# Copyright © 2024 Vulcanize

# 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 <http:#www.gnu.org/licenses/>.

import click
from python_on_whales import DockerClient
import requests
from typing import List

from stack_orchestrator.opts import opts
from stack_orchestrator.util import include_exclude_check, error_exit
from stack_orchestrator.build.build_util import get_containers_in_scope

# Experimental fetch-container command


def _local_tag_for(container: str):
    return f"{container}:local"


# Emulate this:
# $ curl -u "my-username:my-token" -X GET "https://<container-registry-hostname>/v2/cerc-io/cerc/test-container/tags/list"
# {"name":"cerc-io/cerc/test-container","tags":["202402232130","202402232208"]}
def _get_tags_for_container(container: str, registry: str, registry_username: str, registry_token: str) -> List[str]:
    # registry looks like: git.vdb.to/cerc-io
    registry_parts = registry.split("/")
    url = f"https://{registry_parts[0]}/v2/{registry_parts[1]}/{container}/tags/list"
    if opts.o.debug:
        print(f"Fetching tags from: {url}")
    response = requests.get(url, auth=(registry_username, registry_token))
    if response.status_code == 200:
        tag_info = response.json()
        if opts.o.debug:
            print(f"Got this: {tag_info}")
        tags_array = tag_info["tags"]
        return tags_array
    else:
        error_exit(f"failed to fetch tags from image registry, status code: {response.status_code}")


def _find_latest(candidate_tags: List[str]):
    # HACK: return the first one for now
    return candidate_tags[0]


def _get_latest_image(container: str, registry: str, registry_username: str, registry_token: str):
    all_tags = _get_tags_for_container(container, registry, registry_username, registry_token)
    latest_tag = _find_latest(all_tags)
    return f"{container}:{latest_tag}"


def _fetch_image(tag: str, registry: str, registry_username: str, registry_token: str):
    docker = DockerClient()
    docker.login(registry, registry_username, registry_token)
    remote_tag = f"{registry}/{tag}"
    if opts.o.debug:
        print(f"Attempting to pull this image: {remote_tag}")
    docker.image.pull(remote_tag)


def _exists_locally(container: str):
    docker = DockerClient()
    return docker.image.exists(_local_tag_for(container))


def _remove_local_tag(container: str):
    # TODO Do we need this?
    pass


def _add_local_tag(remote_tag: str, registry: str, local_tag: str):
    docker = DockerClient()
    docker.image.tag(f"{registry}/{remote_tag}", local_tag)


@click.command()
@click.option('--include', help="only fetch these containers")
@click.option('--exclude', help="don\'t fetch these containers")
@click.option("--force-local-overwrite", is_flag=True, default=False, help="Overwrite a locally built image, if present")
@click.option("--image-registry", required=True, help="Specify the image registry to fetch from")
@click.option("--registry-username", required=True, help="Specify the image registry username")
@click.option("--registry-token", required=True, help="Specify the image registry access token")
@click.pass_context
def command(ctx, include, exclude, force_local_overwrite, image_registry, registry_username, registry_token):
    '''EXPERIMENTAL: fetch the images for a stack from remote registry'''

    # Generate list of target containers
    stack = ctx.obj.stack
    containers_in_scope = get_containers_in_scope(stack)
    for container in containers_in_scope:
        local_tag = _local_tag_for(container)
        if include_exclude_check(container, include, exclude):
            if opts.o.debug:
                print(f"Processing: {container}")
            # For each container, attempt to find the latest of a set of
            # images with the correct name and platform in the specified registry
            image_to_fetch = _get_latest_image(container, image_registry, registry_username, registry_token)
            if opts.o.debug:
                print(f"Fetching: {image_to_fetch}")
            _fetch_image(image_to_fetch, image_registry, registry_username, registry_token)
            # Now check if the target container already exists exists locally already
            if (_exists_locally(container)):
                if not opts.o.quiet:
                    print(f"Container image {container} already exists locally")
                # if so, fail unless the user specified force-local-overwrite
                if (force_local_overwrite):
                    # In that case remove the existing :local tag
                    if not opts.o.quiet:
                        print(f"Warning: removing local tag from this image: {container} because "
                              "--force-local-overwrite was specified")
                    _remove_local_tag(local_tag)
                else:
                    if not opts.o.quiet:
                        print(f"Skipping local tagging for this image: {container} because that would "
                              "overwrite an existing :local tagged image, use --force-local-overwrite to do so.")
            # Tag the fetched image with the :local tag
            _add_local_tag(image_to_fetch, image_registry, local_tag)
        else:
            if opts.o.verbose:
                print(f"Excluding: {container}")