using System.Collections.Generic;
using System.Globalization;
using GeometryTD.DataTable;
using GeometryTD.Definition;
using UnityEngine;

namespace GeometryTD.CustomComponent
{
    internal sealed class PhaseLoopRuntime
    {
        private readonly List<DRLevelPhase> _phases = new();

        private DRLevelPhase _currentPhase;
        private int _currentPhaseIndex = -1;
        private int _displayPhaseIndex;
        private int _completedLoopCount;
        private bool _canEndCombat;
        private bool _endCombatRequested;
        private float _currentPhaseElapsed;

        public DRLevelPhase CurrentPhase => _currentPhase;
        public int DisplayPhaseIndex => _displayPhaseIndex;
        public bool CanEndCombat => _canEndCombat;
        public bool IsEndCombatRequested => _endCombatRequested;
        public float CurrentPhaseElapsed => _currentPhaseElapsed;
        public int PhaseCount => _phases.Count;

        public void Reset()
        {
            _phases.Clear();
            _currentPhase = null;
            _currentPhaseIndex = -1;
            _displayPhaseIndex = 0;
            _completedLoopCount = 0;
            _canEndCombat = false;
            _endCombatRequested = false;
            _currentPhaseElapsed = 0f;
        }

        public void SetPhases(IReadOnlyList<DRLevelPhase> phases)
        {
            _phases.Clear();
            if (phases == null)
            {
                return;
            }

            for (int i = 0; i < phases.Count; i++)
            {
                DRLevelPhase phase = phases[i];
                if (phase != null)
                {
                    _phases.Add(phase);
                }
            }
        }

        public bool TryRequestEndCombat()
        {
            if (!_canEndCombat)
            {
                return false;
            }

            _endCombatRequested = true;
            return true;
        }

        public void AdvancePhaseElapsed(float elapseSeconds)
        {
            _currentPhaseElapsed += elapseSeconds;
        }

        public bool ShouldEndCurrentPhase(bool isPhaseSpawnCompleted, int aliveEnemyCount)
        {
            if (_currentPhase == null)
            {
                return false;
            }

            switch (_currentPhase.EndType)
            {
                case PhaseEndType.TimeElapsed:
                    return _currentPhaseElapsed >= ResolveTimeElapsedThreshold(_currentPhase);
                case PhaseEndType.EnemiesCleared:
                case PhaseEndType.BossDead:
                    return isPhaseSpawnCompleted && aliveEnemyCount <= 0;
                case PhaseEndType.None:
                default:
                    if (_currentPhase.DurationSeconds > 0 && _currentPhaseElapsed >= _currentPhase.DurationSeconds)
                    {
                        return true;
                    }

                    return isPhaseSpawnCompleted && aliveEnemyCount <= 0;
            }
        }

        public bool TryEnterNextPhase(out DRLevelPhase nextPhase)
        {
            nextPhase = null;
            if (_phases.Count <= 0)
            {
                return false;
            }

            _currentPhaseIndex++;
            if (_currentPhaseIndex >= _phases.Count)
            {
                _completedLoopCount++;
                _canEndCombat = true;

                if (_endCombatRequested)
                {
                    _currentPhase = null;
                    return false;
                }

                _currentPhaseIndex = 0;
            }

            _currentPhase = _phases[_currentPhaseIndex];
            _displayPhaseIndex = _completedLoopCount * _phases.Count + _currentPhaseIndex + 1;
            _currentPhaseElapsed = 0f;
            nextPhase = _currentPhase;
            return true;
        }

        private static float ResolveTimeElapsedThreshold(DRLevelPhase phase)
        {
            if (!string.IsNullOrWhiteSpace(phase.EndParam) &&
                float.TryParse(phase.EndParam, NumberStyles.Float, CultureInfo.InvariantCulture, out float parsed))
            {
                return parsed;
            }

            if (phase.DurationSeconds > 0)
            {
                return phase.DurationSeconds;
            }

            return 0f;
        }
    }
}