using Microsoft.SemanticKernel.ChatCompletion;

namespace AI.Models.Store
{
    /// <summary>
    /// 会话存储条目的抽象基类。每条为 TextEntry（角色+文本）或 SpecialEntry（类型+YAML 载荷）。
    /// 存储由 ChatSession 持有，作为 UI 与 Prompt 构建的唯一事实来源。
    /// </summary>
    public abstract class ConversationEntry
    {
        /// <summary>
        /// 条目种类：Text 或 Special，用于序列化/反序列化与类型判别。
        /// </summary>
        public abstract string Kind { get; }
    }

    /// <summary>
    /// 纯文本消息条目：角色（User/Assistant/System）+ 文本内容。
    /// </summary>
    public sealed class TextConversationEntry : ConversationEntry
    {
        public override string Kind => "Text";

        /// <summary>角色</summary>
        public AuthorRole Role { get; set; }

        /// <summary>文本内容</summary>
        public string Content { get; set; } = string.Empty;

        public TextConversationEntry() { }

        public TextConversationEntry(AuthorRole role, string content)
        {
            Role = role;
            Content = content ?? string.Empty;
        }
    }

    /// <summary>
    /// 特殊消息条目：类型（Form/ParameterSet/Table/ColumnMatch/WorkflowStatus）+ YAML 载荷。
    /// </summary>
    public sealed class SpecialConversationEntry : ConversationEntry
    {
        public override string Kind => "Special";

        /// <summary>特殊消息类型名</summary>
        public string Type { get; set; } = string.Empty;

        /// <summary>YAML 载荷（与 ISpecialMessage 可序列化/反序列化对应）</summary>
        public string Payload { get; set; } = string.Empty;

        public SpecialConversationEntry() { }

        public SpecialConversationEntry(string type, string payload)
        {
            Type = type ?? string.Empty;
            Payload = payload ?? string.Empty;
        }
    }
}