import sys
import os
import shutil
import csv
import datetime
from drive import Drive
from csvfile import CSVFile
from pathlib import Path
from utils import subtract, nextWeek, sumKV

SEARCH_PATH = "/mnt/"

class DiskUsage:
    # I probably should be using a database instead of CSV.
    def __init__(self, basepath) -> None:
        basepath = Path(basepath)
        self.SIZE_FILE = basepath.joinpath("size_daily.csv")
        self.DIFF_FILE = basepath.joinpath("diff_daily.csv")
        self.WEEKLY_SIZE_FILE = basepath.joinpath("size_weekly.csv")
        self.WEEKLY_DIFF_FILE = basepath.joinpath("diff_weekly.csv")
        pass

    @staticmethod
    def __daily2weeklyRow(row_):
        row = row_.copy()
        row["time"] = row["next_week"]
        row.pop("next_week")
        return row


    def update(self):
        nextWeek_ = nextWeek().isoformat()

        sizeDaily = CSVFile(self.SIZE_FILE)
        currentlyUsed = Drive.getUsed(SEARCH_PATH)
        sizeDaily.addRow(currentlyUsed)
        sizeDaily.efficientWriteFile()
        if sizeDaily.length < 2:
            return 0 # Break for new files
        
        sizeWeekly = CSVFile(self.WEEKLY_SIZE_FILE)
        sizeWeeklyRow = self.__daily2weeklyRow(currentlyUsed)
        previousNextWeek = sizeDaily.getRow(-2).get("next_week")
        if sizeWeekly.length < 1:
            sizeWeekly.addRow(sizeWeeklyRow)
        elif previousNextWeek == nextWeek_:
            sizeWeekly.replaceByKV("time", nextWeek_, sizeWeeklyRow, backwards=True, start=-1)
        else:
            sizeWeekly.addRow(sizeWeeklyRow)
            previousWeeklyRow = sizeWeeklyRow.copy()
            previousWeeklyRow.update({ "time" : previousNextWeek })
            sizeWeekly.replaceByKV("time", previousNextWeek, previousWeeklyRow, backwards=True, start=-1)
        sizeWeekly.efficientWriteFile()

        delta = subtract(sizeDaily.getRow(-1),sizeDaily.getRow(-2))
        diffDaily = CSVFile(self.DIFF_FILE)
        diffDaily.addRow(delta)
        diffDaily.efficientWriteFile()
        
        
        if sizeWeekly.length < 2:
            return 0 # Break for new files
        diffWeekly = CSVFile(self.WEEKLY_DIFF_FILE)
        previousNextWeek = diffDaily.getRow(-2).get("next_week")
        delta = subtract(sizeWeekly.getRow(-1), sizeWeekly.getRow(-2))
        print(previousNextWeek == nextWeek_)
        print(delta)
        if previousNextWeek == nextWeek_:
            diffWeekly.replaceByKV("time", previousNextWeek, delta, backwards=True, start=-1)
        else:
            delta.update({ "time" : previousNextWeek })
            diffWeekly.replaceByKV("time", previousNextWeek, delta, backwards=True, start=-1)
            empty = diffDaily.fill()
            empty.update({"time" : nextWeek_})
            diffWeekly.addRow(empty)
        diffWeekly.efficientWriteFile()

if __name__ == '__main__':
    DiskUsage("/home/peter/scripts/datalogging/disk-usage/testfiles").update()