using FsCheck;
using FsCheck.Xunit;
using WorkCameraExport.Services;
using Xunit;

namespace WorkCameraExport.Tests
{
    /// <summary>
    /// LogService 属性测试
    /// Feature: work-camera-2.0.1, Property 13: 日志记录
    /// Validates: Requirements 12.3
    /// </summary>
    public class LogServicePropertyTests : IDisposable
    {
        private readonly string _testLogPath;
        private readonly LogService _logService;

        public LogServicePropertyTests()
        {
            // 为每个测试创建唯一的临时目录
            _testLogPath = Path.Combine(Path.GetTempPath(), $"WorkCameraExport_LogTest_{Guid.NewGuid():N}");
            Directory.CreateDirectory(_testLogPath);
            _logService = new LogService(_testLogPath);
        }

        public void Dispose()
        {
            // 清理测试目录
            try
            {
                if (Directory.Exists(_testLogPath))
                {
                    Directory.Delete(_testLogPath, true);
                }
            }
            catch
            {
                // 忽略清理错误
            }
        }

        /// <summary>
        /// Property 13: 日志记录
        /// For any 用户操作，应在日志文件中记录操作信息，包含时间戳和操作类型。
        /// </summary>
        [Property(MaxTest = 100)]
        public Property LogEntry_ShouldContainTimestampAndLevel()
        {
            return Prop.ForAll(
                Arb.From<NonEmptyString>(),
                (message) =>
                {
                    // 过滤掉包含换行符的消息，避免解析问题
                    var safeMessage = new string(message.Get
                        .Where(c => !char.IsControl(c) && c != '\r' && c != '\n')
                        .ToArray());

                    if (string.IsNullOrWhiteSpace(safeMessage))
                    {
                        return true.Label("Skipped: empty after filtering");
                    }

                    // Act: 记录日志
                    var beforeLog = DateTime.Now;
                    _logService.Info(safeMessage);
                    var afterLog = DateTime.Now;

                    // 读取日志文件
                    var logFiles = _logService.GetLogFiles();
                    if (logFiles.Count == 0)
                    {
                        return false.Label("No log files found");
                    }

                    var logContent = File.ReadAllText(logFiles[0]);
                    var lines = logContent.Split(Environment.NewLine, StringSplitOptions.RemoveEmptyEntries);
                    var lastLine = lines.LastOrDefault();

                    if (string.IsNullOrEmpty(lastLine))
                    {
                        return false.Label("Log file is empty");
                    }

                    // 解析日志条目
                    var (timestamp, level, logMessage) = LogService.ParseLogEntry(lastLine);

                    // Assert: 验证日志包含时间戳和级别
                    return (timestamp != null)
                        .Label("Timestamp should be present")
                        .And(timestamp >= beforeLog.AddSeconds(-1) && timestamp <= afterLog.AddSeconds(1))
                        .Label("Timestamp should be within expected range")
                        .And(level == "INFO")
                        .Label("Level should be INFO")
                        .And(logMessage == safeMessage)
                        .Label("Message should match");
                });
        }

        /// <summary>
        /// Property 13 扩展: 日志格式化后应可正确解析
        /// </summary>
        [Property(MaxTest = 100)]
        public Property LogFormat_RoundTrip_ShouldPreserveData()
        {
            var validLevels = new[] { "INFO", "WARN", "ERROR", "DEBUG" };
            
            return Prop.ForAll(
                Arb.From<NonEmptyString>(),
                Gen.Elements(validLevels).ToArbitrary(),
                (message, level) =>
                {
                    // 过滤掉包含换行符的消息
                    var safeMessage = new string(message.Get
                        .Where(c => !char.IsControl(c) && c != '\r' && c != '\n')
                        .ToArray());

                    if (string.IsNullOrWhiteSpace(safeMessage))
                    {
                        return true.Label("Skipped: empty after filtering");
                    }

                    // Arrange
                    var timestamp = DateTime.Now;

                    // Act: 格式化日志
                    var formatted = LogService.FormatLogEntry(timestamp, level, safeMessage);

                    // 解析日志
                    var (parsedTimestamp, parsedLevel, parsedMessage) = LogService.ParseLogEntry(formatted);

                    // Assert: 验证解析结果
                    return (parsedTimestamp != null)
                        .Label("Parsed timestamp should not be null")
                        .And(Math.Abs((parsedTimestamp.Value - timestamp).TotalMilliseconds) < 1)
                        .Label("Timestamp should match within 1ms")
                        .And(parsedLevel == level)
                        .Label("Level should match")
                        .And(parsedMessage == safeMessage)
                        .Label("Message should match");
                });
        }

        /// <summary>
        /// Property 13 扩展: 不同级别的日志应写入正确的文件
        /// </summary>
        [Property(MaxTest = 50)]
        public Property ErrorLog_ShouldWriteToErrorFile()
        {
            return Prop.ForAll(
                Arb.From<NonEmptyString>(),
                (message) =>
                {
                    var safeMessage = new string(message.Get
                        .Where(c => !char.IsControl(c) && c != '\r' && c != '\n')
                        .ToArray());

                    if (string.IsNullOrWhiteSpace(safeMessage))
                    {
                        return true.Label("Skipped: empty after filtering");
                    }

                    // Act: 记录错误日志
                    _logService.Error(safeMessage);

                    // 检查错误日志文件
                    var errorLogFile = Path.Combine(_testLogPath, $"error_{DateTime.Now:yyyy-MM-dd}.log");
                    var appLogFile = Path.Combine(_testLogPath, $"app_{DateTime.Now:yyyy-MM-dd}.log");

                    // Assert: 错误日志应同时写入 error 和 app 文件
                    return File.Exists(errorLogFile)
                        .Label("Error log file should exist")
                        .And(File.Exists(appLogFile))
                        .Label("App log file should exist")
                        .And(File.ReadAllText(errorLogFile).Contains(safeMessage))
                        .Label("Error log should contain message")
                        .And(File.ReadAllText(appLogFile).Contains(safeMessage))
                        .Label("App log should contain message");
                });
        }

        /// <summary>
        /// Property 13 扩展: 日志文件应按日期分割
        /// </summary>
        [Fact]
        public void LogFiles_ShouldBeSplitByDate()
        {
            // Arrange & Act
            _logService.Info("Test message 1");
            _logService.Warn("Test message 2");
            _logService.Error("Test message 3");

            // Assert
            var logFiles = _logService.GetLogFiles();
            var today = DateTime.Now.ToString("yyyy-MM-dd");

            // 应该有 app 和 error 两个日志文件
            Assert.Contains(logFiles, f => f.Contains($"app_{today}"));
            Assert.Contains(logFiles, f => f.Contains($"error_{today}"));
        }
    }
}