#!/usr/bin/env python
# This file is part of the pycalver project
# https://github.com/mbarkhau/pycalver
#
# (C) 2018 Manuel Barkhau (@mbarkhau)
# SPDX-License-Identifier: MIT

import io
import difflib
import logging
import typing as typ

from . import parse

log = logging.getLogger("pycalver.rewrite")


def rewrite(
    new_version: str,
    file_patterns: typ.Dict[str, str],
    dry=False,
    verbose=False,
) -> None:
    new_version_nfo = parse.parse_version_info(new_version)
    new_version_fmt_kwargs = new_version_nfo._asdict()

    matches: typ.List[parse.PatternMatch]
    for filepath, patterns in file_patterns.items():
        with io.open(filepath, mode="rt", encoding="utf-8") as fh:
            content = fh.read()

        old_lines = content.splitlines()
        new_lines = old_lines.copy()

        matches = parse.parse_patterns(old_lines, patterns)
        for m in matches:
            replacement = m.pattern.format(**new_version_fmt_kwargs)
            span_l, span_r = m.span
            new_line = m.line[:span_l] + replacement + m.line[span_r:]
            new_lines[m.lineno] = new_line

        if dry or verbose:
            print("\n".join(difflib.unified_diff(
                old_lines,
                new_lines,
                lineterm="",
                fromfile="a/" + filepath,
                tofile="b/" + filepath,
            )))

        if dry:
            continue

        new_content = "\n".join(new_lines)
        with io.open(filepath, mode="wt", encoding="utf-8") as fh:
            fh.write(new_content)