using System;
using System.Collections.Generic;
using Sirenix.OdinInspector;
using UnityEngine;

namespace Ichni.Story
{
    /// <summary>
    /// 通用剧情条件树的节点基类。通过多态组合出“与 / 或 / 非 + 叶子条件”的复合表达式。
    /// 由 <see cref="StoryCondition"/> 借助 <c>[SerializeReference]</c> 序列化持有，
    /// Odin 会以类型下拉框展示可选的节点类型。
    /// </summary>
    [Serializable]
    public abstract class StoryConditionNode
    {
        /// <summary>
        /// 对该节点求值。
        /// </summary>
        /// <param name="getVariable">按变量名返回其整型值的委托。</param>
        /// <param name="isBlockCompleted">按 blockId 判断该 Block 是否已完成的委托。</param>
        public abstract bool Evaluate(Func<string, int> getVariable, Func<string, bool> isBlockCompleted);

#if UNITY_EDITOR
        /// <summary>
        /// 返回 Inspector 中使用的紧凑摘要。条件编辑器只读取该文本，不影响运行时求值逻辑。
        /// </summary>
        public virtual string GetEditorSummary() => GetType().Name;
#endif
    }

    /// <summary>
    /// 复合节点（逻辑与 AND）：所有子条件均满足时才满足。子列表为空视为满足。
    /// </summary>
    [Serializable]
    [LabelText("All Of (AND)")]
    public class AllOfCondition : StoryConditionNode
    {
        [HideLabel]
        [SerializeReference]
        [ListDrawerSettings(ShowFoldout = true, DefaultExpandedState = true)]
        public List<StoryConditionNode> conditions = new List<StoryConditionNode>();

        public override bool Evaluate(Func<string, int> getVariable, Func<string, bool> isBlockCompleted)
        {
            foreach (StoryConditionNode child in conditions)
            {
                if (child != null && !child.Evaluate(getVariable, isBlockCompleted))
                    return false;
            }

            return true;
        }

#if UNITY_EDITOR
        public override string GetEditorSummary() => $"All Of ({conditions?.Count ?? 0})";
#endif
    }

    /// <summary>
    /// 复合节点（逻辑或 OR）：任一子条件满足即满足。子列表为空视为不满足。
    /// </summary>
    [Serializable]
    [LabelText("Any Of (OR)")]
    public class AnyOfCondition : StoryConditionNode
    {
        [HideLabel]
        [SerializeReference]
        [ListDrawerSettings(ShowFoldout = true, DefaultExpandedState = true)]
        public List<StoryConditionNode> conditions = new List<StoryConditionNode>();

        public override bool Evaluate(Func<string, int> getVariable, Func<string, bool> isBlockCompleted)
        {
            if (conditions.Count == 0)
                return false;

            foreach (StoryConditionNode child in conditions)
            {
                if (child != null && child.Evaluate(getVariable, isBlockCompleted))
                    return true;
            }

            return false;
        }

#if UNITY_EDITOR
        public override string GetEditorSummary() => $"Any Of ({conditions?.Count ?? 0})";
#endif
    }

    /// <summary>
    /// 复合节点（逻辑非 NOT）：对子条件取反。子条件为空视为满足（等价于“非 假”）。
    /// </summary>
    [Serializable]
    [LabelText("Not")]
    public class NotCondition : StoryConditionNode
    {
        [HideLabel]
        [SerializeReference]
        public StoryConditionNode condition;

        public override bool Evaluate(Func<string, int> getVariable, Func<string, bool> isBlockCompleted)
        {
            return condition == null || !condition.Evaluate(getVariable, isBlockCompleted);
        }

#if UNITY_EDITOR
        public override string GetEditorSummary() => $"Not ({condition?.GetEditorSummary() ?? "None"})";
#endif
    }

    /// <summary>
    /// 叶子节点：指定 Block 已完成时满足。
    /// </summary>
    [Serializable]
    [LabelText("Block Completed")]
    public class BlockCompletedCondition : StoryConditionNode
    {
        [LabelText("Block ID")]
        [LabelWidth(50)]
        [Tooltip("必须已完成的 StoryBlock ID。可用于表达显式前置条件；通常连接关系已由 Connected Rule 自动处理。")]
        public string blockId;

        public override bool Evaluate(Func<string, int> getVariable, Func<string, bool> isBlockCompleted)
        {
            return !string.IsNullOrEmpty(blockId) && isBlockCompleted(blockId);
        }

#if UNITY_EDITOR
        public override string GetEditorSummary() => string.IsNullOrWhiteSpace(blockId)
            ? "Block Completed: <missing ID>"
            : $"Block Completed: {blockId}";
#endif
    }

    /// <summary>
    /// 叶子节点：将指定变量的当前值与目标值按比较方式求值。
    /// 既可用于解锁条件，也可用于 Forbidden Condition；例如当路线变量等于另一条路线的值时禁用 Block。
    /// </summary>
    [Serializable]
    [LabelText("Variable Compare")]
    public class VariableCondition : StoryConditionNode
    {
        [HorizontalGroup("VariableComparison", 0.50f)]
        [LabelText("Var")]
        [LabelWidth(24)]
        [Tooltip("章节剧情变量名。使用小写英文、数字和下划线；可由 Yarn 的 set_* 指令写入。")]
        public string variableName;

        [HorizontalGroup("VariableComparison", 0.22f)]
        [LabelText("Op")]
        [LabelWidth(20)]
        [Tooltip("变量值与目标值之间的比较方式。")]
        public VariableComparison comparison;

        [HorizontalGroup("VariableComparison")]
        [LabelText("Value")]
        [LabelWidth(35)]
        [Tooltip("用于比较的整数目标值。Bool 条件使用 0 / 1。")]
        public int value;

        public override bool Evaluate(Func<string, int> getVariable, Func<string, bool> isBlockCompleted)
        {
            int actual = getVariable(variableName);
            return comparison switch
            {
                VariableComparison.Equal          => actual == value,
                VariableComparison.NotEqual       => actual != value,
                VariableComparison.Greater        => actual > value,
                VariableComparison.GreaterOrEqual => actual >= value,
                VariableComparison.Less           => actual < value,
                VariableComparison.LessOrEqual    => actual <= value,
                _                                 => false
            };
        }

#if UNITY_EDITOR
        public override string GetEditorSummary()
        {
            string variable = string.IsNullOrWhiteSpace(variableName) ? "<missing variable>" : variableName;
            string operation = comparison switch
            {
                VariableComparison.Equal          => "==",
                VariableComparison.NotEqual       => "!=",
                VariableComparison.Greater        => ">",
                VariableComparison.GreaterOrEqual => ">=",
                VariableComparison.Less           => "<",
                VariableComparison.LessOrEqual    => "<=",
                _                                 => "?"
            };
            return $"{variable} {operation} {value}";
        }
#endif
    }
}

#if UNITY_EDITOR
namespace Ichni.Story.Editor
{
    /// <summary>
    /// 通用 StoryCondition 的 Odin Inspector Drawer。
    /// <para>Unlock、Forbidden 与 Helper Availability 共用同一条件模型；此 Drawer 只改变编辑器中的
    /// 折叠呈现方式，不修改条件树的序列化结构或运行时求值结果。</para>
    /// <para>默认仅显示可读摘要。需要调整条件时再展开，避免 SerializeReference 条件树长期占据 Block 的编辑空间。</para>
    /// </summary>
    public class StoryConditionDrawer : Sirenix.OdinInspector.Editor.OdinValueDrawer<StoryCondition>
    {
        private bool _isExpanded;

        protected override void DrawPropertyLayout(UnityEngine.GUIContent label)
        {
            StoryCondition condition = ValueEntry.SmartValue;
            string summary = condition == null ? "None" : condition.GetEditorSummary();

            // 父属性若保留了简短标签（例如 Helper 的 Availability），则与摘要合并显示；
            // StoryBlock 中使用 HideLabel 时只保留摘要，避免重复占用左侧标签列。
            string prefix = label == null || string.IsNullOrWhiteSpace(label.text)
                ? string.Empty
                : $"{label.text}: ";

            UnityEngine.GUIContent foldoutLabel = new UnityEngine.GUIContent(
                prefix + summary,
                "留空表示未配置条件。展开后可选择 All Of (AND)、Any Of (OR)、Not、Block Completed 或 Variable Compare。"
            );

            _isExpanded = UnityEditor.EditorGUILayout.Foldout(_isExpanded, foldoutLabel, true);
            if (!_isExpanded)
            {
                return;
            }

            UnityEditor.EditorGUI.indentLevel++;
            // 继续调用 Odin 的默认 SerializeReference 绘制链，使类型选择、嵌套条件和 Undo 行为保持原样。
            CallNextDrawer(UnityEngine.GUIContent.none);
            UnityEditor.EditorGUI.indentLevel--;
        }
    }
}
#endif