import xml.etree.ElementTree as ET
import sys
import os
import errno  

#svndiff.py http://code.taobao.org/svn/elk/trunk/code/python -r100:200
#导出指定svn之间的所有修改的代码文件


if __name__ == "__main__":
    if len(sys.argv) != 3 :
        print('  usage: svn_diff <svn_url> <-rfirst:second>')
        print('  example: svn_diff.py http://code.taobao.org/svn/elk/trunk/code/ -r45:56')
        exit()
    url = sys.argv[1]
    revision = sys.argv[2]

#1, svn info  and parse Root
#svn info http://code.taobao.org/svn/elk/trunk/code/ --xml > svninfo.xml
    cmd = "svn info " + url + " --xml > svninfo.xml"
    os.system(cmd)
    tree = ET.parse('svninfo.xml')
    root = tree.getroot()
    svn_root_url = ""
    for item in root.iter('root'):
        svn_root_url = item.text

#2, svn diff http://code.taobao.org/svn/elk/trunk/code/ -r45:head --summarize --xml 
    cmd = "svn diff "+url + " " + revision + "  --summarize --xml > svndiff.xml"
    os.system(cmd)
    
#3 parse svndiff.xml
    tree = ET.parse('svndiff.xml')
    root = tree.getroot()
    path_set = set()
    for child in root:
        for paths in child.iter('paths'):
            for path in paths:
                if(path.get('kind')=="file"):
                    path_set.add(path.text)

#4 mkdir & svn export http://code.taobao.org/svn/elk/trunk/code/gpb/weblog.proto trunk/code/gpb
    svn_url_len = len(svn_root_url)+1                   
    for i in path_set:
        end = i.rfind("/")
        path = i[svn_url_len:end]
        try:
            print("mkdir " + path)
            os.makedirs(path)
        except OSError as exc: 
            if exc.errno == errno.EEXIST and os.path.isdir(path):  
                pass
            else:                
                print("failed:"+ path)
                raise
        cmd = "svn export "+  i + " " + path
        print(cmd)
        os.system(cmd)
    print("all export finish")     


#os.system("svn export "+svn_file + "  r"+revision)