__init__.py

########################################################################
#
#  zxing.py -- a quick and dirty wrapper for zxing for python
#
#  this allows you to send images and get back data from the ZXing
#  library:  http://code.google.com/p/zxing/
#

import glob
import os
import pathlib
import re
import subprocess as sp
import sys
import urllib.parse
import zipfile
from enum import Enum
from io import IOBase
from itertools import chain
from types import GeneratorType

try:
    from PIL.Image import Image
    from tempfile import NamedTemporaryFile
    have_pil = True
except ImportError:
    have_pil = None

from .version import __version__  # noqa: F401


def file_uri_to_path(s):
    uri = urllib.parse.urlparse(s)
    if (uri.scheme, uri.netloc, uri.query, uri.fragment) != ('file', '', '', ''):
        raise ValueError(uri)
    return urllib.parse.unquote_plus(uri.path)

class BarCodeReaderException(Exception):
    def __init__(self, message, filename=None):
        self.message, self.filename = message, filename
        super().__init__(message, filename)


class BarCodeReader(object):
    cls = "com.google.zxing.client.j2se.CommandLineRunner"
    classpath_sep = ';' if sys.platform == 'nt' else ':'  # https://stackoverflow.com/a/60211688

    def __init__(self, classpath=None, java=None):
        self.java = java or 'java'
        self.zxing_version = self.zxing_version_info = None
        if classpath:
            self.classpath = classpath if isinstance(classpath, str) else self.classpath_sep.join(classpath)
        elif "ZXING_CLASSPATH" in os.environ:
            self.classpath = os.environ.get("ZXING_CLASSPATH", "")
        else:
            self.classpath = os.path.join(os.path.dirname(__file__), 'java', '*')

        for fn in chain.from_iterable(glob.glob(cp) for cp in self.classpath.split(self.classpath_sep)):
            if os.path.basename(fn) == 'core.jar':
                self.core_jar = fn
                with zipfile.ZipFile(self.core_jar) as c:
                    for line in c.open('META-INF/MANIFEST.MF'):
                        if line.startswith(b'Bundle-Version: '):
                            self.zxing_version = line.split(b' ', 1)[1].strip().decode()
                            self.zxing_version_info = tuple(int(n) for n in self.zxing_version.split('.'))
                            break
                return
        raise BarCodeReaderException("Java JARs not found in classpath (%s)" % self.classpath, self.classpath)

    def decode(self, filenames, try_harder=False, possible_formats=None, pure_barcode=False, products_only=False):
        possible_formats = (possible_formats,) if isinstance(possible_formats, str) else possible_formats

        if isinstance(filenames, (list, set, tuple, GeneratorType)):
            one_file = False
        else:
            one_file = True
            filenames = filenames,

        file_uris = []
        temp_files = []
        for fn_or_im in filenames:
            if have_pil and isinstance(fn_or_im, Image):
                tf = NamedTemporaryFile(prefix='PIL_image_', suffix='.png')
                temp_files.append(tf)
                fn_or_im.save(tf, compresslevel=0)
                tf.flush()
                fn = tf.name
            elif isinstance(fn_or_im, IOBase):
                tf = NamedTemporaryFile(prefix='temp_', suffix=os.path.splitext(fn_or_im.name)[1] or '.bin')
                temp_files.append(tf)
                tf.write(fn_or_im.read())
                tf.flush()
                fn = tf.name
            else:
                fn = fn_or_im
            file_uris.append(pathlib.Path(fn).absolute().as_uri())

        cmd = [self.java, '-cp', self.classpath, self.cls] + file_uris
        if self.zxing_version_info and self.zxing_version_info >= (3, 5, 3):
            # The --raw option was added in 3.5.0, but broken for certain barcode types (PDF_417 and maybe others) until 3.5.3
            # See https://github.com/zxing/zxing/issues/1682 and https://github.com/zxing/zxing/issues/1683
            cmd.append('--raw')
        if try_harder:
            cmd.append('--try_harder')
        if pure_barcode:
            cmd.append('--pure_barcode')
        if products_only:
            cmd.append('--products_only')
        if possible_formats:
            for pf in possible_formats:
                cmd += ['--possible_formats', pf]

        try:
            p = sp.Popen(cmd, stdout=sp.PIPE, stderr=sp.STDOUT, universal_newlines=False)
        except OSError as e:
            raise BarCodeReaderException("Could not execute specified Java binary", self.java) from e
        else:
            stdout, stderr = p.communicate()
        finally:
            for tf in temp_files:
                tf.close()

        if stdout.startswith((b'Error: Could not find or load main class com.google.zxing.client.j2se.CommandLineRunner',
                              b'Exception in thread "main" java.lang.NoClassDefFoundError:')):
            raise BarCodeReaderException("Java JARs not found in classpath (%s)" % self.classpath, self.classpath)
        elif stdout.startswith((b'''Exception in thread "main" javax.imageio.IIOException: Can't get input stream from URL!''',
                                b'''Exception in thread "main" java.util.concurrent.ExecutionException: javax.imageio.IIOException: Can't get input stream from URL!''')):  # noqa: E501
            # Find the line that looks like: "Caused by: java.io.FileNotFoundException: $FILENAME ({No such file or directory,Permission denied,*)"
            fn, err = next((map(bytes.decode, l[42:].rsplit(b' (', 1)) for l in stdout.splitlines()
                            if l.startswith(b"Caused by: java.io.FileNotFoundException: ")), ('', ''))
            if err == 'No such file or directory)':
                err = FileNotFoundError(fn)
            elif err == 'Permission denied)':
                err = PermissionError(fn)
            else:
                err = OSError(err[:-1])
            raise BarCodeReaderException("Java library could not read image", fn) from err
        elif stdout.startswith(b'''Exception in thread "main" java.io.IOException: Could not load '''):
            # First line ends with file:// URI
            fn = file_uri_to_path(stdout.splitlines()[0][63:].decode())
            raise BarCodeReaderException("Java library could not read image (is it in a supported format?)", fn)
        elif stdout.startswith(b'''Exception '''):
            raise BarCodeReaderException("Unknown Java exception", self.java) from sp.CalledProcessError(0, cmd, stdout)
        elif p.returncode:
            raise BarCodeReaderException("Unexpected Java subprocess return code", self.java) from sp.CalledProcessError(p.returncode, cmd, stdout)

        file_results = []
        for line in stdout.splitlines(True):
            if line.startswith((b'file:///', b'Exception')):
                file_results.append(line)
            else:
                file_results[-1] += line
        codes = [BarCode.parse(result) for result in file_results]

        if one_file:
            return codes[0]
        else:
            # zxing (insanely) randomly reorders the output blocks, so we have to put them back in the
            # expected order, based on their URIs
            d = {c.uri: c for c in codes}
            return [d[f] for f in file_uris]


class CLROutputBlock(Enum):
    UNKNOWN = 0
    RAW = 1
    PARSED = 2
    POINTS = 3
    RAW_BITS = 4


class BarCode(object):
    @classmethod
    def parse(cls, zxing_output):
        block = CLROutputBlock.UNKNOWN
        uri = format = type = None
        raw = parsed = raw_bits = b''
        points = []

        for l in zxing_output.splitlines(True):
            if block == CLROutputBlock.UNKNOWN:
                if l.endswith(b': No barcode found\n'):
                    return cls(l.rsplit(b':', 1)[0].decode(), None, None, None, None, None)
                m = re.match(rb"(\S+) \(format:\s*([^,]+),\s*type:\s*([^)]+)\)", l)
                if m:
                    uri, format, type = m.group(1).decode(), m.group(2).decode(), m.group(3).decode()
                elif l.startswith(b"Raw result:"):
                    block = CLROutputBlock.RAW
            elif block == CLROutputBlock.RAW:
                if l.startswith(b"Parsed result:"):
                    block = CLROutputBlock.PARSED
                else:
                    raw += l
            elif block == CLROutputBlock.PARSED:
                if l.startswith(b"Raw bits:"):
                    block = CLROutputBlock.RAW_BITS
                elif re.match(rb"Found\s+\d+\s+result\s+points?", l):
                    block = CLROutputBlock.POINTS
                else:
                    parsed += l
            elif block == CLROutputBlock.RAW_BITS:
                if re.match(rb"Found\s+\d+\s+result\s+points?", l):
                    block = CLROutputBlock.POINTS
                else:
                    raw_bits += l
            elif block == CLROutputBlock.POINTS:
                m = re.match(rb"\s*Point\s*\d+:\s*\(([\d.]+),([\d.]+)\)", l)
                if m:
                    points.append((float(m.group(1)), float(m.group(2))))

        parsed = parsed[:-1].decode()
        raw = raw[:-1].decode()
        raw_bits = bytes.fromhex(raw_bits[:-1].decode())
        return cls(uri, format, type, raw, parsed, raw_bits, points)

    def __bool__(self):
        return bool(self.raw)

    def __init__(self, uri, format=None, type=None, raw=None, parsed=None, raw_bits=None, points=None):
        self.raw = raw
        self.parsed = parsed
        self.raw_bits = raw_bits
        self.uri = uri
        self.format = format
        self.type = type
        self.points = points

    @property
    def path(self):
        try:
            return file_uri_to_path(self.uri)
        except ValueError:
            pass

    def __repr__(self):
        return '{}(raw={!r}, parsed={!r}, raw_bits={!r}, {}={!r}, format={!r}, type={!r}, points={!r})'.format(
            self.__class__.__name__, self.raw, self.parsed, self.raw_bits.hex() if self.raw_bits else None,
            'path' if self.path else 'uri', self.path or self.uri,
            self.format, self.type, self.points)