using System;
using System.Collections.Generic;
using System.Text;
using SalsaModel.Scheduling;
using Microsoft.DirectX;
using Microsoft.DirectX.Direct3D;
using System.Drawing;

namespace SalsaModel
{
    class ShowTimeLine : IScene
    {
        TimeLine _timeLine;
        Timing _timing;
        Location _loc;

        const int _width = 200;

        public ShowTimeLine(TimeLine timeLine, Timing timing, Location loc)
        {
            _timeLine = timeLine;
            _timing = timing;
            _loc = loc;
        }

        Microsoft.DirectX.Direct3D.Device _dev;
        BasicDrawing _drawing = new BasicDrawing();
        Message3D _helloMsg;
        public void Setup(Microsoft.DirectX.Direct3D.Device dev)
        {
            _dev = dev;
            _drawing.Setup(dev);

            _helloMsg = new Message3D(_dev, "hello", 0.05f);
        }

        Dictionary<string, Message3D> _msgs = new Dictionary<string, Message3D>();
        public Message3D Message(string msg)
        {
            Message3D rv;
            if (!_msgs.TryGetValue(msg, out rv))
            {
                rv = new Message3D(_dev, msg, 0.05f);
                _msgs.Add(msg, rv);
            }
            return rv;
        }

        public void Draw()
        {
            Matrix oldview = _dev.Transform.View;
            Matrix oldProj = _dev.Transform.Projection;

            float angle = (float)-Math.PI / 2.0f;
            _dev.Transform.View = Matrix.LookAtLH(new Vector3((float)(300 * Math.Cos(angle)), 0, (float)(300 * Math.Sin(angle))), new Vector3(0, 0, 0), new Vector3(0, 1, 0));

            const int beatsBefore = 8;
            const int beatsAfter = 8;
            double midTime = _timing.GlobalBeat() + _timing.Percent();
            double startTime = midTime - beatsBefore;
            double endTime = midTime + beatsAfter;

            const double barHeight = 5.0;
            HeightManager hgts = new HeightManager(barHeight * 1.2);
            foreach (EventRecord evtRec in _timeLine.EventsBetween(startTime, endTime))
            {
                double evtStartPct = ((evtRec.Start - midTime) / (endTime - startTime));
                double evtStopPct = ((evtRec.Stop - midTime - evtRec.Duration * 0.1) / (endTime - startTime));

                double height = hgts.Add(evtStartPct, evtStopPct);
                FlatLine(_loc.Plus(_width * evtStartPct, height, 0),_loc.Plus(_width * evtStopPct, height, 0),
                    barHeight/2.0, Color.BlanchedAlmond);

                Message(evtRec.Event.DescriptiveCode).DrawStartingAt(_dev, _loc.Plus(_width * evtStartPct, height - barHeight * 0.2, -1), barHeight, _drawing.Material(Color.Black));
            }

            for (int beat = -beatsBefore; beat < beatsAfter; ++beat)
            {
                int thisBeat = _timing.GlobalBeat() + beat;
                int beatNum = ((thisBeat - 1) % 8) + 1;
                double pct = ((thisBeat - midTime) / (endTime - startTime));
                Message(beatNum.ToString()).DrawStartingAt(_dev, _loc.Plus(_width * pct, - barHeight * 2, -1), barHeight, _drawing.Material(Color.BlanchedAlmond));
            }

            FlatTriangle(_loc.Plus(0, -10.0, 0), _loc.Plus(0, 15.0, 0),
                1.0, Color.Red);

            _dev.Transform.View = oldview;
            _dev.Transform.Projection = oldProj;
        }

        class HeightManager
        {
            class Extent
            {
                public Extent(double start, double stop, double height)
                {
                    Start = start;
                    Stop = stop;
                    Height = height;
                }
                public readonly double Start;
                public readonly double Stop;
                public readonly double Height;
                public bool Overlaps(double start, double stop)
                {
                    return (start < this.Stop && stop > this.Start);
                }
            }

            public HeightManager(double gap)
            {
                _gap = gap;
            }
            List<Extent> _extents = new List<Extent>();
            double _gap;
            public double Add(double start, double stop)
            {
                double height = 0.0;
                foreach (Extent ext in _extents)
                {
                    if (ext.Overlaps(start, stop))
                    {
                        height = Math.Max(height, ext.Height + _gap);
                    }
                }
                _extents.Add(new Extent(start, stop, height));
                return height;
            }
        }

        public void FlatLine(Location a, Location b, double height, Color color)
        {
            CustomVertex.PositionOnly[] vertices = new CustomVertex.PositionOnly[4];

            Location off = b.Minus(a);
            Location radius = off.CrossWithZ().Normalised().Scale(height);

            int v = 0;
            double raise = 0.0;
            vertices[v++] = new CustomVertex.PositionOnly(BasicDrawing.Vec3(a.Plus(radius).Plus(0, 0, raise)));
            vertices[v++] = new CustomVertex.PositionOnly(BasicDrawing.Vec3(a.Minus(radius).Plus(0, 0, raise)));
            vertices[v++] = new CustomVertex.PositionOnly(BasicDrawing.Vec3(b.Plus(radius).Plus(0, 0, raise)));
            vertices[v++] = new CustomVertex.PositionOnly(BasicDrawing.Vec3(b.Minus(radius).Plus(0, 0, raise)));

            _dev.VertexFormat = CustomVertex.PositionOnly.Format;
            _dev.Material = _drawing.Material(color);
            _dev.DrawUserPrimitives(PrimitiveType.TriangleStrip, 2, vertices);
        }

        public void FlatTriangle(Location a, Location b, double height, Color color)
        {
            CustomVertex.PositionOnly[] vertices = new CustomVertex.PositionOnly[4];

            Location off = b.Minus(a);
            Location radius = off.CrossWithZ().Normalised().Scale(height);

            int v = 0;
            double raise = 0.0;
            vertices[v++] = new CustomVertex.PositionOnly(BasicDrawing.Vec3(a.Plus(radius).Plus(0, 0, raise)));
            vertices[v++] = new CustomVertex.PositionOnly(BasicDrawing.Vec3(a.Minus(radius).Plus(0, 0, raise)));
            vertices[v++] = new CustomVertex.PositionOnly(BasicDrawing.Vec3(b.Plus(0, 0, raise)));

            _dev.VertexFormat = CustomVertex.PositionOnly.Format;
            _dev.Material = _drawing.Material(color);
            _dev.DrawUserPrimitives(PrimitiveType.TriangleStrip, 1, vertices);
        }

    }
}