using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using TimeKeeper.Models.Types;

namespace TimeKeeper.Database {
  public class TDatabase : DatabaseDriver, IDisposable {
    private static TDatabase instance;

    private TDatabase() : base(StaticConfig.DbConfig.Engine, StaticConfig.DbConfig.Host, StaticConfig.DbConfig.Port, StaticConfig.DbConfig.Db, StaticConfig.DbConfig.User, StaticConfig.DbConfig.Pass, new DatabaseEngine[] { DatabaseEngine.Mysql}) {
      // Try and Reconnect
      try {
        Connect();

        // Try to get the database version
        try {
          if(base.Query("SELECT dbver FROM _version LIMIT 1").Count == 0)
            throw new Exception();
        } catch {
          base.Execute(Utils.GetResourceAsString("TimeKeeper.Database.SQL.MySQL.Install.sql"));
        }
      } catch(Exception) {
        if(Connection != null)
          Connection.Dispose();

        throw;
      }
    }

    public static TDatabase getInstance() {
      if(instance == null) {
        instance = new TDatabase();
      }
      return instance;
    }

    ~TDatabase() {
      if(!IsDisposed)
        base.Dispose();
    }

    internal void addWorking(WorkMessage m) {
      List<Dictionary<String, Object>> dayItems = this.getWorkOnDay(m.time);
      if(dayItems.Count == 0 && m.working == 1) {
        this.insertStartWork(m.time, m.jobID);
      } else if(dayItems.Count > 0) {
        int started = -1;
        int job = -1;
        foreach(Dictionary<String, Object> dayItem in dayItems) {
          if((TimeSpan)dayItem["stop"] == TimeSpan.Zero) {
            started = (int)dayItem["id"];
            job = (int)dayItem["location"];
            break;
          }
        }
        if(started != -1 && m.working == 0 && m.jobID == job) {
          this.updateStopWorking(started, m.time);
        } else if(started == -1 && m.working == 1) {
          this.insertStartWork(m.time, m.jobID);
        } else {
          throw new NotImplementedException();
        }
      } else {
        throw new NotImplementedException();
      }
    }

    private void updateStopWorking(Int32 started, DateTime time) {
      base.Execute("UPDATE `work` SET stop=@P0 WHERE id=@P1",
          time.ToString("HH:mm:ss"), started.ToString());
    }

    internal bool insertStartWork(DateTime time, Int32 jobID) {
      int Rows = base.Execute("INSERT INTO `work` (`date`, `start`, `type`, `location`) VALUES (@P0, @P1, @P2, @P3)",
          time.ToString("yyyy-MM-dd"), time.ToString("HH:mm:ss"), "ok", jobID.ToString()
      );
      return (Rows != 0);
    }

    internal List<Dictionary<String, Object>> getWorkOnDay(DateTime time) {
      return base.Query("SELECT * FROM `work` WHERE date=@P0 ORDER BY `start` ASC", time.ToString("yyyy-MM-dd"));
    }

    /// <summary>
    /// Returns the number of accounts in the database
    /// </summary>
    /// <returns></returns>
    public int GetNumAccounts() {
      var Row = base.Query("SELECT COUNT(id) AS count FROM accounts");
      return Int32.Parse(Row[0]["count"].ToString());
    }
  }
}