using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;

namespace SKMC.Api.Common.Version
{
    /// <summary>
    /// git指令帮助类
    /// </summary>
    internal static class GitCommandHelper
    {
        private static readonly Dictionary<string, Dictionary<string, string>> _cache = new Dictionary<string, Dictionary<string, string>>();
        private static readonly object _lock = new object();
        /// <summary>
        /// 通过执行git指令获取git提交的哈希值/id
        /// </summary>
        /// <param name="workingDir">git文件存在的文件夹</param>
        /// <param name="args"></param>
        /// <param name="noCache"></param>
        /// <returns></returns>
        public static string Run(string workingDir, string args, bool noCache = false)
        {
            if (string.IsNullOrEmpty(workingDir)) return string.Empty;

            lock (_lock)
            {
                if (!noCache && _cache.TryGetValue(workingDir, out var dict) && dict.TryGetValue(args, out var v))
                    return v;
            }

            try
            {
                var psi = new ProcessStartInfo
                {
                    FileName = "git",
                    Arguments = args,
                    WorkingDirectory = workingDir,
                    UseShellExecute = false,
                    RedirectStandardOutput = true,
                    RedirectStandardError = true,
                    StandardOutputEncoding = Encoding.UTF8,
                    CreateNoWindow = true
                };

                var process = System.Diagnostics.Process.Start(psi);
                process.WaitForExit(1000);
                var output = process.StandardOutput.ReadToEnd().Trim();
                var error = process.StandardError.ReadToEnd().Trim();

                if (process.ExitCode != 0 || !string.IsNullOrEmpty(error))
                    return string.Empty;

                lock (_lock)
                {
                    if (!_cache.ContainsKey(workingDir))
                        _cache[workingDir] = new Dictionary<string, string>();
                    _cache[workingDir][args] = output;
                }

                return output;
            }
            catch
            {
                return string.Empty;
            }
        }

        public static void ClearCache(string dir = null)
        {
            lock (_lock)
            {
                if (dir == null) _cache.Clear();
                else _cache.Remove(dir);
            }
        }
    }
}