package com.dalab.autodelete.controller;

import com.dalab.autodelete.dto.*;
import com.dalab.autodelete.service.IDeletionTaskService;
import com.dalab.autodelete.service.exception.DeletionTaskNotFoundException;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.http.MediaType;
import org.springframework.security.test.context.support.WithMockUser;
import org.springframework.test.web.servlet.MockMvc;

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

import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.Mockito.*;
import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.csrf;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@WebMvcTest(DeletionTaskController.class)
class DeletionTaskControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private IDeletionTaskService taskService;

    @Autowired
    private ObjectMapper objectMapper;

    private DeletionTaskRequest sampleTaskRequest;
    private DeletionTaskResponse sampleTaskResponse;
    private DeletionTaskStatusDTO sampleTaskStatusDTO;
    private String sampleTaskId;

    @BeforeEach
    void setUp() {
        sampleTaskId = UUID.randomUUID().toString();

        DeletionTaskRequest.DeletionScope scope = DeletionTaskRequest.DeletionScope.builder()
                .assetIds(List.of("asset1", "asset2"))
                .build();
        sampleTaskRequest = DeletionTaskRequest.builder()
                .taskName("Test Deletion Task")
                .scope(scope)
                .build();

        sampleTaskResponse = DeletionTaskResponse.builder()
                .taskId(sampleTaskId)
                .taskName("Test Deletion Task")
                .status("SUBMITTED")
                .submittedAt(LocalDateTime.now())
                .build();
        
        sampleTaskStatusDTO = DeletionTaskStatusDTO.builder()
                .taskId(sampleTaskId)
                .taskName("Test Deletion Task")
                .status("SUBMITTED")
                .submittedAt(LocalDateTime.now())
                .scope(scope) // Assuming DeletionTaskRequest.DeletionScope is compatible or mapped
                .totalAssetsInScope(2)
                .build();
    }

    @Test
    @WithMockUser(authorities = "ROLE_ADMIN")
    void submitDeletionTask_AsAdmin_ValidRequest_ShouldReturnAccepted() throws Exception {
        when(taskService.submitDeletionTask(any(DeletionTaskRequest.class))).thenReturn(sampleTaskResponse);

        mockMvc.perform(post("/api/v1/deletion/tasks")
                        .with(csrf())
                        .contentType(MediaType.APPLICATION_JSON)
                        .content(objectMapper.writeValueAsString(sampleTaskRequest)))
                .andExpect(status().isAccepted())
                .andExpect(jsonPath("$.taskId").value(sampleTaskId))
                .andExpect(jsonPath("$.status").value("SUBMITTED"));
    }
    
    @Test
    @WithMockUser(authorities = "ROLE_ADMIN")
    void submitDeletionTask_InvalidScope_ShouldReturnBadRequest() throws Exception {
        DeletionTaskRequest invalidRequest = DeletionTaskRequest.builder().taskName("Invalid Task").scope(null).build();
        // Service returns a specific response for validation failure
        DeletionTaskResponse validationFailedResponse = DeletionTaskResponse.builder()
            .taskId(null)
            .taskName(invalidRequest.getTaskName())
            .status("FAILED_VALIDATION") 
            .message("Scope is null or empty")
            .submittedAt(LocalDateTime.now())
            .build();
        when(taskService.submitDeletionTask(any(DeletionTaskRequest.class))).thenReturn(validationFailedResponse);

        mockMvc.perform(post("/api/v1/deletion/tasks")
                        .with(csrf())
                        .contentType(MediaType.APPLICATION_JSON)
                        .content(objectMapper.writeValueAsString(invalidRequest)))
                .andExpect(status().isBadRequest()) // Controller logic changes status for FAILED_VALIDATION
                .andExpect(jsonPath("$.status").value("FAILED_VALIDATION"));
    }

    @Test
    @WithMockUser(authorities = "ROLE_USER") // Assuming USER can get status of their own tasks (logic in service)
    void getDeletionTaskStatus_WhenTaskExists_ShouldReturnStatus() throws Exception {
        when(taskService.getTaskStatus(sampleTaskId)).thenReturn(sampleTaskStatusDTO);

        mockMvc.perform(get("/api/v1/deletion/tasks/{taskId}", sampleTaskId))
                .andExpect(status().isOk())
                .andExpect(jsonPath("$.taskId").value(sampleTaskId))
                .andExpect(jsonPath("$.status").value("SUBMITTED"));
    }

    @Test
    @WithMockUser(authorities = "ROLE_USER")
    void getDeletionTaskStatus_WhenTaskNotExists_ShouldReturnNotFound() throws Exception {
        when(taskService.getTaskStatus(sampleTaskId)).thenReturn(null); // Service returns null for not found

        mockMvc.perform(get("/api/v1/deletion/tasks/{taskId}", sampleTaskId))
                .andExpect(status().isNotFound());
    }

    @Test
    @WithMockUser(authorities = "ROLE_DATA_STEWARD")
    void listDeletionTasks_ShouldReturnPageOfTasks() throws Exception {
        List<DeletionTaskStatusDTO> taskList = Collections.singletonList(sampleTaskStatusDTO);
        PageImpl<DeletionTaskStatusDTO> page = new PageImpl<>(taskList, PageRequest.of(0, 20), 1);
        DeletionTaskListResponse listResponse = DeletionTaskListResponse.fromPage(page);

        when(taskService.listTasks(any(Pageable.class))).thenReturn(listResponse);

        mockMvc.perform(get("/api/v1/deletion/tasks").param("page", "0").param("size", "20"))
                .andExpect(status().isOk())
                .andExpect(jsonPath("$.tasks[0].taskId").value(sampleTaskId));
    }

    @Test
    @WithMockUser(authorities = "ROLE_ADMIN")
    void approveDeletionTask_AsAdmin_WhenTaskApprovable_ShouldReturnOk() throws Exception {
        DeletionTaskStatusDTO approvedStatus = DeletionTaskStatusDTO.builder().taskId(sampleTaskId).status("APPROVED").build();
        when(taskService.approveTask(eq(sampleTaskId), any())).thenReturn(approvedStatus);

        mockMvc.perform(post("/api/v1/deletion/tasks/{taskId}/approve", sampleTaskId)
                        .with(csrf()))
                .andExpect(status().isOk())
                .andExpect(jsonPath("$.status").value("APPROVED"));
    }
    
    @Test
    @WithMockUser(authorities = "ROLE_ADMIN")
    void approveDeletionTask_TaskNotApprovable_ShouldReturnConflict() throws Exception {
        DeletionTaskStatusDTO conflictStatus = DeletionTaskStatusDTO.builder()
                                                .taskId(sampleTaskId)
                                                .status("COMPLETED") // Example of a non-approvable state
                                                .errorMessages(List.of("Task not in approvable state"))
                                                .build();
        when(taskService.approveTask(eq(sampleTaskId), any())).thenReturn(conflictStatus);

        mockMvc.perform(post("/api/v1/deletion/tasks/{taskId}/approve", sampleTaskId)
                        .with(csrf()))
                .andExpect(status().isConflict()) // Controller maps this from DTO having errorMessages
                .andExpect(jsonPath("$.status").value("COMPLETED"));
    }

    @Test
    @WithMockUser(authorities = "ROLE_DATA_STEWARD")
    void rejectDeletionTask_AsDataSteward_WhenTaskRejectable_ShouldReturnOk() throws Exception {
        DeletionTaskStatusDTO rejectedStatus = DeletionTaskStatusDTO.builder().taskId(sampleTaskId).status("REJECTED").build();
        when(taskService.rejectTask(eq(sampleTaskId), any())).thenReturn(rejectedStatus);

        mockMvc.perform(post("/api/v1/deletion/tasks/{taskId}/reject", sampleTaskId)
                        .with(csrf()))
                .andExpect(status().isOk())
                .andExpect(jsonPath("$.status").value("REJECTED"));
    }
}