# Copyright 2021 Canonical Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Module for rendering templates inside containers."""

import logging
import os
from pathlib import (
    Path,
)
from typing import (
    TYPE_CHECKING,
)

import ops.pebble

if TYPE_CHECKING:
    import ops_sunbeam.core as sunbeam_core
    import ops.model

import jinja2

log = logging.getLogger(__name__)


# def get_container(
#     containers: list[ops.model.Container], name: str
# ) -> ops.model.Container | None:
#     """Search for container with given name inlist of containers."""
#     container = None
#     for c in containers:
#         if c.name == name:
#             container = c
#     return container


def sidecar_config_render(
    container: "ops.model.Container",
    config: "sunbeam_core.ContainerConfigFile",
    template_dir: str,
    context: "sunbeam_core.OPSCharmContexts",
) -> bool:
    """Render templates inside containers.

    :return: Whether file was updated.
    :rtype: bool
    """
    file_updated = False
    try:
        original_contents = container.pull(config.path).read()
    except (ops.pebble.PathError, FileNotFoundError):
        original_contents = None
    loader = jinja2.FileSystemLoader(template_dir)
    _tmpl_env = jinja2.Environment(loader=loader)
    try:
        template = _tmpl_env.get_template(
            os.path.basename(config.path) + ".j2"
        )
    except jinja2.exceptions.TemplateNotFound:
        template = _tmpl_env.get_template(os.path.basename(config.path))
    contents = template.render(context)
    if original_contents == contents:
        log.debug(
            f"{config.path} in {container.name} matches desired content."
        )
    else:
        kwargs = {
            "user": config.user,
            "group": config.group,
            "permissions": config.permissions,
        }
        parent_dir = str(Path(config.path).parent)
        if not container.isdir(parent_dir):
            container.make_dir(parent_dir, make_parents=True)
        container.push(config.path, contents, **kwargs)
        file_updated = True
        log.debug(
            f"Wrote template {config.path} in container {container.name}."
        )
    return file_updated