#!/usr/bin/env python3
import argparse
import pathlib
import os
import subprocess
import re
import tempfile


CWD = pathlib.Path(os.getcwd())
BASE_DIR = pathlib.Path(os.path.dirname(os.path.abspath(__file__)))
TEMPLATE_FILE = BASE_DIR / 'main.tex'
OUTPUT_FILE = CWD / 'output.pdf'
CONTEXT_FILE = CWD / 'context.yaml'
WORDCOUNT_TEMPLATE = BASE_DIR / 'wordcount.yaml'


def build(input_file: pathlib.Path, additional_args=None):
    build_args = ['pandoc', str(input_file)]

    if CONTEXT_FILE.exists():
        build_args.append(str(CONTEXT_FILE))

    if additional_args is not None:
        build_args.extend(additional_args)

    build_args.extend([
        '--template',
        str(TEMPLATE_FILE),
        '-o',
        str(OUTPUT_FILE)
    ])
    return subprocess.run(build_args, cwd=str(BASE_DIR), check=True)


def get_word_count() -> int:
    words = subprocess.check_output([
        'pdftotext', str(OUTPUT_FILE), '-'
    ], cwd=str(BASE_DIR))
    return len(re.findall(r'\w+', words.decode()))


def write_wordcount() -> pathlib.Path:
    _, out_file_path = tempfile.mkstemp(suffix='.yaml')
    wordcount = get_word_count()
    with open(out_file_path, 'w') as out_file:
        with WORDCOUNT_TEMPLATE.open() as template:
            out_file.write(template.read().format(wordcount=wordcount))
    return pathlib.Path(out_file_path)


def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument("-v", "--verbose", help="Set verbosity level (repeat argument)", action="count", default=0)
    parser.add_argument("input", help="Input File", action='store', type=pathlib.Path,)
    parser.add_help = True
    return parser.parse_args()


if __name__ == '__main__':
    args = parse_args()
    input_file = args.input.resolve()
    if not input_file.is_file():
        raise ValueError("Failed to find {}".format(input_file))
    build(input_file)
    wordcount_metadata_file = write_wordcount()
    build(input_file, [str(wordcount_metadata_file)])