WaveGenerator

using System.Collections.Generic;
using System.Linq;
using PlinioJRM.Entities;
using UnityEngine;

namespace PlinioJRM.Systems.Waves {
    public struct SpawnData {
        public List<EnemyType> enemies;
    }

    public class WaveGenerator {
        private List<WaveGenerationRule> _rules;
        private bool                     _isGroup;
        private int                      _groupChance;
        private EnemyType                _defaultEnemy;

        public WaveGenerator(
            List<WaveGenerationRule> rules,
            EnemyType defaultEnemy,
            bool isGroup = false,
            int groupChance = 0) {

            _rules = rules.OrderBy(R => R.chance).ToList();
            _defaultEnemy = defaultEnemy;
            _isGroup = isGroup;
            _groupChance = groupChance;
        }

        public SpawnData GenerateSpawnInfo() {
            float RandomRoll() {
                int roll = Random.Range(0, 10000);
                return (float)roll / 100;
            }

            SpawnData data = new () {
                enemies = new List<EnemyType>()
            };

            if (!_isGroup) {
                data.enemies.Add(Roll());
                return data;
            }

            float chance = _groupChance;
            float chanceRoll = 100f;
            while (chanceRoll <= chance) {
                data.enemies.Add(Roll());

                chance *= 0.12f;
                chanceRoll = RandomRoll();
            };

            return data;
        }

        private EnemyType Roll() {
            int chance = Random.Range(0, 100);
            foreach (WaveGenerationRule rule in _rules) {
                if (chance <= rule.chance)
                    return rule.enemyType;
            }

            return _defaultEnemy;
        }
    }
}