using System;
using System.Collections.Generic;
using System.IO;
using System.Text.Json;
using System.Text.Json.Serialization;
using Godot;
using Models;

/// <summary>
/// Location identifiers used by the campus behavior system.
/// These map to Node2D markers in campus.tscn so the AI can pick targets by name.
/// </summary>
public enum CampusLocationId
{
	None,
	Laboratory,
	Library,
	Canteen,
	Dormitory,
	ArtificialLake,
	CoffeeShop,
	AdministrationBuilding,
	FootballField,
	RandomWander
}

/// <summary>
/// Action identifiers used by the behavior planner and state machine.
/// Each action is configured via campus_behavior.json for duration and stat deltas.
/// </summary>
public enum CampusActionId
{
	None,
	Experimenting,
	Writing,
	Eating,
	Sleeping,
	Chilling,
	Staring,
	CoffeeBreak,
	Administration,
	Running,
	Socializing,
	Wandering
}

/// <summary>
/// Priority levels match the design doc ordering: lower value = higher priority.
/// </summary>
public enum CampusBehaviorPriority
{
	Critical = 0,
	AssignedTask = 1,
	Needs = 2,
	Trait = 3,
	Idle = 4
}

/// <summary>
/// Minimal task types for the campus demo. These are not full gameplay tasks,
/// just drivers for the assigned-task priority in the AI.
/// </summary>
public enum CampusTaskType
{
	Experiment,
	Writing,
	Administration,
	Exercise,
	Coding,
	Social
}

/// <summary>
/// Action configuration loaded from JSON. Deltas are applied per second while
/// the action is running, so longer actions accumulate more effect.
/// </summary>
public sealed class CampusActionConfig
{
	public CampusActionId ActionId { get; set; }
	public CampusLocationId LocationId { get; set; }
	public float DurationSeconds { get; set; }
	public float HungerDelta { get; set; }
	public float EnergyDelta { get; set; }
	public float StaminaDelta { get; set; }
	public float StressDelta { get; set; }
	public float MoodDelta { get; set; }
	public float SocialDelta { get; set; }
	public float SanityDelta { get; set; }
	public float HealthDelta { get; set; }
}

/// <summary>
/// Global behavior configuration for campus AI. This is intentionally data-driven
/// so balancing can happen in JSON without touching code.
/// </summary>
public sealed class CampusBehaviorConfig
{
	public float CriticalSanityThreshold { get; set; } = 15f;
	public float CriticalStaminaThreshold { get; set; } = 12f;
	public float CriticalStressThreshold { get; set; } = 90f;
	public float HungerThreshold { get; set; } = 30f;
	public float EnergyThreshold { get; set; } = 25f;
	public float SocialThreshold { get; set; } = 35f;
	public float LowMoodThreshold { get; set; } = 25f;
	public float HungerDecayPerSecond { get; set; } = 0.6f;
	public float EnergyDecayPerSecond { get; set; } = 0.5f;
	public float StaminaDecayPerSecond { get; set; } = 0.4f;
	public float StressGrowthPerSecond { get; set; } = 0.45f;
	public float SocialDecayPerSecond { get; set; } = 0.35f;
	public float DecisionIntervalSeconds { get; set; } = 0.5f;
	public float ActionDurationVariance { get; set; } = 0.25f;
	public float MinPlannedActionSeconds { get; set; } = 2.0f;
	public List<CampusActionConfig> ActionConfigs { get; set; } = new();

	private readonly Dictionary<CampusActionId, CampusActionConfig> _actionLookup = new();

	public CampusActionConfig GetActionConfig(CampusActionId id)
	{
		if (_actionLookup.Count == 0)
		{
			BuildLookup();
		}

		return _actionLookup.TryGetValue(id, out var config) ? config : null;
	}

	private void BuildLookup()
	{
		_actionLookup.Clear();
		if (ActionConfigs == null) return;
		foreach (var config in ActionConfigs)
		{
			_actionLookup[config.ActionId] = config;
		}
	}

	public static CampusBehaviorConfig Load(string path)
	{
		if (string.IsNullOrWhiteSpace(path))
		{
			GD.PushWarning("Campus behavior config path is empty; using defaults.");
			return new CampusBehaviorConfig();
		}

		var resolvedPath = path.StartsWith("res://") || path.StartsWith("user://")
			? ProjectSettings.GlobalizePath(path)
			: path;

		if (!File.Exists(resolvedPath))
		{
			GD.PushWarning($"Campus behavior config not found at {resolvedPath}; using defaults.");
			return new CampusBehaviorConfig();
		}

		var json = File.ReadAllText(resolvedPath);
		if (string.IsNullOrWhiteSpace(json))
		{
			GD.PushWarning($"Campus behavior config is empty at {resolvedPath}; using defaults.");
			return new CampusBehaviorConfig();
		}

		var options = new JsonSerializerOptions
		{
			PropertyNameCaseInsensitive = true
		};
		options.Converters.Add(new JsonStringEnumConverter());

		try
		{
			var config = JsonSerializer.Deserialize<CampusBehaviorConfig>(json, options);
			return config ?? new CampusBehaviorConfig();
		}
		catch (Exception ex)
		{
			GD.PushWarning($"Failed to parse campus behavior config: {ex.Message}");
			return new CampusBehaviorConfig();
		}
	}
}

/// <summary>
/// Simple location registry that maps logical location ids to scene positions.
/// This keeps the behavior system independent from scene tree details.
/// </summary>
public sealed class CampusLocationRegistry
{
	private readonly Dictionary<CampusLocationId, Vector2> _locations = new();

	public void Register(CampusLocationId id, Vector2 position)
	{
		if (id == CampusLocationId.None) return;
		_locations[id] = position;
	}

	public bool TryGetPosition(CampusLocationId id, out Vector2 position)
	{
		return _locations.TryGetValue(id, out position);
	}
}

/// <summary>
/// Tracks current occupancy per location so traits like social phobia can react
/// to crowd size without hard-coding scene knowledge.
/// </summary>
public sealed class CampusBehaviorWorld
{
	private readonly Dictionary<CampusLocationId, int> _occupancy = new();

	public void Clear()
	{
		_occupancy.Clear();
	}

	public void AddOccupant(CampusLocationId id)
	{
		if (id == CampusLocationId.None || id == CampusLocationId.RandomWander) return;
		if (!_occupancy.ContainsKey(id))
		{
			_occupancy[id] = 0;
		}

		_occupancy[id] += 1;
	}

	public int GetOccupancy(CampusLocationId id)
	{
		return _occupancy.TryGetValue(id, out var count) ? count : 0;
	}
}

/// <summary>
/// Lightweight task container for the campus demo; it just tracks remaining work.
/// </summary>
public sealed class CampusTask
{
	public CampusTaskType Type { get; }
	public float RemainingSeconds { get; private set; }

	public CampusTask(CampusTaskType type, float remainingSeconds)
	{
		Type = type;
		RemainingSeconds = Mathf.Max(0f, remainingSeconds);
	}

	public void Advance(float delta)
	{
		RemainingSeconds = Mathf.Max(0f, RemainingSeconds - delta);
	}

	public bool IsComplete => RemainingSeconds <= 0f;
}

/// <summary>
/// Custom needs that are not yet part of the core UnitModel (hunger/social/energy).
/// Uses PropertyValue so it plugs into the existing numeric system.
/// </summary>
public sealed class CampusAgentNeeds
{
	public PropertyValue Hunger { get; }
	public PropertyValue Energy { get; }
	public PropertyValue Social { get; }
	public PropertyValue Health { get; }

	public CampusAgentNeeds(float hunger, float energy, float social, float health)
	{
		Hunger = new PropertyValue(hunger);
		Energy = new PropertyValue(energy);
		Social = new PropertyValue(social);
		Health = new PropertyValue(health);
	}
}