// i'd like to thank hvo-busterkomo because i learned a lot from his fireball spell
// i'd like to thank Flame_phoenix because i learned a lot from his vjass tutorial
//thanks to Thanathos for helping me out

scope UnholyP initializer Init
//*************************************************************************************************************
//****Configuration. You can set these values to fit your needs.****
globals
    private constant integer    SPELL_ID = 'A000'                                                     //rawcode of the Unholy Presence ability
    private constant integer    BUFF_ID = 'B000'                                                      //rawcode of the Unholy Presence buff
    private constant string     TARGET_FX = "Abilities\\Weapons\\IllidanMissile\\IllidanMissile.mdl"  //Special effect attached to the origin of enemy units
    private constant string     TARGET_ATTACH_FX = "origin"                                           //attachement point for the effect
    private constant real       INTERVAL = 0.20                                                       //This is the interval of the spell. .20 means units get damaged every .20 seconds, 2: every 2 seconds, etc.
    private constant real       STRENGTH = 0.05                                                       //Set this to a value for how much you will heal (in %) off of Strength each second. 0 means you dont want to heal from Strength
    private constant boolean    STRENGTH_BONUSES = true                                               //true means include bonuses for Strength
    private constant real       INTELLIGENCE = 0.00                                                   //Set this to a value for how much you will heal (in %) off of Intelligence each second. 0 means you dont want to heal from intel
    private constant boolean    INTELLIGENCE_BONUSES = false                                          //true means include bonuses for intelligence
    private constant real       AGILITY = 0.00                                                        //Set this to a value for how much you will heal( in %) off of Agility each second. 0 means you dont want to heal from intel
    private constant boolean    AGILITY_BONUSES = false                                               //true means include bonuses for agility
    private constant attacktype AT = ATTACK_TYPE_NORMAL                                               //attack type
    private constant damagetype DT = DAMAGE_TYPE_FIRE                                                 //damage type
    private constant weapontype WT = WEAPON_TYPE_WHOKNOWS                                             //weapon type
 
endglobals

private constant function Damage takes integer level returns real
    return (level * 5. + 100.) * INTERVAL  //does 100 damage + (level of the ability x 5) divided by the interval
endfunction

private constant function AoE takes integer level returns real
    return level * 5. + 350. // the AOE is 350 + (level of the ability x 5)
endfunction

private constant function Heal takes integer attribute returns real
    return attribute  * INTERVAL  //takes attribute(s) you want of the triggering unit and multiplies it by 0.05 and divides it by the interval. 
endfunction

//****End of configuration*************************************************************************************
//*************************************************************************************************************
//Don't touch this stuff unless you know what you're doing
private struct UnholyP
    unit u
    integer level
    real attribute
endstruct

globals
    private boolexpr filter 
    private constant group Group = CreateGroup()
    private constant timer Tim = CreateTimer()
    private integer total = 0
    private player UnholyPOwner
    private UnholyP array queue
endglobals
private function Timer takes nothing returns nothing

    local integer i = 0
    local UnholyP data
    local unit f
    local real damage
    loop
        exitwhen i >= total 
        set data = queue[i]
        set UnholyPOwner = GetOwningPlayer(data.u)
        call GroupClear(Group)//Clears the global group.
        if (GetUnitAbilityLevel(data.u, BUFF_ID) > 0) then //Checks if the triggering unit has the buff (this means the spell can be dispelled)
           
            call GroupEnumUnitsInRange(Group, GetUnitX(data.u), GetUnitY(data.u), AoE(data.level), filter)//Groups all nearby units.
            set damage = Damage(data.level) 
            loop
            
                set f = FirstOfGroup(Group) //first unit selected in range
                exitwhen f == null 
                call DestroyEffect(AddSpecialEffectTarget(TARGET_FX, f, TARGET_ATTACH_FX)) // creates the effect at the origin of the enemy unit
                call UnitDamageTarget(data.u, f, damage, true, false, AT, DT, WT)//Damages the enemy.
                call SetWidgetLife(data.u, GetWidgetLife(data.u) + Heal(R2I(data.attribute)))  //heals the triggering unit for 5% of its strength
                call GroupRemoveUnit(Group, f)//Removes the first selected unit from the group
            endloop
        else
        call data.destroy()
        set total = total - 1
        set queue[i] = queue[total]
        set i = i - 1
        endif
    set i = i + 1
    endloop
    if total == 0 then
        call PauseTimer(Tim)
    endif
endfunction

private function Conditions takes nothing returns boolean
    return GetSpellAbilityId() == SPELL_ID//Checks if the spell being used is this one
endfunction

private function UnholyP_Filter takes nothing returns boolean
    return GetUnitState(GetFilterUnit(), UNIT_STATE_LIFE) > 0. and IsUnitEnemy(GetFilterUnit(), UnholyPOwner) and (IsUnitType(GetFilterUnit(), UNIT_TYPE_MAGIC_IMMUNE) == false)//Chooses which units are affected.
//                 Is the unit alive?                                  Is the unit an enemy to the caster?                Is the unit immune to spells?
endfunction

private function Actions takes nothing returns nothing

    local UnholyP data = UnholyP.create()
    set data.u = GetTriggerUnit() // stores the triggering unit into a struct
    set data.level = GetUnitAbilityLevel(data.u, SPELL_ID)//Stores the level of the ability in a struct.
    //thanks to -JonNny :D
    set data.attribute = GetHeroStr(data.u, STRENGTH_BONUSES) * STRENGTH + GetHeroInt(data.u, INTELLIGENCE_BONUSES) * INTELLIGENCE + GetHeroAgi(data.u, AGILITY_BONUSES) * AGILITY
    
    if total == 0 then
        call TimerStart(Tim, INTERVAL, true, function Timer)
    endif
    
    set queue[total] = data
    set total = total + 1
endfunction

private constant function AntiLeak takes nothing returns boolean
        return true
endfunction

private function Init takes nothing returns nothing
    local trigger trig = CreateTrigger()//Creates the trigger.
    local filterfunc f = Filter(function AntiLeak)
    local integer i = 0
    loop
            call TriggerRegisterPlayerUnitEvent(trig, Player(i),EVENT_PLAYER_UNIT_SPELL_EFFECT, f) // registers the event for each player who casts the spell
            set i = i + 1
            exitwhen i == bj_MAX_PLAYER_SLOTS
        endloop
    call TriggerAddCondition(trig, Condition(function Conditions))//Adds the condition.
    call TriggerAddAction(trig, function Actions)//Adds the action.
    call Preload(TARGET_FX)//Preloads the effect, preventing it from lagging the first time it's cast.
    set  filter = Filter(function UnholyP_Filter)//Stores a global boolexp. Much faster than creating and destroying one all the time.
    call DestroyFilter(f)
    set trig = null
    set f = null
endfunction
endscope