package com.dalab.autodelete.service.impl;

import com.dalab.autodelete.dto.*;
import com.dalab.autodelete.mapper.DeletionTaskMapper;
import com.dalab.autodelete.model.DeletionStatus;
import com.dalab.autodelete.model.DeletionTaskEntity;
import com.dalab.autodelete.repository.DeletionTaskRepository;
import com.dalab.autodelete.service.IDeletionConfigService;
import com.dalab.autodelete.service.exception.DeletionTaskNotFoundException;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.ArgumentCaptor;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.junit.jupiter.MockitoExtension;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Optional;
import java.util.UUID;

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

@ExtendWith(MockitoExtension.class)
class DeletionTaskServiceImplTest {

    @Mock
    private DeletionTaskRepository taskRepository;

    @Mock
    private DeletionTaskMapper taskMapper;

    @Mock
    private IDeletionConfigService deletionConfigService;

    @InjectMocks
    private DeletionTaskServiceImpl taskService;

    private DeletionTaskRequest sampleTaskRequest;
    private DeletionTaskEntity sampleTaskEntity;
    private DeletionTaskStatusDTO sampleTaskStatusDTO;
    private DeletionTaskResponse sampleTaskResponse;
    private DeletionConfigDTO globalConfigDefault;
    private DeletionConfigDTO globalConfigSoftDeleteApproval;
    private String sampleTaskId;

    @BeforeEach
    void setUp() {
        sampleTaskId = UUID.randomUUID().toString();
        DeletionTaskRequest.DeletionScope scope = DeletionTaskRequest.DeletionScope.builder()
                .assetIds(List.of("asset1")).build();

        sampleTaskRequest = DeletionTaskRequest.builder()
                .taskName("Test Task")
                .scope(scope)
                .triggeredBy("user@test.com")
                .build();

        sampleTaskEntity = new DeletionTaskEntity();
        sampleTaskEntity.setTaskId(sampleTaskId);
        sampleTaskEntity.setTaskName("Test Task");
        sampleTaskEntity.setStatus(DeletionStatus.SUBMITTED);
        sampleTaskEntity.setSubmittedAt(LocalDateTime.now());
        sampleTaskEntity.setScope(new DeletionTaskEntity.DeletionScopeData(List.of("asset1")));
        sampleTaskEntity.setAssetStatuses(new ArrayList<>());

        sampleTaskStatusDTO = DeletionTaskStatusDTO.builder().taskId(sampleTaskId).status(DeletionStatus.SUBMITTED.name()).build();
        sampleTaskResponse = DeletionTaskResponse.builder().taskId(sampleTaskId).status(DeletionStatus.SUBMITTED.name()).build();
        
        globalConfigDefault = DeletionConfigDTO.builder()
                                .enabled(true)
                                .softDeleteByDefault(false) // Hard delete by default
                                .requireApprovalForHardDelete(false) // No approval for hard delete
                                .requireApprovalForSoftDelete(true) // Approval for soft delete
                                .build();
        
        globalConfigSoftDeleteApproval = DeletionConfigDTO.builder()
                                .enabled(true)
                                .softDeleteByDefault(true) // Soft delete by default
                                .requireApprovalForHardDelete(true) // Approval for hard delete
                                .requireApprovalForSoftDelete(true) // Approval for soft delete
                                .build();
    }

    @Test
    void submitDeletionTask_ValidRequest_NoApprovalNeeded_ShouldSaveAndReturnResponse() {
        when(deletionConfigService.getDeletionConfig()).thenReturn(globalConfigDefault);
        when(taskMapper.requestToEntity(sampleTaskRequest)).thenReturn(sampleTaskEntity); // sampleTaskEntity is already set up
        when(taskRepository.save(any(DeletionTaskEntity.class))).thenReturn(sampleTaskEntity);
        when(taskMapper.entityToTaskResponse(sampleTaskEntity)).thenReturn(sampleTaskResponse);

        DeletionTaskResponse response = taskService.submitDeletionTask(sampleTaskRequest);

        assertNotNull(response);
        assertEquals(DeletionStatus.SUBMITTED.name(), response.getStatus());
        ArgumentCaptor<DeletionTaskEntity> entityCaptor = ArgumentCaptor.forClass(DeletionTaskEntity.class);
        verify(taskRepository).save(entityCaptor.capture());
        assertEquals(DeletionStatus.SUBMITTED, entityCaptor.getValue().getStatus());
        assertNotNull(entityCaptor.getValue().getAssetStatuses());
        assertEquals(1, entityCaptor.getValue().getAssetsPendingProcessing());
        assertEquals("HARD", entityCaptor.getValue().getAssetStatuses().get(0).getDeletionType());
    }
    
    @Test
    void submitDeletionTask_RequiresHardDeleteApproval_ShouldSetPendingApproval() {
        DeletionConfigDTO config = DeletionConfigDTO.builder().softDeleteByDefault(false).requireApprovalForHardDelete(true).build();
        when(deletionConfigService.getDeletionConfig()).thenReturn(config);
        when(taskMapper.requestToEntity(sampleTaskRequest)).thenReturn(sampleTaskEntity);
        when(taskRepository.save(any(DeletionTaskEntity.class))).thenReturn(sampleTaskEntity);

        taskService.submitDeletionTask(sampleTaskRequest);

        ArgumentCaptor<DeletionTaskEntity> entityCaptor = ArgumentCaptor.forClass(DeletionTaskEntity.class);
        verify(taskRepository).save(entityCaptor.capture());
        assertEquals(DeletionStatus.PENDING_APPROVAL, entityCaptor.getValue().getStatus());
    }

    @Test
    void submitDeletionTask_SoftDeleteOverride_RequiresSoftApproval_ShouldSetPendingApproval() {
        sampleTaskRequest.setOverrideConfig(DeletionTaskRequest.DeletionConfigOverride.builder().softDelete(true).build());
        when(deletionConfigService.getDeletionConfig()).thenReturn(globalConfigSoftDeleteApproval);
        when(taskMapper.requestToEntity(sampleTaskRequest)).thenReturn(sampleTaskEntity);
        when(taskRepository.save(any(DeletionTaskEntity.class))).thenReturn(sampleTaskEntity);

        taskService.submitDeletionTask(sampleTaskRequest);
        ArgumentCaptor<DeletionTaskEntity> entityCaptor = ArgumentCaptor.forClass(DeletionTaskEntity.class);
        verify(taskRepository).save(entityCaptor.capture());
        assertEquals(DeletionStatus.PENDING_APPROVAL, entityCaptor.getValue().getStatus());
         assertEquals("SOFT", entityCaptor.getValue().getAssetStatuses().get(0).getDeletionType());
    }

    @Test
    void submitDeletionTask_InvalidScope_ShouldReturnFailedStatus() {
        DeletionTaskRequest invalidRequest = DeletionTaskRequest.builder().taskName("Invalid").scope(null).build();
        DeletionTaskResponse response = taskService.submitDeletionTask(invalidRequest);
        assertEquals(DeletionStatus.FAILED.name(), response.getStatus());
        verify(taskRepository, never()).save(any());
    }

    @Test
    void getTaskStatus_TaskExists_ShouldReturnDTO() {
        when(taskRepository.findById(sampleTaskId)).thenReturn(Optional.of(sampleTaskEntity));
        when(taskMapper.entityToStatusDTO(sampleTaskEntity)).thenReturn(sampleTaskStatusDTO);

        DeletionTaskStatusDTO result = taskService.getTaskStatus(sampleTaskId);

        assertNotNull(result);
        assertEquals(sampleTaskId, result.getTaskId());
    }

    @Test
    void getTaskStatus_TaskNotExists_ShouldReturnNull() {
        when(taskRepository.findById(sampleTaskId)).thenReturn(Optional.empty());
        DeletionTaskStatusDTO result = taskService.getTaskStatus(sampleTaskId);
        assertNull(result);
    }

    @Test
    void listTasks_ShouldReturnPaginatedDTOs() {
        Pageable pageable = PageRequest.of(0, 10);
        List<DeletionTaskEntity> taskList = Collections.singletonList(sampleTaskEntity);
        Page<DeletionTaskEntity> page = new PageImpl<>(taskList, pageable, 1);
        when(taskRepository.findAll(pageable)).thenReturn(page);
        when(taskMapper.entityToStatusDTO(sampleTaskEntity)).thenReturn(sampleTaskStatusDTO);

        DeletionTaskListResponse response = taskService.listTasks(pageable);

        assertNotNull(response);
        assertEquals(1, response.getTasks().size());
        assertEquals(sampleTaskId, response.getTasks().get(0).getTaskId());
    }

    @Test
    void approveTask_TaskExistsAndPending_ShouldApprove() {
        sampleTaskEntity.setStatus(DeletionStatus.PENDING_APPROVAL);
        when(taskRepository.findById(sampleTaskId)).thenReturn(Optional.of(sampleTaskEntity));
        when(taskRepository.save(any(DeletionTaskEntity.class))).thenReturn(sampleTaskEntity);
        when(taskMapper.entityToStatusDTO(any(DeletionTaskEntity.class))).thenAnswer(invocation -> {
            DeletionTaskEntity entity = invocation.getArgument(0);
            return DeletionTaskStatusDTO.builder().taskId(entity.getTaskId()).status(entity.getStatus().name()).build();
        });

        TaskApprovalRequest approvalReq = TaskApprovalRequest.builder().comments("Approved by test").build();
        DeletionTaskStatusDTO result = taskService.approveTask(sampleTaskId, approvalReq);

        assertEquals(DeletionStatus.APPROVED.name(), result.getStatus());
        assertEquals("Approved by test", sampleTaskEntity.getApprovalComments());
        verify(taskRepository).save(sampleTaskEntity);
    }

    @Test
    void approveTask_TaskNotPending_ShouldReturnCurrentStatusWithErrors() {
        sampleTaskEntity.setStatus(DeletionStatus.COMPLETED);
        when(taskRepository.findById(sampleTaskId)).thenReturn(Optional.of(sampleTaskEntity));
        // Mapper will be called to return the current DTO
        when(taskMapper.entityToStatusDTO(sampleTaskEntity)).thenReturn(DeletionTaskStatusDTO.builder().taskId(sampleTaskId).status(DeletionStatus.COMPLETED.name()).build());

        DeletionTaskStatusDTO result = taskService.approveTask(sampleTaskId, new TaskApprovalRequest());

        assertEquals(DeletionStatus.COMPLETED.name(), result.getStatus());
        assertNotNull(result.getErrorMessages());
        assertFalse(result.getErrorMessages().isEmpty());
        verify(taskRepository, never()).save(any());
    }
    
    @Test
    void approveTask_TaskNotFound_ShouldThrowException() {
        when(taskRepository.findById(sampleTaskId)).thenReturn(Optional.empty());
        assertThrows(DeletionTaskNotFoundException.class, () -> {
            taskService.approveTask(sampleTaskId, new TaskApprovalRequest());
        });
    }

    @Test
    void rejectTask_TaskExistsAndPending_ShouldReject() {
        sampleTaskEntity.setStatus(DeletionStatus.PENDING_APPROVAL);
        when(taskRepository.findById(sampleTaskId)).thenReturn(Optional.of(sampleTaskEntity));
        when(taskRepository.save(any(DeletionTaskEntity.class))).thenReturn(sampleTaskEntity);
         when(taskMapper.entityToStatusDTO(any(DeletionTaskEntity.class))).thenAnswer(invocation -> {
            DeletionTaskEntity entity = invocation.getArgument(0);
            return DeletionTaskStatusDTO.builder().taskId(entity.getTaskId()).status(entity.getStatus().name()).build();
        });

        TaskApprovalRequest rejectionReq = TaskApprovalRequest.builder().comments("Rejected by test").build();
        DeletionTaskStatusDTO result = taskService.rejectTask(sampleTaskId, rejectionReq);

        assertEquals(DeletionStatus.REJECTED.name(), result.getStatus());
        assertEquals("Rejected by test", sampleTaskEntity.getRejectionComments());
        verify(taskRepository).save(sampleTaskEntity);
    }
}