package main

import (
	"context"
	"image/color"
	"log"
	"net"
	"os"
	"sync"

	"gioui.org/app"
	"gioui.org/layout"
	"gioui.org/op"
	"gioui.org/text"
	"gioui.org/unit"
	"gioui.org/widget"
	"gioui.org/widget/material"

	"xengineering.eu/soundbox-go/soundbox"
)

func main() {
	config, err := loadConfig()
	if err != nil {
		log.Fatal(err)
	}

	ui := NewUi(config)
	go func() {
		err := ui.Run()
		if err != nil {
			log.Fatal(err)
		}
		os.Exit(0)
	}()
	app.Main()
}

type State struct {
	sync.Mutex
	Config          Config
	Theme           *material.Theme
	IsPlaying       bool
	Title           string
	UrlSelector     widget.Enum
	PlayPauseButton widget.Clickable
	PlayerContext   context.Context
	PlayerCancel    context.CancelFunc
}

type Ui struct {
	Window *app.Window
	State  State
}

func NewUi(config Config) *Ui {
	ui := Ui{}

	ui.State.Config = config

	ui.State.IsPlaying = false

	ui.State.Theme = material.NewTheme()

	ui.Window = new(app.Window)
	ui.Window.Option(app.Title("soundbox"))

	ui.State.Title = "soundbox"

	return &ui
}

func (ui *Ui) Cleanup() {
	ui.State.Lock()
	defer ui.State.Unlock()

	if ui.State.PlayerCancel != nil {
		done := ui.State.PlayerContext.Done()
		ui.State.PlayerCancel()
		<-done
	}
}

func (ui *Ui) Run() error {
	defer ui.Cleanup()
	var ops op.Ops
	for {
		switch e := ui.Window.Event().(type) {
		case app.DestroyEvent:
			return e.Err
		case app.FrameEvent:
			gtx := app.NewContext(&ops, e)
			ui.HandleInputs(gtx)
			ui.Layout(gtx)
			e.Frame(gtx.Ops)
		}
	}
}

func (ui *Ui) HandleInputs(gtx layout.Context) {
	ui.State.Lock()
	defer ui.State.Unlock()

	if ui.State.PlayPauseButton.Clicked(gtx) {
		if ui.State.IsPlaying {
			ui.State.PlayerCancel()
		} else {
			if ui.State.UrlSelector.Value == "" {
				log.Println("A URL has to be selected.")
			} else {
				ui.State.PlayerContext, ui.State.PlayerCancel = context.WithCancel(context.Background())
				var targets []net.HardwareAddr
				for _, entry := range ui.State.Config.Soundboxes {
					if entry.Enabled {
						targets = append(targets, net.HardwareAddr(entry.Mac))
					}
				}
				go play(ui.State.PlayerContext, ui.State.UrlSelector.Value, targets, ui)
			}
		}
	}
}

func (ui *Ui) Layout(gtx layout.Context) layout.Dimensions {
	ui.State.Lock()
	defer ui.State.Unlock()

	inset := layout.UniformInset(unit.Dp(10))

	flex := layout.Flex{
		Axis:    layout.Vertical,
		Spacing: layout.SpaceEnd,
	}

	h1 := material.H1(ui.State.Theme, ui.State.Title)
	h1.Color = color.NRGBA{R: 88, G: 88, B: 88, A: 255}
	h1.Alignment = text.Middle

	var playPauseButtonText string
	if ui.State.IsPlaying {
		playPauseButtonText = "Stop"
	} else {
		playPauseButtonText = "Play"
	}
	button := material.Button(ui.State.Theme, &ui.State.PlayPauseButton, playPauseButtonText)

	entries := []layout.FlexChild{
		layout.Rigid(h1.Layout),
		layout.Rigid(layout.Spacer{Height: unit.Dp(25)}.Layout),
	}

	for _, url := range ui.State.Config.URLs {
		entries = append(entries, layout.Rigid(material.RadioButton(
			ui.State.Theme, &ui.State.UrlSelector,
			url.Url, url.Name).Layout))
	}

	entries = append(entries, layout.Rigid(layout.Spacer{Height: unit.Dp(25)}.Layout))
	entries = append(entries, layout.Rigid(button.Layout))

	return inset.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
		return flex.Layout(gtx, entries...)
	})
}

func play(ctx context.Context, url string, targets []net.HardwareAddr, ui *Ui) {
	setPlayingState := func(isPlaying bool) {
		ui.State.Lock()
		defer ui.Window.Invalidate()
		defer ui.State.Unlock()
		ui.State.IsPlaying = isPlaying
	}

	setPlayingState(true)
	defer setPlayingState(false)

	err := soundbox.StreamURLContext(ctx, url, targets)
	if err != nil {
		log.Println(err)
	}
}