//
//  rhimportd
//
//  The Radio Helsinki Rivendell Import Daemon
//
//
//  Copyright (C) 2015 Christian Pointner <equinox@helsinki.at>
//
//  This file is part of rhimportd.
//
//  rhimportd 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
//  any later version.
//
//  rhimportd 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 rhimportd. If not, see <http://www.gnu.org/licenses/>.
//

package main

import (
	"bufio"
	"fmt"
	"helsinki.at/rhimport"
	"net"
	"strings"
)

const (
	prompt = "rhimportd> "
)

type TelnetClient struct {
	conn    net.Conn
	scanner *bufio.Scanner
	writer  *bufio.Writer
}

func (c *TelnetClient) write_string(text string) (err error) {
	if _, err = c.writer.WriteString(text); err != nil {
		return
	}
	return c.writer.Flush()
}

func (c *TelnetClient) handle_command(cmd string) bool {
	if cmd == "quit" {
		return true
	} else if strings.HasPrefix(cmd, "help") {
		c.write_string(fmt.Sprintf("usage: tba...\n"))
	} else {
		c.write_string("unknown command\n")
	}
	return false
}

func (c *TelnetClient) handle() {
	defer c.conn.Close()

	if err := c.write_string(prompt); err != nil {
		return
	}
	for c.scanner.Scan() {
		if exit := c.handle_command(c.scanner.Text()); exit {
			return
		}

		if err := c.write_string(prompt); err != nil {
			return
		}
	}
	if err := c.scanner.Err(); err != nil {
		rhdl.Printf("telnet-ctrl(%s): read command error: %s", c.conn.RemoteAddr(), err)
	} else {
		rhdl.Printf("telnet-ctrl(%s): connection closed", c.conn.RemoteAddr())
	}
}

func newTelnetClient(conn net.Conn) (c *TelnetClient) {
	rhl.Println("telnet-ctrl: new client from:", conn.RemoteAddr())
	c = &TelnetClient{}
	c.conn = conn
	c.scanner = bufio.NewScanner(conn)
	c.writer = bufio.NewWriter(conn)
	return c
}

func StartControlTelnet(addr_s string, conf *rhimport.Config, rddb *rhimport.RdDb) {
	rhl.Println("telnet-ctrl: listening on", addr_s)

	server, err := net.Listen("tcp", addr_s)
	if err != nil {
		rhl.Println("telnet-ctrl: Listen() Error:", err)
		return
	}

	for {
		conn, err := server.Accept()
		if err != nil {
			rhl.Println("telnet-ctrl: Accept() Error:", err)
			return
		}

		c := newTelnetClient(conn)
		go c.handle()
	}
}