import sys, os

PYTHON_VERSION_MAJOR = sys.version_info[0]

if PYTHON_VERSION_MAJOR < 3:
    # In python 2, io.open does not support encoding parameter
    from codecs import open
else:
    from io import open
    # In python 3, strings are used so unicode() is a pass-through
    def unicode(s):
        return s

def canonicalId(id):
    if isinstance(id, str):
        idLen = len(id)
        if idLen == 1:
            id = ord(id)
        elif idLen >= 2 and idLen <= 5:
            id = int(id, 16)
        else:
            raise ValueError("Character id must be a 1-character string with the character itself, or 2-5 hex digit unicode codepoint.")
    if not isinstance(id, int):
        raise ValueError("canonicalId: id must be int or str")
    if id > 0xf and id <= 0xfffff:
        return "%05x" % (id)
    raise ValueError("Character id out of range")

class SvgFileInfo:
    def __init__(self, file, dir):
        self.path = os.path.join(dir, file)
        if file[-4:].lower() != ".svg":
            raise Exception("File should have .svg exension. (%s)" % (str(self.path)))
        parts = (file[:-4]).split('-')
        if len(parts) == 2:
            self.variant = parts[1]
        elif len(parts) != 1:
            raise Exception("File should have at most 2 parts separated by a dash. (%s)" % (str(file)))
        self.id = parts[0]
        if self.id != canonicalId(self.id):
            raise Exception("File name not in canonical format (%s)" % (str(self.path)))

    def __repr__(self):
         return repr(vars(self))

    def read(self, SVGHandler=None):    
        if SVGHandler is None:
            from kanjivg import SVGHandler 
        handler = SVGHandler()
        parseXmlFile(self.path, handler)
        parsed = list(handler.kanjis.values())
        if len(parsed) != 1:
            raise Exception("File does not contain 1 kanji entry. (%s)" % (self.path))
        return parsed[0]

def parseXmlFile(path, handler):
    from xml.sax import parse
    parse(path, handler)

def listSvgFiles(dir):
    return [
        SvgFileInfo(f, dir)
        for f in os.listdir(dir)
    ]

def readXmlFile(path, KanjisHandler=None):
    if KanjisHandler is None:
        from kanjivg import KanjisHandler
    handler = KanjisHandler()
    parseXmlFile(path, handler)
    parsed = list(handler.kanjis.values())
    if len(parsed) == 0:
        raise Exception("File does not contain any kanji entries. (%s)" % (path))
    return handler.kanjis