using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using BulkArchiveMailer.Core;
using Xunit;

namespace BulkArchiveMailer.Core.Tests
{
    /// <summary>
    /// ArchiveScanner.Scan touches the real file system (Directory.Exists/
    /// EnumerateFiles), so these tests set up a throwaway folder under
    /// Path.GetTempPath() per test and delete it afterwards (IDisposable),
    /// rather than mocking - the existing precedent in this test project
    /// (SendLogStoreTests-equivalent file-based tests) already treats this
    /// as an acceptable pattern for .NET file-system-touching code.
    /// </summary>
    public class ArchiveScannerTests : IDisposable
    {
        private readonly string tempDir;

        public ArchiveScannerTests()
        {
            tempDir = Path.Combine(Path.GetTempPath(), "BulkArchiveMailerTests_" + Guid.NewGuid().ToString("N"));
            Directory.CreateDirectory(tempDir);
        }

        public void Dispose()
        {
            try
            {
                if (Directory.Exists(tempDir))
                {
                    Directory.Delete(tempDir, recursive: true);
                }
            }
            catch
            {
                // Best-effort cleanup only - never fail a passing test over
                // a locked/leftover temp file.
            }
        }

        private static void WriteArchive(string path) => File.WriteAllBytes(path, new byte[] { 1, 2, 3 });

        [Fact]
        public void Scan_LoginMatchesTemplateLoginPattern_IsReady()
        {
            var filePath = Path.Combine(tempDir, "a-makarov_ssh_access.7z");
            WriteArchive(filePath);

            var templates = new List<MailTemplateDefinition>
            {
                new MailTemplateDefinition
                {
                    DisplayName = "SSH-доступ (только a-*)",
                    FileSuffix = "ssh_access",
                    Subject = "Доступ — {Login}",
                    BodyHtml = "<p>{Login}</p>",
                    LoginPattern = "^a-.*",
                },
            };

            var result = ArchiveScanner.Scan(tempDir, "redlab.lo", templates);

            var job = Assert.Single(result.Jobs);
            Assert.Equal(SendStatus.Ready, job.Status);
            Assert.Equal("a-makarov", job.Login);
            Assert.Equal("a.makarov@redlab.lo", job.Email);
            Assert.Empty(result.UnrecognizedFiles);
        }

        [Fact]
        public void Scan_LoginDoesNotMatchTemplateLoginPattern_IsErrorInUnrecognized()
        {
            var filePath = Path.Combine(tempDir, "b-petrov_ssh_access.7z");
            WriteArchive(filePath);

            var templates = new List<MailTemplateDefinition>
            {
                new MailTemplateDefinition
                {
                    DisplayName = "SSH-доступ (только a-*)",
                    FileSuffix = "ssh_access",
                    Subject = "Доступ — {Login}",
                    BodyHtml = "<p>{Login}</p>",
                    LoginPattern = "^a-.*",
                },
            };

            var result = ArchiveScanner.Scan(tempDir, "redlab.lo", templates);

            Assert.Empty(result.Jobs);
            var row = Assert.Single(result.UnrecognizedFiles);
            Assert.Equal(SendStatus.Error, row.Status);
            Assert.Contains("b-petrov", row.ErrorMessage);
            Assert.Contains("SSH-доступ (только a-*)", row.ErrorMessage);
            Assert.Contains("^a-.*", row.ErrorMessage);
        }

        [Fact]
        public void Scan_EmptyLoginPattern_MatchesAnyLogin_UnchangedLegacyBehavior()
        {
            var filePath = Path.Combine(tempDir, "z-unrelated_ssh_access.7z");
            WriteArchive(filePath);

            var templates = new List<MailTemplateDefinition>
            {
                new MailTemplateDefinition
                {
                    DisplayName = "SSH-доступ",
                    FileSuffix = "ssh_access",
                    Subject = "Доступ — {Login}",
                    BodyHtml = "<p>{Login}</p>",
                    LoginPattern = "",
                },
            };

            var result = ArchiveScanner.Scan(tempDir, "redlab.lo", templates);

            var job = Assert.Single(result.Jobs);
            Assert.Equal(SendStatus.Ready, job.Status);
            Assert.Equal("z-unrelated", job.Login);
        }

        [Fact]
        public void Scan_InvalidLoginPatternRegex_TreatedAsNoMatchRatherThanThrowing()
        {
            var filePath = Path.Combine(tempDir, "a-makarov_ssh_access.7z");
            WriteArchive(filePath);

            var templates = new List<MailTemplateDefinition>
            {
                new MailTemplateDefinition
                {
                    DisplayName = "SSH-доступ (битый regex)",
                    FileSuffix = "ssh_access",
                    Subject = "Доступ — {Login}",
                    BodyHtml = "<p>{Login}</p>",
                    // Unbalanced group - not a valid regex.
                    LoginPattern = "(a-",
                },
            };

            var result = ArchiveScanner.Scan(tempDir, "redlab.lo", templates);

            Assert.Empty(result.Jobs);
            var row = Assert.Single(result.UnrecognizedFiles);
            Assert.Equal(SendStatus.Error, row.Status);
        }
    }
}