//! ## FileTransfer
//!
//! `filetransfer` is the module which provides the trait file transfers must implement and the different file transfers

/*
*
*   Copyright (C) 2020 Christian Visintin - christian.visintin1997@gmail.com
*
* 	This file is part of "TermSCP"
*
*   TermSCP 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.
*
*   TermSCP 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 TermSCP.  If not, see <http://www.gnu.org/licenses/>.
*
*/

use std::path::{Path, PathBuf};
use std::fs::File;

use crate::fs::FsEntry;

// Transfers
pub mod sftp_transfer;

// Types
pub type ProgressCallback = dyn Fn(usize, usize);

/// ## FileTransferProtocol
///
/// This enum defines the different transfer protocol available in TermSCP

#[derive(std::cmp::PartialEq, std::fmt::Debug, std::clone::Clone)]
pub enum FileTransferProtocol {
    Sftp,
    Ftp,
}

/// ## FileTransferError
///
/// FileTransferError defines the possible errors available for a file transfer

pub enum FileTransferError {
    AuthenticationFailed,
    BadAddress,
    ConnectionError,
    DirStatFailed,
    FileCreateDenied,
    FileReadonly,
    IoErr(std::io::Error),
    NoSuchFileOrDirectory,
    ProtocolError,
    UninitializedSession,
    //UnknownError,
}

impl std::fmt::Display for FileTransferError {
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
        let err: String = match self {
            FileTransferError::AuthenticationFailed => String::from("Authentication failed: bad credentials"),
            FileTransferError::BadAddress => String::from("Bad address syntax"),
            FileTransferError::ConnectionError => String::from("Connection error"),
            FileTransferError::DirStatFailed => String::from("Could not stat directory"),
            FileTransferError::FileCreateDenied => String::from("Failed to create file"),
            FileTransferError::FileReadonly => String::from("File is readonly"),
            FileTransferError::IoErr(err) => format!("IO Error: {}", err),
            FileTransferError::NoSuchFileOrDirectory => String::from("No such file or directory"),
            FileTransferError::ProtocolError => String::from("Protocol error"),
            FileTransferError::UninitializedSession => String::from("Uninitialized session"),
            //FileTransferError::UnknownError => String::from("Unknown error"),
        };
        write!(f, "{}", err)
    }
}

/// ## FileTransfer
/// 
/// File transfer trait must be implemented by all the file transfers and defines the method used by a generic file transfer

pub trait FileTransfer {

    /// ### connect
    /// 
    /// Connect to the remote server

    fn connect(&mut self, address: String, port: u16, username: Option<String>, password: Option<String>) -> Result<(), FileTransferError>;

    /// ### disconnect
    /// 
    /// Disconnect from the remote server

    fn disconnect(&mut self) -> Result<(), FileTransferError>;

    /// ### is_connected
    /// 
    /// Indicates whether the client is connected to remote
    fn is_connected(&self) -> bool;

    /// ### pwd
    /// 
    /// Print working directory

    fn pwd(&self) -> Result<PathBuf, FileTransferError>;

    /// ### change_dir
    /// 
    /// Change working directory

    fn change_dir(&mut self, dir: &Path) -> Result<PathBuf, FileTransferError>;

    /// ### list_dir
    /// 
    /// List directory entries

    fn list_dir(&self, path: &Path) -> Result<Vec<FsEntry>, FileTransferError>;

    /// ### mkdir
    /// 
    /// Make directory
    fn mkdir(&self, dir: &Path) -> Result<(), FileTransferError>;

    /// ### remove
    /// 
    /// Remove a file or a directory
    fn remove(&self, file: &FsEntry) -> Result<(), FileTransferError>;

    /// ### rename
    /// 
    /// Rename file or a directory
    fn rename(&self, file: &FsEntry, dst: &Path) -> Result<(), FileTransferError>;

    /// ### send_file
    /// 
    /// Send file to remote
    /// File name is referred to the name of the file as it will be saved
    /// Data contains the file data
    fn send_file(&self, file_name: &Path, file: &mut File, prog_cb: Option<Box<ProgressCallback>>) -> Result<(), FileTransferError>;

    /// ### recv_file
    /// 
    /// Receive file from remote with provided name
    fn recv_file(&self, file_name: &Path, dest_file: &mut File, prog_cb: Option<Box<ProgressCallback>>) -> Result<(), FileTransferError>;

}