top percentage

//config/formats.js

{
		name: "Top Percentage",
		section: "Other Metagames",
		mod: 'toppercentage',

		ruleset: ['OU'],
		onBegin: function () {
			console.log("ok");
			for (var i = 0; i < this.sides.length; i++) {
				this.sides[i].metaCount = 400;
				console.log("done once!");

			}
		},
		onDamage: function (damage, target) {
			//only should work if does not make target faint
			let percentage = 100 * damage / target.maxhp;
			if (damage >= target.hp) {
				percentage = 100 * target.hp / target.maxhp;
			}
			target.side.metaCount -= percentage;
			console.log(target.id + ": " + target.side.metaCount);
			this.add('-message', target.id.slice(4) + ": " + Math.round(target.side.metaCount));
			if (target.side.metaCount <= 0.1) {
				//note: making this 0.1 because I got 1.10 times 10^-15 once
				//something silly with rounding
				//this works well enough
				this.win(target.side.foe);
			}

		}
	},

//mods/toppercentage/moves.js
'use strict';

exports.BattleMovedex = {
	perishsong: {
		inherit: true,
		effect: {
			duration: 4,
			onEnd: function (target) {
				target.side.metaCount -= (100 * target.hp / target.maxhp);
				this.add('-start', target, 'perish0');
				console.log(target.id + ": " + target.side.metaCount);
				this.add('-message', target.id.slice(4) + ": " + Math.round(target.side.metaCount));
				target.faint();
				if (target.side.metaCount <= 0.1) {
					this.win(target.side.foe);
				}
			},
			onResidual: function (pokemon) {
				let duration = pokemon.volatiles['perishsong'].duration;
				this.add('-start', pokemon, 'perish' + duration);
			}
		}
	},
	destinybond: {
		inherit: true,
		effect: {
			onFaint: function (target, source, effect) {
				if (!source || !effect) return;
				if (effect.effectType === 'Move' && !effect.isFutureMove) {
					this.add('-activate', target, 'Destiny Bond');
					source.faint();
					console.log(source.id + ": " + source.side.metaCount);
					this.add('-message', source.id.slice(4) + ": " + Math.round(source.side.metaCount));

					if (source.side.metaCount <= 0.1) {
						this.win(source.side.foe);
					}
				}
			}
		}
	}
}

//mods/toppercentage/scripts.js
'use strict';

exports.BattleScripts = {
	useMove: function (move, pokemon, target, sourceEffect) {

		//addition
		if (move.selfdestruct) {
			pokemon.side.metaCount -= 100 * (pokemon.hp / pokemon.maxhp);
			console.log(pokemon.id + ": " + pokemon.side.metaCount);
			this.add('-message', pokemon.id.slice(4) + ": " + Math.round(pokemon.side.metaCount));
			if (pokemon.side.metaCount <= 0.1) {
				this.win(pokemon.side.foe);
			}
		}

		if (!sourceEffect && this.effect.id) sourceEffect = this.effect;
		move = this.getMoveCopy(move);
		if (this.activeMove) move.priority = this.activeMove.priority;
		let baseTarget = move.target;
		if (!target && target !== false) target = this.resolveTarget(pokemon, move);
		if (move.target === 'self' || move.target === 'allies') {
			target = pokemon;
		}
		if (sourceEffect) move.sourceEffect = sourceEffect.id;
		let moveResult = false;

		this.setActiveMove(move, pokemon, target);

		this.singleEvent('ModifyMove', move, null, pokemon, target, move, move);
		if (baseTarget !== move.target) {
			// Target changed in ModifyMove, so we must adjust it here
			// Adjust before the next event so the correct target is passed to the
			// event
			target = this.resolveTarget(pokemon, move);
		}
		move = this.runEvent('ModifyMove', pokemon, target, move, move);
		if (baseTarget !== move.target) {
			// Adjust again
			target = this.resolveTarget(pokemon, move);
		}
		if (!move) return false;

		let attrs = '';
		if (pokemon.fainted) {
			return false;
		}

		if (move.flags['charge'] && !pokemon.volatiles[move.id]) {
			attrs = '|[still]'; // suppress the default move animation
		}

		let movename = move.name;
		if (move.id === 'hiddenpower') movename = 'Hidden Power';
		if (sourceEffect) attrs += '|[from]' + this.getEffect(sourceEffect);
		this.addMove('move', pokemon, movename, target + attrs);

		if (target === false) {
			this.attrLastMove('[notarget]');
			this.add('-notarget');
			if (move.target === 'normal') pokemon.isStaleCon = 0;
			return true;
		}

		let targets = pokemon.getMoveTargets(move, target);

		if (!sourceEffect) {
			let extraPP = 0;
			for (let i = 0; i < targets.length; i++) {
				let ppDrop = this.singleEvent('DeductPP', targets[i].getAbility(), targets[i].abilityData, targets[i], pokemon, move);
				if (ppDrop !== true) {
					extraPP += ppDrop || 0;
				}
			}
			if (extraPP > 0) {
				pokemon.deductPP(move, extraPP);
			}
		}

		if (!this.runEvent('TryMove', pokemon, target, move)) {
			return true;
		}

		this.singleEvent('UseMoveMessage', move, null, pokemon, target, move);

		if (move.ignoreImmunity === undefined) {
			move.ignoreImmunity = (move.category === 'Status');
		}

		let damage = false;
		if (move.target === 'all' || move.target === 'foeSide' || move.target === 'allySide' || move.target === 'allyTeam') {
			damage = this.tryMoveHit(target, pokemon, move);
			if (damage || damage === 0 || damage === undefined) moveResult = true;
		} else if (move.target === 'allAdjacent' || move.target === 'allAdjacentFoes') {
			if (move.selfdestruct) {
				this.faint(pokemon, pokemon, move);
			}
			if (!targets.length) {
				this.attrLastMove('[notarget]');
				this.add('-notarget');
				return true;
			}
			if (targets.length > 1) move.spreadHit = true;
			damage = 0;
			for (let i = 0; i < targets.length; i++) {
				let hitResult = this.tryMoveHit(targets[i], pokemon, move, true);
				if (hitResult || hitResult === 0 || hitResult === undefined) moveResult = true;
				damage += hitResult || 0;
			}
			if (!pokemon.hp) pokemon.faint();
		} else {
			target = targets[0];
			let lacksTarget = target.fainted;
			if (!lacksTarget) {
				if (move.target === 'adjacentFoe' || move.target === 'adjacentAlly' || move.target === 'normal' || move.target === 'randomNormal') {
					lacksTarget = !this.isAdjacent(target, pokemon);
				}
			}
			if (lacksTarget) {
				this.attrLastMove('[notarget]');
				this.add('-notarget');
				if (move.target === 'normal') pokemon.isStaleCon = 0;
				return true;
			}
			damage = this.tryMoveHit(target, pokemon, move);
			if (damage || damage === 0 || damage === undefined) moveResult = true;
		}
		if (!pokemon.hp) {
			this.faint(pokemon, pokemon, move);
		}

		if (!moveResult) {
			this.singleEvent('MoveFail', move, null, target, pokemon, move);
			return true;
		}

		if (move.selfdestruct) {
			this.faint(pokemon, pokemon, move);
		}

		if (!move.negateSecondary && !(pokemon.hasAbility('sheerforce') && pokemon.volatiles['sheerforce'])) {
			this.singleEvent('AfterMoveSecondarySelf', move, null, pokemon, target, move);
			this.runEvent('AfterMoveSecondarySelf', pokemon, target, move);
		}
		return true;
	}
}