# Copyright 2020 MongoDB Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
# KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
# WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
#

import io
import os
import tarfile
import time
import zipfile
from distutils.spawn import find_executable

import git
import SCons

__distsrc_callbacks = []


class DistSrcFile:
    def __init__(self, **kwargs):
        [setattr(self, key, val) for (key, val) in list(kwargs.items())]

    def __str__(self):
        return self.name


class DistSrcArchive:
    def __init__(self, archive_type, archive_file, filename, mode):
        self.archive_type = archive_type
        self.archive_file = archive_file
        self.archive_name = filename
        self.archive_mode = mode

    @staticmethod
    def Open(filename):
        if filename.endswith("tar"):
            return DistSrcTarArchive(
                "tar",
                tarfile.open(filename, "r", format=tarfile.PAX_FORMAT),
                filename,
                "r",
            )
        elif filename.endswith("zip"):
            return DistSrcZipArchive(
                "zip",
                zipfile.ZipFile(filename, "a"),
                filename,
                "a",
            )

    def close(self):
        self.archive_file.close()


class DistSrcTarArchive(DistSrcArchive):
    def __iter__(self):
        file_list = self.archive_file.getnames()
        for name in file_list:
            yield name

    def __getitem__(self, key):
        item_data = self.archive_file.getmember(key)
        return DistSrcFile(
            name=key,
            size=item_data.size,
            mtime=item_data.mtime,
            mode=item_data.mode,
            type=item_data.type,
            uid=item_data.uid,
            gid=item_data.gid,
            uname=item_data.uname,
            gname=item_data.uname,
        )

    def append_file_contents(
        self,
        filename,
        file_contents,
        mtime=None,
        mode=0o644,
        uname="root",
        gname="root",
    ):
        if mtime is None:
            mtime = time.time()
        file_metadata = tarfile.TarInfo(name=filename)
        file_metadata.mtime = mtime
        file_metadata.mode = mode
        file_metadata.uname = uname
        file_metadata.gname = gname
        file_metadata.size = len(file_contents)
        file_buf = io.BytesIO(file_contents.encode("utf-8"))
        if self.archive_mode == "r":
            self.archive_file.close()
            self.archive_file = tarfile.open(
                self.archive_name,
                "a",
                format=tarfile.PAX_FORMAT,
            )
            self.archive_mode = "a"
        self.archive_file.addfile(file_metadata, fileobj=file_buf)

    def append_file(self, filename, localfile):
        self.archive_file.add(localfile, arcname=filename)


class DistSrcZipArchive(DistSrcArchive):
    def __iter__(self):
        file_list = self.archive_file.namelist()
        for name in file_list:
            yield name

    def __getitem__(self, key):
        item_data = self.archive_file.getinfo(key)
        fixed_time = item_data.date_time + (0, 0, 0)
        is_dir = key.endswith("/")
        return DistSrcFile(
            name=key,
            size=item_data.file_size,
            mtime=time.mktime(fixed_time),
            mode=0o775 if is_dir else 0o664,
            type=tarfile.DIRTYPE if is_dir else tarfile.REGTYPE,
            uid=0,
            gid=0,
            uname="root",
            gname="root",
        )

    def append_file_contents(
        self,
        filename,
        file_contents,
        mtime=None,
        mode=0o644,
        uname="root",
        gname="root",
    ):
        if mtime is None:
            mtime = time.time()
        self.archive_file.writestr(filename, file_contents)

    def append_file(self, filename, localfile):
        self.archive_file.write(localfile, arcname=filename)


def build_error_action(msg):
    def error_stub(target=None, source=None, env=None):
        print(msg)
        env.Exit(1)

    return [error_stub]


def distsrc_action_generator(source, target, env, for_signature):
    # This is done in two stages because env.WhereIs doesn't seem to work
    # correctly on Windows, but we still want to be able to override the PATH
    # using the env.
    git_path = env.WhereIs("git")
    if not git_path:
        git_path = find_executable("git")

    if not git_path:
        return build_error_action("Could not find git - cannot create distsrc archive")

    def run_distsrc_callbacks(target=None, source=None, env=None):
        archive_wrapper = DistSrcArchive.Open(str(target[0]))
        for fn in __distsrc_callbacks:
            fn(env, archive_wrapper)
        archive_wrapper.close()

    target_ext = str(target[0])[-3:]
    if target_ext not in ["zip", "tar"]:
        print("Invalid file format for distsrc. Must be tar or zip file")
        env.Exit(1)

    def create_archive(target=None, source=None, env=None):
        try:
            git_repo = git.Repo(os.getcwd())
            # get the original HEAD position of repo
            head_commit_sha = git_repo.head.object.hexsha

            # add and commit the uncommited changes
            git_repo.git.add(all=True)
            # only commit changes if there are any
            if len(git_repo.index.diff("HEAD")) != 0:
                with git_repo.git.custom_environment(
                    GIT_COMMITTER_NAME="Evergreen", GIT_COMMITTER_EMAIL="evergreen@mongodb.com"
                ):
                    git_repo.git.commit("--author='Evergreen <>'", "-m", "temp commit")

            # archive repo
            dist_src_prefix = env.get("MONGO_DIST_SRC_PREFIX")
            git_repo.git.archive(
                "--format", target_ext, "--output", target[0], "--prefix", dist_src_prefix, "HEAD"
            )

            # reset branch to original state
            git_repo.git.reset("--mixed", head_commit_sha)
        except Exception as e:
            env.FatalError(f"Error archiving: {e}")

    return [
        SCons.Action.Action(create_archive, "Creating archive for $TARGET"),
        SCons.Action.Action(
            run_distsrc_callbacks,
            "Running distsrc callbacks for $TARGET",
        ),
    ]


def add_callback(env, fn):
    __distsrc_callbacks.append(fn)


def generate(env, **kwargs):
    env.AddMethod(add_callback, "AddDistSrcCallback")
    env["BUILDERS"]["__DISTSRC"] = SCons.Builder.Builder(
        generator=distsrc_action_generator,
    )

    def DistSrc(env, target, **kwargs):
        result = env.__DISTSRC(target=target, source=[], **kwargs)
        env.AlwaysBuild(result)
        env.NoCache(result)
        return result

    env.AddMethod(DistSrc, "DistSrc")


def exists(env):
    return True