEquals("Project One", result.get(0).getName());
        assertEquals("Project Two", result.get(1).getName());
        assertEquals("Project Three", result.get(2).getName());
    }

    // ==================== updateProject Tests ====================

    @Test
    void updateProject_shouldUpdateAndReturnProject() {
        // Given
        Long projectId = 1L;
        ProjectRequest request = new ProjectRequest("Updated Name", "Updated Description");
        Project existingProject = new Project(1L, "Original Name", "Original Description", LocalDateTime.now());
        Project updatedProject = new Project(1L, "Updated Name", "Updated Description", existingProject.getCreatedAt());

        when(projectRepository.findById(projectId)).thenReturn(java.util.Optional.of(existingProject));
        when(projectRepository.save(any(Project.class))).thenReturn(updatedProject);

        // When
        ProjectResponse response = projectService.updateProject(projectId, request);

        // Then
        assertNotNull(response);
        assertEquals("Updated Name", response.getName());
        assertEquals("Updated Description", response.getDescription());
        verify(projectRepository, times(1)).findById(projectId);
        verify(projectRepository, times(1)).save(any(Project.class));
    }

    @Test
    void updateProject_shouldThrowExceptionWhenNotFound() {
        // Given
        Long projectId = 999L;
        ProjectRequest request = new ProjectRequest("Updated Name", "Updated Description");

        when(projectRepository.findById(projectId)).thenReturn(java.util.Optional.empty());

        // When & Then
        RuntimeException exception = assertThrows(RuntimeException.class, () -> {
            projectService.updateProject(projectId, request);
        });

        assertTrue(exception.getMessage().contains("Project not found"));
        verify(projectRepository, times(1)).findById(projectId);
        verify(projectRepository, never()).save(any(Project.class));
    }

    @Test
    void getAllProjects_shouldIncludeReportCount() {
        // Given
        Project project1 = new Project(1L, "Project One", "Description 1", LocalDateTime.now());
        Project project2 = new Project(2L, "Project Two", "Description 2", LocalDateTime.now());
        when(projectRepository.findAll()).thenReturn(Arrays.asList(project1, project2));
        when(reportRepository.countByProjectId(1L)).thenReturn(5L);
        when(reportRepository.countByProjectId(2L)).thenReturn(3L);

        // When
        List<ProjectResponse> result = projectService.getAllProjects();

        // Then
        assertNotNull(result);
        assertEquals(2, result.size());
        assertEquals(5L, result.get(0).getReportCount());
        assertEquals(3L, result.get(1).getReportCount());
        verify(reportRepository, times(1)).countByProjectId(1L);
        verify(reportRepository, times(1)).countByProjectId(2L);
    }

    @Test
    void getProjectById_shouldIncludeReportCount() {
        // Given
        Long projectId = 1L;
        Project project = new Project(1L, "Test Project", "Description", LocalDateTime.now());
        when(projectRepository.findById(projectId)).thenReturn(java.util.Optional.of(project));
        when(reportRepository.countByProjectId(projectId)).thenReturn(10L);

        // When
        ProjectResponse response = projectService.getProjectById(projectId);

        // Then
        assertNotNull(response);
        assertEquals(10L, response.getReportCount());
        verify(reportRepository, times(1)).countByProjectId(projectId);
    }

    @Test
    void getAllProjects_withNoReports_shouldHaveZeroReportCount() {
        // Given
        Project project = new Project(1L, "Empty Project", "No reports", LocalDateTime.now());
        when(projectRepository.findAll()).thenReturn(Collections.singletonList(project));
        when(reportRepository.countByProjectId(1L)).thenReturn(0L);

        // When
        List<ProjectResponse> result = projectService.getAllProjects();

        // Then
        assertNotNull(result);
        assertEquals(1, result.size());
        assertEquals(0L, result.get(0).getReportCount());
    }

    @Test
    void updateProject_withMultipartCoverImage_shouldReturnUpdatedProjectWithReportCount() {
        // Given
        Long projectId = 1L;
        Project existingProject = new Project(1L, "Original Name", "Description", LocalDateTime.now());
        Project updatedProject = new Project(1L, "Updated Name", "Description", existingProject.getCreatedAt());
        updatedProject.setCoverImage("/uploads/covers/1/test.png");

        when(projectRepository.findById(projectId)).thenReturn(java.util.Optional.of(existingProject));
        when(projectRepository.save(any(Project.class))).thenReturn(updatedProject);
        when(reportRepository.countByProjectId(projectId)).thenReturn(5L);

        // When
        ProjectResponse response = projectService.updateProject(projectId, "Updated Name", null, null);

        // Then
        assertNotNull(response);
        assertEquals(5L, response.getReportCount());
        verify(reportRepository, times(1)).countByProjectId(projectId);
    }

    // ==================== deleteProject Tests ====================

    @Test
    void deleteProject_shouldDeleteSuccessfully() {
        // Given
        Long projectId = 1L;
        when(projectRepository.existsById(projectId)).thenReturn(true);
        doNothing().when(projectRepository).deleteById(projectId);

        // When
        projectService.deleteProject(projectId);

        // Then
        verify(projectRepository, times(1)).existsById(projectId);
        verify(projectRepository, times(1)).deleteById(projectId);
    }

    @Test
    void deleteProject_shouldThrowExceptionWhenNotFound() {
        // Given
        Long projectId = 999L;
        when(projectRepository.existsById(projectId)).thenReturn(false);

        // When & Then
        RuntimeException exception = assertThrows(RuntimeException.class, () -> {
            projectService.deleteProject(projectId);
        });

        assertTrue(exception.getMessage().contains("Project not found"));
        verify(projectRepository, times(1)).existsById(projectId);
        verify(projectRepository, never()).deleteById(any());
    }
}