-- and (IsServer or weaponInstance:IsDescendantOf(Players.LocalPlayer))

function WeaponsSystem.onWeaponAdded(weaponInstance)
	local weapon = WeaponsSystem.getWeaponForInstance(weaponInstance)
	if not weapon then
		WeaponsSystem.createWeaponForInstance(weaponInstance)
	end
end

function WeaponsSystem.onWeaponRemoved(weaponInstance)
	local weapon = WeaponsSystem.getWeaponForInstance(weaponInstance)
	if weapon then
		weapon:onDestroyed()
	end
	WeaponsSystem.knownWeapons[weaponInstance] = nil
end

function WeaponsSystem.getRemoteEvent(name)
	if not WeaponsSystem.networkFolder then
		return
	end

	local remoteEvent = WeaponsSystem.remoteEvents[name]
	if IsServer then
		if not remoteEvent then
			warn("No RemoteEvent named ", name)
			return nil
		end

		return remoteEvent
	else
		if not remoteEvent then
			remoteEvent = WeaponsSystem.networkFolder:WaitForChild(name, math.huge)
		end

		return remoteEvent
	end
end

function WeaponsSystem.getRemoteFunction(name)
	if not WeaponsSystem.networkFolder then
		return
	end

	local remoteFunc = WeaponsSystem.remoteFunctions[name]
	if IsServer then
		if not remoteFunc then
			warn("No RemoteFunction named ", name)
			return nil
		end

		return remoteFunc
	else
		if not remoteFunc then
			remoteFunc = WeaponsSystem.networkFolder:WaitForChild(name, math.huge)
		end

		return remoteFunc
	end
end

function WeaponsSystem.setWeaponEquipped(weapon, equipped)
	assert(not IsServer, "WeaponsSystem.setWeaponEquipped should only be called on the client.")
	if not weapon then
		return
	end

	local lastWeapon = WeaponsSystem.currentWeapon
	local hasWeapon = false
	local weaponChanged = false

	if lastWeapon == weapon then
		if not equipped then
			WeaponsSystem.currentWeapon = nil
			hasWeapon = false
			weaponChanged = true
		else
			weaponChanged = false
		end
	else
		if equipped then
			WeaponsSystem.currentWeapon = weapon
			hasWeapon = true
			weaponChanged = true
		end
	end

	if WeaponsSystem.camera then
		WeaponsSystem.camera:resetZoomFactor()
		WeaponsSystem.camera:setHasScope(false)

		if WeaponsSystem.currentWeapon then
			WeaponsSystem.camera:setZoomFactor(WeaponsSystem.currentWeapon:getConfigValue("ZoomFactor", 1.1))
			WeaponsSystem.camera:setHasScope(WeaponsSystem.currentWeapon:getConfigValue("HasScope", false))
		end
	end

	if WeaponsSystem.gui then
		WeaponsSystem.gui:setEnabled(hasWeapon)

		if WeaponsSystem.currentWeapon then
			WeaponsSystem.gui:setCrosshairWeaponScale(WeaponsSystem.currentWeapon:getConfigValue("CrosshairScale", 1))
		else
			WeaponsSystem.gui:setCrosshairWeaponScale(1)
		end
	end

	if weaponChanged then
		WeaponsSystem.CurrentWeaponChanged:Fire(weapon.instance, lastWeapon and lastWeapon.instance)
	end
end

function WeaponsSystem.getHumanoid(part)
	while part and part ~= workspace do
		if part:IsA("Model") and part.PrimaryPart and part.PrimaryPart.Name == "HumanoidRootPart" then
			return part:FindFirstChildOfClass("Humanoid")
		end

		part = part.Parent
	end
end

function WeaponsSystem.getPlayerFromHumanoid(humanoid)
	for _, player in ipairs(Players:GetPlayers()) do
		if player.Character and humanoid:IsDescendantOf(player.Character) then
			return player
		end
	end
end

local function _defaultDamageCallback(system, target, amount, damageType, dealer, hitInfo, damageData)
	if target:IsA("Humanoid") then
		target:TakeDamage(amount)
	end
end

function WeaponsSystem.doDamage(target, amount, damageType, dealer, hitInfo, damageData)
	if not target or ancestorHasTag(target, "WeaponsSystemIgnore") then
		return
	end
	if IsServer then
		if target:IsA("Humanoid") and dealer:IsA("Player") and dealer.Character then
			local dealerHumanoid = dealer.Character:FindFirstChildOfClass("Humanoid")
			local targetPlayer = Players:GetPlayerFromCharacter(target.Parent)
			if dealerHumanoid and target ~= dealerHumanoid and targetPlayer then
				-- Trigger the damage indicator
				WeaponData:FireClient(targetPlayer, "HitByOtherPlayer", dealer.Character.HumanoidRootPart.CFrame.Position)
			end
		end

		-- NOTE:  damageData is a more or less free-form parameter that can be used for passing information from the code that is dealing damage about the cause.
		-- .The most obvious usage is extracting icons from the various weapon types (in which case a weapon instance would likely be passed in)
		-- ..The default weapons pass in that data
		local handler = _damageCallback or _defaultDamageCallback
		handler(WeaponsSystem, target, amount, damageType, dealer, hitInfo, damageData)
	end
end

local function _defaultGetTeamCallback(player)
	return 0
end

function WeaponsSystem.getTeam(player)
	local handler = _getTeamCallback or _defaultGetTeamCallback
	return handler(player)
end

function WeaponsSystem.playersOnDifferentTeams(player1, player2)
	if player1 == player2 or player1 == nil or player2 == nil then
		-- This allows players to damage themselves and NPC's
		return true
	end

	local player1Team = WeaponsSystem.getTeam(player1)
	local player2Team = WeaponsSystem.getTeam(player2)
	return player1Team == 0 or player1Team ~= player2Team
end

return WeaponsSystem