Feature: Add AICategorizePreview page for AI transaction categorization

Add new page that allows users to:
- Generate AI categorization suggestions for uncategorized transactions
- Review proposals with confidence levels before applying
- Select specific transactions from Transactions page for AI review
- Choose to create mapping rules for high-confidence matches
- Support both OpenAI and LlamaCpp providers with model selection

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

MoneyMap/Pages/AICategorizePreview.cshtml

@@ -0,0 +1,231 @@
+@page
+@model MoneyMap.Pages.AICategorizePreviewModel
+@{
+    ViewData["Title"] = "AI Categorization Preview";
+}
+
+<div class="d-flex justify-content-between align-items-center mb-3">
+    <h2>AI Categorization Preview</h2>
+    <div>
+        <a asp-page="/Recategorize" class="btn btn-outline-secondary">Back to Recategorize</a>
+    </div>
+</div>
+
+@if (!string.IsNullOrEmpty(Model.ErrorMessage))
+{
+    <div class="alert alert-danger alert-dismissible fade show" role="alert">
+        @Model.ErrorMessage
+        <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
+    </div>
+}
+
+@if (!Model.Proposals.Any())
+{
+    <div class="card shadow-sm">
+        <div class="card-header">
+            <strong>Generate AI Suggestions</strong>
+        </div>
+        <div class="card-body">
+            @if (Model.TransactionIds != null && Model.TransactionIds.Length > 0)
+            {
+                <p>Generate AI categorization suggestions for <strong>@Model.SelectedTransactionCount selected transaction(s)</strong>. You can review and approve them before applying.</p>
+
+                <form method="post" asp-page-handler="GenerateForIds"
+                      onsubmit="this.querySelector('button[type=submit]').disabled = true; this.querySelector('button[type=submit]').innerHTML = '<span class=\'spinner-border spinner-border-sm me-2\'></span>Analyzing transactions...';">
+                    @foreach (var id in Model.TransactionIds!)
+                    {
+                        <input type="hidden" name="transactionIds" value="@id" />
+                    }
+                    @if (Model.AIProvider.Equals("LlamaCpp", StringComparison.OrdinalIgnoreCase) && Model.AvailableModels.Any())
+                    {
+                        <div class="mb-3" style="max-width: 400px;">
+                            <label for="model" class="form-label">Model</label>
+                            <select name="model" id="model" class="form-select">
+                                @foreach (var m in Model.AvailableModels)
+                                {
+                                    var isSelected = m.Id == Model.SelectedModel;
+                                    <option value="@m.Id" selected="@isSelected">
+                                        @(m.IsLoaded ? "● " : "○ ")@m.Id
+                                    </option>
+                                }
+                            </select>
+                            <div class="form-text">
+                                <span style="color: #28a745;">●</span> Loaded
+                                <span class="ms-2" style="color: #6c757d;">○</span> Not loaded
+                            </div>
+                        </div>
+                    }
+                    <button type="submit" class="btn btn-primary">
+                        Generate Suggestions for @Model.SelectedTransactionCount Transaction(s)
+                    </button>
+                </form>
+            }
+            else
+            {
+                <p>Generate AI categorization suggestions for uncategorized transactions. You can review and approve them before applying.</p>
+
+                <form method="post" asp-page-handler="Generate"
+                      onsubmit="this.querySelector('button[type=submit]').disabled = true; this.querySelector('button[type=submit]').innerHTML = '<span class=\'spinner-border spinner-border-sm me-2\'></span>Analyzing transactions...';">
+                    @if (Model.AIProvider.Equals("LlamaCpp", StringComparison.OrdinalIgnoreCase) && Model.AvailableModels.Any())
+                    {
+                        <div class="mb-3" style="max-width: 400px;">
+                            <label for="model" class="form-label">Model</label>
+                            <select name="model" id="model" class="form-select">
+                                @foreach (var m in Model.AvailableModels)
+                                {
+                                    var isSelected = m.Id == Model.SelectedModel;
+                                    <option value="@m.Id" selected="@isSelected">
+                                        @(m.IsLoaded ? "● " : "○ ")@m.Id
+                                    </option>
+                                }
+                            </select>
+                            <div class="form-text">
+                                <span style="color: #28a745;">●</span> Loaded
+                                <span class="ms-2" style="color: #6c757d;">○</span> Not loaded
+                            </div>
+                        </div>
+                    }
+                    <button type="submit" class="btn btn-primary">
+                        Generate Suggestions (up to 50 uncategorized)
+                    </button>
+                </form>
+            }
+        </div>
+    </div>
+}
+else
+{
+    <form method="post" asp-page-handler="Apply">
+        <div class="card shadow-sm mb-3">
+            <div class="card-header d-flex justify-content-between align-items-center">
+                <strong>Review Proposals (@Model.Proposals.Count suggestions)</strong>
+                <div>
+                    <button type="button" class="btn btn-sm btn-outline-secondary" onclick="selectAll(true)">Select All</button>
+                    <button type="button" class="btn btn-sm btn-outline-secondary" onclick="selectAll(false)">Deselect All</button>
+                </div>
+            </div>
+            <div class="card-body p-0">
+                <div class="table-responsive">
+                    <table class="table table-hover mb-0">
+                        <thead class="table-light">
+                            <tr>
+                                <th style="width: 40px;">
+                                    <input type="checkbox" class="form-check-input" id="selectAllCheckbox" onchange="selectAll(this.checked)" checked>
+                                </th>
+                                <th>Transaction</th>
+                                <th>Current</th>
+                                <th>Proposed</th>
+                                <th>Merchant</th>
+                                <th style="width: 100px;">Confidence</th>
+                                <th style="width: 100px;">Create Rule</th>
+                            </tr>
+                        </thead>
+                        <tbody>
+                            @foreach (var proposal in Model.Proposals)
+                            {
+                                var confidenceClass = proposal.Confidence >= 0.8m ? "bg-success" :
+                                                     proposal.Confidence >= 0.6m ? "bg-warning text-dark" : "bg-secondary";
+                                <tr>
+                                    <td>
+                                        <input type="checkbox" class="form-check-input proposal-checkbox"
+                                               name="selectedIds" value="@proposal.TransactionId" checked>
+                                    </td>
+                                    <td>
+                                        <div class="fw-bold">@proposal.TransactionName</div>
+                                        @if (!string.IsNullOrWhiteSpace(proposal.TransactionMemo))
+                                        {
+                                            <small class="text-muted">@proposal.TransactionMemo</small>
+                                        }
+                                        <div class="small text-muted">
+                                            @proposal.TransactionDate.ToString("yyyy-MM-dd") | @proposal.TransactionAmount.ToString("C")
+                                        </div>
+                                    </td>
+                                    <td>
+                                        @if (!string.IsNullOrWhiteSpace(proposal.CurrentCategory))
+                                        {
+                                            <span class="badge bg-secondary">@proposal.CurrentCategory</span>
+                                        }
+                                        else
+                                        {
+                                            <span class="text-muted small">(none)</span>
+                                        }
+                                    </td>
+                                    <td>
+                                        <span class="badge bg-primary">@proposal.ProposedCategory</span>
+                                        @if (!string.IsNullOrWhiteSpace(proposal.Reasoning))
+                                        {
+                                            <div class="small text-muted mt-1" title="@proposal.Reasoning">
+                                                @(proposal.Reasoning.Length > 60 ? proposal.Reasoning.Substring(0, 60) + "..." : proposal.Reasoning)
+                                            </div>
+                                        }
+                                    </td>
+                                    <td>
+                                        @if (!string.IsNullOrWhiteSpace(proposal.ProposedMerchant))
+                                        {
+                                            <div>@proposal.ProposedMerchant</div>
+                                        }
+                                        @if (!string.IsNullOrWhiteSpace(proposal.ProposedPattern))
+                                        {
+                                            <code class="small">@proposal.ProposedPattern</code>
+                                        }
+                                    </td>
+                                    <td>
+                                        <span class="badge @confidenceClass">@proposal.Confidence.ToString("P0")</span>
+                                    </td>
+                                    <td>
+                                        <input type="checkbox" class="form-check-input"
+                                               name="createRules" value="@proposal.TransactionId"
+                                               @(proposal.CreateRule ? "checked" : "")
+                                               title="Create a mapping rule for this pattern">
+                                    </td>
+                                </tr>
+                            }
+                        </tbody>
+                    </table>
+                </div>
+            </div>
+            <div class="card-footer d-flex justify-content-between">
+                <form method="post" asp-page-handler="Cancel" class="d-inline">
+                    <button type="submit" class="btn btn-outline-secondary">Cancel</button>
+                </form>
+                <button type="submit" class="btn btn-success">
+                    Apply Selected Categorizations
+                </button>
+            </div>
+        </div>
+    </form>
+
+    <div class="card shadow-sm">
+        <div class="card-header">
+            <strong>Legend</strong>
+        </div>
+        <div class="card-body">
+            <div class="row">
+                <div class="col-md-6">
+                    <h6>Confidence Levels</h6>
+                    <ul class="list-unstyled mb-0">
+                        <li><span class="badge bg-success">80%+</span> High confidence - likely correct</li>
+                        <li><span class="badge bg-warning text-dark">60-79%</span> Medium confidence - review recommended</li>
+                        <li><span class="badge bg-secondary">&lt;60%</span> Low confidence - verify carefully</li>
+                    </ul>
+                </div>
+                <div class="col-md-6">
+                    <h6>Create Rule</h6>
+                    <p class="small text-muted mb-0">
+                        When checked, a category mapping rule will be created using the proposed pattern.
+                        Future transactions matching this pattern will be automatically categorized.
+                    </p>
+                </div>
+            </div>
+        </div>
+    </div>
+}
+
+@section Scripts {
+    <script>
+        function selectAll(checked) {
+            document.querySelectorAll('.proposal-checkbox').forEach(cb => cb.checked = checked);
+            document.getElementById('selectAllCheckbox').checked = checked;
+        }
+    </script>
+}

MoneyMap/Pages/AICategorizePreview.cshtml.cs

@@ -0,0 +1,321 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.Mvc.RazorPages;
+using Microsoft.EntityFrameworkCore;
+using MoneyMap.Data;
+using MoneyMap.Models;
+using MoneyMap.Services;
+using System.Text.Json;
+
+namespace MoneyMap.Pages
+{
+    public class AICategorizePreviewModel : PageModel
+    {
+        private readonly MoneyMapContext _db;
+        private readonly ITransactionAICategorizer _aiCategorizer;
+        private readonly LlamaCppVisionClient _llamaClient;
+        private readonly IConfiguration _config;
+
+        public AICategorizePreviewModel(
+            MoneyMapContext db,
+            ITransactionAICategorizer aiCategorizer,
+            LlamaCppVisionClient llamaClient,
+            IConfiguration config)
+        {
+            _db = db;
+            _aiCategorizer = aiCategorizer;
+            _llamaClient = llamaClient;
+            _config = config;
+        }
+
+        public List<ProposalViewModel> Proposals { get; set; } = new();
+        public string ModelUsed { get; set; } = "";
+        public string AIProvider => _config["AI:CategorizationProvider"] ?? "OpenAI";
+        public List<LlamaCppModel> AvailableModels { get; set; } = new();
+        public string SelectedModel => _config["AI:CategorizationModel"] ?? "qwen2.5-coder-32b-instruct-q6_k";
+
+        [TempData]
+        public string? StoredTransactionIds { get; set; }
+
+        public long[]? TransactionIds { get; set; }
+
+        [TempData]
+        public string? ProposalsJson { get; set; }
+
+        [TempData]
+        public string? SuccessMessage { get; set; }
+
+        [TempData]
+        public string? ErrorMessage { get; set; }
+
+        public int SelectedTransactionCount { get; set; }
+
+        public async Task<IActionResult> OnGetAsync()
+        {
+            // Load models for the dropdown
+            if (AIProvider.Equals("LlamaCpp", StringComparison.OrdinalIgnoreCase))
+            {
+                AvailableModels = await _llamaClient.GetAvailableModelsAsync();
+            }
+
+            // Load transaction IDs from TempData if available
+            if (!string.IsNullOrEmpty(StoredTransactionIds))
+            {
+                TransactionIds = JsonSerializer.Deserialize<long[]>(StoredTransactionIds);
+                // Keep in TempData for the generate form
+                StoredTransactionIds = JsonSerializer.Serialize(TransactionIds);
+            }
+
+            // Count selected transactions if IDs provided
+            if (TransactionIds != null && TransactionIds.Length > 0)
+            {
+                SelectedTransactionCount = await _db.Transactions
+                    .CountAsync(t => TransactionIds.Contains(t.Id));
+            }
+
+            // Check if we have proposals from TempData
+            if (!string.IsNullOrEmpty(ProposalsJson))
+            {
+                var storedProposals = JsonSerializer.Deserialize<List<StoredProposal>>(ProposalsJson);
+                if (storedProposals != null)
+                {
+                    await LoadProposalViewModels(storedProposals);
+                }
+            }
+
+            return Page();
+        }
+
+        public IActionResult OnPostStoreIds(long[] transactionIds)
+        {
+            if (transactionIds == null || transactionIds.Length == 0)
+            {
+                return RedirectToPage("/Transactions");
+            }
+
+            StoredTransactionIds = JsonSerializer.Serialize(transactionIds);
+            return RedirectToPage();
+        }
+
+        public async Task<IActionResult> OnPostGenerateAsync(string? model)
+        {
+            var uncategorized = await _db.Transactions
+                .Include(t => t.Card)
+                .Include(t => t.Account)
+                .Include(t => t.Merchant)
+                .Include(t => t.TransferToAccount)
+                .Where(t => string.IsNullOrWhiteSpace(t.Category))
+                .OrderByDescending(t => t.Date)
+                .Take(50)
+                .ToListAsync();
+
+            if (uncategorized.Count == 0)
+            {
+                ErrorMessage = "No uncategorized transactions to process.";
+                return RedirectToPage("/Recategorize");
+            }
+
+            var proposals = await _aiCategorizer.ProposeBatchCategorizationAsync(uncategorized, model);
+
+            if (proposals.Count == 0)
+            {
+                ErrorMessage = "AI could not generate any categorization proposals.";
+                return RedirectToPage("/Recategorize");
+            }
+
+            // Store proposals in TempData
+            var storedProposals = proposals.Select(p => new StoredProposal
+            {
+                TransactionId = p.TransactionId,
+                Category = p.Category,
+                CanonicalMerchant = p.CanonicalMerchant,
+                Pattern = p.Pattern,
+                Priority = p.Priority,
+                Confidence = p.Confidence,
+                Reasoning = p.Reasoning,
+                CreateRule = p.CreateRule
+            }).ToList();
+
+            ProposalsJson = JsonSerializer.Serialize(storedProposals);
+            ModelUsed = model ?? SelectedModel;
+
+            return RedirectToPage();
+        }
+
+        public async Task<IActionResult> OnPostGenerateForIdsAsync(long[]? transactionIds, string? model)
+        {
+            // Try to get IDs from form first, then from TempData
+            if ((transactionIds == null || transactionIds.Length == 0) && !string.IsNullOrEmpty(StoredTransactionIds))
+            {
+                transactionIds = JsonSerializer.Deserialize<long[]>(StoredTransactionIds);
+            }
+
+            if (transactionIds == null || transactionIds.Length == 0)
+            {
+                ErrorMessage = "No transactions selected.";
+                return RedirectToPage("/Transactions");
+            }
+
+            var transactions = await _db.Transactions
+                .Include(t => t.Card)
+                .Include(t => t.Account)
+                .Include(t => t.Merchant)
+                .Include(t => t.TransferToAccount)
+                .Where(t => transactionIds.Contains(t.Id))
+                .OrderByDescending(t => t.Date)
+                .Take(50)
+                .ToListAsync();
+
+            if (transactions.Count == 0)
+            {
+                ErrorMessage = "Selected transactions not found.";
+                return RedirectToPage("/Transactions");
+            }
+
+            var proposals = await _aiCategorizer.ProposeBatchCategorizationAsync(transactions, model);
+
+            if (proposals.Count == 0)
+            {
+                ErrorMessage = "AI could not generate any categorization proposals.";
+                return RedirectToPage("/Transactions");
+            }
+
+            // Store proposals in TempData
+            var storedProposals = proposals.Select(p => new StoredProposal
+            {
+                TransactionId = p.TransactionId,
+                Category = p.Category,
+                CanonicalMerchant = p.CanonicalMerchant,
+                Pattern = p.Pattern,
+                Priority = p.Priority,
+                Confidence = p.Confidence,
+                Reasoning = p.Reasoning,
+                CreateRule = p.CreateRule
+            }).ToList();
+
+            ProposalsJson = JsonSerializer.Serialize(storedProposals);
+            ModelUsed = model ?? SelectedModel;
+
+            return RedirectToPage();
+        }
+
+        public async Task<IActionResult> OnPostApplyAsync(long[] selectedIds, long[] createRules)
+        {
+            if (string.IsNullOrEmpty(ProposalsJson))
+            {
+                ErrorMessage = "No proposals to apply. Please generate new suggestions.";
+                return RedirectToPage("/Recategorize");
+            }
+
+            var storedProposals = JsonSerializer.Deserialize<List<StoredProposal>>(ProposalsJson);
+            if (storedProposals == null || storedProposals.Count == 0)
+            {
+                ErrorMessage = "No proposals to apply.";
+                return RedirectToPage("/Recategorize");
+            }
+
+            var selectedSet = selectedIds?.ToHashSet() ?? new HashSet<long>();
+            var createRulesSet = createRules?.ToHashSet() ?? new HashSet<long>();
+
+            int applied = 0;
+            int rulesCreated = 0;
+
+            foreach (var stored in storedProposals)
+            {
+                if (!selectedSet.Contains(stored.TransactionId))
+                    continue;
+
+                var proposal = new AICategoryProposal
+                {
+                    TransactionId = stored.TransactionId,
+                    Category = stored.Category,
+                    CanonicalMerchant = stored.CanonicalMerchant,
+                    Pattern = stored.Pattern,
+                    Priority = stored.Priority,
+                    Confidence = stored.Confidence,
+                    Reasoning = stored.Reasoning,
+                    CreateRule = stored.CreateRule
+                };
+
+                // Check if user wants to create rule for this one
+                var shouldCreateRule = createRulesSet.Contains(stored.TransactionId);
+
+                var result = await _aiCategorizer.ApplyProposalAsync(stored.TransactionId, proposal, shouldCreateRule);
+                if (result.Success)
+                {
+                    applied++;
+                    if (result.RuleCreated)
+                        rulesCreated++;
+                }
+            }
+
+            SuccessMessage = $"Applied {applied} categorizations. Created {rulesCreated} new mapping rules.";
+            return RedirectToPage("/Recategorize");
+        }
+
+        public IActionResult OnPostCancel()
+        {
+            return RedirectToPage("/Recategorize");
+        }
+
+        private async Task LoadProposalViewModels(List<StoredProposal> storedProposals)
+        {
+            var transactionIds = storedProposals.Select(p => p.TransactionId).ToList();
+            var transactions = await _db.Transactions
+                .Where(t => transactionIds.Contains(t.Id))
+                .ToDictionaryAsync(t => t.Id);
+
+            foreach (var stored in storedProposals)
+            {
+                if (transactions.TryGetValue(stored.TransactionId, out var txn))
+                {
+                    Proposals.Add(new ProposalViewModel
+                    {
+                        TransactionId = stored.TransactionId,
+                        TransactionName = txn.Name,
+                        TransactionMemo = txn.Memo,
+                        TransactionAmount = txn.Amount,
+                        TransactionDate = txn.Date,
+                        CurrentCategory = txn.Category,
+                        ProposedCategory = stored.Category,
+                        ProposedMerchant = stored.CanonicalMerchant,
+                        ProposedPattern = stored.Pattern,
+                        Confidence = stored.Confidence,
+                        Reasoning = stored.Reasoning,
+                        CreateRule = stored.CreateRule
+                    });
+                }
+            }
+
+            // Keep proposals in TempData for the apply action
+            ProposalsJson = JsonSerializer.Serialize(storedProposals);
+        }
+
+        public class ProposalViewModel
+        {
+            public long TransactionId { get; set; }
+            public string TransactionName { get; set; } = "";
+            public string? TransactionMemo { get; set; }
+            public decimal TransactionAmount { get; set; }
+            public DateTime TransactionDate { get; set; }
+            public string? CurrentCategory { get; set; }
+            public string ProposedCategory { get; set; } = "";
+            public string? ProposedMerchant { get; set; }
+            public string? ProposedPattern { get; set; }
+            public decimal Confidence { get; set; }
+            public string? Reasoning { get; set; }
+            public bool CreateRule { get; set; }
+        }
+
+        public class StoredProposal
+        {
+            public long TransactionId { get; set; }
+            public string Category { get; set; } = "";
+            public string? CanonicalMerchant { get; set; }
+            public string? Pattern { get; set; }
+            public int Priority { get; set; }
+            public decimal Confidence { get; set; }
+            public string? Reasoning { get; set; }
+            public bool CreateRule { get; set; }
+        }
+    }
+}