refactor: move services and AITools to MoneyMap.Core

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

MoneyMap.Core/Services/CardResolver.cs

@@ -0,0 +1,158 @@
+using MoneyMap.Data;
+using MoneyMap.Models.Import;
+using System.Text.RegularExpressions;
+
+namespace MoneyMap.Services
+{
+    /// <summary>
+    /// Service for resolving payment methods (cards/accounts) for transactions.
+    /// </summary>
+    public interface ICardResolver
+    {
+        Task<PaymentResolutionResult> ResolvePaymentAsync(string? memo, ImportContext context);
+    }
+
+    public class CardResolver : ICardResolver
+    {
+        private readonly MoneyMapContext _db;
+
+        public CardResolver(MoneyMapContext db)
+        {
+            _db = db;
+        }
+
+        public async Task<PaymentResolutionResult> ResolvePaymentAsync(string? memo, ImportContext context)
+        {
+            if (context.PaymentMode == PaymentSelectMode.Card)
+                return ResolveCard(context);
+
+            if (context.PaymentMode == PaymentSelectMode.Account)
+                return ResolveAccount(context);
+
+            return await ResolveAutomaticallyAsync(memo, context);
+        }
+
+        private PaymentResolutionResult ResolveCard(ImportContext context)
+        {
+            if (context.SelectedCardId is null)
+                return PaymentResolutionResult.Failure("Pick a card or switch to Auto.");
+
+            var card = context.AvailableCards.FirstOrDefault(c => c.Id == context.SelectedCardId);
+            if (card is null)
+                return PaymentResolutionResult.Failure("Selected card not found.");
+
+            // Card must have a linked account
+            if (!card.AccountId.HasValue)
+                return PaymentResolutionResult.Failure($"Card {card.DisplayLabel} is not linked to an account. Please link it to an account first.");
+
+            return PaymentResolutionResult.SuccessCard(card.Id, card.AccountId.Value, card.Last4);
+        }
+
+        private PaymentResolutionResult ResolveAccount(ImportContext context)
+        {
+            if (context.SelectedAccountId is null)
+                return PaymentResolutionResult.Failure("Pick an account or switch to Auto/Card mode.");
+
+            var account = context.AvailableAccounts.FirstOrDefault(a => a.Id == context.SelectedAccountId);
+            if (account is null)
+                return PaymentResolutionResult.Failure("Selected account not found.");
+
+            return PaymentResolutionResult.SuccessAccount(account.Id, account.Last4);
+        }
+
+        private Task<PaymentResolutionResult> ResolveAutomaticallyAsync(string? memo, ImportContext context)
+        {
+            // Extract last4 from both memo and filename
+            var last4FromFile = CardIdentifierExtractor.FromFileName(context.FileName);
+            var last4FromMemo = CardIdentifierExtractor.FromMemo(memo);
+
+            // PRIORITY 1: Try memo first (for per-transaction card detection like "usbank.com.2765")
+            if (!string.IsNullOrWhiteSpace(last4FromMemo))
+            {
+                var result = TryResolveByLast4(last4FromMemo, context);
+                if (result != null) return Task.FromResult(result);
+            }
+
+            // PRIORITY 2: Fall back to filename (for account-level CSVs or when memo has no card)
+            if (!string.IsNullOrWhiteSpace(last4FromFile))
+            {
+                var result = TryResolveByLast4(last4FromFile, context);
+                if (result != null) return Task.FromResult(result);
+            }
+
+            // Nothing found - error
+            var searchedLast4 = last4FromMemo ?? last4FromFile;
+            if (string.IsNullOrWhiteSpace(searchedLast4))
+            {
+                return Task.FromResult(PaymentResolutionResult.Failure(
+                    "Couldn't determine card or account from memo or file name. Choose an account manually."));
+            }
+
+            return Task.FromResult(PaymentResolutionResult.Failure(
+                $"Couldn't find account or card with last4 '{searchedLast4}'. Choose an account manually."));
+        }
+
+        private PaymentResolutionResult? TryResolveByLast4(string last4, ImportContext context)
+        {
+            // Look for both card and account matches
+            var matchingCard = context.AvailableCards.FirstOrDefault(c => c.Last4 == last4);
+            var matchingAccount = context.AvailableAccounts.FirstOrDefault(a => a.Last4 == last4);
+
+            // Prioritize card matches (for credit card CSVs or memo-based card detection)
+            if (matchingCard != null)
+            {
+                // Card found - it must have an account
+                if (!matchingCard.AccountId.HasValue)
+                    return PaymentResolutionResult.Failure($"Card {matchingCard.DisplayLabel} is not linked to an account. Please link it first or choose an account manually.");
+
+                return PaymentResolutionResult.SuccessCard(matchingCard.Id, matchingCard.AccountId.Value, matchingCard.Last4);
+            }
+
+            // Fall back to account match (for direct account transactions)
+            if (matchingAccount != null)
+            {
+                return PaymentResolutionResult.SuccessAccount(matchingAccount.Id, matchingAccount.Last4);
+            }
+
+            return null; // No match found
+        }
+    }
+
+    /// <summary>
+    /// Utility class for extracting card/account identifiers from memos and filenames.
+    /// </summary>
+    public static class CardIdentifierExtractor
+    {
+        // Match patterns: "usbank.com.2765" or "usbank.com.0479" or similar formats
+        private static readonly Regex MemoLast4Pattern = new(@"\.(\d{4})(?:\D|$)", RegexOptions.Compiled);
+        private const int Last4Length = 4;
+
+        public static string? FromMemo(string? memo)
+        {
+            if (string.IsNullOrWhiteSpace(memo))
+                return null;
+
+            // Try to find all matches and return the last one (most likely to be card/account number)
+            var matches = MemoLast4Pattern.Matches(memo);
+            if (matches.Count == 0)
+                return null;
+
+            // Return the last match (typically the card number at the end)
+            return matches[^1].Groups[1].Value;
+        }
+
+        public static string? FromFileName(string fileName)
+        {
+            var name = Path.GetFileNameWithoutExtension(fileName);
+            var parts = name.Split(new[] { '-', '_', ' ' }, StringSplitOptions.RemoveEmptyEntries);
+
+            foreach (var part in parts.Select(p => p.Trim()))
+            {
+                if (part.Length == Last4Length && int.TryParse(part, out _))
+                    return part;
+            }
+
+            return null;
+        }
+    }
+}