// Copyright 2018 Yuya Nishihara <yuya@tcha.org>

//

// This software may be used and distributed according to the terms of the

// GNU General Public License version 2 or any later version.

//! cHg extensions to command server client.

use std::ffi::OsStr;

use std::io;

use std::os::unix::ffi::OsStrExt;

use std::os::unix::io::AsRawFd;

use std::path::Path;

use tokio_hglib::protocol::{OneShotQuery, OneShotRequest};

use tokio_hglib::{Client, Connection};

use super::attachio::AttachIo;

use super::message::{self, Instruction};

use super::runcommand::ChgRunCommand;

use super::uihandler::SystemHandler;

pub trait ChgClientExt<C>

where

    C: Connection + AsRawFd,

{

    /// Attaches the client file descriptors to the server.

    fn attach_io<I, O, E>(self, stdin: I, stdout: O, stderr: E) -> AttachIo<C, I, O, E>

    where

        I: AsRawFd,

        O: AsRawFd,

        E: AsRawFd;

    /// Changes the working directory of the server.

    fn set_current_dir<P>(self, dir: P) -> OneShotRequest<C>

    where

        P: AsRef<Path>;

    /// Updates the environment variables of the server.

    fn set_env_vars_os<I, P>(self, vars: I) -> OneShotRequest<C>

    where

        I: IntoIterator<Item = (P, P)>,

        P: AsRef<OsStr>;

    /// Runs the specified Mercurial command with cHg extension.

    fn run_command_chg<I, P, H>(self, handler: H, args: I) -> ChgRunCommand<C, H>

    where

        I: IntoIterator<Item = P>,

        P: AsRef<OsStr>,

        H: SystemHandler;

    /// Validates if the server can run Mercurial commands with the expected

    /// configuration.

    ///

    /// The `args` should contain early command arguments such as `--config`

    /// and `-R`.

    ///

    /// Client-side environment must be sent prior to this request, by

    /// `set_current_dir()` and `set_env_vars_os()`.

    fn validate<I, P>(self, args: I) -> OneShotQuery<C, fn(Bytes) -> io::Result<Vec<Instruction>>>

    where

        I: IntoIterator<Item = P>,

        P: AsRef<OsStr>;

}

impl<C> ChgClientExt<C> for Client<C>

where

    C: Connection + AsRawFd,

{

    fn attach_io<I, O, E>(self, stdin: I, stdout: O, stderr: E) -> AttachIo<C, I, O, E>

    where

        I: AsRawFd,

        O: AsRawFd,

        E: AsRawFd,

    {

        AttachIo::with_client(self, stdin, stdout, Some(stderr))

    }

    fn set_current_dir<P>(self, dir: P) -> OneShotRequest<C>

    where

        P: AsRef<Path>,

    {

        OneShotRequest::start_with_args(self, b"chdir", dir.as_ref().as_os_str().as_bytes())

    }

    fn set_env_vars_os<I, P>(self, vars: I) -> OneShotRequest<C>

    where

        I: IntoIterator<Item = (P, P)>,

        P: AsRef<OsStr>,

    {

        OneShotRequest::start_with_args(self, b"setenv", message::pack_env_vars_os(vars))

    }

    fn run_command_chg<I, P, H>(self, handler: H, args: I) -> ChgRunCommand<C, H>

    where

        I: IntoIterator<Item = P>,

        P: AsRef<OsStr>,

        H: SystemHandler,

    {

        ChgRunCommand::with_client(self, handler, message::pack_args_os(args))

    }

    fn validate<I, P>(self, args: I) -> OneShotQuery<C, fn(Bytes) -> io::Result<Vec<Instruction>>>

    where

        I: IntoIterator<Item = P>,

        P: AsRef<OsStr>,

    {

        OneShotQuery::start_with_args(

            self,

            b"validate",

            message::pack_args_os(args),

            message::parse_instructions,

        )

    }

}