using System;
using System.Diagnostics;
using System.IO;

namespace SafeMobileLib
{
    public static class DBInteraction
    {

        public static string safemobilePath = Utils.GetRegValue("Path", "SafeMobile");


        public static string SafeMobilePath
        {
            get { return safemobilePath; }
            set { safemobilePath = value; }
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="connStr">”host = 10.120.1.130 port = 5432 user = postgres dbname = safedispatchdb”</param>
        public static bool RewindCommand(string connStr)
        {
            Process process = new Process();
            ProcessStartInfo startInfo = new ProcessStartInfo();
            startInfo.WindowStyle = ProcessWindowStyle.Hidden;
            startInfo.FileName = "cmd.exe";
            startInfo.Verb = "runas";
            startInfo.RedirectStandardInput = true;
            startInfo.RedirectStandardOutput = true;
            startInfo.UseShellExecute = false;
            process.StartInfo = startInfo;
            process.Start();
            using (StreamWriter sw = process.StandardInput)
            {
                if (sw.BaseStream.CanWrite)
                {
                    string appPath = safemobilePath + "\\postgresql\\pgsql\\bin";
                    string dbPath = safemobilePath + "\\postgresql\\SafeDB";

                    sw.WriteLine("pushd " + appPath);
                    sw.WriteLine($"pg_rewind.exe –-target-pgdata= {dbPath}  –-source-server= {connStr}");

                }
                sw.Close();

            }
            using (StreamReader reader = process.StandardOutput)
            {
                string output = reader.ReadToEnd();
                process.WaitForExit();

                if (output.Contains("Done!"))
                {
                    Utils.WriteLine("RewindCommand: " + output, ConsoleColor.Magenta);
                    return true;
                }

                return false;
            }

        }


        public static void ReceiveXlogCommand(string archive_folder, string slot_name, string connStr)
        {
            Process process = new Process();
            ProcessStartInfo startInfo = new ProcessStartInfo();
            startInfo.WindowStyle = ProcessWindowStyle.Hidden;
            startInfo.FileName = "cmd.exe";
            startInfo.Verb = "runas";
            startInfo.RedirectStandardInput = true;
            startInfo.RedirectStandardOutput = true;
            startInfo.UseShellExecute = false;
            process.StartInfo = startInfo;
            process.Start();
            using (StreamWriter sw = process.StandardInput)
            {
                if (sw.BaseStream.CanWrite)
                {
                    string appPath = safemobilePath + "\\postgresql\\pgsql\\bin";

                    sw.WriteLine("pushd " + appPath);
                    sw.WriteLine($"pg_receivexlog.exe –-D {archive_folder} -v --slot= {slot_name}  -d= {connStr} ");

                }
                sw.Close();

            }
            using (StreamReader reader = process.StandardOutput)
            {
                string output = reader.ReadToEnd();
                process.WaitForExit();
                
                Utils.WriteLine("ReceiveXlogCommand: " + output, ConsoleColor.Magenta);
            }
        }


        public static void BaseBackup(string masterIP)
        {


            try
            {
                string extractPath = $"{safemobilePath}\\postgresql\\pgsql\\bin\\SafeDBMaster";
                string SafeDbFolder = $"{safemobilePath}\\postgresql\\SafeDB";

                if (Directory.Exists(extractPath))
                    Directory.Delete(extractPath, true);

                Process process = new Process();
                ProcessStartInfo startInfo = new ProcessStartInfo();
                startInfo.WindowStyle = ProcessWindowStyle.Hidden;
                startInfo.FileName = "cmd.exe";
                startInfo.Verb = "runas";
                startInfo.RedirectStandardInput = true;
                startInfo.RedirectStandardOutput = true;
                startInfo.UseShellExecute = false;
                process.StartInfo = startInfo;
                process.Start();
                using (StreamWriter sw = process.StandardInput)
                {
                    if (sw.BaseStream.CanWrite)
                    {
                        string appPath = safemobilePath + "\\postgresql\\pgsql\\bin";

                        sw.WriteLine("pushd " + appPath);
                        sw.WriteLine($"pg_basebackup.exe -X stream -P -h {masterIP} -U postgres -D SafeDBMaster");

                    }
                    sw.Close();

                }
                using (StreamReader reader = process.StandardOutput)
                {
                    string output = reader.ReadToEnd();
                    process.WaitForExit();

                    Utils.WriteLine("BaseBackup completed: " + output, ConsoleColor.Magenta);
                }

                // Get our files (recursive and any of them, based on the 2nd param of the Directory.GetFiles() method
                string[] originalFiles = Directory.GetFiles(extractPath, "*", SearchOption.AllDirectories);

                // Dealing with a string array, so let's use the actionable Array.ForEach() with a anonymous method
                Array.ForEach(originalFiles, (originalFileLocation) =>
                {
                    // Get the FileInfo for both of our files
                    FileInfo originalFile = new FileInfo(originalFileLocation);
                    FileInfo destFile = new FileInfo(originalFileLocation.Replace(extractPath, SafeDbFolder));
                    // ^^ We can fill the FileInfo() constructor with files that don't exist...

                    // ... because we check it here
                    if (destFile.Exists)
                    {

                        originalFile.CopyTo(destFile.FullName, true);

                    }
                    else // ... otherwise create any missing directories and copy the folder over
                    {
                        Directory.CreateDirectory(destFile.DirectoryName); // Does nothing on directories that already exist
                        originalFile.CopyTo(destFile.FullName, true); // Copy but don't over-write  
                    }

                });
                Utils.WriteLine("SafeDB folder was successfully updated!!! " + SafeDbFolder, ConsoleColor.DarkGreen);
            }
            catch (Exception ex)
            {
                Utils.WriteLine("Replication slot ERROR: " + ex.ToString(), ConsoleColor.Red);
            }
        }

        /// <summary>
        /// Creates a replication Slot in the database
        /// </summary>
        public static void CreateReplicationSlot()
        {
            try
            {
                Utils.WriteLine("Creating Replication Slot");

                Process process = new Process();
                ProcessStartInfo startInfo = new ProcessStartInfo();
                startInfo.WindowStyle = ProcessWindowStyle.Hidden;
                startInfo.FileName = "cmd.exe";
                startInfo.Verb = "runas";
                startInfo.RedirectStandardInput = true;
                startInfo.RedirectStandardOutput = true;
                startInfo.UseShellExecute = false;
                process.StartInfo = startInfo;
                process.Start();

                using (StreamWriter sw = process.StandardInput)
                {
                    if (sw.BaseStream.CanWrite)
                    {
                        string appPath = safemobilePath + "\\postgresql\\pgsql\\bin";
                        sw.WriteLine("pushd " + appPath);
                        sw.WriteLine("psql.exe -U postgres");
                        sw.WriteLine("SELECT * FROM pg_create_physical_replication_slot('replication_slot_node');");
                        sw.WriteLine("SELECT * FROM pg_replication_slots;");

                    }
                    sw.Close();
                }

                using (StreamReader reader = process.StandardOutput)
                {
                    string output = reader.ReadToEnd();
                    process.WaitForExit();
                    Utils.WriteLine("Replication Slot Created " + output, ConsoleColor.Magenta);
                }
            }
            catch (Exception ex)
            {
                Utils.WriteLine("Replication slot ERROR: " + ex.ToString(), ConsoleColor.Red);
            }
        }

        public static void DropReplicationSlot()
        {
            try
            {
                Utils.WriteLine("Dropping Replication Slot");

                Process process = new Process();
                ProcessStartInfo startInfo = new ProcessStartInfo();
                startInfo.WindowStyle = ProcessWindowStyle.Hidden;
                startInfo.FileName = "cmd.exe";
                startInfo.Verb = "runas";
                startInfo.RedirectStandardInput = true;
                startInfo.RedirectStandardOutput = true;
                startInfo.UseShellExecute = false;
                process.StartInfo = startInfo;
                process.Start();

                using (StreamWriter sw = process.StandardInput)
                {
                    if (sw.BaseStream.CanWrite)
                    {
                        string appPath = safemobilePath + "\\postgresql\\pgsql\\bin";
                        sw.WriteLine("pushd " + appPath);
                        sw.WriteLine("psql.exe -U postgres");
                        sw.WriteLine("select pg_drop_replication_slot('replication_slot_node');");
                        sw.WriteLine("SELECT * FROM pg_replication_slots;");
                    }
                    sw.Close();

                }

                using (StreamReader reader = process.StandardOutput)
                {
                    string output = reader.ReadToEnd();
                    process.WaitForExit();
                    Utils.WriteLine("Replication Slot Deleted!!!! " + output, ConsoleColor.Magenta);
                }
            }
            catch (Exception ex)
            {
                Utils.WriteLine("Replication slot ERROR: " + ex.ToString(), ConsoleColor.Red);
            }
        }

        public static bool CheckExistingReplicationSlot()
        {

            try
            {
                Process process = new Process();
                ProcessStartInfo startInfo = new ProcessStartInfo();
                startInfo.WindowStyle = ProcessWindowStyle.Hidden;
                startInfo.FileName = "cmd.exe";
                startInfo.Verb = "runas";
                startInfo.RedirectStandardInput = true;
                startInfo.RedirectStandardOutput = true;
                startInfo.UseShellExecute = false;
                process.StartInfo = startInfo;
                process.Start();

                using (StreamWriter sw = process.StandardInput)
                {
                    if (sw.BaseStream.CanWrite)
                    {
                        string appPath = safemobilePath + "\\postgresql\\pgsql\\bin";
                        sw.WriteLine("pushd " + appPath);
                        sw.WriteLine("psql.exe -U postgres");
                        sw.WriteLine("SELECT * FROM pg_replication_slots;");
                    }
                    sw.Close();
                }

                using (StreamReader reader = process.StandardOutput)
                {
                    string output = reader.ReadToEnd();
                    process.WaitForExit();
                    //Utils.WriteLine("Replication Slot Created " + output, ConsoleColor.Magenta);
                    if (output.Contains("replication_slot_node") == false)
                    {
                        return false;
                    }
                    else
                    {
                        return true;
                    }
                }
            }
            catch (Exception ex)
            {
                Utils.WriteLine("Existing Replication slot ERROR: " + ex.ToString(), ConsoleColor.Red);
                return false;
            }
        }



        public static bool CheckReplicationIsActive()
        {

            try
            {
                Process process = new Process();
                ProcessStartInfo startInfo = new ProcessStartInfo();
                startInfo.WindowStyle = ProcessWindowStyle.Hidden;
                startInfo.FileName = "cmd.exe";
                startInfo.Verb = "runas";
                startInfo.RedirectStandardInput = true;
                startInfo.RedirectStandardOutput = true;
                startInfo.UseShellExecute = false;
                process.StartInfo = startInfo;
                process.Start();

                using (StreamWriter sw = process.StandardInput)
                {
                    if (sw.BaseStream.CanWrite)
                    {
                        string appPath = safemobilePath + "\\postgresql\\pgsql\\bin";
                        sw.WriteLine("pushd " + appPath);
                        sw.WriteLine("psql.exe -U postgres");
                        sw.WriteLine("SELECT * FROM pg_replication_slots;");
                    }
                    sw.Close();
                }

                using (StreamReader reader = process.StandardOutput)
                {
                    string output = reader.ReadToEnd();
                    process.WaitForExit();
                    if (output.Contains(" | t      |") == false)
                    {
                        return false;
                    }
                    else
                    {
                        return true;
                    }
                }
            }
            catch (Exception ex)
            {
                Utils.WriteLine("Replication slot ERROR: " + ex.ToString(), ConsoleColor.Red);
                return false;
            }
        }

        public static void CheckDelay()
        {

            try
            {
                Process process = new Process();
                ProcessStartInfo startInfo = new ProcessStartInfo();
                startInfo.WindowStyle = ProcessWindowStyle.Maximized;
                startInfo.FileName = "cmd.exe";
                startInfo.Verb = "runas";
                startInfo.RedirectStandardInput = true;
                startInfo.RedirectStandardOutput = true;
                startInfo.UseShellExecute = false;
                process.StartInfo = startInfo;
                process.Start();

                using (StreamWriter sw = process.StandardInput)
                {
                    if (sw.BaseStream.CanWrite)
                    {
                        string appPath = safemobilePath + "\\postgresql\\pgsql\\bin";
                        sw.WriteLine("pushd " + appPath);
                        sw.WriteLine("psql.exe -U postgres");
                        sw.WriteLine("select case when pg_last_xlog_receive_location() = pg_last_xlog_replay_location() then 0 else extract (epoch from now() - pg_last_xact_replay_timestamp()) end as log_delay;");
                    }
                    sw.Close();
                }

                using (StreamReader file = process.StandardOutput)
                {
                    int counter = 0;
                    bool writeNextLine = false;
                    string line;

                    // Read the file and display it line by line.
                    while ((line = file.ReadLine()) != null)
                    {
                        if (writeNextLine)
                        {
                            Utils.WriteLine(line.Trim().ToString() + " seconds delay from Master server");
                        }
                        writeNextLine = line.Contains("-----------");
                        counter++;
                    }
                    file.Close();
                    
                }

            }
            catch (Exception ex)
            {
                Utils.WriteLine("Check Delay ERROR: " + ex.ToString(), ConsoleColor.Red);
            }
        }
    }
}