#!/usr/bin/python

# Copyright (c) Contributors to the Ansible project
# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
# SPDX-License-Identifier: GPL-3.0-or-later

from __future__ import annotations

DOCUMENTATION = r"""
author:
  - Laszlo Szomor (@lszomor)
module: lvg_rename
short_description: Renames LVM volume groups
description:
  - This module renames volume groups using the C(vgchange) command.
extends_documentation_fragment:
  - community.general.attributes
attributes:
  check_mode:
    support: full
  diff_mode:
    support: full
version_added: 7.1.0
options:
  vg:
    description:
      - The name or UUID of the source VG.
      - See V(vgrename(8\)) for valid values.
    type: str
    required: true
  vg_new:
    description:
      - The new name of the VG.
      - See V(lvm(8\)) for valid names.
    type: str
    required: true
seealso:
  - module: community.general.lvg
notes:
  - This module does not modify VG renaming-related configurations like C(fstab) entries or boot parameters.
"""

EXAMPLES = r"""
- name: Rename a VG by name
  community.general.lvg_rename:
    vg: vg_orig_name
    vg_new: vg_new_name

- name: Rename a VG by UUID
  community.general.lvg_rename:
    vg_uuid: SNgd0Q-rPYa-dPB8-U1g6-4WZI-qHID-N7y9Vj
    vg_new: vg_new_name
"""

from ansible.module_utils.basic import AnsibleModule

argument_spec = dict(
    vg=dict(type="str", required=True),
    vg_new=dict(type="str", required=True),
)


class LvgRename:
    def __init__(self, module):
        """
        Orchestrates the lvg_rename module logic.

        :param module: An AnsibleModule instance.
        """
        self.module = module
        self.result = {"changed": False}
        self.vg_list = []
        self._load_params()

    def run(self):
        """Performs the module logic."""

        self._load_vg_list()

        old_vg_exists = self._is_vg_exists(vg=self.vg)
        new_vg_exists = self._is_vg_exists(vg=self.vg_new)

        if old_vg_exists:
            if new_vg_exists:
                self.module.fail_json(msg=f"The new VG name ({self.vg_new}) is already in use.")
            else:
                self._rename_vg()
        else:
            if new_vg_exists:
                self.result["msg"] = f"The new VG ({self.vg_new}) already exists, nothing to do."
                self.module.exit_json(**self.result)
            else:
                self.module.fail_json(msg=f"Both current ({self.vg}) and new ({self.vg_new}) VG are missing.")

        self.module.exit_json(**self.result)

    def _load_params(self):
        """Load the parameters from the module."""

        self.vg = self.module.params["vg"]
        self.vg_new = self.module.params["vg_new"]

    def _load_vg_list(self):
        """Load the VGs from the system."""

        vgs_cmd = self.module.get_bin_path("vgs", required=True)
        vgs_cmd_with_opts = [vgs_cmd, "--noheadings", "--separator", ";", "-o", "vg_name,vg_uuid"]
        dummy, vg_raw_list, dummy = self.module.run_command(vgs_cmd_with_opts, check_rc=True)

        for vg_info in vg_raw_list.splitlines():
            vg_name, vg_uuid = vg_info.strip().split(";")
            self.vg_list.append(vg_name)
            self.vg_list.append(vg_uuid)

    def _is_vg_exists(self, vg):
        """
        Checks VG existence by name or UUID. It removes the '/dev/' prefix before checking.

        :param vg: A string with the name or UUID of the VG.
        :returns: A boolean indicates whether the VG exists or not.
        """

        vg_found = False
        dev_prefix = "/dev/"

        if vg.startswith(dev_prefix):
            vg_id = vg[len(dev_prefix) :]
        else:
            vg_id = vg

        vg_found = vg_id in self.vg_list

        return vg_found

    def _rename_vg(self):
        """Renames the volume group."""

        vgrename_cmd = self.module.get_bin_path("vgrename", required=True)

        if self.module._diff:
            self.result["diff"] = {"before": {"vg": self.vg}, "after": {"vg": self.vg_new}}

        if self.module.check_mode:
            self.result["msg"] = f"Running in check mode. The module would rename VG {self.vg} to {self.vg_new}."
            self.result["changed"] = True
        else:
            vgrename_cmd_with_opts = [vgrename_cmd, self.vg, self.vg_new]
            dummy, vg_rename_out, dummy = self.module.run_command(vgrename_cmd_with_opts, check_rc=True)

            self.result["msg"] = vg_rename_out
            self.result["changed"] = True


def setup_module_object():
    module = AnsibleModule(argument_spec=argument_spec, supports_check_mode=True)
    return module


def main():
    module = setup_module_object()
    lvg_rename = LvgRename(module=module)
    lvg_rename.run()


if __name__ == "__main__":
    main()