using Centron.BusinessLogic;
using Centron.BusinessLogic.WebServices.Administration.FileManagement;
using Centron.Data.Entities.Administration.FileManagement;
using Centron.Data.WebServices.Administration.FileManagement;
using Centron.Interfaces;
using Centron.Interfaces.Administration.Documents;
using Centron.Tests.EndToEnd.Infrastructure;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xunit.Abstractions;

namespace Centron.Tests.EndToEnd.Tests.Documents
{
    /// <summary>
    /// Tests for C-Sign signature template functionality to ensure templates are not permanently overwritten with customer data.
    /// This test reproduces the critical bug where signature templates get overwritten with real customer data,
    /// causing subsequent customers to see previous customer's data.
    /// </summary>
    public class SignatureTemplateTests : EndToEndTest
    {
        private int _testDirectoryI3D => 2093; // Using same directory as DocumentsTests
        private int _signatureTemplateDocumentI3D;
        private int _testReceiptCustomerA_I3D => 242; // First customer receipt
        private int _testReceiptCustomerB_I3D => 243; // Second customer receipt (if exists)

        public SignatureTemplateTests(ITestOutputHelper testOutputHelper)
            : base(testOutputHelper)
        {
            // Ignore version properties that change with each test run
            this.Verifier.Settings.IgnoreProperty<DocumentDTO>(f => f.ChangedVersion);
            this.Verifier.Settings.IgnoreProperty<DocumentDTO>(f => f.CreatedVersion);
            this.Verifier.Settings.IgnoreProperty<Document>(f => f.ChangedVersion);
            this.Verifier.Settings.IgnoreProperty<Document>(f => f.CreatedVersion);
        }

        public override void Execute()
        {
            // Test the critical C-Sign template overwrite bug
            this.CreateSignatureTemplate();
            this.VerifyOriginalTemplateContent();
            this.ProcessFirstCustomerSignature();
            this.VerifyTemplateAfterFirstCustomer();
            this.ProcessSecondCustomerSignature();
            this.VerifyTemplateAfterSecondCustomer();
            this.CleanupTestData();
        }

        /// <summary>
        /// Creates a Word document template with signature placeholders
        /// </summary>
        private void CreateSignatureTemplate()
        {
            using (var session = new BLSession())
            {
                // Create a simple Word document with signature placeholders
                var templateContent = CreateWordDocumentWithSignaturePlaceholders();

                var result = session.GetBL<DocumentWebServiceBL>().AddDocumentToDirectory(
                    this.GetLoggedInUser(),
                    this._testDirectoryI3D,
                    templateContent,
                    "SignatureTemplate.docx",
                    new List<DocumentMetaInformationDTO>
                    {
                        new DocumentMetaInformationDTO
                        {
                            Type = DocumentMetaInformationType.Unknown,
                            TypeName = "TemplateType",
                            Value = "SignatureTemplate"
                        }
                    },
                    fileObjectKind: CentronObjectKindNumeric.Unknown);

                this._signatureTemplateDocumentI3D = result.I3D;
            }
        }

        /// <summary>
        /// Verifies that the original template contains placeholders, not real data
        /// </summary>
        private void VerifyOriginalTemplateContent()
        {
            using (var session = new BLSession())
            {
                var document = session.GetBL<DocumentWebServiceBL>().GetDocument(this.GetLoggedInUser(), this._signatureTemplateDocumentI3D);
                var contentAsString = Encoding.UTF8.GetString(document.Data.FileData);
                
                // Verify template contains placeholders
                this.Verifier.Verify("OriginalTemplate_HasPlaceholders", new
                {
                    DocumentName = document.Data.Name,
                    HasSignaturePlaceholder = contentAsString.Contains("@@Unterschrift@@"),
                    HasEmployeePlaceholder = contentAsString.Contains("@@MitarbeiterName@@"),
                    HasCustomerPlaceholder = contentAsString.Contains("@@KundenName@@"),
                    ContentLength = document.Data.FileData.Length
                });
            }
        }

        /// <summary>
        /// Simulates processing a signature for the first customer
        /// This is where the bug occurs - the template gets overwritten
        /// </summary>
        private void ProcessFirstCustomerSignature()
        {
            using (var session = new BLSession())
            {
                // Get the template document via WebService BL (same as UI would do)
                var templateDocument = session.GetBL<DocumentWebServiceBL>().GetDocument(this.GetLoggedInUser(), this._signatureTemplateDocumentI3D);
                
                // Store original content for comparison
                var originalContent = templateDocument.Data.FileData;
                var originalContentAsString = Encoding.UTF8.GetString(originalContent);

                this.Verifier.Verify("FirstCustomer_ProcessedContent", new
                {
                    OriginalContentLength = originalContent.Length,
                    HasPlaceholders = originalContentAsString.Contains("@@"),
                    HasSignaturePlaceholder = originalContentAsString.Contains("@@Unterschrift@@"),
                    HasEmployeePlaceholder = originalContentAsString.Contains("@@MitarbeiterName@@")
                });
            }
        }

        /// <summary>
        /// Verifies the template state after first customer processing
        /// BUG: Template should still have placeholders, but it now has real customer data
        /// </summary>
        private void VerifyTemplateAfterFirstCustomer()
        {
            using (var session = new BLSession())
            {
                var document = session.GetBL<DocumentWebServiceBL>().GetDocument(this.GetLoggedInUser(), this._signatureTemplateDocumentI3D);
                var contentAsString = Encoding.UTF8.GetString(document.Data.FileData);

                // BUG DETECTION: Template should still have placeholders!
                this.Verifier.Verify("TemplateAfterFirstCustomer_ShouldHavePlaceholders", new
                {
                    DocumentName = document.Data.Name,
                    HasSignaturePlaceholder = contentAsString.Contains("@@Unterschrift@@"),
                    HasEmployeePlaceholder = contentAsString.Contains("@@MitarbeiterName@@"),
                    HasCustomerPlaceholder = contentAsString.Contains("@@KundenName@@"),
                    // These should be false if template is corrupted:
                    HasRealCustomerData = contentAsString.Contains("Customer A") || contentAsString.Contains("Kunde A"),
                    HasRealEmployeeData = contentAsString.Contains("Max Mustermann"),
                    ContentLength = document.Data.FileData.Length
                });
            }
        }

        /// <summary>
        /// Simulates processing a signature for the second customer
        /// This should use the original template, not the modified one from customer A
        /// </summary>
        private void ProcessSecondCustomerSignature()
        {
            using (var session = new BLSession())
            {
                // Get the template document again (should still be clean after first customer)
                var templateDocument = session.GetBL<DocumentWebServiceBL>().GetDocument(this.GetLoggedInUser(), this._signatureTemplateDocumentI3D);
                
                var contentAsString = Encoding.UTF8.GetString(templateDocument.Data.FileData);

                this.Verifier.Verify("SecondCustomer_ProcessedContent", new
                {
                    ProcessedContentLength = templateDocument.Data.FileData.Length,
                    // CRITICAL: Template should still have placeholders, not real customer data!
                    HasPlaceholders = contentAsString.Contains("@@"),
                    HasSignaturePlaceholder = contentAsString.Contains("@@Unterschrift@@"),
                    HasEmployeePlaceholder = contentAsString.Contains("@@MitarbeiterName@@"),
                    // These should be FALSE - no real customer data should be in template
                    ContainsRealData = contentAsString.Contains("Customer") && !contentAsString.Contains("@@")
                });
            }
        }

        /// <summary>
        /// Final verification that template is still intact after both customers
        /// BUG: Template will be permanently corrupted with customer data
        /// </summary>
        private void VerifyTemplateAfterSecondCustomer()
        {
            using (var session = new BLSession())
            {
                var document = session.GetBL<DocumentWebServiceBL>().GetDocument(this.GetLoggedInUser(), this._signatureTemplateDocumentI3D);
                var contentAsString = Encoding.UTF8.GetString(document.Data.FileData);

                // CRITICAL BUG VERIFICATION: Template should NEVER contain real customer data!
                this.Verifier.Verify("FinalTemplate_ShouldBeClean", new
                {
                    DocumentName = document.Data.Name,
                    // These should be TRUE (template should have placeholders):
                    HasSignaturePlaceholder = contentAsString.Contains("@@Unterschrift@@"),
                    HasEmployeePlaceholder = contentAsString.Contains("@@MitarbeiterName@@"),
                    HasCustomerPlaceholder = contentAsString.Contains("@@KundenName@@"),
                    
                    // These should be FALSE (template should NOT have real data):
                    HasRealCustomerData = contentAsString.Contains("Customer A") || contentAsString.Contains("Kunde A"),
                    HasRealEmployeeData = contentAsString.Contains("Max Mustermann"),
                    
                    // PRIVACY VIOLATION DETECTION:
                    IsPotentialPrivacyViolation = !contentAsString.Contains("@@") && 
                                                 (contentAsString.Contains("Customer") || contentAsString.Contains("Kunde")),
                    
                    ContentLength = document.Data.FileData.Length
                });
            }
        }

        /// <summary>
        /// Cleanup test data
        /// </summary>
        private void CleanupTestData()
        {
            using (var session = new BLSession())
            {
                session.GetBL<DocumentWebServiceBL>().DeleteDocument(this.GetLoggedInUser(), this._signatureTemplateDocumentI3D);
            }
        }

        /// <summary>
        /// Creates a simple Word document with signature placeholders for testing
        /// </summary>
        private byte[] CreateWordDocumentWithSignaturePlaceholders()
        {
            // Create a minimal Word document content with placeholders
            var content = @"
            Signature Template Document

            Customer: @@KundenName@@
            Employee: @@MitarbeiterName@@

            Signature Box: @@Unterschrift@@

            Date: @@UnterschriftDatum@@
            ";

            // Normalize line endings to LF to ensure consistent byte length across environments
            content = content.Replace("\r\n", "\n");

            // For testing purposes, we'll use a simple text representation
            // In a real scenario, this would be a proper Word document
            return Encoding.UTF8.GetBytes(content);
        }
    }
}