import json
from flask import Flask
from flask_cors import CORS
from flask import request
from initial_learning import get_initial_path
from review_learning import get_review_path
from pre_exam_learning import get_pre_exam_path

app = Flask(__name__)
CORS(app, resources = r'/*')

@app.route('/get_study_path', methods=["POST"])
def get_study_path():
    '''
    以RESTful的方式获取初始学习路径推荐结果
    传入参数为: course_id,student_id,method
    :param course_id: 教学课堂ID
    :param student_id: 学生ID
    :param method: 学习路径场景
                    0: 初始学习路径 1: 复习学习路径 2: 考前学习路径
    :return 以json格式返回学习路径
    '''
    result = {}

    course_id = request.form.get('course_id', type=str, default='')
    student_id = request.form.get('student_id', type=str, default='')    
    method = request.form.get('method', type=str, default='0')
    platform = request.form.get('platform', type=str, default='0')
    
    # course_id为空时，参数错误
    if course_id.strip() == '':
        result = {
            "course_id": str('False'),
            "error_msg": str('参数错误: 缺少course_id')
        }
        return json.dumps(result, ensure_ascii=False)   
    
    #用户ID为空，推荐初始学习路径
    if student_id.strip() == '':
        recommend_results=get_initial_path(course_id, platform)
        result = {
        "course_id": str(course_id),
        "student_id": str(student_id),
        "recommend_count": str(len(recommend_results)),
        "recommend_results": recommend_results
    }
        
        return json.dumps(result, ensure_ascii=False)
    
    # 0：初始学习路径推荐
    if method == '0':
        recommend_results=get_initial_path(course_id, platform)
        result = {
        "course_id": str(course_id),
        "student_id": str(student_id),
        "recommend_count": str(len(recommend_results)),
        "recommend_results": recommend_results
    }
        return json.dumps(result, ensure_ascii=False)
    
    # 1：复习学习路径推荐
    if method == '1':
        recommend_results=get_review_path(course_id, platform=platform)
        result = {
        "course_id": str(course_id),
        "student_id": str(student_id),
        "recommend_count": str(len(recommend_results)),
        "recommend_results": recommend_results
        }
        return json.dumps(result, ensure_ascii=False)
    
    # 2：考前学习路径推荐
    if method == '2':
        
        recommend_results=get_pre_exam_path(course_id, platform=platform)
        result = {
        "course_id": str(course_id),
        "student_id": str(student_id),
        "recommend_count": str(len(recommend_results)),
        "recommend_results": recommend_results
        }
        return json.dumps(result, ensure_ascii=False)
    
    # method不在取值范围中，参数错误
    if method not in ['0','1','2']:
        result = {
            "method": str('False'),
            "error_msg": str("参数错误: method不属于['0','1','2']的应用场景")
        }
        return json.dumps(result, ensure_ascii=False)   

# python -m flask run
if __name__ == '__main__':
    app.run(host='0.0.0.0', port=8087, debug=True, use_reloader=False)