import os

import docker

from docker.errors import ContainerError, NotFound

__all__ = ["ContainerError", "Containers"]

class Containers:

    def __init__(self):

        self._docker = docker.from_env()

    def get_engine_version(self):  # pragma: no cover

        versions = self._docker.version()

        engine_details = [c for c in versions["Components"] if c["Name"] == "Engine"]

        assert len(engine_details) == 1

        return engine_details[0]["Version"]

    def get_container(self, name):

        return self._docker.containers.get(name)

    def is_running(self, name):

        try:

            container = self.get_container(name)

            return container.status == "running"  # pragma: no cover

        except NotFound:  # pragma: no cover

            return False

    def get_mapped_port_for_host(self, name, container_port):

        """

        Given a port on a container return the port on the host to which it is

        mapped

        """

        container_port = f"{container_port}/tcp"

        container = self.get_container(name)

        port_config = container.attrs["NetworkSettings"]["Ports"][container_port]

        host_port = port_config[0]["HostPort"]

        return host_port

    def get_container_ip(self, name):

        """

        Given a container name, return it IP address

        """

        container = self.get_container(name)

        return container.attrs["NetworkSettings"]["IPAddress"]

    # All available arguments documented here:

    # https://docker-py.readthedocs.io/en/stable/containers.html#docker.models.containers.ContainerCollection.run

    def run_bg(self, name, image, **kwargs):  # pragma: no cover

        return self._run(name=name, image=image, detach=True, **kwargs)

    # All available arguments documented here:

    # https://docker-py.readthedocs.io/en/stable/containers.html#docker.models.containers.ContainerCollection.run

    def run_captured(self, image, **kwargs):

        return self._run(image=image, detach=False, stdout=True, stderr=True, **kwargs)

    def _run(self, **kwargs):  # pragma: no cover

        # Run as non-root by default to match production

        kwargs.setdefault("user", os.getuid())

        return self._docker.containers.run(remove=True, **kwargs)