import pandas as pd
from dateutil.tz import tzoffset
from dateutil.parser import parse
from dateutil.utils import default_tzinfo

class CSVParser:

    def __init__ (self, path):
        self.df = pd.read_csv(path)
        tz = tzoffset(name="saw", offset=-10800)
        self.df['time'] = self.df['time'].transform(lambda x: default_tzinfo(parse(x), tz).timestamp())
        self.exercises = self.df['exercise_id'].unique().tolist()
        self.exercises.sort()

    def getSubmissions (self, exercise_id):
        dataFrame:pd.DataFrame = self.df
        submissionData = dataFrame[dataFrame['exercise_id'] == exercise_id]
        if 0.01 in submissionData['grade'].values :
            submissionData['grade'] = submissionData['grade'].transform(lambda x: x*10 if x != 1 and not pd.isna(x) else x)
        students = submissionData['user_id'].unique().tolist()
        students.sort()
        return (submissionData, students)

    def getStudentFirstInteraction (self, submissionData, studentID):
        # filter and sort user_id submission and turn them in tuples
        subTuple = submissionData[submissionData['user_id'] == studentID].sort_values(by='time').itertuples(index=False, name="Submission")
        subList = list(subTuple)
        size = len(subList)
        for i in range(size):
            if subList[i].action == 'uploaded_submission':
                foundPos = self._backtrackViewDescription(subList, i)
                if foundPos >= 0:
                    return subList[foundPos].time
                else:
                    return -1
        print("firt intereaction not found: %i"%size)
        return -1

    def getStudentValidSubmissions (self, submissionData, studentID):
        # filter and sort user_id submission and turn them in tuples
        filteredDF = submissionData[(submissionData['user_id'] == studentID) & (submissionData['action'] == 'uploaded_submission')].dropna().sort_values(by='time')
        filteredDF = filteredDF.drop_duplicates(subset="submission_id")
        subList = list(filteredDF.itertuples(index=False, name="Submission"))
        return subList

    def getStudentLastSubmission (self, submissionData, studentID):
        filteredDF = submissionData[(submissionData['user_id'] == studentID) & (submissionData['action'] == 'uploaded_submission')].dropna().sort_values(by='submission_id')
        filteredDF = filteredDF.drop_duplicates(subset="submission_id")
        subList = list(filteredDF.itertuples(index=False, name="Submission"))
        return subList

    def _backtrackViewDescription (self, subList, start_pos):
        i = start_pos - 1
        while (i >= 0):
            if subList[i].action == 'view_description':
                return i
            i = i - 1
        print("Backtrack view not found")
        return -1