# SPDX-License-Identifier: GPL-3.0-or-later

# Definitions of helper commands to use with setuptools
#
# This file is part of Hydrilla
#
# Copyright (C) 2021 Wojtek Kosior
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
#
# I, Wojtek Kosior, thereby promise not to sue for violation of this file's
# license. Although I request that you do not make use this code in a
# proprietary program, I am not going to enforce this in court.

from setuptools import Command
from setuptools.command.build_py import build_py
import sys
from pathlib import Path
import subprocess
import re
import os
import json
import importlib

def mypath(path_or_string):
    return Path(path_or_string).resolve()

class Helper:
    def __init__(self, project_root, app_package_name, locales_dir,
                 locales=['en', 'pl'], default_locale='en', locale_domain=None,
                 packages_root=None, debian_dir=None, config_path=None):
        self.project_root       = mypath(project_root)
        self.app_package_name   = app_package_name
        self.locales_dir        = mypath(locales_dir)
        self.locales            = locales
        self.default_locale     = default_locale
        self.locale_domain      = locale_domain or app_package_name
        self.packages_root      = mypath(packages_root or project_root / 'src')
        self.app_package_dir    = self.packages_root / app_package_name
        self.debian_dir         = mypath(debian_dir or project_root / 'debian')
        self.config_path        = config_path and mypath(config_path)
        self.locale_files_list  = None

    def run_command(self, command, verbose, runner=subprocess.run, **kwargs):
        cwd = kwargs.get('cwd')
        if cwd:
            cwd = mypath(cwd)
            where = f'from {cwd} '
        else:
            cwd = Path.cwd().resolve()
            where = ''

        str_command = [str(command[0])]

        for arg in command[1:]:
            if isinstance(arg, Path):
                try:
                    arg = str(arg.relative_to(cwd))
                except ValueError:
                    arg = str(arg)

            str_command.append(arg)

        if verbose:
            print(f'{where}executing {" ".join(str_command)}')
        runner(str_command, **kwargs)

    def create_mo_files(self, dry_run=False, verbose=False):
        self.locale_files_list = []

        for locale in self.locales:
            messages_dir = self.locales_dir / locale / 'LC_MESSAGES'

            for po_path in messages_dir.glob('*.po'):
                mo_path = po_path.with_suffix('.mo')

                if not dry_run:
                    command = ['msgfmt', po_path, '-o', mo_path]
                    self.run_command(command, verbose=verbose, check=True)

                self.locale_files_list.extend([po_path, mo_path])

    def locale_files(self):
        if self.locale_files_list is None:
            self.create_mo_files(dry_run=True)

        return self.locale_files_list

    def locale_files_relative(self, to=None):
        if to is None:
            to = self.app_package_dir

        return [file.relative_to(to) for file in self.locale_files()]

    def flask_run(self, locale=None):
        for var, val in (('ENV', 'development'), ('DEBUG', 'True')):
            os.environ[f'FLASK_{var}'] = os.environ.get(f'FLASK_{var}', val)

        config = {'lang': locale or self.default_locale}

        sys.path.insert(0, str(self.packages_root))
        package = importlib.import_module(self.app_package_name)

        # make relative paths in json config resolve from project's directory
        os.chdir(self.project_root)

        kwargs = {'config_path': self.config_path} if self.config_path else {}
        package.create_app(flask_config=config, **kwargs).run()

    def update_po_files(self, verbose=False):
        pot_path = self.locales_dir / f'{self.locale_domain}.pot'
        rglob = self.app_package_dir.rglob
        command = ['xgettext', '-d', self.locale_domain, '--language=Python',
                   '-o', pot_path, *rglob('*.py'), *rglob('*.html')]

        self.run_command(command, verbose=verbose, check=True,
                         cwd=self.app_package_dir)

        for locale in self.locales:
            messages_dir = self.locales_dir / locale / 'LC_MESSAGES'

            for po_path in messages_dir.glob('*.po'):
                if po_path.stem != self.app_package_name:
                    continue;

                if po_path.exists():
                    command = ['msgmerge', '--update', po_path, pot_path]
                else:
                    command = ['cp', po_path, pot_path]

                self.run_command(command, verbose=verbose, check=True)

        if (verbose):
            print('removing generated .pot file')
        pot_path.unlink()

    # we exclude these from the source archive we produce
    bad_file_regex = re.compile(r'^\..*|build|debian|dist')

    changelog_line_regex = re.compile(r'''
    ^ # match from the beginning of each line
    \s* # skip initial whitespace (if any)
    (?P<source_name> # capture name
        [^\s(]+
    )
    \s* # again skip whitespace (if any)
    \(
    (?P<version> # capture version which is enclosed in parantheses
        [^)]+
    )
    -
    (?P<debrel> # capture debrel part of version separately
        [0-9]+
    )
    \)
    ''', re.VERBOSE)

    def make_tarballs(self, verbose=False):
        changelog_path = self.project_root / 'debian' / 'changelog'
        with open(changelog_path, 'rt') as file_handle:
            for line in file_handle.readlines():
                match = changelog_line_regex.match(line)
                if match:
                    break

        if not match:
            raise ValueError("Couldn't extract version from debian/changelog.")

        name, ver, debrel = \
            [match.group(gn) for gn in ('source_name', 'version', 'debrel')]

        source_dirname      = f'{name}-{ver}'
        source_tarball_name = f'{name}_{ver}.orig.tar.gz'
        debian_tarball_name = f'{name}_{ver}-{debrel}.debian.tar.gz'

        source_args = [f'--prefix={source_dirname}/', '-o',
                       self.project_root.parent / source_tarball_name, 'HEAD']

        for filepath in self.project_root.iterdir():
            if not self.bad_file_regex.search(filepath.parts[-1]):
                 source_args.append(filepath)

        debian_args = ['-o', self.project_root.parent / debian_tarball_name,
                       'HEAD', self.debian_dir]

        for args in [source_args, debian_args]:
            command = ['git', 'archive', '--format=tar.gz', *args]
            self.run_command(command, verbose=verbose, check=True)

    def commands(self):
        helper = self

        class MsgfmtCommand(Command):
            '''A custom command to run msgfmt on all .po files below '{}'.'''

            description = 'use msgfmt to generate .mo files from .po files'
            user_options = []

            def initialize_options(self):
                pass

            def finalize_options(self):
                pass

            def run(self):
                helper.create_mo_files(verbose=self.verbose)

        MsgfmtCommand.__doc__ = MsgfmtCommand.__doc__.format(helper.locales_dir)

        class RunCommand(Command):
            '''
            A custom command to run the app using flask.

            This is similar in effect to:
                PYTHONPATH='{packages_root}' FLASK_APP={app_package_name} \\
                    FLASK_ENV=development flask run
            '''

            description = 'run the Flask app from source directory'

            user_options = [
                ('locale=', 'l',
                 "app locale (one of: %s; default: '%s')" %
                 (', '.join([f"'{l}'" for l in helper.locales]),
                  helper.default_locale))
            ]

            def initialize_options(self):
                self.locale = helper.default_locale

            def finalize_options(self):
                if self.locale not in helper.locales:
                    raise ValueError("Locale '%s' not supported" % self.lang)

            def run(self):
                helper.flask_run(locale=self.locale)

        RunCommand.__doc__ = RunCommand.__doc__.format(
            packages_root=self.packages_root,
            app_package_name=self.app_package_name
        )

        class MsgmergeCommand(Command):
            '''
            A custom command to run xgettext and msgmerge to update project's
            .po files below '{}'.
            '''

            description = 'use xgettext and msgmerge to update (or generate) .po files for this project'
            user_options = []

            def initialize_options(self):
                pass

            def finalize_options(self):
                pass

            def run(self):
                helper.update_po_files(verbose=self.verbose)

        MsgmergeCommand.__doc__ = \
            MsgmergeCommand.__doc__.format(helper.locales_dir)

        class TarballsCommand(Command):
            '''
            A custom command to run git archive to create debian tarballs of
            this project.
            '''

            description = 'use git archive to create .orig.tar.gz and .debian.tar.gz files for this project'
            user_options = []

            def initialize_options(self):
                pass

            def finalize_options(self):
                pass

            def run(self):
                helper.make_tarballs(verbose=self.verbose)

        class BuildCommand(build_py):
            '''
            The build command but runs the custom msgfmt command before build.
            '''
            def run(self, *args, **kwargs):
                self.run_command('msgfmt')
                super().run(*args, **kwargs)

        return {
            'msgfmt': MsgfmtCommand,
            'run': RunCommand,
            'msgmerge': MsgmergeCommand,
            'tarballs': TarballsCommand,
            'build_py': BuildCommand
        }