#include <sourcemod>
#include <sdktools>
#include sdkhooks

#pragma tabsize 0

float iGrenade = 500.0
float iPipe = 300.0
float iBarrel = 600.0

float iRadiusG = 400.0
float iRadiusP = 200.0
float iRadiusB = 500.0

float iGrenadeflint = 600.0
float iPipeflint = 100.0
float iBarrelflint = 250.0

Handle sdkCallPushPlayer;

public OnPluginStart()
{
    Handle GameConf = LoadGameConfigFile("StaggerInfected");
    StartPrepSDKCall(SDKCall_Player);
    PrepSDKCall_SetFromConf(GameConf, SDKConf_Signature, "CTerrorPlayer_OnStaggered");
    PrepSDKCall_AddParameter(SDKType_CBaseEntity, SDKPass_Pointer);
    PrepSDKCall_AddParameter(SDKType_Vector, SDKPass_ByRef);
    sdkCallPushPlayer = EndPrepSDKCall();
}

public void OnEntityDestroyed(int entity)
{
    if (IsValidEntity(entity) && IsValidEdict(entity))
    {
        char classname[128];
        GetEdictClassname(entity, classname, 128);
        if (StrEqual(classname, "grenade_launcher_projectile", false))
        {
            float bPos[3]
            GetEntPropVector(entity, Prop_Send, "m_vecOrigin", bPos);
            for (new i = 1; i <= MaxClients; i++)
            {
                if(IsValidInfected(i) && GetEntProp(i, Prop_Send, "m_zombieClass") < 6)
                {
                    float vPos[3]
                    GetEntPropVector(i, Prop_Send, "m_vecOrigin", vPos);
                    if (!IsVisibleTo(bPos, vPos)) continue;

                    int iCreator = GetEntPropEnt(entity, Prop_Send, "m_hThrower")
                    float fTargetDistance = GetVectorDistance(bPos, vPos);
                    if(fTargetDistance < iRadiusG)
                    {
                        float vTransit = iRadiusG - fTargetDistance
                        float vForward =  iRadiusG / vTransit
                        int iTotal = RoundToCeil(iGrenade / (vForward * vForward * vForward));
                        ForceDamageEntity(iCreator, iTotal, i)
                    }
                    if(fTargetDistance < iGrenadeflint)
                    {
                        SDKCall(sdkCallPushPlayer, i, iCreator, bPos);
                    }
                }
            }
        }
        if (StrEqual(classname, "pipe_bomb_projectile", false))
        {
            float bPos[3]
            GetEntPropVector(entity, Prop_Send, "m_vecOrigin", bPos);
            for (new i = 1; i <= MaxClients; i++)
            {
                if(IsValidInfected(i) && GetEntProp(i, Prop_Send, "m_zombieClass") < 6)
                {
                    float vPos[3]
                    GetEntPropVector(i, Prop_Send, "m_vecOrigin", vPos);
                    if (!IsVisibleTo(bPos, vPos)) continue;

                    int iOwner = GetEntPropEnt(entity, Prop_Send, "m_hThrower")
                    float fTargetDistance = GetVectorDistance(bPos, vPos);
                    if(fTargetDistance < iRadiusP)
                    {
                        float vTransit = iRadiusP - fTargetDistance
                        float vForward =  iRadiusP / vTransit
                        int iTotal = RoundToCeil(iPipe / (vForward * vForward * vForward));
                        ForceDamageEntity(iOwner, iTotal, i)
                    }
                    if(fTargetDistance < iPipeflint)
                    {
                        SDKCall(sdkCallPushPlayer, i, iOwner, bPos);
                    }
                }
            }
        }
        if (StrEqual(classname, "prop_fuel_barrel", false))
        {
            float bPos[3]
            GetEntPropVector(entity, Prop_Send, "m_vecOrigin", bPos);
            for (new i = 1; i <= MaxClients; i++)
            {
                if(IsValidInfected(i) && GetEntProp(i, Prop_Send, "m_zombieClass") < 6)
                {
                    float vPos[3]
                    GetEntPropVector(i, Prop_Send, "m_vecOrigin", vPos);
                    if (!IsVisibleTo(bPos, vPos)) continue;

                    float fTargetDistance = GetVectorDistance(bPos, vPos);
                    if(fTargetDistance < iRadiusB)
                    {
                        float vTransit = iRadiusB - fTargetDistance
                        float vForward =  iRadiusB / vTransit
                        int iTotal = RoundToCeil(iBarrel / (vForward * vForward * vForward));
                        ForceDamageEntity(i, iTotal, i)
                    }
                    if(fTargetDistance < iBarrelflint)
                    {
                        SDKCall(sdkCallPushPlayer, i, entity, bPos);
                    }
                }
            }
        }
    }
}

stock void ForceDamageEntity(int causer, int damage, int victim) // thanks to 达斯*维达
{
    float victim_origin[3];
    char rupture[32];
    char damage_victim[32];
    IntToString(damage, rupture, sizeof(rupture));
    Format(damage_victim, sizeof(damage_victim), "hurtme%d", victim);
    GetEntPropVector(victim, Prop_Send, "m_vecOrigin", victim_origin);
    int entity = CreateEntityByName("point_hurt");
    DispatchKeyValue(victim, "targetname", damage_victim);
    DispatchKeyValue(entity, "DamageTarget", damage_victim);
    DispatchKeyValue(entity, "Damage", rupture);
    DispatchSpawn(entity);
    TeleportEntity(entity, victim_origin, NULL_VECTOR, NULL_VECTOR);
    AcceptEntityInput(entity, "Hurt", (causer > 0 && causer <= MaxClients) ? causer : -1);
    DispatchKeyValue(entity, "classname", "point_hurt");
    DispatchKeyValue(victim, "targetname", "null");
    AcceptEntityInput(entity, "Kill");
}

static bool IsVisibleTo(float position[3], float targetposition[3])
{
    float vAngles[3], vLookAt[3];

    MakeVectorFromPoints(position, targetposition, vLookAt); // compute vector from start to target
    GetVectorAngles(vLookAt, vAngles); // get angles from vector for trace

    // execute Trace
    Handle trace = TR_TraceRayFilterEx(position, vAngles, MASK_SHOT, RayType_Infinite, _TraceFilter);

    bool isVisible = false;
    if (TR_DidHit(trace))
    {
        float vStart[3];
        TR_GetEndPosition(vStart, trace); // retrieve our trace endpoint

        if ((GetVectorDistance(position, vStart, false) + 25.0) >= GetVectorDistance(position, targetposition))
        {
            isVisible = true; // if trace ray length plus tolerance equal or bigger absolute distance, you hit the target
        }
    }

    return isVisible;
}

public bool _TraceFilter(int entity, int contentsMask)
{
    if (!entity || entity <= MaxClients || !IsValidEntity(entity)) // dont let WORLD, or invalid entities be hit
    {
        return false;
    }
    return true;
}

stock bool:IsValidInfected( client )
{
    if ( client < 1 || client > MaxClients ) return false;
    if ( !IsClientConnected( client )) return false;
    if ( !IsClientInGame( client )) return false;
    if ( GetClientTeam( client ) != 3 ) return false;
    return true;
}