feat：商户管理

src/Infrastructure/TakeoutSaaS.Infrastructure/App/Services/MerchantExportService.cs

@@ -0,0 +1,152 @@
+using QuestPDF.Fluent;
+using QuestPDF.Helpers;
+using QuestPDF.Infrastructure;
+using System.Globalization;
+using TakeoutSaaS.Domain.Common.Enums;
+using TakeoutSaaS.Domain.Merchants.Entities;
+using TakeoutSaaS.Domain.Merchants.Enums;
+using TakeoutSaaS.Domain.Merchants.Services;
+using TakeoutSaaS.Domain.Stores.Entities;
+using TakeoutSaaS.Domain.Stores.Enums;
+
+namespace TakeoutSaaS.Infrastructure.App.Services;
+
+/// <summary>
+/// 商户导出服务实现（PDF）。
+/// </summary>
+public sealed class MerchantExportService : IMerchantExportService
+{
+    public MerchantExportService()
+    {
+        QuestPDF.Settings.License = LicenseType.Community;
+    }
+
+    /// <inheritdoc />
+    public Task<byte[]> ExportToPdfAsync(
+        Merchant merchant,
+        string? tenantName,
+        IReadOnlyList<Store> stores,
+        IReadOnlyList<MerchantAuditLog> auditLogs,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(merchant);
+
+        var safeStores = stores ?? Array.Empty<Store>();
+        var safeAuditLogs = auditLogs ?? Array.Empty<MerchantAuditLog>();
+
+        var document = Document.Create(container =>
+        {
+            container.Page(page =>
+            {
+                page.Size(PageSizes.A4);
+                page.Margin(24);
+                page.DefaultTextStyle(x => x.FontSize(10));
+
+                page.Content().Column(column =>
+                {
+                    column.Spacing(10);
+                    column.Item().Text("Merchant Export").FontSize(16).SemiBold();
+
+                    column.Item().Element(section => BuildBasicSection(section, merchant, tenantName));
+                    column.Item().Element(section => BuildStoresSection(section, safeStores, cancellationToken));
+                    column.Item().Element(section => BuildAuditSection(section, safeAuditLogs, cancellationToken));
+                });
+            });
+        });
+
+        return Task.FromResult(document.GeneratePdf());
+    }
+
+    private static void BuildBasicSection(IContainer container, Merchant merchant, string? tenantName)
+    {
+        container.Border(1).BorderColor(Colors.Grey.Lighten2).Padding(10).Column(column =>
+        {
+            column.Spacing(4);
+            column.Item().Text("Basic Information").SemiBold();
+            column.Item().Text($"Merchant: {merchant.BrandName}");
+            column.Item().Text($"Tenant: {tenantName ?? "-"} (ID: {merchant.TenantId})");
+            column.Item().Text($"Operating Mode: {ResolveOperatingMode(merchant.OperatingMode)}");
+            column.Item().Text($"Status: {merchant.Status}");
+            column.Item().Text($"Frozen: {(merchant.IsFrozen ? "Yes" : "No")}");
+            column.Item().Text($"License Number: {merchant.BusinessLicenseNumber ?? "-"}");
+            column.Item().Text($"Legal Representative: {merchant.LegalPerson ?? "-"}");
+            column.Item().Text($"Registered Address: {merchant.Address ?? "-"}");
+            column.Item().Text($"Contact Phone: {merchant.ContactPhone}");
+            column.Item().Text($"Contact Email: {merchant.ContactEmail ?? "-"}");
+            column.Item().Text($"Approved At: {FormatDateTime(merchant.ApprovedAt)}");
+            column.Item().Text($"Approved By: {merchant.ApprovedBy?.ToString() ?? "-"}");
+        });
+    }
+
+    private static void BuildStoresSection(IContainer container, IReadOnlyList<Store> stores, CancellationToken cancellationToken)
+    {
+        container.Border(1).BorderColor(Colors.Grey.Lighten2).Padding(10).Column(column =>
+        {
+            column.Spacing(4);
+            column.Item().Text("Stores").SemiBold();
+
+            if (stores.Count == 0)
+            {
+                column.Item().Text("No stores.");
+                return;
+            }
+
+            for (var i = 0; i < stores.Count; i++)
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+
+                var store = stores[i];
+                column.Item().Text($"{i + 1}. {store.Name} | {ResolveStoreStatus(store.Status)} | {store.Address ?? "-"} | {store.Phone ?? "-"}");
+            }
+        });
+    }
+
+    private static void BuildAuditSection(IContainer container, IReadOnlyList<MerchantAuditLog> auditLogs, CancellationToken cancellationToken)
+    {
+        container.Border(1).BorderColor(Colors.Grey.Lighten2).Padding(10).Column(column =>
+        {
+            column.Spacing(4);
+            column.Item().Text("Audit History").SemiBold();
+
+            if (auditLogs.Count == 0)
+            {
+                column.Item().Text("No audit records.");
+                return;
+            }
+
+            for (var i = 0; i < auditLogs.Count; i++)
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+
+                var log = auditLogs[i];
+                var title = string.IsNullOrWhiteSpace(log.Title) ? log.Action.ToString() : log.Title;
+                column.Item().Text($"{i + 1}. {title} | {log.OperatorName ?? "-"} | {FormatDateTime(log.CreatedAt)}");
+                if (!string.IsNullOrWhiteSpace(log.Description))
+                {
+                    column.Item().Text($"   {log.Description}");
+                }
+            }
+        });
+    }
+
+    private static string ResolveOperatingMode(OperatingMode? mode)
+        => mode switch
+        {
+            OperatingMode.SameEntity => "SameEntity",
+            OperatingMode.DifferentEntity => "DifferentEntity",
+            _ => "-"
+        };
+
+    private static string ResolveStoreStatus(StoreStatus status)
+        => status switch
+        {
+            StoreStatus.Closed => "Closed",
+            StoreStatus.Preparing => "Preparing",
+            StoreStatus.Operating => "Operating",
+            StoreStatus.Suspended => "Suspended",
+            _ => status.ToString()
+        };
+
+    private static string FormatDateTime(DateTime? value)
+        => value.HasValue ? value.Value.ToString("yyyy-MM-dd HH:mm", CultureInfo.InvariantCulture) : "-";
+}