##################################################
#
#   The main walker
#
#   1) called with arguments: inputDir, outputDir
#   2) Walks through entire inputDir and outputs to outputDir
#
##################################################


import os
from UniqueNameGenerator import UniqueNameGenerator
import HtmlParser
import traceback
from HtmlParser import logToOutput


def walk(inputDir, outputDir, failDir):
    """Initialization function for walker"""

    # Some initialziation
    nameGenerator = UniqueNameGenerator()
    inputDir = os.path.abspath( inputDir)
    outputDir = os.path.abspath( outputDir)
    failDir = os.path.abspath( failDir)
    g = open(failDir,'w+')

    # Now walk
    for root, dirs, files in os.walk(inputDir):

        # Recurse on each file
        for file in files:

            #print os.getcwd()

            # Note that the root contains the root
            file = os.path.join( os.path.abspath(root), file)
            outputFDir = getOutputFDir(outputDir, inputDir, file)

            if getFileExtension( file) == ".html":
                try:
                    parseFunction( file, nameGenerator.getID(), outputFDir)

                except Exception, e:
                    #For the output
                    traceback.print_exc()

                    g.write("==================================================\n")
                    g.write("Error at file: " + file + "\n")
                    g.write( str(e) )
                    g.write( "\n")
                    traceback.print_exc(100, g)






def getFileExtension( fileName):
    """Raises Exception if none. """

    ext = os.path.splitext(fileName)[1]
    if ext == '':
        return "NO_FILE_EXTENSION"

    else:
        return ext




def getOutputFDir(outputDir, baseString, currentFName):
    """1) Finds the "difference between file and inputDir, then adds that to outputDir,
    then output just to the folder level.

    e.g. (/output/dir, /input/dir, /input/dir/shit/fuck) => /output/dir/shit"""

    # Check if outputDir, baseString or currentFName all ends with /
    outputDir = fixSlashes( outputDir)
    baseString = fixSlashes( baseString)
    currentFName = fixSlashes( currentFName )

    baseList = baseString.split(os.path.sep)
    currentList = currentFName.split( os.path.sep)
    differenceList = currentList[len(baseList):]

    ########################################
    # Important here: we should only return up to the last directory
    # so /home/disappearedng/python.py you should just return /home/disappearedng
    # because in htmlParser the python.py will be changed to python_py.TREC

    if len(differenceList) == 0:
        raise Exception("No difference")

    elif len(differenceList) > 1:
        suffix = os.path.sep.join( differenceList)

    else:
        suffix = differenceList[0]

    # Modfication: return up to the last folder
    ret = os.path.sep.join( [outputDir, suffix])
    ret = os.path.split(ret)

    return ret[0]




def fixSlashes(string):
    """Removes trailing / and ensures that string begins with /"""

    stringList = string.split(os.path.sep)

    # Now remove every '' except the first one
    stringList = [x for x in stringList if x]
    stringList.insert(0, '')

    return os.path.sep.join( stringList)


if __name__ == "__main__":
    import sys

    if len(sys.argv) != 4:
        print "Usage: python main_walker.py inputDirectory outputDirectory errorLog"

    else:
        parseFunction = HtmlParser.parseFile
        walk( sys.argv[1], sys.argv[2], sys.argv[3] )