MoneyMap/MoneyMap/Pages/Merchants.cshtml.cs

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

namespace MoneyMap.Pages
{
    public class MerchantsModel : PageModel
    {
        private readonly IMerchantService _merchantService;

        public MerchantsModel(IMerchantService merchantService)
        {
            _merchantService = merchantService;
        }

        public List<MerchantRow> Merchants { get; set; } = new();
        public int TotalMerchants { get; set; }

        [TempData]
        public string? SuccessMessage { get; set; }

        [TempData]
        public string? ErrorMessage { get; set; }

        public async Task OnGetAsync()
        {
            await LoadDataAsync();
        }

        public async Task<IActionResult> OnPostAddMerchantAsync(AddMerchantModel model)
        {
            if (!ModelState.IsValid)
            {
                ErrorMessage = "Please fill in all required fields.";
                await LoadDataAsync();
                return Page();
            }

            // Check if merchant already exists
            var existing = await _merchantService.FindByNameAsync(model.Name);
            if (existing != null)
            {
                ErrorMessage = $"Merchant '{model.Name}' already exists.";
                await LoadDataAsync();
                return Page();
            }

            var merchant = await _merchantService.GetOrCreateAsync(model.Name);

            SuccessMessage = $"Added merchant '{merchant.Name}'.";
            return RedirectToPage();
        }

        public async Task<IActionResult> OnPostUpdateMerchantAsync(UpdateMerchantModel model)
        {
            if (!ModelState.IsValid)
            {
                ErrorMessage = "Please fill in all required fields.";
                await LoadDataAsync();
                return Page();
            }

            var result = await _merchantService.UpdateMerchantAsync(model.Id, model.Name);

            if (result.Success)
            {
                SuccessMessage = result.Message;
            }
            else
            {
                ErrorMessage = result.Message;
                await LoadDataAsync();
                return Page();
            }

            return RedirectToPage();
        }

        public async Task<IActionResult> OnPostDeleteMerchantAsync(int id)
        {
            var result = await _merchantService.DeleteMerchantAsync(id);

            if (result.Success)
            {
                SuccessMessage = result.Message;
            }
            else
            {
                ErrorMessage = result.Message;
            }

            return RedirectToPage();
        }

        private async Task LoadDataAsync()
        {
            var merchantsWithStats = await _merchantService.GetAllMerchantsWithStatsAsync();

            Merchants = merchantsWithStats.Select(m => new MerchantRow
            {
                Id = m.Id,
                Name = m.Name,
                TransactionCount = m.TransactionCount,
                MappingCount = m.MappingCount
            }).ToList();

            TotalMerchants = Merchants.Count;
        }

        public class MerchantRow
        {
            public int Id { get; set; }
            public string Name { get; set; } = "";
            public int TransactionCount { get; set; }
            public int MappingCount { get; set; }
        }

        public class AddMerchantModel
        {
            [Required(ErrorMessage = "Merchant name is required")]
            [StringLength(100)]
            public string Name { get; set; } = "";
        }

        public class UpdateMerchantModel
        {
            [Required]
            public int Id { get; set; }

            [Required(ErrorMessage = "Merchant name is required")]
            [StringLength(100)]
            public string Name { get; set; } = "";
        }
    }
}