//
//  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 (
	"errors"
	"os"
	"sort"
	"strings"
	"time"

	"github.com/naoina/toml"
)

type ConfigSwitchInputs []struct {
	Number  SwitchInputNum `toml:"number"`
	Server  string         `toml:"server"`
	Channel string         `toml:"channel"`
}

func (p ConfigSwitchInputs) Len() int           { return len(p) }
func (p ConfigSwitchInputs) Swap(i, j int)      { p[i], p[j] = p[j], p[i] }
func (p ConfigSwitchInputs) Less(i, j int) bool { return p[i].Number < p[j].Number }
func (p ConfigSwitchInputs) GetNumber(server, channel string) (SwitchInputNum, error) {
	for _, i := range p {
		if i.Server == server && i.Channel == channel {
			return i.Number, nil
		}
	}
	return SwitchInputNum(0), errors.New("no such server/channel")
}
func (p ConfigSwitchInputs) GetServerAndChannel(in SwitchInputNum) (string, string, error) {
	for _, i := range p {
		if i.Number == in {
			return i.Server, i.Channel, nil
		}
	}
	return "", "", errors.New("no such input")
}

type Config struct {
	Audioswitch struct {
		Device   string             `toml:"dev"`
		Baudrate Baudrate           `toml:"baud"`
		Timeout  Duration           `toml:"timeout"`
		Unit     SwitchUnitID       `toml:"unit"`
		Inputs   ConfigSwitchInputs `toml:"inputs"`
	}

	Servers map[string]struct {
		Device             string   `toml:"dev"`
		Baudrate           Baudrate `toml:"baud"`
		HeartbeatTimeout   Duration `toml:"heartbeat_timeout"`
		HeartbeatThreshold uint     `toml:"heartbeat_threshold"`
	}

	Timing struct {
		Settling struct {
			Awakening    Duration `toml:"awakening"`
			SelectServer Duration `toml:"select_server"`
			UpdateStates Duration `toml:"update_states"`
		}

		StaleStates struct {
			CheckInterval Duration `toml:"check_interval"`
			MaxAge        Duration `toml:"max_age"`
		}
	}

	Clients struct {
		Web struct {
			Address   string `toml:"addr"`
			StaticDir string `toml:"static_files"`
		}
		Telnet struct {
			Address string `toml:"addr"`
		}
	}
}

type Duration struct {
	time.Duration
}

func (d *Duration) UnmarshalTOML(data []byte) (err error) {
	ds := strings.Trim(string(data), "\"")
	d.Duration, err = time.ParseDuration(ds)
	if err == nil && d.Duration < 0 {
		err = errors.New("negative durations are not allowed")
	}
	return
}

func ReadConfig(configfile string) (conf *Config, err error) {
	conf = &Config{}

	var f *os.File
	if f, err = os.Open(configfile); err != nil {
		return
	}
	defer f.Close()

	decoder := toml.NewDecoder(f)
	if err = decoder.Decode(conf); err != nil {
		return
	}

	sort.Sort(conf.Audioswitch.Inputs)
	for i := 1; i < len(conf.Audioswitch.Inputs); i++ {
		if conf.Audioswitch.Inputs[i].Number == conf.Audioswitch.Inputs[i-1].Number {
			return nil, errors.New("audioswitch port assignments must be unique")
		}
	}

	return
}