Hydrilla

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

# Building Hydrilla packages.

#

# This file is part of Hydrilla

#

# Copyright (C) 2022 Wojtek Kosior

#

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU Affero 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 Affero General Public License for more details.

#

# You should have received a copy of the GNU Affero 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.

# Enable using with Python 3.7.

from __future__ import annotations

import json

import re

import zipfile

import subprocess

from pathlib import Path, PurePosixPath

from hashlib import sha256

from sys import stderr

from contextlib import contextmanager

from tempfile import TemporaryDirectory, TemporaryFile

from typing import Optional, Iterable, Union

import jsonschema

import click

from .. import util

from . import _version

from . import local_apt

from .piggybacking import Piggybacked

from .common_errors import *

here = Path(__file__).resolve().parent

_ = util.translation(here / 'locales').gettext

index_validator = util.validator_for('package_source-2.schema.json')

schemas_root = 'https://hydrilla.koszko.org/schemas'

generated_by = {

    'name': 'hydrilla.builder',

    'version': _version.version

}

class ReuseError(SubprocessError):

    """

    Exception used to report various problems when calling the REUSE tool.

    """

def generate_spdx_report(root: Path) -> bytes:

    """

    Use REUSE tool to generate an SPDX report for sources under 'root' and

    return the report's contents as 'bytes'.

    In case the directory tree under 'root' does not constitute a

    REUSE-compliant package, as exception is raised with linting report

    included in it.

    In case the reuse tool is not installed, an exception is also raised.

    """

    for command in [

            ['reuse', '--root', str(root), 'lint'],

            ['reuse', '--root', str(root), 'spdx']

    ]:

        try:

            cp = subprocess.run(command, capture_output=True, text=True)

        except FileNotFoundError:

            msg = _('couldnt_execute_{}_is_it_installed').format('reuse')

            raise ReuseError(msg)

        if cp.returncode != 0:

            msg = _('command_{}_failed').format(' '.join(command))

            raise ReuseError(msg, cp)

    return cp.stdout.encode()

class FileRef:

    """Represent reference to a file in the package."""

    def __init__(self, path: PurePosixPath, contents: bytes) -> None:

        """Initialize FileRef."""

        self.include_in_distribution   = False

        self.include_in_source_archive = True

        self.path                      = path

        self.contents                  = contents

        self.contents_hash = sha256(contents).digest().hex()

    def make_ref_dict(self) -> dict[str, str]:

        """

        Represent the file reference through a dict that can be included in JSON

        defintions.

        """

        return {

            'file':   str(self.path),

            'sha256': self.contents_hash

        }

@contextmanager

def piggybacked_system(piggyback_def: Optional[dict],

                       piggyback_files: Optional[Path]) \

                       -> Iterable[Piggybacked]:

    """

    Resolve resources from a foreign software packaging system. Optionally, use

    package files (.deb's, etc.) from a specified directory instead of resolving

    and downloading them.

    """

    if piggyback_def is None:

        yield Piggybacked()

    else:

        # apt is the only supported system right now

        assert piggyback_def['system'] == 'apt'

        with local_apt.piggybacked_system(piggyback_def, piggyback_files) \

             as piggybacked:

            yield piggybacked

class Build:

    """

    Build a Hydrilla package.

    """

    def __init__(self, srcdir: Path, index_json_path: Path,

                 piggyback_files: Optional[Path]=None):

        """

        Initialize a build. All files to be included in a distribution package

        are loaded into memory, all data gets validated and all necessary

        computations (e.g. preparing of hashes) are performed.

        """

        self.srcdir          = srcdir.resolve()

        self.piggyback_files = piggyback_files

        # TODO: the piggyback files we set are ignored for now; use them

        if piggyback_files is None:

            piggyback_default_path = \

                srcdir.parent / f'{srcdir.name}.foreign-packages'

            if piggyback_default_path.exists():

                self.piggyback_files = piggyback_default_path

        self.files_by_path   = {}

        self.resource_list   = []

        self.mapping_list    = []

        if not index_json_path.is_absolute():

            index_json_path = (self.srcdir / index_json_path)

        with open(index_json_path, 'rt') as index_file:

            index_json_text = index_file.read()

        index_obj = json.loads(util.strip_json_comments(index_json_text))

        index_desired_path = PurePosixPath('index.json')

        self.files_by_path[index_desired_path] = \

            FileRef(index_desired_path, index_json_text.encode())

        self._process_index_json(index_obj)

    def _process_file(self, filename: Union[str, PurePosixPath],

                      piggybacked: Piggybacked,

                      include_in_distribution: bool=True):

        """

        Resolve 'filename' relative to srcdir, load it to memory (if not loaded

        before), compute its hash and store its information in

        'self.files_by_path'.

        'filename' shall represent a relative path withing package directory.

        if 'include_in_distribution' is True it shall cause the file to not only

        be included in the source package's zipfile, but also written as one of

        built package's files.

        For each file an attempt is made to resolve it using 'piggybacked'

        object. If a file is found and pulled from foreign software packaging

        system this way, it gets automatically excluded from inclusion in

        Hydrilla source package's zipfile.

        Return file's reference object that can be included in JSON defintions

        of various kinds.

        """

        include_in_source_archive = True

        desired_path = PurePosixPath(filename)

        if '..' in desired_path.parts:

            msg = _('path_contains_double_dot_{}').format(filename)

            raise FileReferenceError(msg)

        path = piggybacked.resolve_file(desired_path)

        if path is None:

            path = (self.srcdir / desired_path).resolve()

            if not path.is_relative_to(self.srcdir):

                raise FileReferenceError(_('loading_{}_outside_package_dir')

                                         .format(filename))

            if str(path.relative_to(self.srcdir)) == 'index.json':

                raise FileReferenceError(_('loading_reserved_index_json'))

        else:

            include_in_source_archive = False

        file_ref = self.files_by_path.get(desired_path)

        if file_ref is None:

            with open(path, 'rb') as file_handle:

                contents = file_handle.read()

            file_ref = FileRef(desired_path, contents)

            self.files_by_path[desired_path] = file_ref

        if include_in_distribution:

            file_ref.include_in_distribution = True

        if not include_in_source_archive:

            file_ref.include_in_source_archive = False

        return file_ref.make_ref_dict()

    def _prepare_source_package_zip(self, source_name: str,

                                    piggybacked: Piggybacked) -> str:

        """

        Create and store in memory a .zip archive containing files needed to

        build this source package.

        'src_dir_name' shall not contain any slashes ('/').

        Return zipfile's sha256 sum's hexstring.

        """

        tf = TemporaryFile()

        source_dir_path      = PurePosixPath(source_name)

        piggybacked_dir_path = PurePosixPath(f'{source_name}.foreign-packages')

        with zipfile.ZipFile(tf, 'w') as zf:

            for file_ref in self.files_by_path.values():

                if file_ref.include_in_source_archive:

                    zf.writestr(str(source_dir_path / file_ref.path),

                                file_ref.contents)

            for desired_path, real_path in piggybacked.archive_files():

                zf.writestr(str(piggybacked_dir_path / desired_path),

                            real_path.read_bytes())

        tf.seek(0)

        self.source_zip_contents = tf.read()

        return sha256(self.source_zip_contents).digest().hex()

    def _process_item(self, item_def: dict, piggybacked: Piggybacked):

        """

        Process 'item_def' as definition of a resource/mapping and store in

        memory its processed form and files used by it.

        Return a minimal item reference suitable for using in source

        description.

        """

        copy_props = ['type', 'identifier', 'long_name', 'description']

        for prop in ('comment', 'uuid'):

            if prop in item_def:

                copy_props.append(prop)

        if item_def['type'] == 'resource':

            item_list = self.resource_list

            copy_props.append('revision')

            script_file_refs = [self._process_file(f['file'], piggybacked)

                                for f in item_def.get('scripts', [])]

            deps = [{'identifier': res_ref['identifier']}

                    for res_ref in item_def.get('dependencies', [])]

            new_item_obj = {

                'dependencies': [*piggybacked.package_must_depend, *deps],

                'scripts':      script_file_refs

            }

        else:

            item_list = self.mapping_list

            payloads = {}

            for pat, res_ref in item_def.get('payloads', {}).items():

                payloads[pat] = {'identifier': res_ref['identifier']}

            new_item_obj = {

                'payloads': payloads

            }

        new_item_obj.update([(p, item_def[p]) for p in copy_props])

        new_item_obj['version'] = util.normalize_version(item_def['version'])

        new_item_obj['$schema'] = f'{schemas_root}/api_{item_def["type"]}_description-1.schema.json'

        new_item_obj['source_copyright'] = self.copyright_file_refs

        new_item_obj['source_name'] = self.source_name

        new_item_obj['generated_by'] = generated_by

        item_list.append(new_item_obj)

        props_in_ref = ('type', 'identifier', 'version', 'long_name')

        return dict([(prop, new_item_obj[prop]) for prop in props_in_ref])

    def _process_index_json(self, index_obj: dict):

        """

        Process 'index_obj' as contents of source package's index.json and store

        in memory this source package's zipfile as well as package's individual

        files and computed definitions of the source package and items defined

        in it.

        """

        index_validator.validate(index_obj)

        match = re.match(r'.*-((([1-9][0-9]*|0)\.)+)schema\.json$',

                         index_obj['$schema'])

        self.source_schema_ver = \

            [int(n) for n in filter(None, match.group(1).split('.'))]

        out_schema = f'{schemas_root}/api_source_description-1.schema.json'

        self.source_name = index_obj['source_name']

        generate_spdx = index_obj.get('reuse_generate_spdx_report', False)

        if generate_spdx:

            contents  = generate_spdx_report(self.srcdir)

            spdx_path = PurePosixPath('report.spdx')

            spdx_ref  = FileRef(spdx_path, contents)

            spdx_ref.include_in_source_archive = False

            self.files_by_path[spdx_path] = spdx_ref

        piggyback_def = None

        if self.source_schema_ver >= [1, 1] and 'piggyback_on' in index_obj:

            piggyback_def = index_obj['piggyback_on']

        with piggybacked_system(piggyback_def, self.piggyback_files) \

             as piggybacked:

            copyright_to_process = [

                *(file_ref['file'] for file_ref in index_obj['copyright']),

                *piggybacked.package_license_files

            ]

            self.copyright_file_refs = [self._process_file(f, piggybacked)

                                        for f in copyright_to_process]

            if generate_spdx and not spdx_ref.include_in_distribution:

                raise FileReferenceError(_('report_spdx_not_in_copyright_list'))

            item_refs = [self._process_item(d, piggybacked)

                         for d in index_obj['definitions']]

            for file_ref in index_obj.get('additional_files', []):

                self._process_file(file_ref['file'], piggybacked,

                                   include_in_distribution=False)

            zipfile_sha256 = self._prepare_source_package_zip\

                (self.source_name, piggybacked)

            source_archives_obj = {'zip' : {'sha256': zipfile_sha256}}

        self.source_description = {

            '$schema':            out_schema,

            'source_name':        self.source_name,

            'source_copyright':   self.copyright_file_refs,

            'upstream_url':       index_obj['upstream_url'],

            'definitions':        item_refs,

            'source_archives':    source_archives_obj,

            'generated_by':       generated_by

        }

        if 'comment' in index_obj:

            self.source_description['comment'] = index_obj['comment']

    def write_source_package_zip(self, dstpath: Path):

        """

        Create a .zip archive containing files needed to build this source

        package and write it at 'dstpath'.

        """

        with open(dstpath, 'wb') as output:

            output.write(self.source_zip_contents)

    def write_package_files(self, dstpath: Path):

        """Write package files under 'dstpath' for distribution."""

        file_dir_path = (dstpath / 'file' / 'sha256').resolve()

        file_dir_path.mkdir(parents=True, exist_ok=True)

        for file_ref in self.files_by_path.values():

            if file_ref.include_in_distribution:

                file_path = file_dir_path / file_ref.contents_hash

                file_path.write_bytes(file_ref.contents)

        source_dir_path = (dstpath / 'source').resolve()

        source_dir_path.mkdir(parents=True, exist_ok=True)

        source_name = self.source_description["source_name"]

        with open(source_dir_path / f'{source_name}.json', 'wt') as output:

            json.dump(self.source_description, output)

        with open(source_dir_path / f'{source_name}.zip', 'wb') as output:

            output.write(self.source_zip_contents)

        for item_type, item_list in [

                ('resource', self.resource_list),

                ('mapping', self.mapping_list)

        ]:

            item_type_dir_path = (dstpath / item_type).resolve()

            for item_def in item_list:

                item_dir_path = item_type_dir_path / item_def['identifier']

                item_dir_path.mkdir(parents=True, exist_ok=True)

                version = '.'.join([str(n) for n in item_def['version']])

                with open(item_dir_path / version, 'wt') as output:

                    json.dump(item_def, output)

dir_type = click.Path(exists=True, file_okay=False, resolve_path=True)

@click.command(help=_('build_package_from_srcdir_to_dstdir'))

@click.option('-s', '--srcdir', default='./', type=dir_type, show_default=True,

              help=_('source_directory_to_build_from'))

@click.option('-i', '--index-json', default='index.json', type=click.Path(),

              help=_('path_instead_of_index_json'))

@click.option('-p', '--piggyback-files', type=click.Path(),

              help=_('path_instead_for_piggyback_files'))

@click.option('-d', '--dstdir', type=dir_type, required=True,

              help=_('built_package_files_destination'))

@click.version_option(version=_version.version, prog_name='Hydrilla builder',

                      message=_('%(prog)s_%(version)s_license'),

                      help=_('version_printing'))

def perform(srcdir, index_json, piggyback_files, dstdir):

    """

    Execute Hydrilla builder to turn source package into a distributable one.

    This command is meant to be the entry point of hydrilla-builder command

    exported by this package.

    """

    build = Build(Path(srcdir), Path(index_json),

                  piggyback_files and Path(piggyback_files))

    build.write_package_files(Path(dstdir))