Costumes dropped from mobs

[CyberDevil]

I thought of including costumes among the mobs, but to avoid complicating my life I created this script that I haven't tested:

-	script	Costume_Drop	-1,{
OnNPCKillEvent:
	if ( rand( 10000 ) <= 3 ) { //0.03% drop rate
		.@item_id = F_Rand( 31236,20156,19524,20120,20394,20334,31178 ); //costume drop list
		announce "Congratulations to the player "+ strcharinfo(0) +" who, after killing a "+ getmonsterinfo( killedrid, MOB_NAME ) +" in "+ strcharinfo(3)", got a rare costume!",0,0x00FF00;
		getitem .@item_id,1;
}

With this script every monster on the server has a 0.03% chance of dropping one of the costumes on the list (I'm not sure it works!) And a global announcement is sent for congratulations.
But now I thought that it is better to insert a specific costume for a specific mob as in this list: https://www.shining-moon.com/helheim/index.php/Costume_Drops#Costume_List (thanx @fr0sty123456789 for this idea!)

In this case I could use the file "/rathena/db/mob_item_ratio.txt" with the simple structure "ItemID, Ratio, MonsterID" but so I would lose the global announcement... so I wanted to know if it was possible to modify this script from someone more experienced than me, to have the same function and structure with attached global announcement!?!

Edited April 11, 2019 by CyberDevil

[crazyarashi]

-	script	costume_drop	-1,{
OnNPCKillEvent:
	.@index = inarray(.mob_id[0],killedrid);
	if(.@index < 0) end;
	if(rand(1,10000) <= .chance){
		explode(.@ID$,.drop_data$[.@index],":");
		announce "Congratulations to the player "+ strcharinfo(0) +" who, after killing a "+ getmonsterinfo( killedrid, MOB_NAME ) +" in "+ strcharinfo(3) +", got a rare costume!",0,0x00FF00;
		getitem atoi(.@ID$[1]),1;
		deletearray .@ID$[0],getarraysize(.@ID$);
	}
	end;
		
OnInit:
	.chance = 3; 
	setarray .drop_data$,
	"1001:501","1002:502","1003:503","1005:504"; //= "Mob ID:Costume ID"
	for(.@i = 0; .@i < getarraysize(.drop_data$); .@i++){
		explode(.@mob_id$,.drop_data$[.@i],":");
		.mob_id[.@i] = atoi(.@mob_id$[0]);
		deletearray .@mob_id$[0],getarraysize(.@mob_id$);
	}
	end;
}

I haven't tested this yet, but it should work fine :))

Edited April 11, 2019 by crazyarashi

[CyberDevil]

Thank you @crazyarashi,
but in this case the variable ".chance = 3;" is it also affected by the server's drop rate?
This option:

// The rate at which equipment is dropped.
item_rate_equip: 100

at: https://github.com/rathena/rathena/blob/master/conf/battle/drops.conf#L62

[crazyarashi]

No it's not. :))