# coding=utf-8

import itertools
import string

from django.db import models
from django.utils import timezone
from django.conf import settings

from utils.exceptions import CustomError
from apps.foundation.models import Chapter

class ExamQuestion(models.Model):
    SINGLE = 1
    MULTIPLE = 2
    FILL = 3
    JUDGMENT = 4
    DISCUSS = 5
    TYPE_CHOICES = (
        (SINGLE, u'单选题'),
        (MULTIPLE, u'多选题'),
        (FILL, u'填空题'),
        (JUDGMENT, u'判断题'),
        (DISCUSS, u'论述题'),
    )
    TYPE_JSON = [{'id': item[0], 'value': item[1]} for item in TYPE_CHOICES]

    SIMPLE = 1
    MID = 2
    HARD = 3
    DIFFICULTY_CHOICES = (
        (SIMPLE, u'简单'),
        (MID, u'中等'),
        (HARD, u'困难'),
    )
    DIFFICULTY_JSON = [{'id': item[0], 'value': item[1]} for item in DIFFICULTY_CHOICES]

    chapter = models.ForeignKey(Chapter, verbose_name=u"章节", on_delete=models.PROTECT)
    type = models.PositiveSmallIntegerField(choices=TYPE_CHOICES, verbose_name=u"题型")
    difficulty = models.PositiveSmallIntegerField(choices=DIFFICULTY_CHOICES, verbose_name=u"难度")
    scores = models.IntegerField(verbose_name=u'分数')
    title = models.TextField(verbose_name=u"题目")
    judgment = models.BooleanField(verbose_name=u'判断题答案', default=False)
    analysis = models.TextField(verbose_name=u"解析", null=True, blank=True)
    discuss_answer = models.TextField(verbose_name=u"论述题答案", null=True, blank=True)
    create_user = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name=u'录入人',related_name='exam_question_user', editable=False, on_delete=models.PROTECT)
    create_time = models.DateTimeField(verbose_name=u"录入时间", default=timezone.now, editable=False)
    delete = models.BooleanField(verbose_name=u'删除', default=False, editable=False)

    class Meta:
        db_table = "exam_question"
        ordering = ['-id']
        verbose_name = u"试题管理"
        default_permissions = ()

    @classmethod
    def batch_create(cls, subject, data, user):  
        for row in data:      
            # print("=====>", row)
            num = row.get('num', None)
            if not num:
                raise CustomError('序号不能为空')
            if not num.isdigit():
                raise CustomError('序号必须为数字')
            
            chapter = row.get('chapter', None)
            if not chapter:
                raise CustomError(f'题目{num}章节不能为空')
            else:
                chapter = Chapter.objects.filter(subject=subject, name=chapter).first()
                if not chapter:
                    raise CustomError(f'题目{num}章节不存在')
            
            title = row.get('title', None)
            if not title:
                raise CustomError(f'题目{num}题文不能为空')
            
            type = row.get('type', None)
            if not type:
                raise CustomError(f'题目{num}题型不能为空')
            found = False
            for item in ExamQuestion.TYPE_CHOICES:
                if item[1] == type:
                    type = item[0]
                    found = True
                    break
            if not found:
                raise CustomError(f'题目{num}题型不存在，可选类型有：填空题、单选题、多选题、判断题、论述题')

            difficulty = row.get('difficulty', None)
            if not difficulty:
                raise CustomError(f'题目{num}题型不能为空')
            found = False
            for item in ExamQuestion.DIFFICULTY_CHOICES:
                if item[1] == difficulty:
                    difficulty = item[0]
                    found = True
                    break
            if not found:
                raise CustomError(f'题目{num}难度无效，可选类型有：简单、中等、困难')

            score = row.get('score', None)
            if not score:
                raise CustomError(f'题目{num}分数不能为空')
            if not score.isdigit():
                raise CustomError(f'题目{num}分数必须为数字')    

            answer = row.get('answer', None)
            if not answer:
                raise CustomError(f'题目{num}答案不能为空')
                    
            if type == ExamQuestion.JUDGMENT and not answer in ('正确', '错误',):
                raise CustomError(f'题目{num}答案无效，可选类型有：正确、错误')
            
            images = row.get('images', None)
            if images:
                for image in images:
                    img = f'<img src="data:image/png;base64,{image}" />'
                    title = title + '<br>' + img

            judgment = False
            if type == ExamQuestion.JUDGMENT:
                judgment = answer == '正确'

            discuss_answer = ''
            if type == ExamQuestion.DISCUSS:
                discuss_answer = answer

            analysis = row.get('analysis', None)

            question = cls.objects.create(
                title=title, 
                type=type,
                difficulty=difficulty, 
                scores=score, 
                discuss_answer=discuss_answer, 
                judgment=judgment, 
                chapter=chapter,
                analysis=analysis,
                create_user=user
            )
            if type == ExamQuestion.SINGLE or type == ExamQuestion.MULTIPLE:
                options = row.get('options', None)         
                options_data = ExamQuestionOption.validate(type, options, answer)
                for option in options_data:
                    ExamQuestionOption.objects.create(main=question, content=option['content'], right=option['right'])
            if type == ExamQuestion.FILL:
                fill_data = ExamQuestionFill.validate(answer)
                for item in fill_data:
                    ExamQuestionFill.objects.create(main=question, content=item['content'], order=item['order'])

class ExamQuestionOption(models.Model):
    main = models.ForeignKey(ExamQuestion, verbose_name=u"试题", on_delete=models.PROTECT)
    content = models.TextField(verbose_name=u"内容")
    right = models.BooleanField(verbose_name=u'正确答案', default=False)
    delete = models.BooleanField(verbose_name=u'删除', default=False, editable=False)

    class Meta:
        db_table = "exam_question_option"
        ordering = ['id']
        verbose_name = u"选择题选项" # 单选、多选
        default_permissions = ()

    @classmethod
    def validate(cls, type, options, answer):
        if not options:
            raise CustomError(f'选项不能为空')
        if len(options) < 2:
            raise CustomError(f'选项不能少于2个')
        if len(options) > 10:
            raise CustomError(f'选项不能多于10个')
        
        answers = list(answer)
        answers_len = len(answers)
        if type == ExamQuestion.SINGLE and answers_len > 1:
            raise CustomError(f'单选题答案只能有一个')
        
        alphabet = string.ascii_uppercase  # 包含 A 到 Z 的字母序列
        cycle_alphabet = itertools.cycle(alphabet)  # 创建无限循环的字母序列
        all_chars = list(itertools.islice(cycle_alphabet, answers_len))  # 截取所需长度的部分

        if len(set(answers).difference(all_chars)) > 0:
            raise CustomError(f'答案选项无效，可选项有：{all_chars}')
        
        validation_data = []
        index = 0
        for option in options:
            item = {
                'content': option,
                'right': False
            }
            for letter in answers:
                if index == ord(letter) - ord('A'):
                    item['right'] = True
                    break
            index += 1

            validation_data.append(item)
        return validation_data
        

class ExamQuestionFill(models.Model):
    main = models.ForeignKey(ExamQuestion, verbose_name=u"试题", on_delete=models.PROTECT)
    content = models.TextField(verbose_name=u"内容")
    order = models.IntegerField(verbose_name=u'排序')
    delete = models.BooleanField(verbose_name=u'删除', default=False, editable=False)

    class Meta:
        db_table = "exam_question_fill"
        ordering = ['order', 'id']
        verbose_name = u"试题填空"
        default_permissions = ()

    @classmethod
    def validate(cls, answer):
        answers = answer.split('$')       

        validation_data = []
        index = 1
        for option in answers:
            item = {
                'content': option,
                'order': index
            }
            index += 1
            validation_data.append(item)
        return validation_data        

class ExamQuestionFeedback(models.Model):
    TYPE = 1
    ANSWER = 2
    ANALYSIS = 3
    OTHER = 4
    TYPE_CHOICES = (
        (TYPE, u'题目类型'),
        (ANSWER, u'题目答案'),
        (ANALYSIS, u'题目解析'),
        (OTHER, u'其它'),
    )
    TYPE_JSON = [{'id': item[0], 'value': item[1]} for item in TYPE_CHOICES]

    UNTREATED = 1
    PROCESSED = 2
    STATUS_CHOICES = (
        (UNTREATED, u'未处理'),
        (PROCESSED, u'已处理'),
    )
    STATUS_JSON = [{'id': item[0], 'value': item[1]} for item in STATUS_CHOICES]

    main = models.ForeignKey(ExamQuestion, verbose_name=u"试题", on_delete=models.PROTECT)
    type = models.PositiveSmallIntegerField(choices=TYPE_CHOICES, verbose_name=u"错误类型")
    desc = models.TextField(verbose_name=u"错误描述", null=True, blank=True)
    create_user = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name=u'反馈人',related_name='exam_question_feedback_user', editable=False, on_delete=models.PROTECT)
    create_time = models.DateTimeField(verbose_name=u"反馈时间", default=timezone.now, editable=False)
    status = models.PositiveSmallIntegerField(choices=STATUS_CHOICES, verbose_name=u'处理状态', default=UNTREATED)
    process_user = models.ForeignKey(settings.AUTH_USER_MODEL, verbose_name=u"处理人", on_delete=models.PROTECT, null=True, related_name="exam_question_feedback_ref_process_user")
    process_time = models.DateTimeField(verbose_name=u'处理时间', null=True)

    class Meta:
        db_table = "exam_question_feedback"
        ordering = ['-id']
        verbose_name = u"错误反馈"
        default_permissions = ()

    @staticmethod
    def getById(id):
        instance = ExamQuestionFeedback.objects.filter(pk=id).first()
        if not instance:
            raise CustomError(u'未找到相应的错误反馈')
        return instance

    def process(self, user):
        self.process_user = user
        self.status = ExamQuestionFeedback.PROCESSED
        self.process_time = timezone.now()