#!/usr/bin/env python

import sys
import string
import os
import anydbm
import zlib

class zip_untangler:
    def __init__(self, file, datasofar):
        self.file = file
        assert len(datasofar) < 30
        self.header = datasofar
        self.data = ""
        self.dataleft = None
        self.decompress = zlib.decompressobj()
        # Zlib header bytes, expected by decompress obj but not
        # present in zip file
        self.decompress.decompress("\x78\x9c")

    def readline(self):
        if self.dataleft == None:
            while len(self.header) < 30:
                s = self.file.read(30 - len(self.header))
                assert s != ""
                self.header = self.header + s
            # Name length and extra length.
            namelen = 256 * ord(self.header[27]) + ord(self.header[26])
            extralen = 256 * ord(self.header[29]) + ord(self.header[28])
            while len(self.header) < 30 + namelen + extralen:
                s = self.file.read(30 + namelen + extralen - len(self.header))
                assert s != ""
                self.header = self.header + s
            self.dataleft = \
            256 * (256 * (256 * ord(self.header[21]) + ord(self.header[20])) \
            + ord(self.header[19])) + ord(self.header[18])
        k = string.find(self.data, "\n")
        while k < 0:
            rlen = self.dataleft
            if rlen > 4096: rlen = 4096
            if rlen == 0: break
            d = self.file.read(rlen)
            if d == "": break
            self.dataleft = self.dataleft - rlen
            self.data = self.data + self.decompress.decompress(d)
            k = string.find(self.data, "\n")
        if k < 0:
            ret = self.data
            self.data = ""
            return ret
        else:
            ret = self.data[:k+1]
            self.data = self.data[k+1:]
            return ret

def hexstr(x):
    s = hex(x)
    if s[-1:] == "L" or s[-1:] == "l":
        s = s[:-1]
    if s[:2] == "0x" or s[:2] == "0X":
        s = s[2:]
    return s

def charname(x):
    if db is not None:
        key = hexstr(x)
        while len(key) < 4: key = "0" + key
        key = string.upper(key)
        if han_translations:
            try:
                value = handb[key]
                return "<han> " + value
            except KeyError:
                pass
        try:
            value = db[key]
            return string.split(value, ";")[1]
        except KeyError:
            return "<no name available>"
    else:
        return ""

def output(char, bytes, errors):
    if output_analysis:
        if char == -1:
            s = "           "
        else:
            s = "U-%08X " % char
        for i in bytes:
            s = s + " %02X" % i
        for i in range(6-len(bytes)):
            s = s + "   "

        if char == -1:
            name = ""
        else:
            name = charname(char)
        if name != "":
            s = s + " " + name
        s = s + errors
        print s
    else:
        if char == -1 or errors != "":
            # problem chars become U+FFFD REPLACEMENT CHARACTER
            sys.stdout.write("\xEF\xBF\xBD")
        else:
            for i in bytes:
                sys.stdout.write(chr(i))

def process_ucs(x, bytes=[], errors=""):
    if x < 0x80:
        utf8 = [x]
        realbytes = 1
    else:
        if x < 0x800:
            tmp = (0xC0, 1)
        elif x < 0x10000:
            tmp = (0xE0, 2)
        elif x < 0x200000:
            tmp = (0xF0, 3)
        elif x < 0x4000000:
            tmp = (0xF8, 4)
        else:
            assert x < 0x80000000L
            tmp = (0xFC, 5)
        realbytes = tmp[1] + 1
        utf8 = [tmp[0] + (x >> (6*tmp[1]))]
        for i in range(tmp[1]-1, -1, -1):
            utf8.append(0x80 + (0x3F & (x >> (i*6))))

    if bytes != [] and len(bytes) > realbytes:
        errors = errors + " (overlong form of"
        for i in utf8:
            errors = errors + " %02X" % i
        errors = errors + ")"
        utf8 = bytes
    if x >= 0xD800 and x <= 0xDFFF:
        errors = errors + " (surrogate)"
    if x >= 0xFFFE and x <= 0xFFFF:
        errors = errors + " (invalid char)"

    output(x, utf8, errors)

def process_utf8(next):
    c = next()
    while c != None:
        char = [c]
        i = c
        if i < 0x80:
            process_ucs(i) # single-byte char
            c = next()
        elif i == 0xfe or i == 0xff:
            output(-1, char, " (invalid UTF-8 byte)")
            c = next()
        elif i >= 0x80 and i <= 0xbf:
            output(-1, char, " (unexpected continuation byte)")
            c = next()
        else:
            if i >= 0xC0 and i <= 0xDF:
                acc = i &~ 0xC0
                cbytes = 1
            elif i >= 0xE0 and i <= 0xEF:
                acc = i &~ 0xE0
                cbytes = 2
            elif i >= 0xF0 and i <= 0xF7:
                acc = i &~ 0xF0
                cbytes = 3
            elif i >= 0xF8 and i <= 0xFB:
                acc = i &~ 0xF8
                cbytes = 4
            elif i >= 0xFC and i <= 0xFD:
                acc = i &~ 0xFC
                cbytes = 5
            gotone = 0
            while cbytes > 0:
                c = next()
                if c == None or c < 0x80 or c > 0xBF:
                    gotone = 1
                    break
                char.append(c)
                acc = (acc << 6) + (c & 0x3F)
                cbytes = cbytes - 1
            if cbytes > 0:
                output(-1, char, " (incomplete sequence)")
            else:
                process_ucs(acc, char)
            if not gotone:
                c = next()

def do(args):
    # Class to turn a list into a callable object that returns one
    # element at a time.
    class liststepper:
        def __init__(self, list):
            self.list = list
            self.index = 0
        def __call__(self):
            if self.index >= len(self.list):
                return None
            ret = self.list[self.index]
            self.index = self.index + 1
            return ret

    list = []
    for arg in args:
        got = ('none')
        if string.upper(arg[0]) == "U":
            assert arg[1] == "+" or arg[1] == "-"
            got = ('ucs', string.atoi(arg[2:], 16))
        elif arg[:2] == "&#":
            # SGML character entity. Either &# followed by a
            # number, or &#x followed by a hex number.
            s = arg
            if s[-1:] == ";": s = s[:-1]
            if string.upper(s[:3]) == "&#X":
                got = ('ucs', string.atoi(s[3:], 16))
            else:
                got = ('ucs', string.atoi(s[2:], 10))
        else:
            got = ('utf8', string.atoi(arg, 16))

        if got[0] == 'utf8':
            list.append(got[1])
        elif got[0] == 'ucs':
            if len(list) > 0:
                process_utf8(liststepper(list))
                list = []
            process_ucs(got[1])

    if len(list) > 0:
        process_utf8(liststepper(list))

def usage(arg):
    print "usage: cvt-utf8 [flags] <hex UTF-8 bytes, U+codepoints, SGML entities>"
    print "  e.g. cvt-utf8 e2 82 ac"
    print "    or cvt-utf8 U+20ac"
    print "    or cvt-utf8 U-10ffff"
    print "    or cvt-utf8 '&#8211;'"
    print ""
    print "where: -o or --output        just output well-formed UTF-8 instead of"
    print "                             an analysis of the input data"
    print "       -h or --han           also give Han definitions from unihan db"
    print ""
    print " also: cvt-utf8 --test       run Markus Kuhn's decoder stress tests" #'
    print "       cvt-utf8 --input (or -i)"
    print "                             read, analyse and decode UTF-8 from stdin"
    if arg == "--help-admin":
        print "       cvt-utf8 --help       display user help text"
        print "       cvt-utf8 --help-admin display admin help text (this one)"
        print "       cvt-utf8 --build <infile> <outfile>"
        print "                             convert UnicodeData.txt to unicode db"
        print "       cvt-utf8 --build-unihan <infile> <outfile>"
        print "                             convert Unihan.txt to unihan db"
        print "       cvt-utf8 --fetch-build <outfile>"
        print "                             "+\
        "build unicode db by download from unicode.org"
        print "       cvt-utf8 --fetch-build-unihan <outfile>"
        print "                             "+\
        "build Unihan db by download from unicode.org"
    else:
        print "       cvt-utf8 --help       display this help text"
        print "       cvt-utf8 --help-admin display admin help text"
    print "       cvt-utf8 --version    report version number"
    print "       cvt-utf8 --licence    display (MIT) licence text"

def licence():
    print "cvt-utf8 is copyright 2002-2004 Simon Tatham."
    print ""
    print "Permission is hereby granted, free of charge, to any person"
    print "obtaining a copy of this software and associated documentation files"
    print "(the \"Software\"), to deal in the Software without restriction,"
    print "including without limitation the rights to use, copy, modify, merge,"
    print "publish, distribute, sublicense, and/or sell copies of the Software,"
    print "and to permit persons to whom the Software is furnished to do so,"
    print "subject to the following conditions:"
    print ""
    print "The above copyright notice and this permission notice shall be"
    print "included in all copies or substantial portions of the Software."
    print ""
    print "THE SOFTWARE IS PROVIDED \"AS IS\", WITHOUT WARRANTY OF ANY KIND,"
    print "EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF"
    print "MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND"
    print "NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS"
    print "BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN"
    print "ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN"
    print "CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE"
    print "SOFTWARE."

def version():
    rev = "$Revision$"
    rev = string.replace(rev, " ", "")
    rev = string.replace(rev, "$", "")
    revs = string.split(rev, ":")
    if len(revs) > 1:
        print "cvt-utf8 revision %s" % revs[1]
    else:
        print "cvt-utf8: unknown version"

args = sys.argv[1:]
output_analysis = 1
han_translations = 0
mode = "cmdline"

if args == []:
    usage("")
    sys.exit(0)

while len(args) > 0 and args[0][:1] == "-":
    if args[0] == "--help" or args[0] == "--help-admin":
        usage(args[0])
        sys.exit(0)

    elif args[0] == "--licence" or args[0] == "--license":
        licence()
        sys.exit(0)

    elif args[0] == "--version":
        version()
        sys.exit(0)

    elif args[0] == "-o" or args[0] == "--output":
        output_analysis = 0
        args = args[1:]

    elif args[0] == "-h" or args[0] == "--han":
        han_translations = 1
        args = args[1:]

    elif args[0] == "--build" or args[0] == "--fetch-build":
        if args[0] == "--build":
            if len(args) != 3:
                print "cvt-utf8: --build expects two filename arguments"
                sys.exit(1)
            infile = open(args[1], "r")
            outfile = args[2]
        else:
            if len(args) != 2:
                print "cvt-utf8: --fetch-build expects one filename argument"
                sys.exit(1)
            import urllib
            infile = urllib.urlopen("http://www.unicode.org/Public/UNIDATA/UnicodeData.txt")
            outfile = args[1]
        # Now build the database.
        if outfile[-3:] == ".db":
            print "cvt-utf8: warning: you should not append .db to db name"

        db = anydbm.open(outfile, "n")
        while 1:
            s = infile.readline()
            if s == "": break
            ss = string.split(s, ";")[0]
            db[ss] = s
        db.close()
        sys.exit(0)

    elif args[0] == "--build-unihan" or args[0] == "--fetch-build-unihan":
        if args[0] == "--build-unihan":
            if len(args) != 3:
                print "cvt-utf8: --build expects two filename arguments"
                sys.exit(1)
            infile = open(args[1], "r")
            s = infile.read(1)
            # Unihan.txt starts with a hash. If this file starts with a
            # P, we assume it's a zip file ("PK").
            if s == "P":
                infile = zip_untangler(infile, s)
                s = ""
            outfile = args[2]
        else:
            if len(args) != 2:
                print "cvt-utf8: --fetch-build-unihan expects one filename argument"
                sys.exit(1)
            import urllib
            infile = urllib.urlopen("ftp://ftp.unicode.org/Public/UNIDATA/Unihan.zip")
            # We know this one is zipped.
            infile = zip_untangler(infile, "")
            outfile = args[1]
            s = ""
        # Now build the database.
        if outfile[-3:] == ".db":
            print "cvt-utf8: warning: you should not append .db to db name"

        db = anydbm.open(outfile, "n")
        while 1:
            s = s + infile.readline()
            if s == "": break
            while s[-1:] == "\r" or s[-1:] == "\n":
                s = s[:-1]
            sa = string.split(s, "\t")
            if len(sa) == 3 and sa[1] == "kDefinition" and sa[0][:2] == "U+":
                db[sa[0][2:]] = sa[2]
            s = ""
        db.close()
        sys.exit(0)

    elif args[0] == "--test":
        mode = "test"
        args = args[1:]

    elif args[0] == "--input" or args[0] == "-i":
        mode = "input"
        args = args[1:]

    else:
        sys.stderr.write("cvt-utf8: unknown argument '%s'" % args[0])
        sys.exit(1)

locations = []
locations.append("/usr/share/unicode/unicode")
locations.append("/usr/lib/unicode/unicode")
locations.append("/usr/local/share/unicode/unicode")
locations.append("/usr/local/lib/unicode/unicode")
locations.append(os.environ["HOME"] + "/share/unicode/unicode")
locations.append(os.environ["HOME"] + "/lib/unicode/unicode")

for loc in locations:
    try:
        db = anydbm.open(loc, "r")
    except IOError:
        db = None
    except anydbm.error:
        db = None
    if db != None:
        break
if han_translations:
    i = string.rfind(loc, "/")
    assert i >= 0
    hanloc = loc[:i+1] + "unihan"
    handb = anydbm.open(hanloc, "r")
    # this has been explicitly required, so we don't squelch exceptions

if mode == "test":
    do(["CE","BA","E1","BD","B9","CF","83","CE","BC","CE","B5"])
    do(["00"])
    do(["C2","80"])
    do(["E0","A0","80"])
    do(["F0","90","80","80"])
    do(["F8","88","80","80","80"])
    do(["FC","84","80","80","80","80"])
    do(["7F"])
    do(["DF","BF"])
    do(["EF","BF","BF"])
    do(["F7","BF","BF","BF"])
    do(["FB","BF","BF","BF","BF"])
    do(["FD","BF","BF","BF","BF","BF"])
    do(["ED","9F","BF"])
    do(["EE","80","80"])
    do(["EF","BF","BD"])
    do(["F4","8F","BF","BF"])
    do(["F4","90","80","80"])
    do(["80"])
    do(["BF"])
    do(["80","BF"])
    do(["80","BF","80"])
    do(["80","BF","80","BF"])
    do(["80","BF","80","BF","80"])
    do(["80","BF","80","BF","80","BF"])
    do(["80","BF","80","BF","80","BF","80"])
    do(["80","81","82","83","84","85","86","87",
    "88","89","8A","8B","8C","8D","8E","8F",
    "90","91","92","93","94","95","96","97",
    "98","99","9A","9B","9C","9D","9E","9F",
    "A0","A1","A2","A3","A4","A5","A6","A7",
    "A8","A9","AA","AB","AC","AD","AE","AF",
    "B0","B1","B2","B3","B4","B5","B6","B7",
    "B8","B9","BA","BB","BC","BD","BE","BF"])
    do(["C0","20","C1","20","C2","20","C3","20",
    "C4","20","C5","20","C6","20","C7","20",
    "C8","20","C9","20","CA","20","CB","20",
    "CC","20","CD","20","CE","20","CF","20",
    "D0","20","D1","20","D2","20","D3","20",
    "D4","20","D5","20","D6","20","D7","20",
    "D8","20","D9","20","DA","20","DB","20",
    "DC","20","DD","20","DE","20","DF","20"])
    do(["E0","20","E1","20","E2","20","E3","20",
    "E4","20","E5","20","E6","20","E7","20",
    "E8","20","E9","20","EA","20","EB","20",
    "EC","20","ED","20","EE","20","EF","20"])
    do(["F0","20","F1","20","F2","20","F3","20",
    "F4","20","F5","20","F6","20","F7","20"])
    do(["F8","20","F9","20","FA","20","FB","20"])
    do(["FC","20","FD","20"])
    do(["C0"])
    do(["E0","80"])
    do(["F0","80","80"])
    do(["F8","80","80","80"])
    do(["FC","80","80","80","80"])
    do(["DF"])
    do(["EF","BF"])
    do(["F7","BF","BF"])
    do(["FB","BF","BF","BF"])
    do(["FD","BF","BF","BF","BF"])
    do(["C0","E0","80","F0","80","80","F8","80",
    "80","80","FC","80","80","80","80",
    "DF","EF","BF","F7","BF","BF","FB",
    "BF","BF","BF","FD","BF","BF","BF","BF"])
    do(["FE"])
    do(["FF"])
    do(["FE","FE","FF","FF"])
    do(["C0","AF"])
    do(["E0","80","AF"])
    do(["F0","80","80","AF"])
    do(["F8","80","80","80","AF"])
    do(["FC","80","80","80","80","AF"])
    do(["C1","BF"])
    do(["E0","9F","BF"])
    do(["F0","8F","BF","BF"])
    do(["F8","87","BF","BF","BF"])
    do(["FC","83","BF","BF","BF","BF"])
    do(["C0","80"])
    do(["E0","80","80"])
    do(["F0","80","80","80"])
    do(["F8","80","80","80","80"])
    do(["FC","80","80","80","80","80"])
    do(["ED","A0","80"])
    do(["ED","AD","BF"])
    do(["ED","AE","80"])
    do(["ED","AF","BF"])
    do(["ED","B0","80"])
    do(["ED","BE","80"])
    do(["ED","BF","BF"])
    do(["ED","A0","80","ED","B0","80"])
    do(["ED","A0","80","ED","BF","BF"])
    do(["ED","AD","BF","ED","B0","80"])
    do(["ED","AD","BF","ED","BF","BF"])
    do(["ED","AE","80","ED","B0","80"])
    do(["ED","AE","80","ED","BF","BF"])
    do(["ED","AF","BF","ED","B0","80"])
    do(["ED","AF","BF","ED","BF","8F"])
    do(["EF","BF","BE"])
    do(["EF","BF","BF"])
elif mode == "input":
    def getchar():
        s = sys.stdin.read(1)
        if s == "":
            return None
        return ord(s) & 0xFF   # ensure it isn't negative
    process_utf8(getchar)
else:
    do(args)