using System;
using System.Collections.Generic;
using System.Text;

namespace BuilderPattern
{
  /// <summary>
  /// 所有课程
  /// </summary>
  public class Coures
  {    
    /// <summary>
    /// 保存课程信息
    /// </summary>
    IDictionary<string, decimal> coures = new Dictionary<string, decimal>();

    /// <summary>
    /// 选课
    /// </summary>
    /// <param name="serialNumber"></param>
    /// <param name="score"></param>
    public void Select(string serialNumber, decimal score)
    {
      coures.Add(serialNumber, score);
    }

    /// <summary>
    /// 计算总学分
    /// </summary>
    /// <returns>总学分</returns>
    public decimal ComputeScores()
    {
      decimal scores = 0;
      foreach (KeyValuePair<string, decimal> kvp in coures) 
      {  
        Console.WriteLine(kvp.Key + ":" + kvp.Value);
        Console.WriteLine(" ");
        scores += kvp.Value;
      }
      return scores;
    }
  }
  
  /// <summary>
  /// 选课建造者抽象类，表现(下面的抽象函数)是相对稳定的。
  /// </summary>
  public abstract class Builder
  {
    /// <summary>
    /// 必修课程成绩
    /// </summary>
    public abstract void BuildCompulsory();

    /// <summary>
    /// 选修课程成绩
    /// </summary>
    public abstract void BuildElective();

    /// <summary>
    /// 限制课程成绩
    /// </summary>
    public abstract void BuildRestriction();

    /// <summary>
    /// 获得课程字典对象
    /// </summary>
    /// <returns></returns>
    public abstract Coures GetCoures();
  }

  /// <summary>
  /// 本科生选课成绩
  /// </summary>
  public class UndergraduateBuilder : Builder
  {
    private Coures coures = new Coures();

    /// <summary>
    /// 本科生选必修课程成绩
    /// </summary>
    public override void BuildCompulsory()
    {
      coures.Select("001", 80M);
    }

    /// <summary>
    /// 本科生选选修课程成绩
    /// </summary>
    public override void BuildElective()
    {
      coures.Select("101", 85M);
    }

    /// <summary>
    /// 本科生选限制课程成绩
    /// </summary>
    public override void BuildRestriction()
    {
      coures.Select("201", 95M);
    }

    /// <summary>
    /// 本科生选获得课程字典对象
    /// </summary>
    /// <returns></returns>
    public override Coures GetCoures()
    {
      return coures;
    }
  }

  /// <summary>
  /// 研究生选课成绩
  /// </summary>
  public class GraduateBuilder : Builder
  {
    private Coures coures = new Coures();

    /// <summary>
    /// 研究生选必修课程成绩
    /// </summary>
    public override void BuildCompulsory()
    {
      coures.Select("S001", 70M);
    }

    /// <summary>
    /// 研究生选选修课程成绩
    /// </summary>
    public override void BuildElective()
    {
      coures.Select("S101", 75M);
    }

    /// <summary>
    /// 研究生选限制课程成绩
    /// </summary>
    public override void BuildRestriction()
    {
      coures.Select("S201", 80M);
    }

    /// <summary>
    /// 研究生选获得课程字典对象
    /// </summary>
    /// <returns></returns>
    public override Coures GetCoures()
    {
      return coures;
    }
  }

  /// <summary>
  /// 课程成绩管理类
  /// </summary>
  public class CourseScoresManager
  {
    /// <summary>
    /// 这里的参数便是未确定的
    /// </summary>
    /// <param name="builder"></param>
    public void CourseScoresManager(Builder builder)
    {
      builder.BuildCompulsory();
      builder.BuildElective();
      builder.BuildRestriction();
    }
  }

  class Program
  {
    static void Main(string[] args)
    {      
      /* Builder instance = new UndergraduateBuilder(); */
      Builder instance = new GraduateBuilder();
      CourseScoresManager courseScoresManager = new CourseScoresManager(instance);
      Coures coures = instance.GetCoures();
      decimal totalScores = coures.ComputeScores();
      Console.WriteLine(totalScores);
      Console.WriteLine(" ");
      Console.ReadLine();
    }
  }
}