import struct
import string
import csv


mii = 0
#we know that each record is 0x9271 bytes long
record_length = 0x9281

record_start = 0

#path to WiiFit data file
infile = 'RPHealth.dat'

FH = open(infile, 'rb');


## It loops through 7 profiles, because I happen to know I have 7.
## A better approach would be to go to the end of the file, of course.
while (mii < 7):

    #go to the start of the current record
    FH.seek(record_start)

    #read the first 30 bytes (header + name)
    line = FH.read(30)

    #for some reason names are stored as N a m e instead of Name.
    #Throw away the header any extranous spaces
    data = struct.unpack("<9xcxcxcxcxcxcxcxcxcxcxc",line)

    #Condense our unpacked characters into a string
    wf_name = string.join(data,'')

    #open a new CSV file for this person.
    #If the name is shorter than 4 characters or has whitespace, the script
    #will exit. This should probably be fixed.
    FW = open('WiiFit_'+wf_name[0:4]+'.csv', 'w')
    recordWriter = csv.writer(FW, delimiter=",", quotechar="'", quoting=csv.QUOTE_MINIMAL)

    #Weigh-in data starts 0x38a1 bytes into the record
    FH.seek(record_start + 0x38a1)

    #we'll loop through the record data until it starts coming up blank
    while(1):
        #4 byte date 
        line = FH.read(4)
        data = struct.unpack(">i",line)
        #bit shift to get the month, day, and year. Could also get time if you wanted.
        year = data[0] >> 20 & 0x7ff
        month = data[0] >> 16 & 0xf
        day = data[0] >> 11 & 0x1f

        #break the loop if the date comes back 0
        if(year == 0): break

        #format the date into something humans like to read
        date = str(int(year)) + '-' + str(int(month)+1) + '-' + str(int(day))

        #the next three sets of 2 byte data represent weight, BMI, and balance
        line = FH.read(17)
        data = struct.unpack(">3H",line[0:6])

        recordWriter.writerow([date] + [data[0]] + [data[1]] + [data[2]])
        

    #now that we're done with the record, advance to the start of the next one
    record_start = record_start + record_length
    
    mii = mii+1