feat: add transactions import, list and categories endpoints

src/AccountTracking.Api/Controllers/TransactionsController.cs

@@ -0,0 +1,92 @@
+using AccountTracking.Api.Data;
+using AccountTracking.Api.Models.Dtos;
+using AccountTracking.Api.Services;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+
+namespace AccountTracking.Api.Controllers;
+
+[ApiController]
+[Route("api/transactions")]
+[Authorize]
+public class TransactionsController : ControllerBase
+{
+    private readonly AppDbContext _db;
+    private readonly CsvImportService _importService;
+
+    public TransactionsController(AppDbContext db, CsvImportService importService)
+    {
+        _db = db;
+        _importService = importService;
+    }
+
+    [HttpPost("import")]
+    public async Task<IActionResult> Import(IFormFile file)
+    {
+        if (file == null || file.Length == 0)
+            return BadRequest(new ErrorResult("Nebyl vybrán žádný soubor."));
+
+        string content;
+        using (var reader = new StreamReader(file.OpenReadStream(), System.Text.Encoding.UTF8))
+            content = await reader.ReadToEndAsync();
+
+        var result = await _importService.ImportAsync(content, file.FileName);
+
+        if (!result.IsSuccess)
+            return BadRequest(new ErrorResult(result.Error!));
+
+        return Ok(result.Value);
+    }
+
+    [HttpGet]
+    public async Task<IActionResult> List(
+        [FromQuery] int year,
+        [FromQuery] int? month,
+        [FromQuery] string? category,
+        [FromQuery] string? search,
+        [FromQuery] int page = 1,
+        [FromQuery] int pageSize = 50)
+    {
+        pageSize = Math.Clamp(pageSize, 1, 200);
+        page = Math.Max(1, page);
+
+        var query = _db.Transactions.AsQueryable();
+
+        query = query.Where(t => t.BookingDate.Year == year);
+        if (month.HasValue)
+            query = query.Where(t => t.BookingDate.Month == month.Value);
+        if (!string.IsNullOrWhiteSpace(category))
+            query = query.Where(t => t.Category == category);
+        if (!string.IsNullOrWhiteSpace(search))
+            query = query.Where(t =>
+                (t.CounterPartyName != null && EF.Functions.Like(t.CounterPartyName, $"%{search}%")) ||
+                (t.Message != null && EF.Functions.Like(t.Message, $"%{search}%")));
+
+        var total = await query.CountAsync();
+        var items = await query
+            .OrderByDescending(t => t.BookingDate)
+            .ThenByDescending(t => t.Id)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .Select(t => new TransactionDto(
+                t.Id, t.BookingDate, t.CounterPartyName,
+                t.Category, t.Amount, t.Balance, t.Message))
+            .ToListAsync();
+
+        return Ok(new TransactionListResponse(items, total, page, pageSize));
+    }
+
+    [HttpGet("categories")]
+    public async Task<IActionResult> Categories()
+    {
+        var cats = await _db.Transactions
+            .Where(t => t.Category != null)
+            .Select(t => t.Category!)
+            .Distinct()
+            .OrderBy(c => c)
+            .ToListAsync();
+
+        return Ok(cats);
+    }
+}