#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# === This file is part of Calamares - <https://github.com/calamares> ===
#
#   Copyright 2014, Aurélien Gâteau <agateau@kde.org>
#   Copyright 2017, Alf Gaida <agaida@siduction.org>
#   Copyright 2019, Adriaan de Groot <groot@kde.org>
#   Copyright 2019, Kevin Kofler <kevin.kofler@chello.at>
#
#   Calamares is free software: you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation, either version 3 of the License, or
#   (at your option) any later version.
#
#   Calamares 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 General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with Calamares. If not, see <http://www.gnu.org/licenses/>.

import tempfile
import subprocess
import os

import libcalamares

import gettext
_ = gettext.translation("calamares-python",
                        localedir=libcalamares.utils.gettext_path(),
                        languages=libcalamares.utils.gettext_languages(),
                        fallback=True).gettext


def pretty_name():
    return _("Mounting partitions.")

def mount_partition(root_mount_point, partition, partitions):
    """
    Do a single mount of @p partition inside @p root_mount_point.

    The @p partitions are used to handle btrfs special-cases:
    then subvolumes are created for root and home.
    """
    # Create mount point with `+` rather than `os.path.join()` because
    # `partition["mountPoint"]` starts with a '/'.
    raw_mount_point = partition["mountPoint"]
    mount_point = root_mount_point + raw_mount_point

    # Ensure that the created directory has the correct SELinux context on
    # SELinux-enabled systems.
    os.makedirs(mount_point, exist_ok=True)
    try:
        subprocess.call(['chcon', '--reference=' + raw_mount_point, mount_point])
    except FileNotFoundError as e:
        libcalamares.utils.warning(str(e))
    except OSError:
        libcalamares.utils.error("Cannot run 'chcon' normally.")
        raise

    fstype = partition.get("fs", "").lower()

    if fstype == "fat16" or fstype == "fat32":
        fstype = "vfat"

    if "luksMapperName" in partition:
        libcalamares.utils.debug(
            "about to mount {!s}".format(partition["luksMapperName"]))
        libcalamares.utils.mount(
            "/dev/mapper/{!s}".format(partition["luksMapperName"]),
            mount_point,
            fstype,
            partition.get("options", ""),
            )

    else:
        libcalamares.utils.mount(partition["device"],
                                 mount_point,
                                 fstype,
                                 partition.get("options", ""),
                                 )

    # If the root partition is btrfs, we create a subvolume "@"
    # for the root mount point.
    # If a separate /home partition isn't defined, we also create
    # a subvolume "@home".
    # Finally we remount all of the above on the correct paths.
    if fstype == "btrfs" and partition["mountPoint"] == '/':
        has_home_mount_point = False
        for p in partitions:
            if "mountPoint" not in p or not p["mountPoint"]:
                continue
            if p["mountPoint"] == "/home":
                has_home_mount_point = True
                break

        subprocess.check_call(['btrfs', 'subvolume', 'create',
                               root_mount_point + '/@'])

        if not has_home_mount_point:
            subprocess.check_call(['btrfs', 'subvolume', 'create',
                                   root_mount_point + '/@home'])

        subprocess.check_call(["umount", "-v", root_mount_point])

        if "luksMapperName" in partition:
            libcalamares.utils.mount(
                "/dev/mapper/{!s}".format(partition["luksMapperName"]),
                mount_point,
                fstype,
                ",".join(
                    ["subvol=@", partition.get("options", "")]),
                )
            if not has_home_mount_point:
                libcalamares.utils.mount(
                    "/dev/mapper/{!s}".format(partition["luksMapperName"]),
                    root_mount_point + "/home",
                    fstype,
                    ",".join(
                        ["subvol=@home", partition.get("options", "")]),
                    )
        else:
            libcalamares.utils.mount(
                partition["device"],
                mount_point,
                fstype,
                ",".join(["subvol=@", partition.get("options", "")]),
                )
            if not has_home_mount_point:
                libcalamares.utils.mount(
                    partition["device"],
                    root_mount_point + "/home",
                    fstype,
                    ",".join(
                        ["subvol=@home", partition.get("options", "")]),
                    )


def run():
    """
    Mount all the partitions from GlobalStorage and from the job configuration.
    Partitions are mounted in-lexical-order of their mountPoint.
    """
    partitions = libcalamares.globalstorage.value("partitions")

    if not partitions:
        libcalamares.utils.warning("partitions is empty, {!s}".format(partitions))
        return (_("Configuration Error"),
                _("No partitions are defined for <pre>{!s}</pre> to use." ).format("mount"))

    root_mount_point = tempfile.mkdtemp(prefix="calamares-root-")

    # Guard against missing keys (generally a sign that the config file is bad)
    extra_mounts = libcalamares.job.configuration.get("extraMounts") or []
    extra_mounts_efi = libcalamares.job.configuration.get("extraMountsEfi") or []
    if not extra_mounts and not extra_mounts_efi:
        libcalamares.utils.warning("No extra mounts defined. Does mount.conf exist?")

    if libcalamares.globalstorage.value("firmwareType") == "efi":
        extra_mounts.extend(extra_mounts_efi)

    # Add extra mounts to the partitions list and sort by mount points.
    # This way, we ensure / is mounted before the rest, and every mount point
    # is created on the right partition (e.g. if a partition is to be mounted
    # under /tmp, we make sure /tmp is mounted before the partition)
    mountable_partitions = [ p for p in partitions + extra_mounts if "mountPoint" in p and p["mountPoint"] ]
    mountable_partitions.sort(key=lambda x: x["mountPoint"])
    for partition in mountable_partitions:
        mount_partition(root_mount_point, partition, partitions)

    libcalamares.globalstorage.insert("rootMountPoint", root_mount_point)

    # Remember the extra mounts for the unpackfs module
    libcalamares.globalstorage.insert("extraMounts", extra_mounts)