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4433399 da13799 068485b 1a7e978 ccc2569 068485b da13799 068485b da13799 1a7e978 ccc2569 068485b ccc2569 068485b 1a7e978 ccc2569 068485b da13799 068485b 78592a1 1a7e978 068485b da13799 1723ad3 da13799 068485b 78592a1 ccc2569 78592a1 068485b da13799 068485b 4433399 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 | using LibraryManagement.Shared.Models;
using DbConnect.Data;
using DbConnect.Entities;
using Microsoft.EntityFrameworkCore;
using Backend.Features.Loyalty;
using Backend.Features.Notification;
namespace Backend.Features.Borrowings
{
public interface IBorrowingService
{
Task<BorrowingDto> BorrowBookAsync(Guid userId, int bookId);
Task<BorrowingDto> RequestReturnAsync(Guid borrowingId);
Task<BorrowingDto> ReturnBookAsync(Guid borrowingId);
Task<IEnumerable<BorrowingDto>> GetUserBorrowingsAsync(Guid userId);
Task<IEnumerable<BorrowingDto>> GetAllBorrowingsAsync();
}
public class BorrowingService : IBorrowingService
{
private readonly AppDbContext _context;
private readonly ILoyaltyService _loyaltyService;
private readonly INotificationService _notificationService;
private const decimal FinePerDay = 500;
public BorrowingService(AppDbContext context, ILoyaltyService loyaltyService, INotificationService notificationService)
{
_context = context;
_loyaltyService = loyaltyService;
_notificationService = notificationService;
}
public async Task<BorrowingDto> BorrowBookAsync(Guid userId, int bookId)
{
// 1. Check for Active Membership
var subscription = await _context.UserSubscriptions
.Include(s => s.Membership)
.Where(s => s.UserId == userId && s.IsActive && s.ExpiryDate > DateTime.UtcNow)
.FirstOrDefaultAsync();
if (subscription == null)
{
throw new Exception("Active membership required to borrow books.");
}
// 2. Check for Overdue Books or Unpaid Fines
var hasBlockers = await _context.Borrowings
.AnyAsync(b => b.UserId == userId &&
((b.Status == "Borrowed" && b.DueDate < DateTime.UtcNow) || (b.FineAmount > 0 && !b.IsFinePaid)));
if (hasBlockers)
{
throw new Exception("Borrowing blocked: You have overdue books or unpaid fines.");
}
// 3. Check MaxBooks limit
var activeBorrowCount = await _context.Borrowings
.CountAsync(b => b.UserId == userId && b.Status == "Borrowed");
if (activeBorrowCount >= subscription.Membership.MaxBooks)
{
throw new Exception($"Borrowing limit reached: You can only borrow {subscription.Membership.MaxBooks} books at a time.");
}
// 4. Check Book Availability
var book = await _context.Books.FindAsync(bookId);
if (book == null || !book.IsActive || book.AvailableCopies <= 0)
{
throw new Exception("Book is currently unavailable.");
}
// 5. Create Borrowing Record
var borrowing = new Borrowing
{
UserId = userId,
BookId = bookId,
BorrowDate = DateTime.UtcNow,
DueDate = DateTime.UtcNow.AddDays(subscription.Membership.BorrowingDays),
Status = "Borrowed",
FineAmount = 0,
IsFinePaid = false
};
// 6. Update Book Stock
book.AvailableCopies--;
if (book.AvailableCopies == 0)
{
book.Status = "Out Of Stock";
}
_context.Borrowings.Add(borrowing);
await _context.SaveChangesAsync();
// Load relations for mapping
await _context.Entry(borrowing).Reference(b => b.Book).LoadAsync();
await _context.Entry(borrowing).Reference(b => b.User).LoadAsync();
return MapToDto(borrowing);
}
public async Task<BorrowingDto> RequestReturnAsync(Guid borrowingId)
{
var borrowing = await _context.Borrowings
.Include(b => b.Book)
.Include(b => b.User)
.FirstOrDefaultAsync(b => b.Id == borrowingId);
if (borrowing == null) throw new Exception("Borrowing record not found.");
if (borrowing.Status != "Borrowed") throw new Exception("Only borrowed books can be requested for return.");
borrowing.Status = "PendingReturn";
await _context.SaveChangesAsync();
return MapToDto(borrowing);
}
public async Task<BorrowingDto> ReturnBookAsync(Guid borrowingId)
{
var borrowing = await _context.Borrowings
.Include(b => b.Book)
.Include(b => b.User)
.FirstOrDefaultAsync(b => b.Id == borrowingId);
if (borrowing == null) throw new Exception("Borrowing record not found.");
if (borrowing.Status == "Returned") throw new Exception("Book has already been returned.");
var now = DateTime.UtcNow;
borrowing.ReturnDate = now;
borrowing.Status = "Returned";
// Calculate Fine
if (now > borrowing.DueDate)
{
var overdueDays = (now.Date - borrowing.DueDate.Date).Days;
if (overdueDays > 0)
{
borrowing.FineAmount = overdueDays * FinePerDay;
}
}
// Update Book Stock
var book = borrowing.Book;
book.AvailableCopies++;
book.Status = "Available";
await _context.SaveChangesAsync();
// Wishlist Notification Trigger
try
{
var interestedUsers = await _context.WishlistItems
.Include(w => w.User)
.Where(w => w.BookId == book.Id)
.ToListAsync();
foreach (var wishlistEntry in interestedUsers)
{
await _notificationService.SendAndSaveNotificationAsync(
wishlistEntry.UserId,
wishlistEntry.User.FcmToken,
"Book Available!",
$"Good news! '{book.Title}' is now available for borrowing. Grab it before someone else does!",
"Success",
"/Books",
"View Book"
);
}
}
catch (Exception ex)
{
Console.WriteLine($"Error sending wishlist notifications: {ex.Message}");
}
// Loyalty Integration: Send RETURN event
string externalUserId = borrowing.UserId.ToString();
string userMobile = borrowing.User?.PhoneNumber ?? "0000000000";
string userEmail = borrowing.User?.Email ?? "No Email";
await _loyaltyService.ProcessEventAsync(
externalUserId: externalUserId,
eventKey: "RETURN",
eventValue: 0,
referenceId: $"RET-{borrowing.Id}",
description: $"Returned Book: {book?.Title}",
email: userEmail,
mobile: userMobile
);
return MapToDto(borrowing);
}
public async Task<IEnumerable<BorrowingDto>> GetUserBorrowingsAsync(Guid userId)
{
var borrowings = await _context.Borrowings
.Include(b => b.Book)
.Include(b => b.User)
.Where(b => b.UserId == userId)
.OrderByDescending(b => b.BorrowDate)
.ToListAsync();
return borrowings.Select(MapToDto);
}
public async Task<IEnumerable<BorrowingDto>> GetAllBorrowingsAsync()
{
var borrowings = await _context.Borrowings
.Include(b => b.Book)
.Include(b => b.User)
.OrderByDescending(b => b.BorrowDate)
.ToListAsync();
return borrowings.Select(MapToDto);
}
private static BorrowingDto MapToDto(Borrowing b)
{
return new BorrowingDto
{
Id = b.Id,
UserId = b.UserId,
UserEmail = b.User?.Email ?? "Unknown",
BookId = b.BookId,
BookTitle = b.Book?.Title ?? "Unknown",
BorrowDate = b.BorrowDate,
DueDate = b.DueDate,
ReturnDate = b.ReturnDate,
Status = b.Status,
FineAmount = b.FineAmount,
IsFinePaid = b.IsFinePaid
};
}
}
}
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