--[[
   Copyright 2007-2017 The OpenRA Developers (see AUTHORS)
   This file is part of OpenRA, which is free software. It is made
   available to you under the terms of the GNU General Public License
   as published by the Free Software Foundation, either version 3 of
   the License, or (at your option) any later version. For more
   information, see COPYING.
]]
IdlingUnits = { }

AttackGroupSize =
{
	easy = 6,
	normal = 8,
	hard = 10
}
AttackDelays =
{
	easy = { DateTime.Seconds(4), DateTime.Seconds(9) },
	normal = { DateTime.Seconds(2), DateTime.Seconds(7) },
	hard = { DateTime.Seconds(1), DateTime.Seconds(5) }
}

OrdosInfantryTypes = { "light_inf", "light_inf", "light_inf", "trooper", "trooper" }
OrdosVehicleTypes = { "raider", "raider", "quad" }

AttackOnGoing = false
HoldProduction = false
HarvesterKilled = true

IdleHunt = function(unit) if not unit.IsDead then Trigger.OnIdle(unit, unit.Hunt) end end

SetupAttackGroup = function()
	local units = { }

	for i = 0, AttackGroupSize[Map.LobbyOption("difficulty")], 1 do
		if #IdlingUnits == 0 then
			return units
		end

		local number = Utils.RandomInteger(1, #IdlingUnits + 1)

		if IdlingUnits[number] and not IdlingUnits[number].IsDead then
			units[i] = IdlingUnits[number]
			table.remove(IdlingUnits, number)
		end
	end

	return units
end

SendAttack = function()
	if Attacking then
		return
	end
	Attacking = true
	HoldProduction = true

	local units = SetupAttackGroup()
	Utils.Do(units, function(unit)
		IdleHunt(unit)
	end)

	Trigger.OnAllRemovedFromWorld(units, function()
		Attacking = false
		HoldProduction = false
	end)
end

ProtectHarvester = function(unit)
	DefendActor(unit)
	Trigger.OnKilled(unit, function() HarvesterKilled = true end)
end

DefendActor = function(unit)
	Trigger.OnDamaged(unit, function(self, attacker)
		if AttackOnGoing then
			return
		end
		AttackOnGoing = true

		local Guards = SetupAttackGroup()

		if #Guards <= 0 then
			AttackOnGoing = false
			return
		end

		Utils.Do(Guards, function(unit)
			if not self.IsDead then
				unit.AttackMove(self.Location)
			end
			IdleHunt(unit)
		end)

		Trigger.OnAllRemovedFromWorld(Guards, function() AttackOnGoing = false end)
	end)
end

InitAIUnits = function()
	IdlingUnits = Reinforcements.Reinforce(ordos, InitialOrdosReinforcements, OrdosPaths[2])
	IdlingUnits[#IdlingUnits + 1] = OTrooper1
	IdlingUnits[#IdlingUnits + 1] = OTrooper2
	IdlingUnits[#IdlingUnits + 1] = ORaider

	Utils.Do(OrdosBase, function(actor)
		DefendActor(actor)
		Trigger.OnDamaged(actor, function(building)
			if building.Health < building.MaxHealth * 3/4 then
				building.StartBuildingRepairs()
			end
		end)
	end)
end

ProduceInfantry = function()
	if OBarracks.IsDead then
		return
	end

	if HoldProduction then
		Trigger.AfterDelay(DateTime.Minutes(1), ProduceInfantry)
		return
	end

	local delay = Utils.RandomInteger(AttackDelays[Map.LobbyOption("difficulty")][1], AttackDelays[Map.LobbyOption("difficulty")][2] + 1)
	local toBuild = { Utils.Random(OrdosInfantryTypes) }
	ordos.Build(toBuild, function(unit)
		IdlingUnits[#IdlingUnits + 1] = unit[1]
		Trigger.AfterDelay(delay, ProduceInfantry)

		if #IdlingUnits >= (AttackGroupSize[Map.LobbyOption("difficulty")] * 2.5) then
			SendAttack()
		end
	end)
end

ProduceVehicles = function()
	if OLightFactory.IsDead then
		return
	end

	if HoldProduction then
		Trigger.AfterDelay(DateTime.Minutes(1), ProduceVehicles)
		return
	end

	local delay = Utils.RandomInteger(AttackDelays[Map.LobbyOption("difficulty")][1], AttackDelays[Map.LobbyOption("difficulty")][2] + 1)
	local toBuild = { Utils.Random(OrdosVehicleTypes) }
	ordos.Build(toBuild, function(unit)
		IdlingUnits[#IdlingUnits + 1] = unit[1]
		Trigger.AfterDelay(delay, ProduceVehicles)

		if #IdlingUnits >= (AttackGroupSize[Map.LobbyOption("difficulty")] * 2.5) then
			SendAttack()
		end
	end)
end

ActivateAI = function()
	Trigger.AfterDelay(0, InitAIUnits)

	OConyard.Produce(AtreidesUpgrades[1])
	OConyard.Produce(AtreidesUpgrades[2])

	-- Finish the upgrades first before trying to build something
	Trigger.AfterDelay(DateTime.Seconds(14), function()
		ProduceInfantry()
		ProduceVehicles()
	end)
end