Modifier Generic Barrier

modifier_generic_barrier = class({})
-- Created by Cykada (@oniisama on discord)
-- Version 1.2

-- require("path/modifier_generic_barrier") in your modifier file
-- and set it to be modifier_name = class(modifier_generic_barrier)


--* Functions that are meant to be replaced/used when creating the barrier:

--! barrier:GetBarrierType() → DAMAGE_TYPES | mandatory
--?  Determines what kind of damage it will block, based on the damage type (ie; DAMAGE_TYPE_PURE for all damage)

--! barrier:GetBarrierMaxHealth() → int | mandatory
--? The max value of the barrier, current health is set to max by default

--* barrier:OnBarrierCreated(kv) → nil | optional
--? The same as a normal OnCreated(kv) function,  must be used instead of OnCreated()!

--* barrier:OnBarrierRefresh(kv) → nil | optional
--? The same as a normal OnRefresh(kv), OnCreated() is automatically called on refresh!

--* barrier:DeclareBonusFunctions() → {modifier_properties} | optional
--? The same as a normal DeclareFunctions(), must be used instead of DeclareFunctions()!

--* barrier:AddBonusCustomTransmitterData() → {properties} | optional
--? The same as a normal AddCustomTransmitterData, you don't need to add a HandleCustomTransmitterData() function!

--* barrier:OnBarrierDamagedFilter(event) → bool [Server side only] | optional
--? Event for when the barrier takes damage, acts like a filter for the barrier
--? The parent unit will take the damage if you return false, so set the event.damage to 0 if you don't want that

--* barrier:IsPersistent() → bool | optional
--? Whether the barrier should be destroyed once the health reaches 0

--* barrier:ShowOnZeroHP() → bool | optional
--? Whether the barrier should be visible when the health is at 0, also controls whether IsBarrier() is true at 0 hp

--* barrier:GetBarrierInitialHealth() → int | optional
--? What the starting value of the barrier is, defaults to the max health



--* Function list

--* barrier:SetBarrierMaxHealth(int) → nil
--* barrier:GetBarrierMaxHealth() → int
--* barrier:SetBarrierHealth(int) → nil
--* barrier:GetBarrierHealth() → int
--* barrier:GetBarrierInitialHealth() → int
--* barrier:SetBarrierType(DAMAGE_TYPES) → nil
--* barrier:GetBarrierType() → DAMAGE_TYPES | use 'IsBarrierFor(DAMAGE_TYPES)' instead!
--* barrier:IsBarrier() → true
--* barrier:IsBarrierFor(DAMAGE_TYPES) → bool
--* barrier:OnBarrierDamagedFilter(event) → bool



--* Options

function modifier_generic_barrier:GetBarrierOptions()

    --? All damage barriers will not block physical or magical (doesn't effect HP Removal)
    self.ALL_BARRIER_ONLY_BLOCKS_PURE = false

    --? All damage barriers will block HP removal damage
    self.ALL_BARRIER_BLOCKS_HP_REMOVAL = false

end


--=======================================================================================


function modifier_generic_barrier:OnCreated(kv)
    self:GetBarrierOptions()
    self:OnBarrierCreated(kv)

    if not IsServer() then return end

    if not self.__barrier_type then self.__barrier_type = self:GetBarrierType() end
    if not self.__max_barrier_health then self.__max_barrier_health = self:GetBarrierMaxHealth() end

    if not self.__current_barrier_health then
        self.__current_barrier_health = self:GetBarrierInitialHealth()
    elseif self:GetBarrierInitialHealth() > self.__current_barrier_health then
        self.__current_barrier_health = self:GetBarrierInitialHealth()
    end

    self:SetHasCustomTransmitterData(true)
end
function modifier_generic_barrier:OnBarrierCreated(kv) end

function modifier_generic_barrier:OnRefresh(kv)
    self:OnCreated(kv)
    self:OnBarrierRefresh(kv)
    if IsServer() then self:SendBuffRefreshToClients() end
end
function modifier_generic_barrier:OnBarrierRefresh(kv) end

function modifier_generic_barrier:AddCustomTransmitterData()
    local data = {
        __barrier_type = self.__barrier_type,
        __max_barrier_health = self.__max_barrier_health,
        __current_barrier_health = self.__current_barrier_health
    }

    local bonus_data = self:AddBonusCustomTransmitterData()
    if #bonus_data > 0 then for k,v in pairs(bonus_data) do data[k] = v end end
    return data
end
function modifier_generic_barrier:AddBonusCustomTransmitterData() return {} end
function modifier_generic_barrier:HandleCustomTransmitterData(data) for k,v in pairs(data) do self[k] = v end end

function modifier_generic_barrier:BarrierUpdate()
    if not self:IsPersistent() then
        if self.__current_barrier_health <= 0 then return self:Destroy() end
    else self.__current_barrier_health = math.max(0, self.__current_barrier_health) end
    if self ~= nil then
        self.__current_barrier_health = math.min( self.__current_barrier_health, self.__max_barrier_health )
        self:SendBuffRefreshToClients()
    end
end

function modifier_generic_barrier:SetBarrierType(dmg_type)
    self.__barrier_type = dmg_type
    self:BarrierUpdate()
end

function modifier_generic_barrier:GetBarrierType() return DAMAGE_TYPE_ALL end

function modifier_generic_barrier:IsPersistent() return false end
function modifier_generic_barrier:ShowOnZeroHP() return false end

function modifier_generic_barrier:IsBarrier()
    if not self:ShowOnZeroHP() and self.__current_barrier_health <= 0 then return false else return true end
end

function modifier_generic_barrier:IsBarrierFor(dmg_type)
    if self:IsPersistent() then
        if self.__current_barrier_health <= 0 and not self:ShowOnZeroHP() then
            return false
        end
    end

    local b = self.__barrier_type
    if b == dmg_type then return true end
    if IsClient() then return false end

    if b == 4 or b == 7 or b == 8 then
        if not self.ALL_BARRIER_BLOCKS_HP_REMOVAL and dmg_type == 8 then return false end
        if self.ALL_BARRIER_ONLY_BLOCKS_PURE and (dmg_type == 1 or dmg_type == 2) then return false end
        return true
    end

    return false
end

function modifier_generic_barrier:SetBarrierMaxHealth(amount)
    self.__max_barrier_health = math.ceil(amount)
    self:BarrierUpdate()
end
function modifier_generic_barrier:GetBarrierMaxHealth() return self.__max_barrier_health end
function modifier_generic_barrier:GetBarrierInitialHealth() return self.__max_barrier_health end

function modifier_generic_barrier:SetBarrierHealth(amount)
    self.__current_barrier_health = math.ceil(amount)
    self:BarrierUpdate()
end
function modifier_generic_barrier:GetBarrierHealth() return self.__current_barrier_health end

function modifier_generic_barrier:DeclareFunctions()
    local funcs = {
        MODIFIER_PROPERTY_INCOMING_PHYSICAL_DAMAGE_CONSTANT,
        MODIFIER_PROPERTY_INCOMING_SPELL_DAMAGE_CONSTANT,
        MODIFIER_PROPERTY_INCOMING_DAMAGE_CONSTANT,
    }

    local bonus_funcs = self:DeclareBonusFunctions()
    if #bonus_funcs > 0 then for _,func in ipairs(bonus_funcs) do table.insert(funcs, func) end end
    return funcs
end
function modifier_generic_barrier:DeclareBonusFunctions() return {} end

function modifier_generic_barrier:GetModifierIncomingPhysicalDamageConstant(keys) return self:DoBarrierBlock(1, keys) end
function modifier_generic_barrier:GetModifierIncomingSpellDamageConstant(keys) return self:DoBarrierBlock(2, keys) end
function modifier_generic_barrier:GetModifierIncomingDamageConstant(keys) return self:DoBarrierBlock(4, keys) end

function modifier_generic_barrier:DoBarrierBlock(d, keys)
    if IsClient() then
        if not self:IsBarrierFor(d) then return end
        if keys.report_max then return self.__max_barrier_health else return self.__current_barrier_health end
    else
        if not self:IsBarrierFor(keys.damage_type) then return 0 end
        if not self:OnBarrierDamagedFilter(keys) then return keys.damage end
    end

    self.__current_barrier_health = self.__current_barrier_health - keys.damage
    Timers:CreateTimer(function() self:BarrierUpdate() end)

    if self.__current_barrier_health <= 0 then
        return keys.damage + self.__current_barrier_health
    else return -keys.damage end
end

function modifier_generic_barrier:OnBarrierDamagedFilter(keys) return true end