#!/usr/bin/env python3

# SPDX-FileCopyrightText: Florian Bruhin (The Compiler) <mail@qutebrowser.org>
#
# SPDX-License-Identifier: GPL-3.0-or-later

"""Various small code checkers."""

import os
import os.path
import re
import sys
import argparse
import subprocess
import tokenize
import traceback
import pathlib
from typing import List, Iterator, Optional, Tuple

REPO_ROOT = pathlib.Path(__file__).resolve().parents[2]
sys.path.insert(0, str(REPO_ROOT))

from scripts import utils
from scripts.dev import recompile_requirements

BINARY_EXTS = {'.png', '.icns', '.ico', '.bmp', '.gz', '.bin', '.pdf',
               '.sqlite', '.woff2', '.whl', '.egg'}


def _get_files(
        *,
        verbose: bool,
        ignored: List[pathlib.Path] = None
) -> Iterator[pathlib.Path]:
    """Iterate over all files and yield filenames."""
    filenames = subprocess.run(
        ['git', 'ls-files', '--cached', '--others', '--exclude-standard', '-z'],
        stdout=subprocess.PIPE,
        text=True,
        check=True,
    )
    all_ignored = ignored or []
    all_ignored.append(
        pathlib.Path('tests', 'unit', 'scripts', 'importer_sample', 'chrome'))

    for filename in filenames.stdout.split('\0'):
        path = pathlib.Path(filename)
        is_ignored = any(path == p or p in path.parents for p in all_ignored)
        if not filename or path.suffix in BINARY_EXTS or is_ignored:
            continue

        try:
            with tokenize.open(path):
                pass
        except SyntaxError as e:
            # Could not find encoding
            utils.print_col("{} - maybe {} should be added to BINARY_EXTS?".format(
                str(e).capitalize(), path.suffix), 'yellow')
            continue

        if verbose:
            print(path)

        yield path


def check_changelog_urls(_args: argparse.Namespace = None) -> bool:
    """Ensure we have changelog URLs for all requirements."""
    ok = True
    all_requirements = set()

    for name in recompile_requirements.get_all_names():
        outfile = recompile_requirements.get_outfile(name)
        missing = set()
        with open(outfile, 'r', encoding='utf-8') as f:
            for line in f:
                line = line.strip()
                if line.startswith('#') or not line:
                    continue
                req, _version = recompile_requirements.parse_versioned_line(line)
                if req.startswith('./'):
                    continue
                if " @ " in req:  # vcs URL
                    req = req.split(" @ ")[0]

                all_requirements.add(req)
                if req not in recompile_requirements.CHANGELOG_URLS:
                    missing.add(req)

        if missing:
            ok = False
            req_str = ', '.join(sorted(missing))
            utils.print_col(
                f"Missing changelog URLs in {name} requirements: {req_str}", 'red')

    extra = set(recompile_requirements.CHANGELOG_URLS) - all_requirements
    if extra:
        ok = False
        req_str = ', '.join(sorted(extra))
        utils.print_col(f"Extra changelog URLs: {req_str}", 'red')

    if not ok:
        print("Hint: Changelog URLs are in scripts/dev/changelog_urls.json")

    return ok


def check_git(_args: argparse.Namespace = None) -> bool:
    """Check for uncommitted git files."""
    if not os.path.isdir(".git"):
        print("No .git dir, ignoring")
        print()
        return False
    untracked = []
    gitst = subprocess.run(['git', 'status', '--porcelain'], check=True,
                           stdout=subprocess.PIPE).stdout
    gitst = gitst.decode('UTF-8').strip()
    for line in gitst.splitlines():
        s, name = line.split(maxsplit=1)
        if s == '??' and name != '.venv/':
            untracked.append(name)
    status = True
    if untracked:
        status = False
        utils.print_col("Untracked files:", 'red')
        print('\n'.join(untracked))
    print()
    return status


def _check_spelling_file(path, fobj, patterns):
    ok = True
    for num, line in enumerate(fobj, start=1):
        for pattern, explanation in patterns:
            match = pattern.search(line)
            if match:
                ok = False
                print(f'{path}:{num}: ', end='')
                utils.print_col(f'Found "{match.group(0)}" - {explanation}', 'blue')
    return ok


def _check_spelling_all(
    args: argparse.Namespace,
    ignored: List[pathlib.Path],
    patterns: List[Tuple[re.Pattern, str]],
) -> Optional[bool]:
    try:
        ok = True
        for path in _get_files(verbose=args.verbose, ignored=ignored):
            with tokenize.open(str(path)) as f:
                if not _check_spelling_file(path, f, patterns):
                    ok = False
        print()
        return ok
    except Exception:
        traceback.print_exc()
        return None


def check_spelling(args: argparse.Namespace) -> Optional[bool]:
    """Check commonly misspelled words."""
    # Words which I often misspell
    words = {'behaviour', 'quitted', 'likelyhood', 'sucessfully',
             'occur[^rs .!,]', 'seperator', 'explicitely', 'auxillary',
             'accidentaly', 'ambigious', 'loosly', 'initialis', 'convienence',
             'similiar', 'uncommited', 'reproducable', 'an user',
             'convienience', 'wether', 'programatically', 'splitted',
             'exitted', 'mininum', 'resett?ed', 'recieved', 'regularily',
             'underlaying', 'inexistant', 'elipsis', 'commiting', 'existant',
             'resetted', 'similarily', 'informations', 'an url', 'treshold',
             'artefact', 'an unix', 'an utf', 'an unicode', 'unparseable',
             'dependancies', 'convertable', 'chosing', 'authentification'}

    # Words which look better when split, but might need some fine tuning.
    words |= {'webelements', 'mouseevent', 'keysequence', 'normalmode',
              'eventloops', 'sizehint', 'statemachine', 'metaobject',
              'logrecord'}

    patterns = [
        (
            re.compile(r'[{}{}]{}'.format(w[0], w[0].upper(), w[1:])),
            "Common misspelling or non-US spelling"
        ) for w in words
    ]

    qtbot_methods = {
        'keyPress',
        'keyRelease',
        'keyClick',
        'keyClicks',
        'keyEvent',
        'mousePress',
        'mouseRelease',
        'mouseClick',
        'mouseMove',
        'mouseDClick',
        'keySequence',
    }

    qtbot_excludes = '|'.join(qtbot_methods)

    patterns += [
        (
            re.compile(r'(?i)# noqa(?!: )'),
            "Don't use a blanket 'noqa', use something like 'noqa: X123' instead.",
        ),
        (
            re.compile(r'# type: (?!ignore(\[|$))'),
            "Don't use type comments, use type annotations instead.",
        ),
        (
            re.compile(r': typing\.'),
            "Don't use typing.SomeType, do 'from typing import SomeType' instead.",
        ),
        (
            re.compile(r"""monkeypatch\.setattr\(['"]"""),
            "Don't use monkeypatch.setattr('obj.attr', value), use "
            "setattr(obj, 'attr', value) instead.",
        ),
        (
            re.compile(r'(exec|print)_\('),
            ".exec_()/.print_() are removed in PyQt 6, use .exec()/.print() instead.",
        ),
        (
            re.compile(r'qApp'),
            "qApp is removed in PyQt 6, use QApplication.instance() instead.",
        ),
        (
            re.compile(r'PYQT_CONFIGURATION'),
            "PYQT_CONFIGURATION is removed in PyQt 6",
        ),
        (
            re.compile(r'Q_(ENUM|FLAG)'),
            "Q_ENUM and Q_FLAG are removed in PyQt 6",
        ),
        (
            re.compile(r'attr\.(s|ib)($|\()'),
            "attrs have been replaced by dataclasses in qutebrowser.",
        ),
        (
            re.compile(r'http://www\.gnu\.org/licenses/'),
            "use https:// URL.",
        ),
        (
            re.compile(r'IOError'),
            "use OSError",
        ),
        (
            re.compile(fr'qtbot\.(?!{qtbot_excludes})[a-z]+[A-Z].*'),
            "use snake-case instead",
        ),
        (
            re.compile(r'\.joinpath\((?!\*)'),
            "use the / operator for joining paths",
        ),
        (
            re.compile(r"""pathlib\.Path\(["']~["']\)\.expanduser\(\)"""),
            "use pathlib.Path.home() instead",
        ),
        (
            re.compile(r'pathlib\.Path\(tmp_path\)'),
            "tmp_path already is a pathlib.Path",
        ),
        (
            re.compile(r'pathlib\.Path\(tmpdir\)'),
            "use tmp_path instead",
        ),
        (
            re.compile(r' Copyright 2'),
            "use 'SPDX-FileCopyrightText: ...' without year instead",
        ),
        (
            re.compile(r'qutebrowser is free software: you can redistribute'),
            "use 'SPDX-License-Identifier: GPL-3.0-or-later' instead",
        ),
    ]

    # Files which should be ignored, e.g. because they come from another
    # package
    hint_data = pathlib.Path('tests', 'end2end', 'data', 'hints')
    ignored = [
        pathlib.Path('scripts', 'dev', 'misc_checks.py'),
        pathlib.Path('scripts', 'dev', 'enums.txt'),
        pathlib.Path('qutebrowser', '3rdparty', 'pdfjs'),
        pathlib.Path('qutebrowser', 'qt', '_core_pyqtproperty.py'),
        pathlib.Path('qutebrowser', 'javascript', 'caret.js'),
        hint_data / 'ace' / 'ace.js',
        hint_data / 'bootstrap' / 'bootstrap.css',
    ]
    return _check_spelling_all(args=args, ignored=ignored, patterns=patterns)


def check_pyqt_imports(args: argparse.Namespace) -> Optional[bool]:
    """Check for direct PyQt imports."""
    ignored = [
        pathlib.Path("qutebrowser", "qt"),
        pathlib.Path("misc", "userscripts"),
        pathlib.Path("scripts"),
    ]
    patterns = [
        (
            re.compile(r"from PyQt.* import"),
            "Use 'from qutebrowser.qt.MODULE import ...' instead",
        ),
        (
            re.compile(r"import PyQt.*"),
            "Use 'import qutebrowser.qt.MODULE' instead",
        )
    ]
    return _check_spelling_all(args=args, ignored=ignored, patterns=patterns)


def check_vcs_conflict(args: argparse.Namespace) -> Optional[bool]:
    """Check VCS conflict markers."""
    try:
        ok = True
        for path in _get_files(verbose=args.verbose):
            if path.suffix in {'.rst', '.asciidoc'}:
                # False positives
                continue
            with tokenize.open(path) as f:
                for line in f:
                    if any(line.startswith(c * 7) for c in '<>=|'):
                        print("Found conflict marker in {}".format(path))
                        ok = False
        print()
        return ok
    except Exception:
        traceback.print_exc()
        return None


def check_userscripts_descriptions(_args: argparse.Namespace = None) -> bool:
    """Make sure all userscripts are described properly."""
    folder = pathlib.Path('misc/userscripts')
    readme = folder / 'README.md'

    described = set()
    for line in readme.open('r'):
        line = line.strip()
        if line == '## Others':
            break

        match = re.fullmatch(r'- \[([^]]*)\].*', line)
        if match:
            described.add(match.group(1))

    present = {path.name for path in folder.iterdir()}
    present -= {'README.md', '.mypy_cache', '__pycache__'}

    missing = present - described
    additional = described - present
    ok = True

    if missing:
        print("Missing userscript descriptions: {}".format(missing))
        ok = False
    if additional:
        print("Additional userscript descriptions: {}".format(additional))
        ok = False

    return ok


def check_userscript_shebangs(_args: argparse.Namespace) -> bool:
    """Check that we're using /usr/bin/env in shebangs and scripts are executable."""
    ok = True
    folder = pathlib.Path('misc/userscripts')

    for sub in folder.iterdir():
        if sub.is_dir() or sub.name == 'README.md':
            continue

        if not os.access(sub, os.X_OK):
            print(f"{sub} is not marked as executable")
            ok = False

        with sub.open('r', encoding='utf-8') as f:
            shebang = f.readline().rstrip('\n')
        assert shebang.startswith('#!'), shebang
        shebang = shebang[2:]

        binary = shebang.split()[0]
        if binary not in ['/bin/sh', '/usr/bin/env']:
            bin_name = pathlib.Path(binary).name
            print(f"In {sub}, use #!/usr/bin/env {bin_name} instead of #!{binary}")
            ok = False
        elif shebang in ['/usr/bin/env python', '/usr/bin/env python2']:
            print(f"In {sub}, use #!/usr/bin/env python3 instead of #!{shebang}")
            ok = False

    return ok


def check_vim_modelines(args: argparse.Namespace) -> bool:
    """Check that we're not using vim modelines."""
    ok = True
    try:
        for path in _get_files(verbose=args.verbose):
            with tokenize.open(str(path)) as f:
                for num, line in enumerate(f, start=1):
                    if not line.startswith("# vim:"):
                        continue
                    print(f"{path}:{num}: Remove vim modeline "
                          "(deprecated in favor of .editorconfig)")
                    ok = False
    except Exception:
        traceback.print_exc()
        ok = False

    return ok


def main() -> int:
    checkers = {
        'git': check_git,
        'vcs': check_vcs_conflict,
        'spelling': check_spelling,
        'pyqt-imports': check_pyqt_imports,
        'userscript-descriptions': check_userscripts_descriptions,
        'userscript-shebangs': check_userscript_shebangs,
        'changelog-urls': check_changelog_urls,
        'vim-modelines': check_vim_modelines,
    }

    parser = argparse.ArgumentParser()
    parser.add_argument('--verbose', action='store_true', help='Show checked filenames')
    parser.add_argument('checker',
                        choices=list(checkers) + ['all'],
                        help="Which checker to run.")
    args = parser.parse_args()

    if args.checker == 'all':
        retvals = []
        for name, checker in checkers.items():
            utils.print_title(name)
            retvals.append(checker(args))
        return 0 if all(retvals) else 1

    checker = checkers[args.checker]
    ok = checker(args)
    return 0 if ok else 1


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