# © 2020 James R. Barlow: github.com/jbarlow83
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

"""Tesseract bad utf8

In some cases, some versions of Tesseract can output binary gibberish or data
that is not UTF-8 compatible, so we are forced to check that we can convert it
and present it to the user.
"""

from contextlib import contextmanager
from subprocess import CalledProcessError
from unittest.mock import patch

from ocrmypdf import hookimpl
from ocrmypdf.builtin_plugins.tesseract_ocr import TesseractOcrEngine


def bad_utf8(*args, **kwargs):
    raise CalledProcessError(
        1,
        'tesseract',
        output=b'\x96\xb3\x8c\xf8\x82\xc8UTF-8\x0a',  # "Invalid UTF-8" in Shift JIS
        stderr=b"",
    )


@contextmanager
def patch_tesseract_run():
    with patch('ocrmypdf._exec.tesseract.run') as mock:
        mock.side_effect = bad_utf8
        yield
        mock.assert_called()


class BadUtf8OcrEngine(TesseractOcrEngine):
    @staticmethod
    def generate_hocr(input_file, output_hocr, output_text, options):
        with patch_tesseract_run():
            TesseractOcrEngine.generate_hocr(
                input_file, output_hocr, output_text, options
            )

    @staticmethod
    def generate_pdf(input_file, output_pdf, output_text, options):
        with patch_tesseract_run():
            TesseractOcrEngine.generate_pdf(
                input_file, output_pdf, output_text, options
            )


@hookimpl
def get_ocr_engine():
    return BadUtf8OcrEngine()