using System;
using Unity.Netcode;

namespace ProjectI.Enemies
{
    public struct EnemyArrivalSnapshot : INetworkSerializable, IEquatable<EnemyArrivalSnapshot>
    {
        public bool Enabled;
        public ulong SpawnIdentity;
        public double BornAt, ReadyAt;
        public bool Valid => Enabled && SpawnIdentity != 0 && EnemyDirectorDefinition.Finite(BornAt) && BornAt >= 0
            && EnemyDirectorDefinition.Finite(ReadyAt) && ReadyAt > BornAt;
        public void NetworkSerialize<T>(BufferSerializer<T> serializer) where T : IReaderWriter
        { serializer.SerializeValue(ref Enabled); serializer.SerializeValue(ref SpawnIdentity); serializer.SerializeValue(ref BornAt); serializer.SerializeValue(ref ReadyAt); }
        public bool Equals(EnemyArrivalSnapshot other) => Enabled == other.Enabled && SpawnIdentity == other.SpawnIdentity && BornAt == other.BornAt && ReadyAt == other.ReadyAt;
    }
    public sealed class EnemyArrivalState
    {
        private bool configured;
        private double bornAt, readyAt;
        public bool ConfigureBeforeSpawn(double start, double duration)
        {
            if (configured || !EnemyDirectorDefinition.Finite(start) || start < 0 || !EnemyDirectorDefinition.Positive(duration)
                || duration > 10 || !EnemyDirectorDefinition.Finite(start + duration) || start + duration <= start) return false;
            configured = true; bornAt = start; readyAt = start + duration; return true;
        }
        public EnemyArrivalSnapshot Bind(ulong identity) => configured && identity != 0
            ? new EnemyArrivalSnapshot { Enabled = true, SpawnIdentity = identity, BornAt = bornAt, ReadyAt = readyAt } : default;
        internal void ClearForNextBirth() { configured = false; bornAt = readyAt = 0; }
        public static bool Ready(EnemyArrivalSnapshot snapshot, ulong identity, double now)
            => !snapshot.Enabled || snapshot.Valid && snapshot.SpawnIdentity == identity && EnemyDirectorDefinition.Finite(now) && now >= snapshot.ReadyAt;
    }
}