penDrone : CCombatDronePuppetEntity
-- penFoe : CPuppetEntity

local Math = import("Content/Shared/Scripts/Math.lua")
local bDebug = false

if bDebug then
  local srZero = CreateScriptedRenderer(worldGlobals.worldInfo, Math.qvIdentity)
end

local afShootChances = {0.25, 0.5, 0.75, 1}
local aiNumberOfShots = {2, 2, 3, 5}
local aiNumberOfShots = {3, 3, 3, 3}

local tblBehavior = { DestinationWaitMin = 0.25, DestinationWaitMax = 0.5, PreShootWaitMin = 0.3, PreShootWaitMax = 0.6, PostDismountDelay = 1.0}

local tblSoldierParams = {}
tblSoldierParams.fShootingDelayMin = 3
tblSoldierParams.fShootingDelayMax = 3
tblSoldierParams.fShootingCount = 6

-- character behavior hints
local ID_KAMIKAZE = "Carry kamikaze"
local ID_FLY_IN_FRONT = "Fly in front of ride"

-- function called from SED so that script can provide list of behavior hints for user to choose using popup menu
function globals.GetStringList()
  return ID_FLY_IN_FRONT, ID_KAMIKAZE
end

-- stop if executing from GUI
if worldGlobals==nil then return end

local worldInfo = worldGlobals.worldInfo --worldInfo : CWorldInfoEntity

local BEH_NORMAL = 0
local BEH_FLY_IN_FRONT = 1

local kamikazeSpawnerName = "Kamikaze_Drone"
--local spwKamikaze = worldInfo:GetEntityByName(kamikazeSpawnerName) -- spwKamikaze : CSpawnerEntity
local spwKamikaze = worldInfo:GetAllEntitiesOfClassAndName("CSpawnerEntity", kamikazeSpawnerName)

--[[print(#spwKamikaze)
for i=1,#spwKamikaze,1 do
  local vPlace = spwKamikaze[i]:GetPos()
  print("("..vPlace.x..","..vPlace.y..","..vPlace.z..")")
end]]--

if (#spwKamikaze == 0) then
  conErrorF("Combat drone found unable to spawn kamikaze! Please resolve this by creating kamikaze spawner named \"" .. kamikazeSpawnerName .. "\" on your level.\n")
  spwKamikaze = nil
else
  spwKamikaze = spwKamikaze[1]
  spwKamikaze:SetTotalCount(100000)
end

--[[if spwKamikaze ~= nil and spwKamikaze:GetClassName() == "CSpawnerEntity" then
  local totalCount = spwKamikaze:GetTotalCount()
  if totalCount < 10000 then
    conWarningF("Drone's kamikaze spawner total count is set to " .. totalCount .. ". It is recommended to set it to something above 10000 in order prevent undesired errors.\n")
  end
end]]--

local function CanBehave(penDrone)
  if penDrone == nil or IsDeleted(penDrone) then
    return false
  end
  while globals.worldInfo:IsCutSceneActive() do
    Wait(Delay(0.5))
    if IsDeleted(penDrone) then
      return false
    end
  end
  if not penDrone:IsAlive() then
    return false
  end
  return true
end

local function CanRiderBehave(penRider, penDrone)
  if penDrone == nil or IsDeleted(penDrone) then
    return false
  end
  if penRider == nil or IsDeleted(penRider) then
    return false
  end
  while globals.worldInfo:IsCutSceneActive() do
    Wait(Delay(0.5))
    if IsDeleted(penDrone) or IsDeleted(penRider) then
      return false
    end
  end
  if not penDrone:IsAlive() or not penRider:IsAlive() then
    return false
  end
  return penDrone:IsRiddenBy(penRider)
end

local function ShouldShoot(penDrone, fShootAngle)
  local penFoe = penDrone:GetFoe()
  if penFoe==nil then
    return false
  end
  local vFoeToMe = mthSafeNormalizeV3f(penDrone:GetPlacement():GetVect()-penFoe:GetPlacement():GetVect())
  vFoeToMe.y = 0
  vFoeToMe = mthSafeNormalizeV3f(vFoeToMe)
  local vFoeLookDirXZ = penFoe:GetLookDir(true)
  local fDot = mthDotV3f(vFoeLookDirXZ, vFoeToMe)
  local fAngle = mthRadToDeg(mthACosF(fDot))
  -- if we see foe
  if fAngle<fShootAngle then
    -- we can shoot
    return true
  end

  -- if we have already skipped several attacks
  penDrone.ctSkippedAttacks = penDrone.ctSkippedAttacks+1
  if penDrone.ctSkippedAttacks>4 then
    -- attack
    penDrone.ctSkippedAttacks = 0
    return true
  end
  return false
end

function worldGlobals.CombatDroneBehavior(penDrone)
  penDrone.BehaviorHint = penDrone:GetBehaviorHint()

  -- handler for kamikaze spawning functionality
  RunAsync(function()
    RunHandled(function() while not IsDeleted(penDrone) do Wait(Times(20, CustomEvent("OnStep"))) end end,
      OnEvery(CustomEvent("DroneSpawnKamikaze")), function(DroneSpawnKamikaze)
        if penDrone.BehaviorHint ~= ID_KAMIKAZE then return end

        local Denemy = DroneSpawnKamikaze:GetEventThrower()
        if Denemy ~= penDrone then return end

        if spwKamikaze == nil then
          conErrorF("Combat drone found unable to spawn kamikaze! Please resolve this by creating kamikaze spawner named \"" .. kamikazeSpawnerName .. "\" on your level.")
          return
        elseif spwKamikaze:GetClassName() ~= "CSpawnerEntity" then
          conErrorF("Found an entity named \"" .. kamikazeSpawnerName .. "\" which is not CSpawnerEntity. Perhaps you named a puppet, but not a spawner? (expand Spawner in puppet properties, there is a 'Name' field too)\n")
          return
        elseif spwKamikaze:GetRemainToSpawnCount() <= 0 then
          conErrorF("Combat drone's kamikaze spawner has run out of total spawn count! Combat drones cannot spawn kamikaze anymore.\nPlease, increase total count of combat drone's kamikaze spawner.\n")
          return
        end

        local Kamikazepuppet = spwKamikaze:SpawnOne() -- Kamikazepuppet : CLeggedCharacterEntity
        Denemy:MountPuppetToDrone(Kamikazepuppet, "Kamikaze")

        while not IsDeleted(Denemy) do

          local foe = Denemy:GetFoe()
            if foe ~= nil then
              if worldInfo:GetDistance(foe, Denemy) < 35 then
                --Denemy:PlayAnim("ThrowKamikaze")
                Denemy:DismountRider()
                if not IsDeleted(Kamikazepuppet) then
                  Kamikazepuppet:SetPlacement(Denemy:GetAttachmentAbsolutePlacement("Kamikaze"))
                end
                break
              end
            end

          Wait(CustomEvent("OnStep"))
          end

          if not IsDeleted(Denemy) and Denemy:IsAlive() and not IsDeleted(Kamikazepuppet) and Kamikazepuppet:IsAlive() then
            local q4plc2 = Denemy:GetAttachmentAbsolutePlacement("Kamikaze")
            local foe = Denemy:GetFoe()
              if not IsDeleted(foe) then
                local foepls = foe:GetPlacement()
                local v3fdir = mthNormalize(mthVector3f(foepls.vx - q4plc2.vx, foepls.vy - q4plc2.vy, foepls.vz - q4plc2.vz))
                v3fdir.x = v3fdir.x * 25
                v3fdir.z = v3fdir.z * 25
                Kamikazepuppet:SetLinearVelocity(v3fdir)
                Kamikazepuppet:ForceFoe(foe)
              end
          end
      end
    )
  end) -- 1st async end

  Wait(Delay(0.1))
  if penDrone:IsMovedUsingSpecialMover() then
    Wait(CustomEvent(penDrone, "StoppedUsingSpecialMover"))
  end

  local strBehaviorHint = penDrone:GetBehaviorHint()
  if strBehaviorHint == ID_FLY_IN_FRONT then
    penDrone.iBehavior = BEH_FLY_IN_FRONT
  end

  -- disable mover
  penDrone:DisableAutoMove()
  -- counter of flights without shooting
  local iShootCounter = 1
  penDrone.ctSkippedAttacks = 0
  local strDifficulty = worldGlobals.worldInfo:GetGameDifficulty()
  local fDifficultyBias = 0

  strDifficulty="Normal"

  if strDifficulty=="Tourist" then
    fDifficultyBias = -1
  elseif strDifficulty=="Easy" then
    fDifficultyBias = -0.5
  elseif strDifficulty=="Normal" then
    fDifficultyBias = 0
  elseif strDifficulty=="Hard" then
    fDifficultyBias = 0.5
  elseif strDifficulty=="Serious" then
    fDifficultyBias = 1
  elseif strDifficulty=="Mental" then
    fDifficultyBias = 1.5
  end

  -- control rider's AI
  RunAsync(function()
    -- while the drone is alive
    while CanBehave(penDrone) do
      -- fetch the rider
      local penRider = penDrone:GetRiderPuppet()
      while penRider == nil and CanBehave(penDrone) do
        penRider = penDrone:GetRiderPuppet()
        Wait(Delay(1))
      end

      -- if a rider is found, get it's attack
      if penRider ~= nil then
        local idAttack = penDrone:GetRiderAttack()
        -- while rider can behave and is riding the drone
        while CanRiderBehave(penRider, penDrone) do
          -- freeze behaviour if requested
          if penDrone:ShouldFreezeAutoActing() then
            while CanRiderBehave(penRider, penDrone) and penDrone:ShouldFreezeAutoActing() do
              Wait(Delay(0.5))
            end
          end

          -- break if can not behave any more
          if not CanRiderBehave(penRider, penDrone) then
            break
          end

          -- wait between shootings
          local fDelay = mthLerpF(tblSoldierParams.fShootingDelayMin, tblSoldierParams.fShootingDelayMax, mthRndF())
          Wait(Delay(fDelay))

          -- break if can not behave any more
          if not CanRiderBehave(penRider, penDrone) then
            break
          end

          -- shoot at foe
          if penRider:GetFoe() and penRider:CanSeeEntity(penRider:GetFoe()) then
            local fShots = tblSoldierParams.fShootingCount
            Wait(penRider:AttackShoot(idAttack, fShots, false))
          end
        end
      end
    end
  end)

  while CanBehave(penDrone) do

    -- while automatic acting should be frozen or if there is a flight request
    while penDrone:ShouldFreezeAutoActing() or penDrone:IsFlightRequested() do
      if not CanBehave(penDrone) then
        break
      end

      -- if there is a flight requested
      if penDrone:IsFlightRequested() then
        local qvRequestedPlacement = penDrone:GetRequestedPlacement()
        Wait(penDrone:FlyToGivenDestination(qvRequestedPlacement, true, true, true))
        if not CanBehave(penDrone) then
          break
        end

        -- if dismount is requested
        if penDrone:IsDismountRequested() then
          penDrone:DismountRider()
          local fDismountDelay = tblBehavior.PostDismountDelay
          Wait(Delay(fDismountDelay))
        end
      end

      -- if freezing, skip some time
      if penDrone:ShouldFreezeAutoActing() then
        Wait(Delay(0.5))
      end
    end

    -- select delay due to difficulty factor
    local fDelay = 0.25
    fDelay = mthClampDnF(fDelay-fDifficultyBias,0.1)

    Wait(Delay(fDelay))
    if not CanBehave(penDrone) then
      break
    end

    local fDestinationWait = mthLerpF( tblBehavior["DestinationWaitMin"], tblBehavior["DestinationWaitMax"], mthRndF())
    local fPreShootWait = mthLerpF( tblBehavior["PreShootWaitMin"], tblBehavior["PreShootWaitMax"], mthRndF())
    local fShootChance = afShootChances[iShootCounter]
    local fShootAngle = 30
    local ctDrones = worldGlobals.worldInfo:GetEnemyCount("Drone_Combat", penFoe)
    if ctDrones<3 then
      fDestinationWait = fDestinationWait/4
      fPreShootWait = fPreShootWait/4
      fShootChance = fShootChance+0.5
      fShootAngle = fShootAngle+30
    elseif ctDrones<6 then
      fDestinationWait = fDestinationWait/2
      fPreShootWait = fPreShootWait/2
      fShootChance = fShootChance+0.25
      fShootAngle = fShootAngle+10
    end

    local bShooting = false
    local penFoe = penDrone:GetFoe()
    if penFoe then
      bShooting = mthRndF() <= fShootChance
    end

    local bAutoFly = true
    if penDrone.iBehavior == BEH_FLY_IN_FRONT then
      local penFoe = penDrone:GetFoe()
      if penFoe~=nil and penFoe:GetRide()~=nil then
        local penRide = penFoe:GetRide()
        local vXZVelocity = penRide:GetLinearVelocity()
        local qvRide = penRide:GetPlacement()
        local fH = mthLerpF(mthDegToRad(-70), mthDegToRad(70), mthRndF())
        local fP = mthLerpF(mthDegToRad(3), mthDegToRad(20), mthRndF())
        local fDistance = mthLerpF(20, 60, mthRndF())
        local qDirRel = mthEulerToQuaternion(mthVector3f(fH,fP,0))
        local qDirAbs = mthMulQ4f(qvRide:GetQuat(), qDirRel)
        local vDirAbs = mthQuaternionToDirection(qDirAbs)
        local vPos = qvRide:GetVect()+vDirAbs*fDistance+vXZVelocity*5
        local qvRequestedPlacement = penDrone:GetPlacement()
        qvRequestedPlacement:SetVect(vPos)
        bAutoFly = false
        if bDebug then
          srZero:AddPoint(vPos, 1)
        end
        Wait(penDrone:FlyToGivenDestination(qvRequestedPlacement, false, true, true))
      end
    end

    if bAutoFly then
      Wait(penDrone:FlyToNewDestination(bShooting))
    end
    if not CanBehave(penDrone) then
      break
    end

    if penDrone:GetFoe() and bShooting then
      if fDestinationWait>0 then
        Wait(Delay(fPreShootWait))
      end
      if CanBehave(penDrone) and ShouldShoot(penDrone, fShootAngle) then
        if penDrone:CanSeeEntity(penDrone:GetFoe()) then
          penDrone.ctSkippedAttacks = 0
          Wait(penDrone:AttackShoot("Shoot_Laser", aiNumberOfShots[iShootCounter], false))
        end
      end
      iShootCounter = 0
    else
      if fDestinationWait>0 then
        Wait(Delay(fDestinationWait))
      end
    end

    if iShootCounter < 4 then
      iShootCounter = iShootCounter + 1
    end
  end
end