using System.Collections.Generic;
using Models;

namespace Core;

/// <summary>
/// 数值解析器（用于统一计算有效属性）
/// 设计说明：
/// 1) 只做“读+合成”，不直接修改 Model。
/// 2) 合成来源包含：羁绊、学科 Buff、特质、装备。
/// 注意事项：
/// - 规则型效果（RuleIds）暂不在此处理，由系统层扩展。
/// 未来扩展：
/// - 可引入“上下文参数”（任务类型/场景）以处理条件加成。
/// </summary>
public sealed class StatResolver
{
	private readonly GameSession _session;

    /// <summary>
    /// 构造函数
    /// </summary>
    /// <param name="session">游戏会话</param>
	public StatResolver(GameSession session)
	{
		_session = session;
	}

    /// <summary>
    /// 获取计算后的属性值
    /// </summary>
    /// <param name="unit">单位</param>
    /// <param name="type">属性类型</param>
    /// <returns>属性值</returns>
	public float GetAttribute(UnitModel unit, AttributeType type)
	{
		var value = GetBaseAttribute(unit, type);
		ApplyBundle(_session.State.Synergy.ActiveModifiers, type, ref value);
		ApplyDiscipline(unit.Tags.DisciplineId, type, ref value);
		ApplyTraits(unit.Tags.TraitIds, type, ref value);
		ApplyItems(unit.Equipment.EquippedItemIds, type, ref value);
		return value;
	}

    /// <summary>
    /// 获取基础属性值
    /// </summary>
    /// <param name="unit">单位</param>
    /// <param name="type">属性类型</param>
    /// <returns>基础值</returns>
	private float GetBaseAttribute(UnitModel unit, AttributeType type)
	{
		return type switch
		{
			AttributeType.Academic => unit.Attributes.Academic.Value,
			AttributeType.Engineering => unit.Attributes.Engineering.Value,
			AttributeType.Writing => unit.Attributes.Writing.Value,
			AttributeType.Financial => unit.Attributes.Financial.Value,
			AttributeType.Social => unit.Attributes.Social.Value,
			AttributeType.Activation => unit.Attributes.Activation.Value,
			_ => 0f
		};
	}

    /// <summary>
    /// 应用学科加成
    /// </summary>
	private void ApplyDiscipline(string disciplineId, AttributeType type, ref float value)
	{
		if (string.IsNullOrWhiteSpace(disciplineId)) return;
		if (!_session.Content.Disciplines.TryGetValue(disciplineId, out var discipline)) return;
		ApplyBundle(discipline.Buff?.Modifiers, type, ref value);
	}

    /// <summary>
    /// 应用特质加成
    /// </summary>
	private void ApplyTraits(List<string> traitIds, AttributeType type, ref float value)
	{
		if (traitIds == null || traitIds.Count == 0) return;
		foreach (var traitId in traitIds)
		{
			if (_session.Content.Traits.TryGetValue(traitId, out var trait))
			{
				ApplyBundle(trait.Modifiers, type, ref value);
			}
		}
	}

    /// <summary>
    /// 应用装备加成
    /// </summary>
	private void ApplyItems(List<string> itemIds, AttributeType type, ref float value)
	{
		if (itemIds == null || itemIds.Count == 0) return;
		foreach (var itemId in itemIds)
		{
			if (_session.Content.Items.TryGetValue(itemId, out var item))
			{
				ApplyBundle(item.Effect?.Modifiers, type, ref value);
			}
		}
	}

    /// <summary>
    /// 应用修正包
    /// </summary>
	private void ApplyBundle(ModifierBundle bundle, AttributeType type, ref float value)
	{
		if (bundle == null) return;
		foreach (var modifier in bundle.AttributeModifiers)
		{
			if (modifier.Type != type) continue;
			value = (value + modifier.Add) * modifier.Multiplier;
		}
	}
}