// Proprietary code of Avination Virtual Limited
// (c) 2012 Melanie Thielker, Leal Duarte
//

using System;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using System.Text;

using OpenMetaverse;
using OpenMetaverse.StructuredData;

using OpenSim.Framework;
using OpenSim.Region.Framework;
using OpenSim.Region.Framework.Scenes;
using OpenSim.Framework.Capabilities;

using ComponentAce.Compression.Libs.zlib;

using OSDArray = OpenMetaverse.StructuredData.OSDArray;
using OSDMap = OpenMetaverse.StructuredData.OSDMap;

namespace OpenSim.Region.ClientStack.Linden
{
    public struct ModelPrimLimits
    {
        
    }

    public class ModelCost
    {

        // upload fee defaults
        // fees are normalized to 1.0
        // this parameters scale them to basic cost ( so 1.0 translates to 10 )

        public float ModelMeshCostFactor = 0.0f; // scale total cost relative to basic (excluding textures)
        public float ModelTextureCostFactor = 1.0f; // scale textures fee to basic.
        public float ModelMinCostFactor = 0.0f; // 0.5f; // minimum total model free excluding textures

        // itens costs in normalized values
        // ie will be multiplied by basicCost and factors above
        public float primCreationCost = 0.002f;  // extra cost for each prim creation overhead
        // weigthed size to normalized cost
        public float bytecost = 1e-5f;

        // mesh upload fees based on compressed data sizes
        // several data sections are counted more that once
        // to promote user optimization
        // following parameters control how many extra times they are added
        // to global size.
        // LOD meshs
        const float medSizeWth = 1f; // 2x
        const float lowSizeWth = 1.5f; // 2.5x
        const float lowestSizeWth = 2f; // 3x
        // favor potencially physical optimized meshs versus automatic decomposition
        const float physMeshSizeWth = 6f; // counts  7x
        const float physHullSizeWth = 8f; // counts  9x      

        // stream cost area factors 
        // more or less like SL
        const float highLodFactor = 17.36f;
        const float midLodFactor = 277.78f;
        const float lowLodFactor = 1111.11f;

        // physics cost is below, identical to SL, assuming shape type convex
        // server cost is below identical to SL assuming non scripted non physical object

        // internal
        const int bytesPerCoord = 6; // 3 coords, 2 bytes per each

        // control prims dimensions
        public float PrimScaleMin = 0.001f;
        public float NonPhysicalPrimScaleMax = 256f;
        public float PhysicalPrimScaleMax = 10f;
        public int ObjectLinkedPartsMax = 512;

        // storage for a single mesh asset cost parameters       
        private class ameshCostParam
        {
            // LOD sizes for size dependent streaming cost
            public int highLODSize;
            public int medLODSize;
            public int lowLODSize;
            public int lowestLODSize;
            // normalized fee based on compressed data sizes
            public float costFee;
            // physics cost
            public float physicsCost;
        }

        // calculates a mesh model costs
        // returns false on error, with a reason on parameter error
        // resources input LLSD request
        // basicCost input region assets upload cost
        // totalcost returns model total upload fee
        // meshcostdata returns detailed costs for viewer 
        // avatarSkeleton if mesh includes a avatar skeleton
        // useAvatarCollider if we should use physics mesh for avatar
        public bool MeshModelCost(LLSDAssetResource resources, int basicCost, out int totalcost,
            LLSDAssetUploadResponseData meshcostdata,out bool avatarSkeleton, out bool useAvatarCollider,
            out string error, ref string warning)
        {
            totalcost = 0;
            error = string.Empty;

            avatarSkeleton = false;
            useAvatarCollider = false;

            if (resources == null ||
                resources.instance_list == null ||
                resources.instance_list.Array.Count == 0)
            {
                error = "missing model information.";
                return false;
            }

            int numberInstances = resources.instance_list.Array.Count;

            if( numberInstances > ObjectLinkedPartsMax )
            {
                error = "Model whould have more than " + ObjectLinkedPartsMax.ToString() + " linked prims";
                return false;
            }

            meshcostdata.model_streaming_cost = 0.0;
            meshcostdata.simulation_cost = 0.0;
            meshcostdata.physics_cost = 0.0;
            meshcostdata.resource_cost = 0.0;

            meshcostdata.upload_price_breakdown.mesh_instance = 0;
            meshcostdata.upload_price_breakdown.mesh_physics = 0;
            meshcostdata.upload_price_breakdown.mesh_streaming = 0;
            meshcostdata.upload_price_breakdown.model = 0;

            int itmp;

            // textures cost
            if (resources.texture_list != null && resources.texture_list.Array.Count > 0)
            {
                float textures_cost = (float)(resources.texture_list.Array.Count * basicCost);
                textures_cost *= ModelTextureCostFactor;

                itmp = (int)(textures_cost + 0.5f); // round
                meshcostdata.upload_price_breakdown.texture = itmp;
                totalcost += itmp;
            }

            // meshs assets cost
            float meshsfee = 0;
            int numberMeshs = 0;
            bool haveMeshs = false;

            bool curskeleton;
            bool curAvatarPhys;

            List<ameshCostParam> meshsCosts = new List<ameshCostParam>();

            if (resources.mesh_list != null && resources.mesh_list.Array.Count > 0)
            {
                numberMeshs = resources.mesh_list.Array.Count;
                
                for (int i = 0; i < numberMeshs; i++)
                {
                    ameshCostParam curCost = new ameshCostParam();
                    byte[] data = (byte[])resources.mesh_list.Array[i];

                    if (!MeshCost(data, curCost,out curskeleton, out curAvatarPhys, out error))
                    {
                        return false;
                    }

                    if (curskeleton)
                    {
                        if (avatarSkeleton)
                        {
                            error = "model can only contain a avatar skeleton";
                            return false;
                        }
                        avatarSkeleton = true;
                    }
                    meshsCosts.Add(curCost);
                    meshsfee += curCost.costFee;
                }
                haveMeshs = true;
            }

            // instances (prims) cost
            

            int mesh;
            int skipedSmall = 0;
            for (int i = 0; i < numberInstances; i++)
            {
                Hashtable inst = (Hashtable)resources.instance_list.Array[i];

                ArrayList ascale = (ArrayList)inst["scale"];
                Vector3 scale;
                double tmp;
                tmp = (double)ascale[0];
                scale.X = (float)tmp;
                tmp = (double)ascale[1];
                scale.Y = (float)tmp;
                tmp = (double)ascale[2];
                scale.Z = (float)tmp;

                if (scale.X < PrimScaleMin || scale.Y < PrimScaleMin || scale.Z < PrimScaleMin)
                {
                    skipedSmall++;
                    continue;
                }

                if (scale.X > NonPhysicalPrimScaleMax || scale.Y > NonPhysicalPrimScaleMax || scale.Z > NonPhysicalPrimScaleMax)
                {
                    error = "Model contains parts with sides larger than " + NonPhysicalPrimScaleMax.ToString() + "m. Please ajust scale";
                    return false;
                }

                if (haveMeshs && inst.ContainsKey("mesh"))
                {
                    mesh = (int)inst["mesh"];

                    if (mesh >= numberMeshs)
                    {
                        error = "Incoerent model information.";
                        return false;
                    }

                    // streamming cost

                    float sqdiam = scale.LengthSquared();

                    ameshCostParam curCost = meshsCosts[mesh];
                    float mesh_streaming = streamingCost(curCost, sqdiam);

                    meshcostdata.model_streaming_cost += mesh_streaming;
                    meshcostdata.physics_cost += curCost.physicsCost;
                }
                else // instance as no mesh ??
                {
                    // to do later if needed
                    meshcostdata.model_streaming_cost += 0.5f;
                    meshcostdata.physics_cost += 1.0f;
                }

                // assume unscripted and static prim server cost
                meshcostdata.simulation_cost += 0.5f;
                // charge for prims creation
                meshsfee += primCreationCost;
            }

            if (skipedSmall > 0)
            {
                if (skipedSmall > numberInstances / 2)
                {
                    error = "Model contains too many prims smaller than " + PrimScaleMin.ToString() +
                        "m minimum allowed size. Please check scalling";
                    return false;
                }
                else
                    warning += skipedSmall.ToString() + " of the requested " +numberInstances.ToString() +
                        " model prims will not upload because they are smaller than " + PrimScaleMin.ToString() +
                        "m minimum allowed size. Please check scalling ";
            }

            if (meshcostdata.physics_cost <= meshcostdata.model_streaming_cost)
                meshcostdata.resource_cost = meshcostdata.model_streaming_cost;
            else
                meshcostdata.resource_cost = meshcostdata.physics_cost;

            if (meshcostdata.resource_cost < meshcostdata.simulation_cost)
                meshcostdata.resource_cost = meshcostdata.simulation_cost;

            // scale cost
            // at this point a cost of 1.0 whould mean basic cost
            meshsfee *= ModelMeshCostFactor;

            if (meshsfee < ModelMinCostFactor)
                meshsfee = ModelMinCostFactor;

            // actually scale it to basic cost
            meshsfee *= (float)basicCost;

            meshsfee += 0.5f; // rounding

            totalcost += (int)meshsfee;

            // breakdown prices
            // don't seem to be in use so removed code for now
            
            return true;
        }

        // single mesh asset cost
        private bool MeshCost(byte[] data, ameshCostParam cost,out bool skeleton, out bool avatarPhys, out string error)
        {
            cost.highLODSize = 0;
            cost.medLODSize = 0;
            cost.lowLODSize = 0;
            cost.lowestLODSize = 0;
            cost.physicsCost = 0.0f;
            cost.costFee = 0.0f;

            error = string.Empty;

            skeleton = false;
            avatarPhys = false;

            if (data == null || data.Length == 0)
            {
                error = "Missing model information.";
                return false;
            }

            OSD meshOsd = null;
            int start = 0;

            error = "Invalid model data";

            using (MemoryStream ms = new MemoryStream(data))
            {
                try
                {
                    OSD osd = OSDParser.DeserializeLLSDBinary(ms);
                    if (osd is OSDMap)
                        meshOsd = (OSDMap)osd;
                    else
                        return false;
                }
                catch (Exception e)
                {
                    return false;
                }
                start = (int)ms.Position;
            }

            OSDMap map = (OSDMap)meshOsd;
            OSDMap tmpmap;

            int highlod_size = 0;
            int medlod_size = 0;
            int lowlod_size = 0;
            int lowestlod_size = 0;
            int skin_size = 0;

            int hulls_size = 0;
            int phys_nhulls;
            int phys_hullsvertices = 0;

            int physmesh_size = 0;
            int phys_ntriangles = 0;

            int submesh_offset = -1;

            if (map.ContainsKey("skeleton"))
            {
                tmpmap = (OSDMap)map["skeleton"];
                if (tmpmap.ContainsKey("offset") && tmpmap.ContainsKey("size"))
                {
                    int sksize = tmpmap["size"].AsInteger();
                    if(sksize > 0)
                        skeleton = true;
                }               
            }

            if (map.ContainsKey("physics_convex"))
            {
                tmpmap = (OSDMap)map["physics_convex"];
                if (tmpmap.ContainsKey("offset"))
                    submesh_offset = tmpmap["offset"].AsInteger() + start;
                if (tmpmap.ContainsKey("size"))
                    hulls_size = tmpmap["size"].AsInteger();
            }

            if (submesh_offset < 0 || hulls_size == 0)
            {
                error = "Missing physics_convex block";
                return false;
            }

            if (!hulls(data, submesh_offset, hulls_size, out phys_hullsvertices, out phys_nhulls))
            {
                error = "Bad physics_convex block";
                return false;
            }

            submesh_offset = -1;
            
            // only look for LOD meshs sizes

            if (map.ContainsKey("high_lod"))
            {
                tmpmap = (OSDMap)map["high_lod"];
                // see at least if there is a offset for this one
                if (tmpmap.ContainsKey("offset"))
                    submesh_offset = tmpmap["offset"].AsInteger() + start;
                if (tmpmap.ContainsKey("size"))
                    highlod_size = tmpmap["size"].AsInteger();
            }

            if (submesh_offset < 0 || highlod_size <= 0)
            {
                error = "Missing high_lod block";
                return false;
            }

            bool haveprev = true;

            if (map.ContainsKey("medium_lod"))
            {
                tmpmap = (OSDMap)map["medium_lod"];
                if (tmpmap.ContainsKey("size"))
                    medlod_size = tmpmap["size"].AsInteger();
                else
                    haveprev = false;
            }

            if (haveprev && map.ContainsKey("low_lod"))
            {
                tmpmap = (OSDMap)map["low_lod"];
                if (tmpmap.ContainsKey("size"))
                    lowlod_size = tmpmap["size"].AsInteger();
                else
                    haveprev = false;
            }

            if (haveprev && map.ContainsKey("lowest_lod"))
            {
                tmpmap = (OSDMap)map["lowest_lod"];
                if (tmpmap.ContainsKey("size"))
                    lowestlod_size = tmpmap["size"].AsInteger();
            }

            if (map.ContainsKey("skin"))
            {
                tmpmap = (OSDMap)map["skin"];
                if (tmpmap.ContainsKey("size"))
                    skin_size = tmpmap["size"].AsInteger();
            }

            cost.highLODSize = highlod_size;
            cost.medLODSize = medlod_size;
            cost.lowLODSize = lowlod_size;
            cost.lowestLODSize = lowestlod_size;

            submesh_offset = -1;

            tmpmap = null;
            if(map.ContainsKey("physics_mesh"))
                tmpmap = (OSDMap)map["physics_mesh"];
            else if (map.ContainsKey("physics_shape")) // old naming
                tmpmap = (OSDMap)map["physics_shape"];

            if(tmpmap != null)
            {
                if (tmpmap.ContainsKey("offset"))
                    submesh_offset = tmpmap["offset"].AsInteger() + start;
                if (tmpmap.ContainsKey("size"))
                    physmesh_size = tmpmap["size"].AsInteger();

                if (submesh_offset >= 0 || physmesh_size > 0)
                {

                    if (!submesh(data, submesh_offset, physmesh_size, out phys_ntriangles))
                    {
                        error = "Model data parsing error";
                        return false;
                    }
                }
            }

            // upload is done in convex shape type so only one hull
            phys_hullsvertices++;
            cost.physicsCost = 0.04f * phys_hullsvertices;

            float sfee;
            
            sfee = data.Length; // start with total compressed data size

            // penalize lod meshs that should be more builder optimized
            sfee += medSizeWth * medlod_size;
            sfee += lowSizeWth * lowlod_size;
            sfee += lowestSizeWth * lowlod_size;

            // physics
            // favor potencial optimized meshs versus automatic decomposition
            if (physmesh_size != 0)
                sfee += physMeshSizeWth * (physmesh_size + hulls_size / 4); // reduce cost of mandatory convex hull
            else
                sfee += physHullSizeWth * hulls_size;

            // bytes to money
            sfee *= bytecost;
           
            cost.costFee = sfee;
            return true;
        }

        // parses a LOD or physics mesh component
        private bool submesh(byte[] data, int offset, int size, out int ntriangles)
        {
            ntriangles = 0;

            OSD decodedMeshOsd = new OSD();
            byte[] meshBytes = new byte[size];
            System.Buffer.BlockCopy(data, offset, meshBytes, 0, size);
            try
            {
                using (MemoryStream inMs = new MemoryStream(meshBytes))
                {
                    using (MemoryStream outMs = new MemoryStream())
                    {
                        using (ZOutputStream zOut = new ZOutputStream(outMs))
                        {
                            byte[] readBuffer = new byte[4096];
                            int readLen = 0;
                            while ((readLen = inMs.Read(readBuffer, 0, readBuffer.Length)) > 0)
                            {
                                zOut.Write(readBuffer, 0, readLen);
                            }
                            zOut.Flush();
                            outMs.Seek(0, SeekOrigin.Begin);

                            byte[] decompressedBuf = outMs.GetBuffer();
                            decodedMeshOsd = OSDParser.DeserializeLLSDBinary(decompressedBuf);
                        }
                    }
                }
            }
            catch (Exception e)
            {
                return false;
            }

            OSDArray decodedMeshOsdArray = null;
            if ((!decodedMeshOsd is OSDArray))
                return false;

            byte[] dummy;

            decodedMeshOsdArray = (OSDArray)decodedMeshOsd;
            foreach (OSD subMeshOsd in decodedMeshOsdArray)
            {
                if (subMeshOsd is OSDMap)
                {
                    OSDMap subtmpmap = (OSDMap)subMeshOsd;
                    if (subtmpmap.ContainsKey("NoGeometry") && ((OSDBoolean)subtmpmap["NoGeometry"]))
                        continue;

                    if (!subtmpmap.ContainsKey("Position"))
                        return false;

                    if (subtmpmap.ContainsKey("TriangleList"))
                    {
                        dummy = subtmpmap["TriangleList"].AsBinary();
                        ntriangles += dummy.Length / bytesPerCoord;
                    }
                    else
                        return false;
                }
            }

            return true;
        }

        // parses convex hulls component
        private bool hulls(byte[] data, int offset, int size, out int nvertices, out int nhulls)
        {
            nvertices = 0;
            nhulls = 1;

            OSD decodedMeshOsd = new OSD();
            byte[] meshBytes = new byte[size];
            System.Buffer.BlockCopy(data, offset, meshBytes, 0, size);
            try
            {
                using (MemoryStream inMs = new MemoryStream(meshBytes))
                {
                    using (MemoryStream outMs = new MemoryStream())
                    {
                        using (ZOutputStream zOut = new ZOutputStream(outMs))
                        {
                            byte[] readBuffer = new byte[4096];
                            int readLen = 0;
                            while ((readLen = inMs.Read(readBuffer, 0, readBuffer.Length)) > 0)
                            {
                                zOut.Write(readBuffer, 0, readLen);
                            }
                            zOut.Flush();
                            outMs.Seek(0, SeekOrigin.Begin);

                            byte[] decompressedBuf = outMs.GetBuffer();
                            decodedMeshOsd = OSDParser.DeserializeLLSDBinary(decompressedBuf);
                        }
                    }
                }
            }
            catch (Exception e)
            {
                return false;
            }

            OSDMap cmap = (OSDMap)decodedMeshOsd;
            if (cmap == null)
                return false;

            byte[] dummy;

            // must have one of this
            if (cmap.ContainsKey("BoundingVerts"))
            {
                dummy = cmap["BoundingVerts"].AsBinary();
                nvertices = dummy.Length / bytesPerCoord;
            }
            else
                return false;

/* upload is done with convex shape type
            if (cmap.ContainsKey("HullList"))
            {
                dummy = cmap["HullList"].AsBinary();
                nhulls += dummy.Length;
            }


            if (cmap.ContainsKey("Positions"))
            {
                dummy = cmap["Positions"].AsBinary();
                nvertices = dummy.Length / bytesPerCoord;
            }
 */

            return true;
        }

        // returns streaming cost from on mesh LODs sizes in curCost and square of prim size length 
        private float streamingCost(ameshCostParam curCost, float sqdiam)
        {
            // compute efective areas
            float ma = 262144f;

            float mh = sqdiam * highLodFactor;
            if (mh > ma)
                mh = ma;
            float mm = sqdiam * midLodFactor;
            if (mm > ma)
                mm = ma;

            float ml = sqdiam * lowLodFactor;
            if (ml > ma)
                ml = ma;

            float mlst = ma;

            mlst -= ml;
            ml -= mm;
            mm -= mh;

            if (mlst < 1.0f)
                mlst = 1.0f;
            if (ml < 1.0f)
                ml = 1.0f;
            if (mm < 1.0f)
                mm = 1.0f;
            if (mh < 1.0f)
                mh = 1.0f;

            ma = mlst + ml + mm + mh;

            // get LODs compressed sizes
            // giving 384 bytes bonus
            int lst = curCost.lowestLODSize - 384;
            int l = curCost.lowLODSize - 384;
            int m = curCost.medLODSize - 384;
            int h = curCost.highLODSize - 384;

            // use previus higher LOD size on missing ones
            if (m <= 0)
                m = h;
            if (l <= 0)
                l = m;
            if (lst <= 0)
                lst = l;

            // force minumum sizes
            if (lst < 16)
                lst = 16;
            if (l < 16)
                l = 16;
            if (m < 16)
                m = 16;
            if (h < 16)
                h = 16;

            // compute cost weighted by relative effective areas
            float cost = (float)lst * mlst + (float)l * ml + (float)m * mm + (float)h * mh;
            cost /= ma;

            cost *= 0.004f; // overall tunning parameter

            return cost;
        }
    }
}