// Copyright (C) 2026 Doan Luu Duc Tai <doan@luuduct.ai>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

use crate::app::store::Store;
use anyhow::{Context, Result, ensure};
use std::fs::{File, OpenOptions};
use std::io::Write;
use std::net::{SocketAddr, TcpListener};
use std::os::unix::fs::OpenOptionsExt;
use std::path::Path;

pub(super) fn lock(directory: &Path) -> Result<File> {
    let file = OpenOptions::new()
        .read(true)
        .write(true)
        .create(true)
        .truncate(false)
        .mode(0o600)
        .open(directory.join("server.lock"))?;
    file.try_lock().context(
        "Chat is already running. Stop it before starting another server or resetting the owner.",
    )?;
    Ok(file)
}

pub(super) fn fingerprint(store: &Store) -> Result<()> {
    let certificate = store.owner()?.context("No owner identity is registered")?;
    writeln!(
        std::io::stdout().lock(),
        "{}",
        stack_chat_crypto::public_identity(&certificate)?
    )?;
    Ok(())
}

pub(super) fn reset(
    store: &mut Store,
    expected: &str,
    address: SocketAddr,
    proxy: bool,
) -> Result<()> {
    let _port = if proxy {
        None
    } else {
        ensure!(
            address.ip().is_loopback(),
            "Reset must use the local chat address"
        );
        Some(
            TcpListener::bind(address)
                .context("Stop the chat server before resetting its owner")?,
        )
    };
    store.reset_owner(expected)?;
    writeln!(
        std::io::stdout().lock(),
        "Owner registration and chat history cleared. Restart chat and use OWNER SETUP to create a new owner file. Existing backup archives were not changed."
    )?;
    Ok(())
}