'''
Das Skript ändert eine Dukascopy csv-File in MESZ + Sommerzeitumstellung
und nimmt Wochenenddaten heraus.

Die Dukascopydaten müssen im folgenden Format heruntergeladen werden:
Time,Open,High,Low,Close,Volume
2014/08/01 12:15:00,137.909,137.91,137.895,137.901,167.48
2014/08/01 12:16:00,137.901,137.915,137.899,137.902,124.4

Die Variable 'Asset' muss jedesmal per Hand entsprechend dem Asset
eingegeben werden.

Die Ausgabefile erhält den gleichen Namen mit dem Präfix 'MEZ_DST_'
'''

import os
import csv
import datetime
import tkFileDialog

# Namen der Assetklasse hier eingeben!!
Asset = 'NZDUSD'


# Function which shifts date & time by h hours
def shiftdata(h):
    global newRow, myDateTime
    myDateTime = myDateTime + datetime.timedelta(hours=h)
    newRow[1] = myDateTime.strftime('%Y%m%d')
    newRow[2] = myDateTime.strftime('%H%M%S')


# Function which returns True if date is within summertime
def summertime(myDateTime):
    year = myDateTime.strftime('%Y')
    MarchSwitchDay = datetime.datetime.strptime(year+'0401', '%Y%m%d')
    OctSwitchDay = datetime.datetime.strptime(year+'1101', '%Y%m%d')
    # Calculate Switchingday in March (last Sunday of March)
    while 1:
        MarchSwitchDay -= datetime.timedelta(days=1)
        if MarchSwitchDay.weekday() == 6:
            break
    # Calculate Switchingday in October (last Sunday of October)
    while 1:
        OctSwitchDay -= datetime.timedelta(days=1)
        if OctSwitchDay.weekday() == 6:
            break
    # Return True if current date is within summer period
    return MarchSwitchDay <= myDateTime < OctSwitchDay


# Get csv-file via dialog and create output filename and path
sourceFile = tkFileDialog.askopenfilename()
myPath, fileName = os.path.split(sourceFile)
outFile = os.path.join(myPath, "MEZ_DST_"+fileName)

try:
    print "Please wait..."

    with open(sourceFile, 'rb') as inputFile, open(outFile, 'wb') as\
         outputFile:

        inputReader = csv.reader(inputFile)
        myFileWriter = csv.writer(outputFile)

        next(inputReader) # Skip header
        header = ['<TICKER>,<DTYYYYMMDD>,<TIME>,<OPEN>,<HIGH>,<LOW>,\
<CLOSE>,<VOL>']
        myFileWriter.writerow(header) # Write own header instead

        rowCount = 0 # Begin to count rows

        for row in inputReader:
            rowCount += 1
            newRow = row[:]

            #Change columns into proper MT4 format
            newRow.insert(0, Asset)
            del newRow[1:2]
            newRow.insert(1, row[0].split()[0].replace("/", ""))
            newRow.insert(2, row[0].split()[1].replace(":", ""))

            # Select Date&Time for further calculations
            dateString = newRow[1] + newRow[2]

            # Check if date & time format are valid (strptime will produce a
            # ValueError if not) and convert into datetime object
            myDateTime = datetime.datetime.strptime(dateString, '%Y%m%d%H%M%S')

            # Shift data
            if summertime(myDateTime):
                shiftdata(2)
            else: shiftdata(1)

            # Skip weekend data
            if myDateTime.weekday() in (5, 6):
                continue

            # Write shifted row into Ouputfile
            myFileWriter.writerow(newRow)

        print "Everything went fine!"

except ValueError:
    print newRow
    print "Fehler in Zeile {}: {} {} entspricht nicht der notwendigen \
Formatierung!".format(rowCount, newRow[1], newRow[2])