//
//  rhlibrary
//
//  The Radio Helsinki Rivendell Library
//
//
//  Copyright (C) 2016 Christian Pointner <equinox@helsinki.at>
//
//  This file is part of rhlibrary.
//
//  rhlibrary 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.
//
//  rhlibrary 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 rhlibrary. If not, see <http://www.gnu.org/licenses/>.
//

package player

import (
	"fmt"
	"github.com/spreadspace/go-gstreamer"
	"path"
)

func init() {
	gst.Init(nil)
}

type Player struct {
	pipe     *gst.Element
	bus      *gst.Bus
	basepath string
}

func (p *Player) onMessage(bus *gst.Bus, msg *gst.Message) {
	switch msg.GetType() {
	case gst.MESSAGE_EOS:
		fmt.Printf("GStreamer Pipeline: EOS reached!\n")
		p.pipe.SetState(gst.STATE_NULL)
	case gst.MESSAGE_WARNING:
		warn, _ := msg.ParseWarning()
		fmt.Printf("GStreamer Pipeline Warning: %s\n", warn)
	case gst.MESSAGE_ERROR:
		p.pipe.SetState(gst.STATE_NULL)
		err, _ := msg.ParseError()
		fmt.Printf("GStreamer Pipeline Error: %s\n", err)
	case gst.MESSAGE_ASYNC_DONE:
		len, ok := p.pipe.QueryDuration(gst.FORMAT_TIME)
		if ok {
			fmt.Printf("GStreamer Pipeline: loaded file has length: %d.%d s\n", len/1000000000, len%1000000000)
		} else {
			fmt.Printf("GStreamer Pipeline Error: unable to query duration of file\n")
		}
	case gst.MESSAGE_STATE_CHANGED:
	default:
		fmt.Printf("GStreamer Message: unknown type '%s'\n", msg.GetTypeName())
	}
}

func (p *Player) Play(cart, cut uint) (err error) {
	filename := path.Join(p.basepath, fmt.Sprintf("%06d_%03d.wav", cart, cut))
	p.pipe.SetProperty("uri", "file://"+filename)
	p.pipe.SetState(gst.STATE_PLAYING)
	return
}

func NewPlayer(basepath string) (p *Player, err error) {
	p = &Player{}
	p.basepath = path.Clean(basepath)

	if p.pipe, err = gst.ElementFactoryMake("playbin", "autoplay"); err != nil {
		return
	}
	if p.bus, err = p.pipe.GetBus(); err != nil {
		return
	}

	p.bus.AddSignalWatch()
	p.bus.Connect("message", func(bus *gst.Bus, msg *gst.Message) { p.onMessage(bus, msg) })

	return
}