using Marco.Pms.DataAccess.Data;
using Marco.Pms.Model.Activities;
using Marco.Pms.Model.Employees;
using Marco.Pms.Model.Mapper;
using Marco.Pms.Model.Projects;
using Marco.Pms.Model.Utilities;
using Marco.Pms.Services.Service;
using MarcoBMS.Services.Helpers;
using MarcoBMS.Services.Service;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;

namespace Marco.Pms.Services.Controllers
{
    [Route("api/[controller]")]
    [ApiController]
    [Authorize]
    public class ImageController : ControllerBase
    {
        private readonly ApplicationDbContext _context;
        private readonly S3UploadService _s3Service;
        private readonly UserHelper _userHelper;
        private readonly ILoggingService _logger;
        private readonly PermissionServices _permission;
        private readonly Guid tenantId;
        public ImageController(ApplicationDbContext context, S3UploadService s3Service, UserHelper userHelper, ILoggingService logger, PermissionServices permission)
        {
            _context = context;
            _s3Service = s3Service;
            _userHelper = userHelper;
            _logger = logger;
            tenantId = userHelper.GetTenantId();
            _permission = permission;
        }

        [HttpGet("images/{projectId}")]
        public async Task<IActionResult> GetImageList(Guid projectId)
        {
            _logger.LogInfo("GetImageList called for ProjectId: {ProjectId}", projectId);

            var loggedInEmployee = await _userHelper.GetCurrentEmployeeAsync();

            // Step 1: Validate project existence
            var isProjectExist = await _context.Projects.AnyAsync(p => p.Id == projectId && p.TenantId == tenantId);
            if (!isProjectExist)
            {
                _logger.LogWarning("Project not found for ProjectId: {ProjectId}", projectId);
                return BadRequest(ApiResponse<object>.ErrorResponse("Project not found", "Project not found in database", 400));
            }

            // Step 2: Check permission
            var hasPermission = await _permission.HasProjectPermission(loggedInEmployee, projectId.ToString());
            if (!hasPermission)
            {
                _logger.LogWarning("No access to ProjectId: {ProjectId} for EmployeeId: {EmployeeId}", projectId, loggedInEmployee.Id);
                return StatusCode(403, ApiResponse<object>.ErrorResponse("You don't have access", "You don't have access", 403));
            }

            // Step 3: Fetch building > floor > work area > work item hierarchy
            var buildings = await _context.Buildings
                .Where(b => b.ProjectId == projectId)
                .Select(b => new { b.Id, b.Name })
                .ToListAsync();

            var buildingIds = buildings.Select(b => b.Id).ToList();

            var floors = await _context.Floor
                .Where(f => buildingIds.Contains(f.BuildingId))
                .Select(f => new { f.Id, f.BuildingId, f.FloorName })
                .ToListAsync();

            var floorIds = floors.Select(f => f.Id).ToList();

            var workAreas = await _context.WorkAreas
                .Where(wa => floorIds.Contains(wa.FloorId))
                .Select(wa => new { wa.Id, wa.FloorId, wa.AreaName })
                .ToListAsync();

            var workAreaIds = workAreas.Select(wa => wa.Id).ToList();

            var workItems = await _context.WorkItems
                .Include(wi => wi.ActivityMaster)
                .Include(wi => wi.WorkCategoryMaster)
                .Where(wi => workAreaIds.Contains(wi.WorkAreaId))
                .Select(wi => new { wi.Id, wi.WorkAreaId, wi.ActivityMaster, wi.WorkCategoryMaster })
                .ToListAsync();

            var workItemIds = workItems.Select(wi => wi.Id).ToList();

            // Step 4: Fetch task and comment data
            var tasks = await _context.TaskAllocations
            .Include(t => t.ReportedBy)
                .Where(t => workItemIds.Contains(t.WorkItemId))
                .ToListAsync();

            var taskIds = tasks.Select(t => t.Id).ToList();

            var comments = await _context.TaskComments
                .Include(c => c.Employee)
                .Where(c => taskIds.Contains(c.TaskAllocationId))
                .ToListAsync();

            var commentIds = comments.Select(c => c.Id).ToList();

            // Step 5: Fetch attachments and related documents
            var attachments = await _context.TaskAttachments
                .Where(ta => taskIds.Contains(ta.ReferenceId) || commentIds.Contains(ta.ReferenceId))
                .ToListAsync();

            var documentIds = attachments.Select(ta => ta.DocumentId).ToList();

            var documents = await _context.Documents
                .Include(d => d.UploadedBy)
                .Where(d => documentIds.Contains(d.Id))
                .ToListAsync();

            // Step 6: Prepare view models
            var documentVM = documents
                .Select(d =>
                {
                    var referenceId = attachments
                        .Where(ta => ta.DocumentId == d.Id)
                        .Select(ta => ta.ReferenceId)
                        .FirstOrDefault();

                    var task = tasks.FirstOrDefault(t => t.Id == referenceId);
                    var comment = comments.FirstOrDefault(c => c.Id == referenceId);

                    string source = "";
                    Employee? uploadedBy = null;
                    if (task != null)
                    {
                        uploadedBy = task.ReportedBy;
                        source = "Report";
                    }
                    else if (comment != null)
                    {
                        task = tasks.FirstOrDefault(t => t.Id == comment.TaskAllocationId);
                        uploadedBy = comment.Employee;
                        source = "Comment";
                    }

                    var workItem = workItems.FirstOrDefault(wi => wi.Id == task?.WorkItemId);
                    var workArea = workAreas.FirstOrDefault(wa => wa.Id == workItem?.WorkAreaId);
                    var floor = floors.FirstOrDefault(f => f.Id == workArea?.FloorId);
                    var building = buildings.FirstOrDefault(b => b.Id == floor?.BuildingId);

                    return new
                    {
                        Id = d.Id,
                        BatchId = d.BatchId,
                        thumbnailUrl = d.ThumbS3Key != null ? _s3Service.GeneratePreSignedUrlAsync(d.ThumbS3Key) : (d.S3Key != null ? _s3Service.GeneratePreSignedUrlAsync(d.S3Key) : null),
                        ImageUrl = d.S3Key != null ? _s3Service.GeneratePreSignedUrlAsync(d.S3Key) : null,
                        UploadedBy = d.UploadedBy?.ToBasicEmployeeVMFromEmployee() ?? uploadedBy?.ToBasicEmployeeVMFromEmployee(),
                        UploadedAt = d.UploadedAt,
                        Source = source,
                        ProjectId = projectId,
                        BuildingId = building?.Id,
                        BuildingName = building?.Name,
                        FloorIds = floor?.Id,
                        FloorName = floor?.FloorName,
                        WorkAreaId = workArea?.Id,
                        WorkAreaName = workArea?.AreaName,
                        TaskId = task?.Id,
                        ActivityName = workItem?.ActivityMaster?.ActivityName,
                        WorkCategoryId = workItem?.WorkCategoryMaster?.Id,
                        WorkCategoryName = workItem?.WorkCategoryMaster?.Name,
                        CommentId = comment?.Id,
                        Comment = comment?.Comment
                    };
                }).ToList();

            _logger.LogInfo("Image list fetched for ProjectId: {ProjectId}. Total documents: {Count}", projectId, documentVM.Count);
            return Ok(ApiResponse<object>.SuccessResponse(documentVM, $"{documentVM.Count} image records fetched successfully", 200));
        }

        [HttpGet("batch/{batchId}")]
        public async Task<IActionResult> GetImagesByBatch(Guid batchId)
        {
            _logger.LogInfo("GetImagesByBatch called for BatchId: {BatchId}", batchId);

            // Step 1: Get the logged-in employee
            var loggedInEmployee = await _userHelper.GetCurrentEmployeeAsync();

            // Step 2: Retrieve all documents in the batch
            var documents = await _context.Documents
                .Include(d => d.UploadedBy)
                .Where(d => d.BatchId == batchId)
                .ToListAsync();

            if (!documents.Any())
            {
                _logger.LogWarning("No documents found for BatchId: {BatchId}", batchId);
                return NotFound(ApiResponse<object>.ErrorResponse("No images found", "No images associated with this batch", 404));
            }

            var documentIds = documents.Select(d => d.Id).ToList();

            // Step 3: Get task/comment reference IDs linked to these documents
            var referenceIds = await _context.TaskAttachments
                .Where(ta => documentIds.Contains(ta.DocumentId))
            .Select(ta => ta.ReferenceId)
                .Distinct()
                .ToListAsync();

            // Step 4: Try to identify the source of the attachment (task or comment)
            var task = await _context.TaskAllocations
                .Include(t => t.ReportedBy)
                .FirstOrDefaultAsync(t => referenceIds.Contains(t.Id));

            TaskComment? comment = null;
            WorkItem? workItem = null;
            Employee? uploadedBy = null;
            string source = "";

            if (task != null)
            {
                uploadedBy = task.ReportedBy;
                workItem = await _context.WorkItems
                .Include(wi => wi.ActivityMaster)
                .Include(wi => wi.WorkCategoryMaster)
                    .FirstOrDefaultAsync(wi => wi.Id == task.WorkItemId);
                source = "Report";
            }
            else
            {
                comment = await _context.TaskComments
                    .Include(tc => tc.TaskAllocation)
                    .Include(tc => tc.Employee)
                    .FirstOrDefaultAsync(tc => referenceIds.Contains(tc.Id));
                var workItemId = comment?.TaskAllocation?.WorkItemId;

                uploadedBy = comment?.Employee;
                workItem = await _context.WorkItems
                    .Include(wi => wi.ActivityMaster)
                    .Include(wi => wi.WorkCategoryMaster)
                    .FirstOrDefaultAsync(wi => wi.Id == workItemId);
                source = "Comment";
            }

            // Step 5: Traverse up to building level
            var workAreaId = workItem?.WorkAreaId;
            var workArea = await _context.WorkAreas
                .Include(wa => wa.Floor)
                .FirstOrDefaultAsync(wa => wa.Id == workAreaId);

            var buildingId = workArea?.Floor?.BuildingId;
            var building = await _context.Buildings
                .FirstOrDefaultAsync(b => b.Id == buildingId);

            // Step 6: Construct the response
            var response = documents.Select(d => new
            {
                Id = d.Id,
                BatchId = d.BatchId,
                thumbnailUrl = d.ThumbS3Key != null
                    ? _s3Service.GeneratePreSignedUrlAsync(d.ThumbS3Key)
                    : (d.S3Key != null ? _s3Service.GeneratePreSignedUrlAsync(d.S3Key) : null),
                ImageUrl = d.S3Key != null ? _s3Service.GeneratePreSignedUrlAsync(d.S3Key) : null,
                UploadedBy = d.UploadedBy?.ToBasicEmployeeVMFromEmployee() ?? uploadedBy?.ToBasicEmployeeVMFromEmployee(),
                UploadedAt = d.UploadedAt,
                Source = source,
                ProjectId = building?.ProjectId,
                BuildingId = building?.Id,
                BuildingName = building?.Name,
                FloorIds = workArea?.Floor?.Id,
                FloorName = workArea?.Floor?.FloorName,
                WorkAreaId = workArea?.Id,
                WorkAreaName = workArea?.AreaName,
                TaskId = task?.Id,
                ActivityName = workItem?.ActivityMaster?.ActivityName,
                WorkCategoryId = workItem?.WorkCategoryMaster?.Id,
                WorkCategoryName = workItem?.WorkCategoryMaster?.Name,
                CommentId = comment?.Id,
                Comment = comment?.Comment
            }).ToList();

            _logger.LogInfo("Fetched {Count} image(s) for BatchId: {BatchId}", response.Count, batchId);

            return Ok(ApiResponse<object>.SuccessResponse(response, "Images for provided batchId fetched successfully", 200));
        }

        [HttpGet("{documentId}")]
        public async Task<IActionResult> GetImage(Guid documentId)
        {
            // Log the start of the image fetch process
            _logger.LogInfo("GetImage called for DocumentId: {DocumentId}", documentId);

            // Step 1: Get the currently logged-in employee (for future use like permission checks or auditing)
            var loggedInEmployee = await _userHelper.GetCurrentEmployeeAsync();

            // Step 2: Fetch the document from the database based on the provided ID
            var document = await _context.Documents.FirstOrDefaultAsync(d => d.Id == documentId);

            // Step 3: If document doesn't exist, return a 400 Bad Request response
            if (document == null)
            {
                _logger.LogWarning("Document not found for DocumentId: {DocumentId}", documentId);
                return BadRequest(ApiResponse<object>.ErrorResponse("Document not found", "Document not found", 400));
            }

            // Step 4: Generate pre-signed URLs for thumbnail and full image (if keys exist)
            string? thumbnailUrl = document.ThumbS3Key != null
                ? _s3Service.GeneratePreSignedUrlAsync(document.ThumbS3Key)
                : null;

            string? imageUrl = document.S3Key != null
                ? _s3Service.GeneratePreSignedUrlAsync(document.S3Key)
                : null;

            // Step 5: Prepare the response object
            var response = new
            {
                ThumbnailUrl = thumbnailUrl,
                ImageUrl = imageUrl
            };

            // Step 6: Log successful fetch and return the result
            _logger.LogInfo("Image fetched successfully for DocumentId: {DocumentId}", documentId);
            return Ok(ApiResponse<object>.SuccessResponse(response, "Image fetched successfully", 200));
        }
    }
}