import argparse
import logging
import os
import re
import subprocess
import sys

from table_ocr.util import working_dir, make_tempdir


def get_logger():
    logger = logging.getLogger(__name__)
    lvl = os.environ.get("PY_LOG_LVL", "info").upper()
    handler = logging.StreamHandler()
    formatter = logging.Formatter(logging.BASIC_FORMAT)
    handler.setFormatter(formatter)
    logger.addHandler(handler)
    handler.setLevel(lvl)
    logger.setLevel(lvl)
    return logger

logger = get_logger()

parser = argparse.ArgumentParser()
parser.add_argument("files", nargs="+")

def main(files):
    pdf_images = []
    for f in files:
        pdf_images.append((f, pdf_to_images(f)))

    for pdf, images in pdf_images:
        for image in images:
            preprocess_img(image)

    for pdf, images in pdf_images:
        print("{}\n{}\n".format(pdf, "\n".join(images)))


def pdf_to_images(pdf_filepath):
    """
    Turn a pdf into images
    """
    directory, filename = os.path.split(pdf_filepath)
    with working_dir(directory):
        image_filenames = pdfimages(pdf_filepath)

    # Since pdfimages creates a number of files named each for there page number
    # and doesn't return us the list that it created
    return [os.path.join(directory, f) for f in image_filenames]


def pdfimages(pdf_filepath):
    """
    Uses the `pdfimages` utility from Poppler
    (https://poppler.freedesktop.org/). Creates images out of each page. Images
    are prefixed by their name sans extension and suffixed by their page number.
    """
    directory, filename = os.path.split(pdf_filepath)
    filename_sans_ext = filename.split(".pdf")[0]
    subprocess.run(["pdfimages", "-png", pdf_filepath, filename.split(".pdf")[0]])
    image_filenames = find_matching_files_in_dir(filename_sans_ext, directory)
    logger.debug("Converted {} into files:\n{}".format(pdf_filepath, "\n".join(image_filenames)))
    return image_filenames


def find_matching_files_in_dir(file_prefix, directory):
    files = [
        filename
        for filename in os.listdir(directory)
        if re.match(r"{}.*\.png".format(re.escape(file_prefix)), filename)
    ]
    return files
def preprocess_img(filepath):
    """
    Processing that involves running shell executables,
    like mogrify to rotate.
    """
    rotate = get_rotate(filepath)
    logger.debug("Rotating {} by {}.".format(filepath, rotate))
    mogrify(filepath, rotate)


def get_rotate(image_filepath):
    output = (
        subprocess.check_output(["tesseract", "--psm", "0", image_filepath, "-"])
        .decode("utf-8")
        .split("\n")
    )
    output = next(l for l in output if "Rotate: " in l)
    output = output.split(": ")[1]
    return output


def mogrify(image_filepath, rotate):
    subprocess.run(["mogrify", "-rotate", rotate, image_filepath])

if __name__ == "__main__":
    args = parser.parse_args()
    main(args.files)