MoneyMap/MoneyMap/Pages/Transactions.cshtml.cs

using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.EntityFrameworkCore;
using MoneyMap.Data;
using MoneyMap.Models;
using MoneyMap.Services;

namespace MoneyMap.Pages
{
    public class TransactionsModel : PageModel
    {
        private readonly MoneyMapContext _db;
        private readonly ITransactionStatisticsService _statsService;
        private readonly IReferenceDataService _referenceDataService;

        public TransactionsModel(MoneyMapContext db, ITransactionStatisticsService statsService, IReferenceDataService referenceDataService)
        {
            _db = db;
            _statsService = statsService;
            _referenceDataService = referenceDataService;
        }

        [BindProperty(SupportsGet = true)]
        public string? Search { get; set; }

        [BindProperty(SupportsGet = true)]
        public string? Category { get; set; }

        [BindProperty(SupportsGet = true)]
        public string? Merchant { get; set; }

        [BindProperty(SupportsGet = true)]
        public string? CardId { get; set; }

        [BindProperty(SupportsGet = true)]
        public DateTime? StartDate { get; set; }

        [BindProperty(SupportsGet = true)]
        public DateTime? EndDate { get; set; }

        [BindProperty(SupportsGet = true)]
        public int PageNumber { get; set; } = 1;

        public int PageSize { get; set; } = 50;
        public int TotalPages { get; set; }
        public int TotalCount { get; set; }

        public List<TransactionRow> Transactions { get; set; } = new();
        public List<string> AvailableCategories { get; set; } = new();
        public List<string> AvailableMerchants { get; set; } = new();
        public List<Card> AvailableCards { get; set; } = new();
        public TransactionStats Stats { get; set; } = new();
        public List<CategoryBreakdown> CategoryBreakdowns { get; set; } = new();

        public async Task OnGetAsync()
        {
            // Default to last 30 days if no date filters provided
            if (!StartDate.HasValue && !EndDate.HasValue)
            {
                StartDate = DateTime.Today.AddDays(-30);
                EndDate = DateTime.Today;
            }

            var query = _db.Transactions
                .Include(t => t.Card)
                    .ThenInclude(c => c!.Account)
                .Include(t => t.Account)
                .Include(t => t.TransferToAccount)
                .Include(t => t.Merchant)
                .AsQueryable();

            // Apply filters (case-insensitive search using EF.Functions.Like)
            if (!string.IsNullOrWhiteSpace(Search))
            {
                var searchPattern = $"%{Search}%";
                query = query.Where(t =>
                    EF.Functions.Like(t.Name, searchPattern) ||
                    (t.Memo != null && EF.Functions.Like(t.Memo, searchPattern)) ||
                    (t.Category != null && EF.Functions.Like(t.Category, searchPattern)) ||
                    (t.Notes != null && EF.Functions.Like(t.Notes, searchPattern)) ||
                    (t.Merchant != null && EF.Functions.Like(t.Merchant.Name, searchPattern)));
            }

            if (!string.IsNullOrWhiteSpace(Category))
            {
                if (Category == "(blank)")
                {
                    query = query.Where(t => string.IsNullOrWhiteSpace(t.Category));
                }
                else
                {
                    query = query.Where(t => t.Category == Category);
                }
            }

            if (!string.IsNullOrWhiteSpace(Merchant))
            {
                if (Merchant == "(blank)")
                {
                    query = query.Where(t => t.MerchantId == null);
                }
                else
                {
                    query = query.Where(t => t.Merchant != null && t.Merchant.Name == Merchant);
                }
            }

            if (!string.IsNullOrWhiteSpace(CardId) && int.TryParse(CardId, out int cardIdInt))
            {
                query = query.Where(t => t.CardId == cardIdInt);
            }

            if (StartDate.HasValue)
            {
                query = query.Where(t => t.Date >= StartDate.Value);
            }

            if (EndDate.HasValue)
            {
                query = query.Where(t => t.Date <= EndDate.Value);
            }

            // Get total count for pagination
            TotalCount = await query.CountAsync();
            TotalPages = (int)Math.Ceiling(TotalCount / (double)PageSize);

            // Ensure page number is valid
            if (PageNumber < 1) PageNumber = 1;
            if (PageNumber > TotalPages && TotalPages > 0) PageNumber = TotalPages;

            // Get paginated transactions
            var transactions = await query
                .OrderByDescending(t => t.Date)
                .ThenByDescending(t => t.Id)
                .Skip((PageNumber - 1) * PageSize)
                .Take(PageSize)
                .ToListAsync();

            // Get receipt counts for the current page only
            var transactionIds = transactions.Select(t => t.Id).ToList();
            var receiptCounts = await _db.Receipts
                .Where(r => r.TransactionId != null && transactionIds.Contains(r.TransactionId.Value))
                .GroupBy(r => r.TransactionId)
                .Select(g => new { TransactionId = g.Key!.Value, Count = g.Count() })
                .ToListAsync();

            var receiptCountDict = receiptCounts.ToDictionary(x => x.TransactionId, x => x.Count);

            Transactions = transactions.Select(t => new TransactionRow
            {
                Id = t.Id,
                Date = t.Date,
                Name = t.Name,
                Memo = t.Memo,
                Amount = t.Amount,
                Category = t.Category ?? "",
                Notes = t.Notes ?? "",
                CardLabel = t.PaymentMethodLabel,
                AccountLabel = t.Card?.Account?.DisplayLabel ?? t.Account?.DisplayLabel ?? "None",
                ReceiptCount = receiptCountDict.ContainsKey(t.Id) ? receiptCountDict[t.Id] : 0
            }).ToList();

            // Calculate stats for filtered results (all pages, not just current)
            Stats = await _statsService.CalculateStatsAsync(query);

            // Calculate category breakdown for pie chart (only expenses)
            var expenseQuery = query.Where(t => t.Amount < 0).ExcludeTransfers();
            var categoryGroups = await expenseQuery
                .GroupBy(t => t.Category ?? "")
                .Select(g => new CategoryBreakdown
                {
                    Category = g.Key,
                    TotalSpend = g.Sum(x => -x.Amount),
                    Count = g.Count()
                })
                .OrderByDescending(x => x.TotalSpend)
                .ToListAsync();

            CategoryBreakdowns = categoryGroups;

            // Get available categories for filter dropdown
            AvailableCategories = await _referenceDataService.GetAvailableCategoriesAsync();

            // Get available merchants for filter dropdown
            var merchants = await _referenceDataService.GetAvailableMerchantsAsync();
            AvailableMerchants = merchants.Select(m => m.Name).ToList();

            // Get available cards for filter dropdown
            AvailableCards = await _referenceDataService.GetAvailableCardsAsync(includeAccount: false);
        }

        public class TransactionRow
        {
            public long Id { get; set; }
            public DateTime Date { get; set; }
            public string Name { get; set; } = "";
            public string Memo { get; set; } = "";
            public decimal Amount { get; set; }
            public string Category { get; set; } = "";
            public string Notes { get; set; } = "";
            public string CardLabel { get; set; } = "";
            public string AccountLabel { get; set; } = "";
            public int ReceiptCount { get; set; }
        }

        public class CategoryBreakdown
        {
            public string Category { get; set; } = "";
            public decimal TotalSpend { get; set; }
            public int Count { get; set; }
        }
    }
}