import subprocess, os, datetime, re, os.path

def getGitBuildVersion(root, project) :
    tag = git("describe --tags --exact --match \"" + project + "-*\"", root)
    if tag :
        return tag.rstrip()[len(project)+1:]
    tag = git("describe --tags --match \"" + project + "-*\"", root)
    if tag :
        m = re.match(project + "-(.*)-(.*)-(.*)", tag)
        if m :
            return m.group(1) + "-dev" + m.group(2)
    return None

def git(cmd, root) :
    full_cmd = "git " + cmd
    p = subprocess.Popen(full_cmd, cwd=root, shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, close_fds=(os.name != "nt"))
    gitVersion = p.stdout.read()
    # error = p.stderr.read()
    # if error:
    #   print "Git error: " + error
    p.stdin.close()
    if p.wait() == 0 :
        return gitVersion
    return None

def getBuildVersion(root, project) :
    versionFilename = os.path.join(root, "VERSION." + project)
    if os.path.isfile(versionFilename) :
        f = open(versionFilename)
        version = f.read().strip()
        f.close()
        return version

    gitVersion = getGitBuildVersion(root, project)
    if gitVersion :
        return gitVersion

    return datetime.date.today().strftime("%Y%m%d")

def convertToWindowsVersion(version) :
    version_match = re.match("(\d+)\.(\d+)(.*)", version)
    major = version_match and int(version_match.group(1)) or 0
    minor = version_match and int(version_match.group(2)) or 0
    if version_match and len(version_match.group(3)) == 0 :
        patch = 60000
    else :
        match = re.match("^beta(\d+)(.*)", version_match.group(3))
        build_string = ""
        if match :
            patch = 1000*int(match.group(1))
            build_string = match.group(2)
        else :
            rc_match = re.match("^rc(\d+)(.*)", version_match.group(3))
            if rc_match :
                patch = 10000*int(rc_match.group(1))
                build_string = rc_match.group(2)
            else :
                patch = 0
                alpha_match = re.match("^alpha(.*)", version_match.group(3))
                if alpha_match :
                    build_string = alpha_match.group(1)

        if len(build_string) > 0 :
            build_match = re.match("^-dev(\d+)", build_string)
            if build_match :
                patch += int(build_match.group(1))

    return (major, minor, patch)