#!/usr/bin/env python
#
#  git-bbdiff
#  
#  Created by Dan Preston on 4/09/08.
#
 
import sys, commands, os, tempfile, filecmp
import thread, threading
from optparse import OptionParser
 
kToolName = "git-bbdiff"
kdiffVersion = kToolName + " version 1.4"
kTempDir = "/tmp/"
kConflictMarker = ".CONFLICT"
kTheirsMarker = ".THEIRS"
 
#----------------------------------------------------------------------------------------------------------------------------
#  fileNotPresentError
#----------------------------------------------------------------------------------------------------------------------------
 
def fileNotPresentError( repositoryPath, revision, chatty=True ):
  if chatty:
    print "\tFile \"%s\" does not exist in repository at revision \"%s\"." % ( repositoryPath, revision )
 
#----------------------------------------------------------------------------------------------------------------------------
#  createTempFileForRevision
#----------------------------------------------------------------------------------------------------------------------------
 
def createTempFileForRevision( revision, repositoryPath, chatty=True ):
  # Escape the path with quotes to handle the case where we have spaces.
  command = "git show " + revision + ':"' + repositoryPath + '"'
  
  # Use git show to get the contents of the head of the file.
  status, output = commands.getstatusoutput( command )
  if status != 0:
    fileNotPresentError( repositoryPath, revision, chatty )
    return None
  
  # git show doesn't seem to append the final carriage return.
  output = output + "\n"
  
  # Create the temp file name and write out the temp file.
  nameRoot, extension = os.path.splitext( repositoryPath )
  _, fileName = os.path.split( nameRoot )
  temp = tempfile.mktemp( "_" + fileName + extension, kToolName + "-" + revision + "_", kTempDir )
  f = open( temp, 'w' )
  f.write( output )
  f.close()
  
  return temp
 
#----------------------------------------------------------------------------------------------------------------------------
#  signalDiffProcessed
#----------------------------------------------------------------------------------------------------------------------------
 
def signalDiffProcessed( condition, diffsLeft ):
  condition.acquire()
  diffsLeft[0] = diffsLeft[0] - 1
  condition.notifyAll()
  condition.release()
 
#----------------------------------------------------------------------------------------------------------------------------
#  performDiff
#----------------------------------------------------------------------------------------------------------------------------
 
def performDiff( compareFile, revision, condition, diffsLeft, chatty=True ):
  revision, _, revision2 = revision.partition( ".." )
  
  realpath = os.path.abspath( compareFile )
  
  head, relativePath = os.path.split( realpath )
  fileName = relativePath
  
  if os.path.isdir( realpath ):
    if chatty:
      print "\t\"" + relativePath + "\" is a directory. " + kToolName + " only compares files."
    signalDiffProcessed( condition, diffsLeft )
    return
  
  found = False;
  # Figure out what the relative path of the file is from the .git folder.
  while ( found == False ) and ( head != "/" ):
    gitPath = os.path.join( head, ".git" )
    found = os.path.exists( gitPath )
    if found == False:
      head, tail = os.path.split( head )
      relativePath = os.path.join( tail, relativePath )
  
  # Make sure we are actually in a git repository.
  if ( found == False ) and ( head == "/" ):
    if chatty:
      print "\tThat file is not in a git repository."
    signalDiffProcessed( condition, diffsLeft )
    return
  
  file1 = createTempFileForRevision( revision, relativePath, chatty )
  if revision2:
    file2 = createTempFileForRevision( revision2, relativePath, chatty )
  else:
    file2 = realpath
    if os.path.exists( file2 ) == False:
      fileNotPresentError( relativePath, "HEAD", chatty )
      file2 = None
    
  if ( file1 == None ) or ( file2 == None ):
    signalDiffProcessed( condition, diffsLeft )
    return
  
  same = filecmp.cmp( file2, file1 )
  if same:
    if chatty:
      print "\tThe file \"" + fileName + "\" has no differences."
  else:
    # Escape the files with quotes to allow for files with spaces.
    command = 'bbdiff "%s" "%s" --wait' % ( file2, file1 )
    output = commands.getoutput( command )
  
  os.remove( file1 )
  if revision2:
    os.remove( file2 )
  
  signalDiffProcessed( condition, diffsLeft )
 
#----------------------------------------------------------------------------------------------------------------------------
#  numConflicts
#----------------------------------------------------------------------------------------------------------------------------
 
def numConflicts( conflictFile ):
  foundStart = False
  foundMiddle = False
  
  conflicts = 0
  f = open( conflictFile, "r" )
  line = f.readline()
  while line:
    if line.startswith( "<<<<<<<" ) and ( foundStart == False ) and ( foundMiddle == False ):
      foundStart = True
    if line.startswith( "=======" ) and foundStart and ( foundMiddle == False ):
      foundMiddle = True
    if line.startswith( ">>>>>>>" ) and foundStart and foundMiddle:
      conflicts = conflicts + 1
      foundStart = False
      foundMiddle = False
    line = f.readline()
  f.close()
  
  return conflicts
 
#----------------------------------------------------------------------------------------------------------------------------
#  uniqueName
#----------------------------------------------------------------------------------------------------------------------------
 
def uniqueName( path, uniqueLabel ):
  base, extension = os.path.splitext( path )
  digit = 2
  uniqueDigit = ""
  if os.path.exists( base + uniqueLabel + uniqueDigit + extension ):
    uniqueDigit = str( digit )
    digit = digit + 1
  
  newPath = base + uniqueLabel + uniqueDigit + extension
  
  return newPath
 
#----------------------------------------------------------------------------------------------------------------------------
#  createConflictFiles
#----------------------------------------------------------------------------------------------------------------------------
 
def createConflictFiles( minePath, theirPath, conflictFile ):
  orig = open( conflictFile, "r" )
  mine = open( minePath, "w" )
  theirs = open( theirPath, "w" )
  
  placeInTheirs = True
  placeInMine = True
  
  line = orig.readline()
  while line:
    if line.startswith( "<<<<<<<" ) and placeInTheirs and placeInMine:
      placeInMine = False
    elif line.startswith( "=======" ) and placeInTheirs and ( placeInMine == False ):
      placeInTheirs = False
      placeInMine = True
    elif line.startswith( ">>>>>>>" ) and ( placeInTheirs == False ) and placeInMine:
      placeInTheirs = True
    else:
      if placeInMine:
        mine.write( line )
      if placeInTheirs:
        theirs.write( line )
    line = orig.readline()
    
  orig.close()
  mine.close()
  theirs.close()
 
#----------------------------------------------------------------------------------------------------------------------------
#  diffConflict
#----------------------------------------------------------------------------------------------------------------------------
 
def diffConflict( conflictFile, chatty=True ):
  conflicts = numConflicts( conflictFile )
  if ( conflicts == 0 ) and chatty:
    basePath, fileName = os.path.split( conflictFile )
    print "\tThe file \"%s\" does not contain any conflicts. SKIPPING." % fileName
  else:
    newConflictPath = uniqueName( conflictFile, kConflictMarker )
    os.rename( conflictFile, newConflictPath )
    
    theirPath = uniqueName( conflictFile, kTheirsMarker )
    
    createConflictFiles( conflictFile, theirPath, newConflictPath )
    command = 'bbdiff "%s" "%s"' % ( conflictFile, theirPath )
    output = commands.getoutput( command )
 
#----------------------------------------------------------------------------------------------------------------------------
#  cleanConflictRelatedFiles
#----------------------------------------------------------------------------------------------------------------------------
 
def cleanConflictRelatedFiles( conflictFile, chatty=True ):
  filePath, extension = os.path.splitext( conflictFile )
  
  # Remove .CONFLICT files.
  tempfile = filePath + kConflictMarker + extension
  if os.path.exists( tempfile ):
    if chatty:
      _, base = os.path.split( filePath )
      base = base + kConflictMarker + extension
      print "\tDeleting file \"%s\"." % base
    command = "rm " + tempfile
    os.remove( tempfile )
  
  #remove .THEIRS files.
  tempfile = filePath + kTheirsMarker + extension
  if os.path.exists( tempfile ):
    if chatty:
      _, base = os.path.split( filePath )
      base = base + kTheirsMarker + extension
      print "\tDeleting file \"%s\"." % base
    command = "rm " + tempfile
    os.remove( tempfile )
 
#----------------------------------------------------------------------------------------------------------------------------
#  compareModified
#----------------------------------------------------------------------------------------------------------------------------
 
def compareModified( chatty=True ):
  command = "git status"
  output = commands.getoutput( command )
  lines = output.split( "\n" )
  modifiedFiles = []
  for line in lines:
    modifiedFile = line.partition( "modified:" )[2].strip()
    if modifiedFile != "":
      modifiedFiles.append( modifiedFile )
  if len( modifiedFiles ) > 0:
    compareFiles( modifiedFiles, "HEAD", chatty )
  elif chatty:
    print( "There are no modified files." )
 
#----------------------------------------------------------------------------------------------------------------------------
#  compareFiles
#----------------------------------------------------------------------------------------------------------------------------
 
def compareFiles( files, revision, chatty=True ):
  diffsLeft = [len( files )];
  
  # Create a condition lock to ensure that we wait until all the diffs are done since we use the --wait option in bbdiff.
  condition = threading.Condition()
  for gitFile in files:
    if chatty:
      print "Comparing \"%s\"." % gitFile
    thread.start_new_thread( performDiff, (gitFile, revision, condition, diffsLeft, chatty) )
  condition.acquire()
  while diffsLeft[0] > 0:
    try:
      condition.wait()
    except KeyboardInterrupt, e:
      print( "\nProcess terminated.")
  condition.release()
 
#----------------------------------------------------------------------------------------------------------------------------
#  main
#----------------------------------------------------------------------------------------------------------------------------
 
def main(argv=None):
  if argv is None:
    argv = sys.argv
  
  # Set up options for the command line that we support.
  description="A utility to compare files in a git repository using bbedit."
  usage = "usage: %prog [--version] | [-h] | [-q | --quiet] [--clean file1 [file2 ...]] [[-c | --conflict] | [-r | --revision <revision(s)>]] file1 [file2 ...]"
  
  parser = OptionParser(version=kdiffVersion, description=description, usage=usage)
  parser.add_option( "-r", "--revision", dest="revision", help="Pass a revision or a revision range using the git syntax (ie: 98d4cf..bfced5) for " + kToolName + " to compare. This option is mutually exclusive to the '-c' option." )
  parser.add_option( "-m", "--modified", action="store_true", dest="modified", help="Compare files that have been modified against HEAD." )
  parser.add_option( "--clean", action="store_true", dest="cleanUp", default=False, help="Conflict (--conflict) related files (\"" + kConflictMarker + "\", \"" + kTheirsMarker + "\") will be deleted for any files that are passed as arguments. Requires at least one file path as an argument." )
  parser.add_option( "-q", "--quiet", action="store_false", dest="chatty", default=True, help="Reduce the chatter of " + kToolName + "." )
  parser.add_option( "-c", "--conflict", action="store_true", dest="conflict", default=False, help="The files being diffed have conflict markers that need to be resolved. This option is mutually exclusive to the '-r' option." )
  
  printUsage = True
  ( options, args ) = parser.parse_args( argv[1:] )
  if options.cleanUp:
    if len( args ) > 0:
      for gitFile in args:
        cleanConflictRelatedFiles( gitFile, options.chatty )
      return 0
  elif options.modified:
    compareModified( options.chatty )
    return 0
  elif len( args ) > 0:
    printUsage = False
  
  # These options are mutually exclusive.
  if options.revision and options.conflict:
    printUsage = True
  
  # See if we can see any reason that we need to print the usage for the app.
  if printUsage:
    parser.print_help()
    return 2
  else:
    if options.conflict:
      for gitFile in args:
        if options.chatty:
          print "Diffing Conflict \"%s\"." % gitFile
        diffConflict( gitFile, options.chatty )
    else:
      if options.revision:
        rev = options.revision
      else:
        rev = "HEAD"
      compareFiles( args, rev, options.chatty )
      
  return 0
 
if __name__ == "__main__":
  sys.exit(main())