#!/usr/bin/env python3

"""
compares two pdf files.
"""
import io
import logging
import sys
from typing import Any, Iterable, List, Optional

import pdfminer.settings
from pdfminer import high_level, layout

pdfminer.settings.STRICT = False


logging.basicConfig()


def compare(file1: str, file2: str, **kwargs: Any) -> Iterable[str]:
    # If any LAParams group arguments were passed,
    # create an LAParams object and
    # populate with given args. Otherwise, set it to None.
    if kwargs.get("laparams", None) is None:
        laparams = layout.LAParams()
        for param in (
            "all_texts",
            "detect_vertical",
            "word_margin",
            "char_margin",
            "line_margin",
            "boxes_flow",
        ):
            paramv = kwargs.get(param, None)
            if paramv is not None:
                setattr(laparams, param, paramv)
        kwargs["laparams"] = laparams

    s1 = io.StringIO()
    with open(file1, "rb") as fp:
        high_level.extract_text_to_fp(fp, s1, **kwargs)

    s2 = io.StringIO()
    with open(file2, "rb") as fp:
        high_level.extract_text_to_fp(fp, s2, **kwargs)

    import difflib

    s1.seek(0)
    s2.seek(0)
    s1_lines, s2_lines = s1.readlines(), s2.readlines()

    import os.path

    try:
        extension = os.path.splitext(kwargs["outfile"])[1][1:4]
        if extension.lower() == "htm":
            return difflib.HtmlDiff().make_file(s1_lines, s2_lines)
    except KeyError:
        pass
    return difflib.unified_diff(s1_lines, s2_lines, n=kwargs["context_lines"])


# main
def main(args: Optional[List[str]] = None) -> int:
    import argparse

    P = argparse.ArgumentParser(description=__doc__)
    P.add_argument("file1", type=str, default=None, help="File 1 to compare.")
    P.add_argument("file2", type=str, default=None, help="File 2 to compare.")
    P.add_argument(
        "-o",
        "--outfile",
        type=str,
        default="-",
        help="Output file(default/'-' is stdout) if .htm or .html,"
        " create an HTML table (or a complete HTML file "
        "containing the table) showing a side by side, "
        "line by line comparison of text with inter-line and "
        "intra-line change  highlights. The table can be "
        "generated in either full or "
        "contextual difference mode.",
    )
    P.add_argument(
        "-N", "--context-lines", default=3, type=int, help="context lines shown"
    )
    P.add_argument(
        "-d", "--debug", default=False, action="store_true", help="Debug output."
    )

    # params for pdf2txt
    P.add_argument(
        "-p",
        "--pagenos",
        type=str,
        help="Comma-separated list of page numbers to parse. "
        "Included for legacy applications, "
        "use --page-numbers for more "
        "idiomatic argument entry.",
    )
    P.add_argument(
        "--page-numbers",
        type=int,
        default=None,
        nargs="+",
        help="Alternative to --pagenos with space-separated "
        "numbers; supercedes --pagenos where it is used.",
    )
    P.add_argument(
        "-m", "--maxpages", type=int, default=0, help="Maximum pages to parse"
    )
    P.add_argument(
        "-P",
        "--password",
        type=str,
        default="",
        help="Decryption password for both PDFs",
    )
    P.add_argument(
        "-t",
        "--output_type",
        type=str,
        default="text",
        help="pdf2txt type: text|html|xml|tag (default is text)",
    )
    P.add_argument("-c", "--codec", type=str, default="utf-8", help="Text encoding")
    P.add_argument("-s", "--scale", type=float, default=1.0, help="Scale")
    P.add_argument(
        "-A",
        "--all-texts",
        default=None,
        action="store_true",
        help="LAParams all texts",
    )
    P.add_argument(
        "-V",
        "--detect-vertical",
        default=None,
        action="store_true",
        help="LAParams detect vertical",
    )
    P.add_argument(
        "-W", "--word-margin", type=float, default=None, help="LAParams word margin"
    )
    P.add_argument(
        "-M", "--char-margin", type=float, default=None, help="LAParams char margin"
    )
    P.add_argument(
        "-L", "--line-margin", type=float, default=None, help="LAParams line margin"
    )
    P.add_argument(
        "-F", "--boxes-flow", type=float, default=None, help="LAParams boxes flow"
    )
    P.add_argument(
        "-Y", "--layoutmode", default="normal", type=str, help="HTML Layout Mode"
    )
    P.add_argument(
        "-n",
        "--no-laparams",
        default=False,
        action="store_true",
        help="Pass None as LAParams",
    )
    P.add_argument("-R", "--rotation", default=0, type=int, help="Rotation")
    P.add_argument(
        "-O", "--output-dir", default=None, help="Output directory for images"
    )
    P.add_argument(
        "-C",
        "--disable-caching",
        default=False,
        action="store_true",
        help="Disable caching",
    )
    P.add_argument(
        "-S",
        "--strip-control",
        default=False,
        action="store_true",
        help="Strip control in XML mode",
    )

    A = P.parse_args(args=args)

    if A.debug:
        logging.getLogger().setLevel(logging.DEBUG)

    if A.page_numbers:
        A.page_numbers = {x - 1 for x in A.page_numbers}
    if A.pagenos:
        A.page_numbers = {int(x) - 1 for x in A.pagenos.split(",")}

    if A.output_type == "text" and A.outfile != "-":
        for override, alttype in (
            (".htm", "html"),
            (".html", "html"),
            (".xml", "xml"),
            (".tag", "tag"),
        ):
            if A.outfile.endswith(override):
                A.output_type = alttype

    if A.outfile == "-":
        outfp = sys.stdout
    else:
        outfp = open(A.outfile, "w", encoding="utf-8")
    outfp.writelines(compare(**vars(A)))
    outfp.close()
    return 0


if __name__ == "__main__":
    sys.exit(main())