using System;
using System.Collections.Generic;
using Server.Items;
using Server.Network;

namespace Server.Misc
{
  public class Weather
  {
    private static Map[] m_Facets;
    private static Dictionary<Map, List<Weather>> m_WeatherByFacet = new Dictionary<Map, List<Weather>>();

    public static void Initialize()
    {
      m_Facets = new[]{ Map.Felucca, Map.Trammel };

      /* Static weather:
       *
       * Format:
       *   AddWeather( temperature, chanceOfPercipitation, chanceOfExtremeTemperature, <area ...> );
       */

      // ice island
      AddWeather( -15, 100, 5, new Rectangle2D( 3850, 160, 390, 320 ), new Rectangle2D( 3900, 480, 380, 180 ), new Rectangle2D( 4160, 660, 150, 110 ) );

      // covetous entrance, around vesper and minoc
      AddWeather( +15,  50, 5, new Rectangle2D( 2425, 725, 250, 250 ) );

      // despise entrance, north of britain
      AddWeather( +15,  50, 5, new Rectangle2D( 1245, 1045, 250, 250 ) );


      /* Dynamic weather:
       *
       * Format:
       *   AddDynamicWeather( temperature, chanceOfPercipitation, chanceOfExtremeTemperature, moveSpeed, width, height, bounds );
       */

      for ( int i = 0; i < 15; ++i )
        AddDynamicWeather( +15, 100, 5, 8, 400, 400, new Rectangle2D( 0, 0, 5120, 4096 ) );
    }

    public static List<Weather> GetWeatherList( Map facet )
    {
      if ( facet == null )
        return null;

      if (!m_WeatherByFacet.TryGetValue( facet, out List<Weather> list ))
        m_WeatherByFacet[facet] = list = new List<Weather>();

      return list;
    }

    public static void AddDynamicWeather( int temperature, int chanceOfPercipitation, int chanceOfExtremeTemperature, int moveSpeed, int width, int height, Rectangle2D bounds )
    {
      for ( int i = 0; i < m_Facets.Length; ++i )
      {
        Rectangle2D area = new Rectangle2D();
        bool isValid = false;

        for ( int j = 0; j < 10; ++j )
        {
          area = new Rectangle2D( bounds.X + Utility.Random( bounds.Width - width ), bounds.Y + Utility.Random( bounds.Height - height ), width, height );

          if ( !CheckWeatherConflict( m_Facets[i], null, area ) )
            isValid = true;

          if ( isValid )
            break;
        }

        if ( !isValid )
          continue;

        new Weather(m_Facets[i], new[] { area }, temperature, chanceOfPercipitation, chanceOfExtremeTemperature,
          TimeSpan.FromSeconds(30.0)) { Bounds = bounds, MoveSpeed = moveSpeed };
      }
    }

    public static void AddWeather( int temperature, int chanceOfPercipitation, int chanceOfExtremeTemperature, params Rectangle2D[] area )
    {
      for ( int i = 0; i < m_Facets.Length; ++i )
        new Weather( m_Facets[i], area, temperature, chanceOfPercipitation, chanceOfExtremeTemperature, TimeSpan.FromSeconds( 30.0 ) );
    }

    public static bool CheckWeatherConflict( Map facet, Weather exclude, Rectangle2D area )
    {
      List<Weather> list = GetWeatherList( facet );

      if ( list == null )
        return false;

      for ( int i = 0; i < list.Count; ++i )
      {
        Weather w = list[i];

        if ( w != exclude && w.IntersectsWith( area ) )
          return true;
      }

      return false;
    }

    public Map Facet { get; }

    public Rectangle2D[] Area { get; set; }

    public int Temperature { get; set; }

    public int ChanceOfPercipitation { get; set; }

    public int ChanceOfExtremeTemperature { get; set; }

    // For dynamic weather:

    public Rectangle2D Bounds { get; set; }

    public int MoveSpeed { get; set; }

    public int MoveAngleX { get; set; }

    public int MoveAngleY { get; set; }

    public static bool CheckIntersection( Rectangle2D r1, Rectangle2D r2 ) => r1.X < r2.X + r2.Width && r2.X < r1.X + r1.Width && r1.Y < r2.Y + r2.Height && r2.Y < r1.Y + r1.Height;

    public static bool CheckContains( Rectangle2D big, Rectangle2D small ) =>
      small.X >= big.X && small.Y >= big.Y && small.X + small.Width <= big.X + big.Width
      && small.Y + small.Height <= big.Y + big.Height;

    public virtual bool IntersectsWith( Rectangle2D area )
    {
      for ( int i = 0; i < Area.Length; ++i )
        if ( CheckIntersection( area, Area[i] ) )
          return true;

      return false;
    }

    public Weather( Map facet, Rectangle2D[] area, int temperature, int chanceOfPercipitation, int chanceOfExtremeTemperature, TimeSpan interval )
    {
      Facet = facet;
      Area = area;
      Temperature = temperature;
      ChanceOfPercipitation = chanceOfPercipitation;
      ChanceOfExtremeTemperature = chanceOfExtremeTemperature;

      List<Weather> list = GetWeatherList( facet );

      list?.Add( this );

      Timer.DelayCall( TimeSpan.FromSeconds( (0.2+Utility.RandomDouble()*0.8) * interval.TotalSeconds ), interval, OnTick );
    }

    public virtual void Reposition()
    {
      if ( Area.Length == 0 )
        return;

      int width = Area[0].Width;
      int height = Area[0].Height;

      Rectangle2D area = new Rectangle2D();
      bool isValid = false;

      for ( int j = 0; j < 10; ++j )
      {
        area = new Rectangle2D( Bounds.X + Utility.Random( Bounds.Width - width ), Bounds.Y + Utility.Random( Bounds.Height - height ), width, height );

        if ( !CheckWeatherConflict( Facet, this, area ) )
          isValid = true;

        if ( isValid )
          break;
      }

      if ( !isValid )
        return;

      Area[0] = area;
    }

    public virtual void RecalculateMovementAngle()
    {
      double angle = Utility.RandomDouble() * Math.PI * 2.0;

      double cos = Math.Cos( angle );
      double sin = Math.Sin( angle );

      MoveAngleX = (int)(100 * cos);
      MoveAngleY = (int)(100 * sin);
    }

    public virtual void MoveForward()
    {
      if ( Area.Length == 0 )
        return;

      for ( int i = 0; i < 5; ++i ) // try 5 times to find a valid spot
      {
        int xOffset = MoveSpeed * MoveAngleX / 100;
        int yOffset = MoveSpeed * MoveAngleY / 100;

        Rectangle2D oldArea = Area[0];
        Rectangle2D newArea = new Rectangle2D( oldArea.X + xOffset, oldArea.Y + yOffset, oldArea.Width, oldArea.Height );

        if ( !CheckWeatherConflict( Facet, this, newArea ) && CheckContains( Bounds, newArea ) )
        {
          Area[0] = newArea;
          break;
        }

        RecalculateMovementAngle();
      }
    }

    private int m_Stage;
    private bool m_Active;
    private bool m_ExtremeTemperature;

    public virtual void OnTick()
    {
      if ( m_Stage == 0 )
      {
        m_Active = ChanceOfPercipitation > Utility.Random( 100 );
        m_ExtremeTemperature = ChanceOfExtremeTemperature > Utility.Random( 100 );

        if ( MoveSpeed > 0 )
        {
          Reposition();
          RecalculateMovementAngle();
        }
      }

      if ( m_Active )
      {
        if ( m_Stage > 0 && MoveSpeed > 0 )
          MoveForward();

        int type, density;
        int temperature = Temperature;

        if ( m_ExtremeTemperature )
          temperature *= -1;

        if ( m_Stage < 15 )
        {
          density = m_Stage * 5;
        }
        else
        {
          density = 150 - m_Stage * 5;

          if ( density < 10 )
            density = 10;
          else if ( density > 70 )
            density = 70;
        }

        if ( density == 0 )
          type = 0xFE;
        else if ( temperature > 0 )
          type = 0;
        else
          type = 2;

        List<NetState> states = NetState.Instances;

        Packet weatherPacket = null;

        for ( int i = 0; i < states.Count; ++i )
        {
          NetState ns = states[i];
          Mobile mob = ns.Mobile;

          if ( mob == null || mob.Map != Facet )
            continue;

          bool contains = Area.Length == 0;

          for ( int j = 0; !contains && j < Area.Length; ++j )
            contains = Area[j].Contains( mob.Location );

          if ( !contains )
            continue;

          if ( weatherPacket == null )
            weatherPacket = Packet.Acquire( new Server.Network.Weather( type, density, temperature ) );

          ns.Send( weatherPacket );
        }

        Packet.Release( weatherPacket );
      }

      m_Stage++;
      m_Stage %= 30;
    }
  }

  public class WeatherMap : MapItem
  {
    public override string DefaultName => "weather map";

    [Constructible]
    public WeatherMap()
    {
      SetDisplay( 0, 0, 5119, 4095, 400, 400 );
    }

    public override void OnDoubleClick( Mobile from )
    {
      Map facet = from.Map;

      if ( facet == null )
        return;

      List<Weather> list = Weather.GetWeatherList( facet );

      ClearPins();

      for ( int i = 0; i < list.Count; ++i )
      {
        Weather w = list[i];

        for ( int j = 0; j < w.Area.Length; ++j )
          AddWorldPin( w.Area[j].X + w.Area[j].Width/2, w.Area[j].Y + w.Area[j].Height/2 );
      }

      base.OnDoubleClick( from );
    }

    public WeatherMap( Serial serial ) : base( serial )
    {
    }

    public override void Serialize(IGenericWriter writer )
    {
      base.Serialize( writer );

      writer.Write( 0 );
    }

    public override void Deserialize( IGenericReader reader )
    {
      base.Deserialize( reader );

      int version = reader.ReadInt();
    }
  }
}