/*
=====Spell Name: Bombardment v1.4a
=====Created by: Mckill2009

REQUIRES:
- JassNewGenPack by Vexorian

REQUIRED LIBRARIES:
- DestructableLib by PitzerMike (http://www.wc3c.net/showthread.php?t=103927)
- T32 by Jesus4Lyf (http://www.thehelper.net/forums/showthread.php/132538-Timer32)
- RegisterSpellEffectEvent by Bribe (http://www.hiveworkshop.com/forums/jass-resources-412/snippet-spelleffectevent-187193/)
- RegisterPlayerUnitEvent by Magtheridon96 (http://www.hiveworkshop.com/forums/jass-resources-412/snippet-registerplayerunitevent-203338/)

OPTIONAL LIBRARIES:
- BoundSentinel by Vexorian (http://www.wc3c.net/showthread.php?t=102576)

HOW TO USE:
- Make a new trigger and convert to custom text via EDIT >>> CONVERT CUSTOM TEXT
- Copy ALL that is written here (overwrite the existing texts in the trigger)
- Copy ALL the required libraries stated above
- Copy the Dummy unit and the custom ability OR make your own
- You MUST input or change the correct raw ID's (see below)
- To view raw ID, press CTRL+D in the object editor
*/

scope Bombardment

globals
    //NOTE: The custom ability should be 'Rain of Fire', or change it if you like
    //but the ability order should be equal to CHANNEL_ORDER_ID
    private constant integer            SPELL_ID = 'A001' //raw code (rain of fire)
    private constant integer           COPTER_ID = 'h001' //raw code
    private constant integer             BOMB_ID = 'h000' //raw code
    private constant integer    CHANNEL_ORDER_ID = 852238 //rain of fire
    private constant real             FALL_SPEED = 10. //fall speed of the bomb
    private constant real             MOVE_SPEED = 15. //copter move speed
    private constant real          COPTER_HEIGHT = 300. //copter default height at creation time
    private constant real      CREATION_INTERVAL = 1.5 //interval for copter creation
    private constant real            COPTER_LIFE = 5.0 //life of copter after bomb is released
    private constant real                    AOE = 300.//area of effect for damage
    private constant attacktype              ATK = ATTACK_TYPE_CHAOS
    private constant damagetype              DMG = DAMAGE_TYPE_NORMAL
    private constant string                  SFX = "Objects\\Spawnmodels\\Other\\NeutralBuildingExplosion\\NeutralBuildingExplosion.mdl"
    private rect Rct
endglobals

private function GetDamage takes integer i returns real
    return 25 + i * 25.
endfunction

private function GetDuration takes integer i returns real
    return 5 + i * 5.
endfunction

private function UnitAlive takes unit u returns boolean
    return not IsUnitType(u, UNIT_TYPE_DEAD) 
endfunction

private interface Bomb
    unit caster
    unit copter
    real damage
    real distance
    real xSpell
    real ySpell
endinterface

//===Bombs Explode
private struct BombExplode extends Bomb
    unit bomb
    real height  
    
    static method getDestructables takes nothing returns boolean
        local destructable d = GetFilterDestructable()
        if IsDestructableTree(d) then
            call KillDestructable(d)
        endif    
        set d = null
        return false
    endmethod  
    
    method periodic takes nothing returns nothing   
        local real x
        local real y
        local unit first
        if .height > 0 then
            set .height = .height - FALL_SPEED
            call SetUnitFlyHeight(.bomb, .height, 0)
        else
            set x = GetUnitX(.bomb)
            set y = GetUnitY(.bomb)
            call DestroyEffect(AddSpecialEffect(SFX, x, y))
            call MoveRectTo(Rct, x, y)
            call EnumDestructablesInRect(Rct, function thistype.getDestructables, null)
            call GroupEnumUnitsInRange(bj_lastCreatedGroup, x, y, AOE, null)
            loop
                set first = FirstOfGroup(bj_lastCreatedGroup)
                exitwhen first==null
                if UnitAlive(first) and IsUnitEnemy(first, GetOwningPlayer(.bomb)) or IsUnitType(first, UNIT_TYPE_STRUCTURE) then
                    call UnitDamageTarget(.bomb, first, .damage, false, false, ATK, DMG, null)
                endif
                call GroupRemoveUnit(bj_lastCreatedGroup, first)
            endloop
            call KillUnit(.bomb)
            call .stopPeriodic()
            call .destroy() 
        endif    
    endmethod
    
    implement T32x 
    
    static method create takes unit b, real d, real h returns thistype
        local thistype this = thistype.allocate()
        set .bomb = b
        set .damage = d
        set .height = h       
        call .startPeriodic()    
        return this
    endmethod

endstruct

//Copters Appear
private struct Copter extends Bomb
    real angle 
    integer chk
    
    method periodic takes nothing returns nothing
        local unit bomb
        if UnitAlive(.copter) then
            call SetUnitPosition(.copter, GetUnitX(.copter)+MOVE_SPEED*Cos(.angle), GetUnitY(.copter)+MOVE_SPEED*Sin(.angle))
            if .distance > 0 then
                set .distance = .distance - MOVE_SPEED
            elseif .chk==1 then
                set .chk = 0
                set bomb = CreateUnit(GetOwningPlayer(.copter), BOMB_ID, .xSpell, .ySpell, GetUnitFacing(.copter))
                call SetUnitFlyHeight(bomb, COPTER_HEIGHT, 0)
                call BombExplode.create(bomb, .damage, COPTER_HEIGHT)
                call UnitApplyTimedLife(.copter, 'BTLF', COPTER_LIFE)
            endif
        else
            call .stopPeriodic()
            call .destroy()            
        endif       
    endmethod
    
    implement T32x  
    
    static method create takes unit copter, real damage, real distance, real x, real y returns thistype
        local thistype this = thistype.allocate()
        set .copter = copter
        set .damage = damage
        set .angle = Atan2(y-GetUnitY(copter), x-GetUnitX(copter))
        set .distance = distance
        set .chk = 1
        set .xSpell = x
        set .ySpell = y
        call .startPeriodic()     
        return this
    endmethod   
endstruct

//===Cast
private struct Bombardment extends Bomb
    real xUnit
    real yUnit
    real duration
    real creationgap 
   
    method periodic takes nothing returns nothing
        local unit copter
        if .duration > 0 and GetUnitCurrentOrder(.caster)==CHANNEL_ORDER_ID and UnitAlive(.caster) then
            set .duration = .duration - T32_PERIOD
            set .creationgap = .creationgap + T32_PERIOD
            if .creationgap >= CREATION_INTERVAL then
                set .creationgap = 0
                set copter = CreateUnit(GetOwningPlayer(.caster), COPTER_ID, .xUnit, .yUnit, GetUnitFacing(.caster))
                call SetUnitFlyHeight(copter, COPTER_HEIGHT, 0)
                call Copter.create(copter, .damage, .distance, .xSpell, .ySpell)
                set copter = null
            endif
        else
            call IssueImmediateOrder(.caster, "stop")
            call .stopPeriodic()
            call .destroy()
        endif   
    endmethod
    
    implement T32x  
    
    private static method create takes nothing returns thistype
        local thistype this = thistype.allocate()
        local integer level
        set .caster = GetTriggerUnit()
        set level = GetUnitAbilityLevel(.caster, SPELL_ID)
        set .xUnit = GetUnitX(.caster)
        set .yUnit = GetUnitY(.caster)
        set .xSpell = GetSpellTargetX()
        set .ySpell = GetSpellTargetY()
        set .duration = GetDuration(level)
        set .damage = GetDamage(level)
        set .distance = SquareRoot((.xSpell-.xUnit) * (.xSpell-.xUnit) + (.ySpell-.yUnit) * (.ySpell-.yUnit)) 
        set .creationgap = CREATION_INTERVAL
        call .startPeriodic()    
        return this
    endmethod
    
    private static method onInit takes nothing returns nothing
        set Rct = Rect(-AOE, -AOE, AOE, AOE)
        call RegisterSpellEffectEvent(SPELL_ID, function thistype.create)
        call Preload(SFX)
    endmethod
endstruct

endscope