using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Entities.Contracts
{
	[Table("questions")]
	public class Question
	{
		[Key]
		[Column("id")]
		public Guid Id { get; set; }

		[Required]
		[Column("question_text")]
		[MaxLength(65535)]
		public string QuestionText { get; set; }

		[Required]
		[Column("question_type")]
		[MaxLength(20)]
		public QuestionType QuestionType { get; set; } 

		[Column("correct_answer")]
		[MaxLength(65535)]
		public string CorrectAnswer { get; set; }

		[Column("difficulty_level")]
		[MaxLength(10)] 
		public DifficultyLevel DifficultyLevel { get; set; } 

		[Column("subject_area")]
		public SubjectAreaEnum SubjectArea { get; set; }

		[Required]
		[Column("created_by")]
		[ForeignKey("Creator")]
		public Guid CreatedBy { get; set; }

		[Column("created_at")]
		public DateTime CreatedAt { get; set; }

		[Column("updated_at")]
		public DateTime UpdatedAt { get; set; }

		[Column("deleted")]
		public bool IsDeleted { get; set; }

		[Column("valid_question")]
		public bool ValidQuestion { get; set; }

		// Navigation Properties
		public User Creator { get; set; }
		public ICollection<AssignmentQuestion> AssignmentQuestions { get; set; }

		public Question()
		{
			Id = Guid.NewGuid();
			AssignmentQuestions = new HashSet<AssignmentQuestion>();
		}
	}

	public enum DifficultyLevel
	{
		easy,
		medium,
		hard
	}

	public enum QuestionType
	{
		Unknown, // 可以有一个未知类型或作为默认
		Spelling,           // 拼写
		Pronunciation,      // 给带点字选择正确读音
		WordFormation,      // 组词
		FillInTheBlanks,    // 选词填空 / 补充词语
		SentenceDictation,  // 默写句子
		SentenceRewriting,  // 仿句 / 改写句子
		ReadingComprehension, // 阅读理解
		Composition         // 作文
							// ... 添加您其他题目类型
	}

	public enum SubjectAreaEnum // 建议命名为 SubjectAreaEnum 以避免与属性名冲突
	{
		Unknown,         // 未知或默认
		Mathematics,     // 数学
		Physics,         // 物理
		Chemistry,       // 化学
		Biology,         // 生物
		History,         // 历史
		Geography,       // 地理
		Literature,      // 语文/文学
		English,         // 英语
		ComputerScience, // 计算机科学
						 // ... 你可以根据需要添加更多科目
	}
}