//
//  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"
	"strings"
	"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 SwitchState struct {
	Audio [SwitchOutputNumMax]struct {
		Inputs  [SwitchInputNumMax]bool
		Silence bool
	}
	AudioInputsUpdated  time.Time
	AudioSilenceUpdated time.Time
	GPI                 [SwitchGPINumMax]bool
	GPIUpdated          time.Time
	Relay               [SwitchRelayNumMax]bool
	RelayUpdated        time.Time
	OC                  [SwitchOCNumMax]bool
	OCUpdated           time.Time
}

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

func (sw *AudioSwitch) updateStateAudio(data string) {
	if len(data) < int(4+2*SwitchInputNumMax) {
		rhl.Printf("Audioswitch: invalid audio status update (too short)")
		return
	}
	var out SwitchOutputNum
	if err := out.fromString(data[3:4]); err != nil {
		rhl.Printf("Audioswitch: invalid audio status update (%s)", err)
		return
	}
	ins := strings.Split(data[5:int(4+2*SwitchInputNumMax)], ",")
	if len(ins) != int(SwitchInputNumMax) {
		rhl.Printf("Audioswitch: invalid audio status update (wrong number of inputs)")
		return
	}
	for i := 0; i < int(SwitchInputNumMax); i++ {
		switch ins[i] {
		case "0":
			sw.state.Audio[out-1].Inputs[i] = false
		case "1":
			sw.state.Audio[out-1].Inputs[i] = true
		default:
			rhl.Printf("Audioswitch: invalid audio status update (state must be either '1' or '0' but is '%s')", ins[i])
		}
	}
	sw.state.AudioInputsUpdated = time.Now()
	sw.StateChanges <- sw.state
}

func (sw *AudioSwitch) updateStateGPI(data string) {
	if len(data) < 8 {
		rhl.Printf("Audioswitch: invalid gpi status update (too short)")
		return
	}
	if data[4] != 'A' {
		// 'SuP,ii,x'
		var in SwitchGPINum
		if err := in.fromString(data[4:6]); err != nil {
			rhl.Printf("Audioswitch: invalid gpi status update: %v", err)
			return
		}

		switch data[7] {
		case '0':
			sw.state.GPI[in] = false
		case '1':
			sw.state.GPI[in] = true
		default:
			rhl.Printf("Audioswitch: invalid gpi status update (state must be either '1' or '0' but is '%s')", data[7:8])
			return
		}
		sw.state.GPIUpdated = time.Now()
		sw.StateChanges <- sw.state
		return
	}

	// 'SuP,A,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x,x'
	if len(data) < int(5+2*SwitchGPINumMax) {
		rhl.Printf("Audioswitch: invalid gpi status update (too short)")
		return
	}

	ins := strings.Split(data[6:int(5+2*SwitchGPINumMax)], ",")
	if len(ins) != int(SwitchGPINumMax) {
		rhl.Printf("Audioswitch: invalid gpi status update (wrong number of inputs)")
		return
	}
	for i := 0; i < int(SwitchGPINumMax); i++ {
		switch ins[i] {
		case "0":
			sw.state.GPI[i] = false
		case "1":
			sw.state.GPI[i] = true
		default:
			rhl.Printf("Audioswitch: invalid gpi status update (state must be either '1' or '0' but is '%s')", ins[i])
		}
	}
	sw.state.GPIUpdated = time.Now()
	sw.StateChanges <- sw.state
}

func (sw *AudioSwitch) updateStateRelay(data string) {
	if len(data) < int(3+2*SwitchRelayNumMax) {
		rhl.Printf("Audioswitch: invalid relay status update (too short)")
		return
	}

	outs := strings.Split(data[4:int(3+2*SwitchRelayNumMax)], ",")
	if len(outs) != int(SwitchRelayNumMax) {
		rhl.Printf("Audioswitch: invalid relay status update (wrong number of outputs)")
		return
	}
	for i := 0; i < int(SwitchRelayNumMax); i++ {
		switch outs[i] {
		case "0":
			sw.state.Relay[i] = false
		case "1":
			sw.state.Relay[i] = true
		default:
			rhl.Printf("Audioswitch: invalid relay status update (state must be either '1' or '0' but is '%s')", outs[i])
		}
	}
	sw.state.RelayUpdated = time.Now()
	sw.StateChanges <- sw.state
}

func (sw *AudioSwitch) updateStateOC(data string) {
	if len(data) < int(3+2*SwitchOCNumMax) {
		rhl.Printf("Audioswitch: invalid oc status update (too short)")
		return
	}

	outs := strings.Split(data[4:int(3+2*SwitchOCNumMax)], ",")
	if len(outs) != int(SwitchOCNumMax) {
		rhl.Printf("Audioswitch: invalid oc status update (wrong number of outputs)")
		return
	}
	for i := 0; i < int(SwitchOCNumMax); i++ {
		switch outs[i] {
		case "0":
			sw.state.OC[i] = false
		case "1":
			sw.state.OC[i] = true
		default:
			rhl.Printf("Audioswitch: invalid oc status update (state must be either '1' or '0' but is '%s')", outs[i])
		}
	}
	sw.state.OCUpdated = time.Now()
	sw.StateChanges <- sw.state
}

func (sw *AudioSwitch) updateStateSilence(data string) {
	if len(data) < int(3+2*SwitchOutputNumMax) {
		rhl.Printf("Audioswitch: invalid silence status update (too short)")
		return
	}

	outs := strings.Split(data[4:int(3+2*SwitchOutputNumMax)], ",")
	if len(outs) != int(SwitchOutputNumMax) {
		rhl.Printf("Audioswitch: invalid silence status update (wrong number of outputs)")
		return
	}
	for i := 0; i < int(SwitchOutputNumMax); i++ {
		switch outs[i] {
		case "0":
			sw.state.Audio[i].Silence = false
		case "1":
			sw.state.Audio[i].Silence = true
		default:
			rhl.Printf("Audioswitch: invalid silence status update (state must be either '1' or '0' but is '%s')", outs[i])
		}
	}
	sw.state.AudioSilenceUpdated = time.Now()
	sw.StateChanges <- sw.state
}

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

	rhdl.Printf("Audioswitch: got data: %q", data)
	if data[0:3] == "RRR" || data[0:3] == "EEE" {
		if sw.current != nil {
			if sw.current.Response != 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)
		}
		return
	}

	if data[0] == 'S' && data[1] == ('0'+byte(sw.unit)) {
		switch data[2] {
		case 'L':
			sw.Updates <- SwitchUpdate{SwitchAudio, data}
			sw.updateStateAudio(data)
		case 'P':
			sw.Updates <- SwitchUpdate{SwitchGPI, data}
			sw.updateStateGPI(data)
		case 'R':
			sw.Updates <- SwitchUpdate{SwitchRelay, data}
			sw.updateStateRelay(data)
		case 'O':
			sw.Updates <- SwitchUpdate{SwitchOC, data}
			sw.updateStateOC(data)
		case 'S':
			sw.Updates <- SwitchUpdate{SwitchSilence, data}
			sw.updateStateSilence(data)
		}
		return
	}

	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:
				if sw.current.Response != nil {
					sw.current.Response <- fmt.Errorf("command timed out")
				}
				sw.current = nil
				sw.timer = nil
			case data := <-sw.port.rx:
				sw.handleData(data)
			}
		} else {
			select {
			case <-stop:
				return
			case cmd := <-sw.Commands:
				c, err := cmd.Cmd.Generate(append(cmd.Args, sw.unit)...)
				if err != nil {
					if cmd.Response != nil {
						cmd.Response <- err
					}
				} else {
					rhdl.Printf("sending '%s' to switch", c)
					sw.current = cmd
					sw.port.tx <- c
					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.Inputs = conf.Audioswitch.Inputs
	sw.StateChanges = make(chan SwitchState, 16)
	sw.Commands = make(chan *SwitchCommand, 16)
	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
}