# -*- coding: utf-8 -*-
#
# Copyright 2020 - Swiss Data Science Center (SDSC)
# A partnership between École Polytechnique Fédérale de Lausanne (EPFL) and
# Eidgenössische Technische Hochschule Zürich (ETHZ).
#
# 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.
"""Serializers for dataset list files."""
import re
from subprocess import PIPE, SubprocessError, run

from humanize import naturalsize

from .tabulate import tabulate


def tabular(client, records, *, columns=None):
    """Format dataset files with a tabular output.

    :param client: LocalClient instance.
    :param records: Filtered collection.
    :param columns: List of columns to display
    """
    if not columns:
        columns = "added,creators,dataset,full_path"

    if "size" in columns.split(","):
        _get_lfs_file_sizes(client, records)

    for record in records:
        record.creators = record.dataset.creators

    return tabulate(
        collection=records,
        columns=columns,
        columns_mapping=DATASET_FILES_COLUMNS,
        columns_alignments=DATASET_FILES_COLUMNS_ALIGNMENTS,
    )


def _get_lfs_file_sizes(client, records):
    # Try to get file size from Git LFS
    lfs_files_sizes = {}

    try:
        lfs_run = run(
            ("git", "lfs", "ls-files", "--name-only", "--size"), stdout=PIPE, cwd=client.path, universal_newlines=True
        )
    except SubprocessError:
        pass
    else:
        lfs_output = lfs_run.stdout.split("\n")
        # Example line format: relative/path/to/file (7.9 MB)
        pattern = re.compile(r"^(.*?)\s*\((.*)\)")

        for line in lfs_output:
            match = pattern.search(line)
            if not match:
                continue
            path, size = match.groups()
            # Fix alignment for bytes
            if size.endswith(" B"):
                size = size.replace(" B", "  B")
            lfs_files_sizes[path] = size

    non_lfs_files_sizes = {o.path: o.size for o in client.repo.tree().traverse() if o.path not in lfs_files_sizes}
    non_lfs_files_sizes = {k: naturalsize(v).upper().replace("BYTES", " B") for k, v in non_lfs_files_sizes.items()}

    for record in records:
        size = lfs_files_sizes.get(record.path) or non_lfs_files_sizes.get(record.path)
        record.size = size


def jsonld(client, records, **kwargs):
    """Format dataset files as JSON-LD.

    :param client: LocalClient instance.
    :param records: Filtered collection.
    """
    from renku.core.models.json import dumps

    data = [record.as_jsonld() for record in records]
    return dumps(data, indent=2)


DATASET_FILES_FORMATS = {
    "tabular": tabular,
    "json-ld": jsonld,
}
"""Valid formatting options."""

DATASET_FILES_COLUMNS = {
    "added": ("added", None),
    "commit": ("commit_sha", "commit"),
    "creators": ("creators_csv", "creators"),
    "creators_full": ("creators_full_csv", "creators"),
    "dataset": ("title", "dataset"),
    "full_path": ("full_path", None),
    "path": ("path", None),
    "short_name": ("dataset_name", "dataset name"),
    "dataset_name": ("dataset_name", "dataset name"),
    "size": ("size", None),
}

DATASET_FILES_COLUMNS_ALIGNMENTS = {"size": "right"}
