import argparse
import getpass
import os
import shutil
import sys
from pathlib import Path
from typing import IO

from .. import tty
from ..errors import ClanError
from .folders import (
    list_objects,
    sops_groups_folder,
    sops_machines_folder,
    sops_secrets_folder,
    sops_users_folder,
)
from .sops import decrypt_file, encrypt_file, ensure_sops_key, read_key, update_keys
from .types import VALID_SECRET_NAME, secret_name_type


def collect_keys_for_type(folder: Path) -> set[str]:
    if not folder.exists():
        return set()
    keys = set()
    for p in folder.iterdir():
        if not p.is_symlink():
            continue
        try:
            target = p.resolve()
        except FileNotFoundError:
            tty.warn(f"Ignoring broken symlink {p}")
            continue
        kind = target.parent.name
        if folder.name != kind:
            tty.warn(f"Expected {p} to point to {folder} but points to {target.parent}")
            continue
        keys.add(read_key(target))
    return keys


def collect_keys_for_path(path: Path) -> set[str]:
    keys = set([])
    keys.update(collect_keys_for_type(path / "machines"))
    keys.update(collect_keys_for_type(path / "users"))
    groups = path / "groups"
    if not groups.is_dir():
        return keys
    for group in groups.iterdir():
        keys.update(collect_keys_for_type(group / "machines"))
        keys.update(collect_keys_for_type(group / "users"))
    return keys


def encrypt_secret(
    flake_dir: Path,
    secret: Path,
    value: IO[str] | str | None,
    add_users: list[str] = [],
    add_machines: list[str] = [],
    add_groups: list[str] = [],
) -> None:
    key = ensure_sops_key(flake_dir)
    keys = set([])

    for user in add_users:
        allow_member(
            users_folder(flake_dir, secret.name),
            sops_users_folder(flake_dir),
            user,
            False,
        )

    for machine in add_machines:
        allow_member(
            machines_folder(flake_dir, secret.name),
            sops_machines_folder(flake_dir),
            machine,
            False,
        )

    for group in add_groups:
        allow_member(
            groups_folder(flake_dir, secret.name),
            sops_groups_folder(flake_dir),
            group,
            False,
        )

    keys = collect_keys_for_path(secret)

    if key.pubkey not in keys:
        keys.add(key.pubkey)
        allow_member(
            users_folder(flake_dir, secret.name),
            sops_users_folder(flake_dir),
            key.username,
            False,
        )

    encrypt_file(secret / "secret", value, list(sorted(keys)))


def remove_secret(flake_dir: Path, secret: str) -> None:
    path = sops_secrets_folder(flake_dir) / secret
    if not path.exists():
        raise ClanError(f"Secret '{secret}' does not exist")
    shutil.rmtree(path)


def remove_command(args: argparse.Namespace) -> None:
    remove_secret(Path(args.flake), args.secret)


def add_secret_argument(parser: argparse.ArgumentParser) -> None:
    parser.add_argument("secret", help="the name of the secret", type=secret_name_type)


def machines_folder(flake_dir: Path, group: str) -> Path:
    return sops_secrets_folder(flake_dir) / group / "machines"


def users_folder(flake_dir: Path, group: str) -> Path:
    return sops_secrets_folder(flake_dir) / group / "users"


def groups_folder(flake_dir: Path, group: str) -> Path:
    return sops_secrets_folder(flake_dir) / group / "groups"


def list_directory(directory: Path) -> str:
    if not directory.exists():
        return f"{directory} does not exist"
    msg = f"\n{directory} contains:"
    for f in directory.iterdir():
        msg += f"\n  {f.name}"
    return msg


def allow_member(
    group_folder: Path, source_folder: Path, name: str, do_update_keys: bool = True
) -> None:
    source = source_folder / name
    if not source.exists():
        msg = f"{name} does not exist in {source_folder}: "
        msg += list_directory(source_folder)
        raise ClanError(msg)
    group_folder.mkdir(parents=True, exist_ok=True)
    user_target = group_folder / name
    if user_target.exists():
        if not user_target.is_symlink():
            raise ClanError(
                f"Cannot add user {name}. {user_target} exists but is not a symlink"
            )
        os.remove(user_target)

    user_target.symlink_to(os.path.relpath(source, user_target.parent))
    if do_update_keys:
        update_keys(
            group_folder.parent,
            list(sorted(collect_keys_for_path(group_folder.parent))),
        )


def disallow_member(group_folder: Path, name: str) -> None:
    target = group_folder / name
    if not target.exists():
        msg = f"{name} does not exist in group in {group_folder}: "
        msg += list_directory(group_folder)
        raise ClanError(msg)

    keys = collect_keys_for_path(group_folder.parent)

    if len(keys) < 2:
        raise ClanError(
            f"Cannot remove {name} from {group_folder.parent.name}. No keys left. Use 'clan secrets remove {name}' to remove the secret."
        )
    os.remove(target)

    if len(os.listdir(group_folder)) == 0:
        os.rmdir(group_folder)

    if len(os.listdir(group_folder.parent)) == 0:
        os.rmdir(group_folder.parent)

    update_keys(
        target.parent.parent, list(sorted(collect_keys_for_path(group_folder.parent)))
    )


def has_secret(flake_dir: Path, secret: str) -> bool:
    return (sops_secrets_folder(flake_dir) / secret / "secret").exists()


def list_secrets(flake_dir: Path) -> list[str]:
    path = sops_secrets_folder(flake_dir)

    def validate(name: str) -> bool:
        return VALID_SECRET_NAME.match(name) is not None and has_secret(flake_dir, name)

    return list_objects(path, validate)


def list_command(args: argparse.Namespace) -> None:
    lst = list_secrets(Path(args.flake))
    if len(lst) > 0:
        print("\n".join(lst))


def decrypt_secret(flake_dir: Path, secret: str) -> str:
    ensure_sops_key(flake_dir)
    secret_path = sops_secrets_folder(flake_dir) / secret / "secret"
    if not secret_path.exists():
        raise ClanError(f"Secret '{secret}' does not exist")
    return decrypt_file(secret_path)


def get_command(args: argparse.Namespace) -> None:
    print(decrypt_secret(Path(args.flake), args.secret), end="")


def set_command(args: argparse.Namespace) -> None:
    env_value = os.environ.get("SOPS_NIX_SECRET")
    secret_value: str | IO[str] | None = sys.stdin
    if args.edit:
        secret_value = None
    elif env_value:
        secret_value = env_value
    elif tty.is_interactive():
        secret_value = getpass.getpass(prompt="Paste your secret: ")
    encrypt_secret(
        Path(args.flake),
        sops_secrets_folder(Path(args.flake)) / args.secret,
        secret_value,
        args.user,
        args.machine,
        args.group,
    )


def rename_command(args: argparse.Namespace) -> None:
    old_path = sops_secrets_folder(Path(args.flake)) / args.secret
    new_path = sops_secrets_folder(Path(args.flake)) / args.new_name
    if not old_path.exists():
        raise ClanError(f"Secret '{args.secret}' does not exist")
    if new_path.exists():
        raise ClanError(f"Secret '{args.new_name}' already exists")
    os.rename(old_path, new_path)


def register_secrets_parser(subparser: argparse._SubParsersAction) -> None:
    parser_list = subparser.add_parser("list", help="list secrets")
    parser_list.set_defaults(func=list_command)

    parser_get = subparser.add_parser("get", help="get a secret")
    add_secret_argument(parser_get)
    parser_get.set_defaults(func=get_command)

    parser_set = subparser.add_parser("set", help="set a secret")
    add_secret_argument(parser_set)
    parser_set.add_argument(
        "--group",
        type=str,
        action="append",
        default=[],
        help="the group to import the secrets to (can be repeated)",
    )
    parser_set.add_argument(
        "--machine",
        type=str,
        action="append",
        default=[],
        help="the machine to import the secrets to (can be repeated)",
    )
    parser_set.add_argument(
        "--user",
        type=str,
        action="append",
        default=[],
        help="the user to import the secrets to (can be repeated)",
    )
    parser_set.add_argument(
        "-e",
        "--edit",
        action="store_true",
        default=False,
        help="edit the secret with $EDITOR instead of pasting it",
    )
    parser_set.set_defaults(func=set_command)

    parser_rename = subparser.add_parser("rename", help="rename a secret")
    add_secret_argument(parser_rename)
    parser_rename.add_argument("new_name", type=str, help="the new name of the secret")
    parser_rename.set_defaults(func=rename_command)

    parser_remove = subparser.add_parser("remove", help="remove a secret")
    add_secret_argument(parser_remove)
    parser_remove.set_defaults(func=remove_command)