//
//  rhctl
//
//  Copyright (C) 2009-2016 Christian Pointner <equinox@helsinki.at>
//
//  This file is part of rhctl.
//
//  rhctl 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.
//
//  rhctl 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 rhctl. If not, see <http://www.gnu.org/licenses/>.
//

package main

import (
	"fmt"
	"time"
)

type SwitchResult uint8

const (
	SwitchOK SwitchResult = iota
	SwitchError
)

func (c SwitchResult) String() string {
	switch c {
	case SwitchOK:
		return "OK"
	case SwitchError:
		return "error"
	}
	return "unknown"
}

type SwitchResponse struct {
	Result  SwitchResult
	Message string
}

type SwitchUpdateType uint8

const (
	SwitchAudio SwitchUpdateType = iota
	SwitchGPI
	SwitchOC
	SwitchRelay
	SwitchSilence
)

func (c SwitchUpdateType) String() string {
	switch c {
	case SwitchAudio:
		return "audio"
	case SwitchGPI:
		return "gpi"
	case SwitchOC:
		return "oc"
	case SwitchRelay:
		return "relay"
	case SwitchSilence:
		return "silence"
	}
	return "unknown"
}

type SwitchUpdate struct {
	Type SwitchUpdateType
	Data string
}

type AudioSwitch struct {
	port     *SerialPort
	timeout  time.Duration
	current  *SwitchCommand
	timer    *time.Timer
	unit     SwitchUnitID
	Commands chan *SwitchCommand
	Updates  chan SwitchUpdate
}

func (sw *AudioSwitch) handleData(data string) {
	if len(data) < 3 {
		rhl.Printf("Audioswitch: ignoring short line")
		return
	}

	rhdl.Printf("Audioswitch: got data: %q", data)
	switch data[0:3] {
	case "RRR":
		fallthrough
	case "EEE":
		if sw.current != nil {
			resp := SwitchResponse{Message: data}
			resp.Result = SwitchError
			if data[0] == 'R' {
				resp.Result = SwitchOK
			}
			sw.current.Response <- resp
			sw.current = nil
			sw.timer.Stop()
			sw.timer = nil
		} else {
			rhl.Printf("Audioswitch: ignoring unexpected response: %q", data)
		}
	case "S0L":
		sw.Updates <- SwitchUpdate{SwitchAudio, data}
	case "S0P":
		sw.Updates <- SwitchUpdate{SwitchGPI, data}
	case "S0O":
		sw.Updates <- SwitchUpdate{SwitchOC, data}
	case "S0R":
		sw.Updates <- SwitchUpdate{SwitchRelay, data}
	case "S0S":
		sw.Updates <- SwitchUpdate{SwitchSilence, data}
	default:
		rhl.Printf("Audioswitch: ignoring invalid data: %q", data)
	}
}

func (sw *AudioSwitch) Run() {
	stop := make(chan bool)
	sw.port.Run(stop)
	sw.current = nil
	sw.timer = nil

	rhdl.Printf("Audioswitch: handler running...")
	for {
		if sw.current != nil {
			select {
			case <-stop:
				return
			case <-sw.timer.C:
				resp := SwitchResponse{SwitchError, "EEE timeout"}
				sw.current.Response <- resp
				sw.current = nil
				sw.timer = nil
			case data := <-sw.port.rx:
				sw.handleData(data)
			}
		} else {
			select {
			case <-stop:
				return
			case cmd := <-sw.Commands:
				sw.current = cmd
				sw.port.tx <- cmd.Cmd.Generate(append(cmd.Args, sw.unit)...)
				sw.timer = time.NewTimer(sw.timeout)
			case data := <-sw.port.rx:
				sw.handleData(data)
			}
		}
	}
}

func SwitchInit(conf *Config) (sw *AudioSwitch, err error) {
	sw = &AudioSwitch{}
	sw.timeout = time.Second
	if conf.Audioswitch.Timeout.Duration > 0 {
		sw.timeout = conf.Audioswitch.Timeout.Duration
	}
	sw.unit = conf.Audioswitch.Unit
	sw.Commands = make(chan *SwitchCommand, 8)
	sw.Updates = make(chan SwitchUpdate, 32)

	if sw.port, err = SerialOpen(conf.Audioswitch.Device, conf.Audioswitch.Baudrate, ""); err != nil {
		err = fmt.Errorf("Audioswitch: error opening serial port: %s", err)
		return
	}
	return
}