# Copyright 2018 AT&T Intellectual Property.  All other rights reserved.
#
# 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.

import logging
import os

import click
import git
import yaml

from prettytable import PrettyTable

from pegleg import config
from pegleg.engine import util
from pegleg.engine.util import files

__all__ = ('collect', 'list_', 'show', 'render')

LOG = logging.getLogger(__name__)


def _read_and_format_yaml(filename):
    with open(filename) as f:
        lines_to_write = f.readlines()
        if lines_to_write[0] != '---\n':
            lines_to_write = ['---\n'] + lines_to_write
        if lines_to_write[-1] != '...\n':
            lines_to_write.append('...\n')
    return lines_to_write or []


def _collect_to_stdout(site_name):
    """Collects all documents related to ``site_name`` and outputs them to
    stdout via ``output_stream``.
    """
    try:
        for repo_base, filename in util.definition.site_files_by_repo(
                site_name):
            for line in _read_and_format_yaml(filename):
                # This code is a pattern to convert \r\n to \n.
                click.echo("\n".join(line.splitlines()))
        res = yaml.safe_dump(_get_deployment_data_doc(),
                             explicit_start=True,
                             explicit_end=True,
                             default_flow_style=False)
        # Click isn't splitting these lines correctly, so do it manually
        for line in res.split('\n'):
            click.echo(line)
    except Exception as ex:
        raise click.ClickException("Error printing output: %s" % str(ex))


def _collect_to_file(site_name, save_location):
    """Collects all documents related to ``site_name`` and outputs them to
    the file denoted by ``save_location``.
    """

    files.check_file_save_location(save_location)

    save_files = dict()
    curr_site_repo = files.path_leaf(config.get_site_repo())

    try:
        for repo_base, filename in util.definition.site_files_by_repo(
                site_name):
            repo_name = os.path.normpath(repo_base).split(os.sep)[-1]
            save_file = os.path.join(save_location, repo_name + '.yaml')
            if repo_name not in save_files:
                save_files[repo_name] = open(save_file, "w")
            LOG.debug("Collecting file %s to file %s", filename, save_file)
            save_files[repo_name].writelines(_read_and_format_yaml(filename))
        save_files[curr_site_repo].writelines(yaml.safe_dump(
            _get_deployment_data_doc(), default_flow_style=False,
            explicit_start=True, explicit_end=True))
    except Exception as ex:
        raise click.ClickException("Error saving output: %s" % str(ex))
    finally:
        for f in save_files.values():
            f.close()


def collect(site_name, save_location):
    if save_location:
        _collect_to_file(site_name, save_location)
    else:
        _collect_to_stdout(site_name)


def render(site_name, output_stream, validate):
    documents = []
    for filename in util.definition.site_files(site_name):
        with open(filename) as f:
            documents.extend(list(yaml.safe_load_all(f)))

    rendered_documents, errors = util.deckhand.deckhand_render(
        documents=documents, validate=validate)
    err_msg = ''
    if errors:
        for err in errors:
            if isinstance(err, tuple) and len(err) > 1:
                err_msg += ': '.join(err) + '\n'
            else:
                err_msg += str(err) + '\n'
        raise click.ClickException(err_msg)
    yaml.dump_all(
        rendered_documents,
        output_stream,
        default_flow_style=False,
        explicit_start=True,
        explicit_end=True)


def list_(output_stream):
    """List site names for a given repository."""

    # Create a table to output site information for all sites for a given repo
    site_table = PrettyTable()
    field_names = ['site_name', 'site_type']
    site_table.field_names = field_names

    for site_name in util.files.list_sites():
        params = util.definition.load_as_params(site_name, *field_names)
        site_table.add_row(list(map(lambda k: params[k], field_names)))
    # Write table to specified output_stream
    output_stream.write(site_table.get_string() + "\n")


def show(site_name, output_stream):
    data = util.definition.load_as_params(site_name)
    data['files'] = list(util.definition.site_files(site_name))
    # Create a table to output site information for specific site
    site_table = PrettyTable()
    site_table.field_names = ['revision', 'site_name', 'site_type', 'files']
    # TODO(felipemonteiro): Drop support for 'revision' once manifest
    # repositories have removed it altogether.
    if 'revision' in data.keys():
        for file in data['files']:
            site_table.add_row(
                [data['revision'], data['site_name'], data['site_type'], file])
    else:
        for file in data['files']:
            site_table.add_row(
                ["", data['site_name'], data['site_type'], file])
    # Write tables to specified output_stream
    output_stream.write(site_table.get_string() + "\n")


def _get_deployment_data_doc():
    stanzas = {files.path_leaf(repo): _get_repo_deployment_data_stanza(repo)
               for repo in config.all_repos()}
    return {
        "schema": "pegleg/DeploymentData/v1",
        "metadata": {
            "schema": "metadata/Document/v1",
            "name": "deployment-version",
            "layeringDefinition": {
                "abstract": False,
                "layer": "global"
            },
            "storagePolicy": "cleartext",
        },
        "data": {
            "documents": stanzas
        }
    }


def _get_repo_deployment_data_stanza(repo_path):
    try:
        repo = git.Repo(repo_path)
        commit = repo.commit()

        # If we're at a particular tag, reference it
        tag = [tag.name for tag in
               repo.tags if tag.commit == commit]
        if tag:
            tag == ", ".join(tag)
        else:
            # Otherwise just use the branch name
            try:
                tag = repo.active_branch.name
            except TypeError as e:
                if "HEAD is a detached symbolic reference" in str(e):
                    tag = "Detached HEAD"
                else:
                    raise e
        return {
            "commit": commit.hexsha,
            "tag": tag,
            "dirty": repo.is_dirty()
        }
    except git.InvalidGitRepositoryError:
        return {
            "commit": "None",
            "tag": "None",
            "dirty": "None"
        }