#!/usr/bin/env python3

import argparse
import difflib
import os
import re

from pathlib import Path


def parse_arguments() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Print supported distributions")

    parser.add_argument("-d", "--docs-dir",
                        type=Path,
                        default=Path(os.path.dirname(os.path.realpath(__file__))) / "documentation",
                        help="Path to documentation/ directory in yocto-docs")

    return parser.parse_args()


glossaries = (
    'ref-manual/variables.rst',
    'ref-manual/terms.rst',
)


def main():

    args = parse_arguments()
    in_glossary = False
    # Pattern to match:
    # :term:`A <ABIEXTENSION>` :term:`B` :term:`C <CACHE>`
    glossary_re = re.compile(r":term:`(?P<letter>[A-Z]{1})( <(?P<varname>[A-Z_]+)>)?`")
    entry_re = re.compile(r"^   :term:`(?P<entry>.+)`\s*$")

    for rst in glossaries:

        glossary = {}
        rst_path = Path(args.docs_dir) / rst

        with open(rst_path, "r") as f:
            for line in f.readlines():
                if "check_glossary_begin" in line:
                    in_glossary = True
                    continue
                if in_glossary:
                    for m in re.finditer(glossary_re, line.strip()):
                        letter = m.group("letter")
                        varname = m.group("varname")
                        if varname is None:
                            varname = letter
                        glossary[letter] = varname
                if "check_glossary_end" in line:
                    in_glossary = False
                    break

        entries = []

        with open(rst_path, "r") as f:
            for line in f.readlines():
                m = re.match(entry_re, line)
                if m:
                    entries.append(m.group("entry"))

        # We lower here because underscore (_) come before lowercase letters
        # (the natural way) but after uppercase letters (which is not natural)
        sorted_entries = sorted(entries, key=lambda t: t.lower())
        diffs = list(difflib.unified_diff(entries,
                                          sorted_entries,
                                          fromfile="original_list",
                                          tofile="sorted_list"))

        if diffs:
            print(f"WARNING: {rst}: entries are not properly sorted:")
            print('\n'.join(diffs))

        for letter in glossary:
            try:
                index = entries.index(glossary[letter])
            except ValueError:
                print(f"WARNING: {rst}: variable "
                      f"{glossary[letter]} in glossary does not exist")
            if index > 0 and entries[index - 1].startswith(letter[0]):
                print(f"WARNING: {rst}: The variable {glossary[letter]} shouldn't be in "
                     "the glossary.")


if __name__ == "__main__":
    main()