package main

import (
	"git.wow.st/gmp/giowrap"

	"fmt"
	"image"
	"image/color"
	"log"
	"os"
	"runtime"
	"runtime/pprof"
	"sync"
	"time"

	"gioui.org/ui"
	"gioui.org/ui/app"
	"gioui.org/ui/f32"
	"gioui.org/ui/gesture"
	"gioui.org/ui/layout"
	"gioui.org/ui/measure"
	"gioui.org/ui/paint"
	"gioui.org/ui/pointer"
	"gioui.org/ui/text"

	"golang.org/x/image/font/gofont/goregular"
	"golang.org/x/image/font/sfnt"
)

var (
	FPS           int = 100
	frames        int64
	frametime     int64 // nanoseconds
	maxframetime  int64
	mux           sync.Mutex
	Profile       bool = true
	RecordMallocs bool = false
)

func NewButton(face text.Face, t string, c color.RGBA) giowrap.Clickable {
	lbl := giowrap.NewLabel(t, giowrap.Face(face), giowrap.Align(text.Middle))
	bg := giowrap.NewBackground(giowrap.Color(c), giowrap.Radius(ui.Dp(4)))
	return giowrap.AsClickable(bg(lbl))
}

func main() {
	go func() {
		ms := &runtime.MemStats{}
		var a1 uint64
		for {
			time.Sleep(time.Second * 3)
			mux.Lock()
			if frames == 0 {
				mux.Unlock()
				continue
			}
			runtime.ReadMemStats(ms)
			a1 = ms.Alloc
			runtime.GC()
			runtime.ReadMemStats(ms)
			log.Printf("Alloc: %d - %d = %d (%d per frame)", a1, ms.Alloc, a1-ms.Alloc, (a1-ms.Alloc)/(3*uint64(FPS)))
			log.Printf("Frametime: %d max Frametime: %d us\n", frametime/(frames*1000), maxframetime/1000)
			frames = 0
			frametime = 0
			maxframetime = 0
			mux.Unlock()
		}
	}()
	switch {
	case len(os.Args) < 2:
		fallthrough
	default:
		log.Fatal(`Usage:
hello [main1|main2|main3|main4]
`)
	case os.Args[1] == "main1":
		log.Print("main1()")
		go main1()
	case os.Args[1] == "main2":
		log.Print("main2()")
		go main2()
	case os.Args[1] == "main3":
		log.Print("main3()")
		go main3()
	case os.Args[1] == "main4":
		log.Print("main4()")
		go main4()
	}
	app.Main()
}

// Example with functional layout
func main1() {
	w := app.NewWindow()
	regular, err := sfnt.Parse(goregular.TTF)
	if err != nil {
		log.Fatal("Cannot parse font.")
	}
	ctx := giowrap.NewContext(w)
	t := time.NewTicker(time.Second / time.Duration(FPS))
	e1 := giowrap.NewEditor("text 1", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))
	e1.Focus()

	e2 := giowrap.NewEditor("text 2", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))

	f1 := giowrap.NewFlex(giowrap.Vertical)
	OuterInset := giowrap.NewInset(giowrap.Size(ui.Dp(10)))
	InnerInset := giowrap.NewInset(giowrap.Size(ui.Dp(10)))

	f2 := giowrap.NewFlex(giowrap.Horizontal)

	btn1 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
		"push1", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
	btn2 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
		"push2", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})

	profiled := false
	startTime := time.Now()

	page := OuterInset(
		f1(
			e1,
			giowrap.Flexible(0.33),
			InnerInset(e2),
			giowrap.Flexible(0.67),
			f2(
				InnerInset(btn1),
				giowrap.Flexible(0.50),
				InnerInset(btn2),
			),
		),
	)

	for {
		select {
		case <-t.C:
			w.Invalidate()
		case e := <-w.Events():
			mux.Lock()
			stime := time.Now()
			switch e := e.(type) {
			case app.DestroyEvent:
				return
			case app.UpdateEvent:
				profileNow := false
				var ms runtime.MemStats
				if Profile && time.Since(startTime) > time.Second*2 {
					startTime = time.Now()
					profileNow = true
				}
				if profileNow {
					if !profiled {
						prof(0)
					}
					runtime.ReadMemStats(&ms)
					if RecordMallocs {
						giowrap.RecordMallocs()
					}
				}
				giowrap.Mallocs("pre-reset")
				ctx.Reset(&e)
				giowrap.Mallocs("pre-layout")
				page.Layout(ctx)
				giowrap.Mallocs("post-layout")
				ctx.Update()
				giowrap.Mallocs("post-update")
				if btn1.Clicked(ctx) {
					log.Print("Clicked: " + e1.Text())
				}
				if btn2.Clicked(ctx) {
					log.Print("Clicked: " + e2.Text())
				}
				giowrap.Mallocs("post-clicked()")
				if profileNow {
					for _, i := range giowrap.AllMallocs {
						fmt.Printf("mallocs: %d (%s)\n", i.Value, i.Text)
					}
					giowrap.AllMallocs = nil
					mallocs := ms.Mallocs
					runtime.ReadMemStats(&ms)
					mallocs = ms.Mallocs - mallocs
					log.Printf("Mallocs = %d\n", mallocs)
					if !profiled {
						prof(1)
						profiled = true
					}
				}
			}
			dur := time.Since(stime).Nanoseconds()
			frames = frames + 1
			frametime = frametime + dur
			if dur > maxframetime {
				maxframetime = dur
			}
			mux.Unlock()
		}
	}
}

func prof(x int) {
	names := []string{"memprofile-1.pprof", "memprofile-2.pprof"}
	f1, err := os.Create(names[x])
	if err != nil {
		log.Fatal("could not create memory profile: ", err)
	}
	if err := pprof.WriteHeapProfile(f1); err != nil {
		log.Fatal("could not write memory profile: ", err)
	}
	f1.Close()
	log.Print("Memory profile written")
}

// Example showing use of WidgetCombinators in the main loop.
func main2() {
	w := app.NewWindow()
	regular, err := sfnt.Parse(goregular.TTF)
	if err != nil {
		log.Fatal("Cannot parse font.")
	}
	ctx := giowrap.NewContext(w)
	t := time.NewTicker(time.Second / time.Duration(FPS))
	e1 := giowrap.NewEditor("text 1", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))
	e1.Focus()

	e2 := giowrap.NewEditor("text 2", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))

	f1 := giowrap.NewFlex(giowrap.Vertical)
	OuterInset := giowrap.NewInset(giowrap.Size(ui.Dp(10)))
	InnerInset := giowrap.NewInset(giowrap.Size(ui.Dp(10)))

	f2 := giowrap.NewFlex(giowrap.Horizontal)

	btn1 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
		"push1", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
	btn2 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
		"push2", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})

	profiled := false
	startTime := time.Now()

	for {
		select {
		case <-t.C:
			w.Invalidate()
		case e := <-w.Events():
			mux.Lock()
			stime := time.Now()
			switch e := e.(type) {
			case app.DestroyEvent:
				return
			case app.UpdateEvent:
				profileNow := false
				var ms runtime.MemStats
				if Profile && time.Since(startTime) > time.Second*2 {
					startTime = time.Now()
					profileNow = true
				}
				if profileNow {
					if !profiled {
						prof(0)
					}
					runtime.ReadMemStats(&ms)
					if RecordMallocs {
						giowrap.RecordMallocs()
					}
				}
				giowrap.Mallocs("pre-reset")
				ctx.Reset(&e)
				giowrap.Mallocs("pre-layout")
				OuterInset(
					f1(
						e1,
						giowrap.Flexible(0.33),
						InnerInset(e2),
						giowrap.Flexible(0.67),
						f2(
							InnerInset(btn1),
							giowrap.Flexible(0.50),
							InnerInset(btn2),
						),
					),
				).Layout(ctx)
				giowrap.Mallocs("post-layout")
				ctx.Update()
				giowrap.Mallocs("post-update")
				if btn1.Clicked(ctx) {
					log.Print("Clicked: " + e1.Text())
				}
				if btn2.Clicked(ctx) {
					log.Print("Clicked: " + e2.Text())
				}
				giowrap.Mallocs("post-clicked()")
				if profileNow {
					for _, i := range giowrap.AllMallocs {
						fmt.Printf("mallocs: %d (%s)\n", i.Value, i.Text)
					}
					giowrap.AllMallocs = nil
					mallocs := ms.Mallocs
					runtime.ReadMemStats(&ms)
					mallocs = ms.Mallocs - mallocs
					log.Printf("Mallocs = %d\n", mallocs)
					if !profiled {
						prof(1)
						profiled = true
					}
				}
			}
			dur := time.Since(stime).Nanoseconds()
			frames = frames + 1
			frametime = frametime + dur
			if dur > maxframetime {
				maxframetime = dur
			}
			mux.Unlock()
		}
	}
}

// Example showing widget allocation within the main loop (causes unnecessary
// memory allocations)
func main3() {
	w := app.NewWindow()
	regular, err := sfnt.Parse(goregular.TTF)
	if err != nil {
		log.Fatal("Cannot parse font.")
	}
	ctx := giowrap.NewContext(w)
	t := time.NewTicker(time.Second / time.Duration(FPS))
	e1 := giowrap.NewEditor("text 1", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))
	e1.Focus()

	e2 := giowrap.NewEditor("text 2", giowrap.Face(ctx.Faces.For(regular, ui.Sp(24))))

	btn1 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
		"push1", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})
	btn2 := NewButton(ctx.Faces.For(regular, ui.Sp(24)),
		"push2", color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6})

	profiled := false
	startTime := time.Now()

	for {
		select {
		case <-t.C:
			w.Invalidate()
		case e := <-w.Events():
			stime := time.Now()
			switch e := e.(type) {
			case app.DestroyEvent:
				return
			case app.UpdateEvent:
				profileNow := false
				var ms runtime.MemStats
				if Profile && time.Since(startTime) > time.Second*2 {
					profileNow = true
					startTime = time.Now()
				}
				if profileNow {
					if !profiled {
						prof(0)
					}
					runtime.ReadMemStats(&ms)
					if RecordMallocs {
						giowrap.RecordMallocs()
					}
				}
				ctx.Reset(&e)
				giowrap.NewInset(giowrap.Size(ui.Dp(10)))(
					giowrap.NewFlex(giowrap.Vertical)(
						e1,
						//giowrap.Flexible(0.33),
						giowrap.NewInset(giowrap.Size(ui.Dp(10)))(e2),
						//giowrap.Flexible(0.67),
						giowrap.NewFlex(giowrap.Horizontal)(
							giowrap.NewInset(giowrap.Size(ui.Dp(10)))(btn1),
							//giowrap.Flexible(0.50),
							giowrap.NewInset(giowrap.Size(ui.Dp(10)))(btn2),
						),
					)).Layout(ctx)
				ctx.Update()
				if btn1.Clicked(ctx) {
					log.Print("Clicked: " + e1.Text())
				}
				if btn2.Clicked(ctx) {
					log.Print("Clicked: " + e2.Text())
				}
				if profileNow {
					for _, i := range giowrap.AllMallocs {
						fmt.Printf("mallocs: %d (%s)\n", i.Value, i.Text)
					}
					giowrap.AllMallocs = nil
					mallocs := ms.Mallocs
					runtime.ReadMemStats(&ms)
					mallocs = ms.Mallocs - mallocs
					log.Printf("Mallocs = %d\n", mallocs)
					if !profiled {
						prof(1)
						profiled = true
					}
				}
			}
			dur := time.Since(stime).Nanoseconds()
			mux.Lock()
			frames = frames + 1
			frametime = frametime + dur
			if dur > maxframetime {
				maxframetime = dur
			}
			mux.Unlock()
		}
	}
}

// Example using the base Gio API.
func main4() {
	w := app.NewWindow()
	q := w.Queue()
	ops := new(ui.Ops)
	var faces measure.Faces
	regular, err := sfnt.Parse(goregular.TTF)
	if err != nil {
		log.Fatal("Cannot parse font.")
	}
	t := time.NewTicker(time.Second / time.Duration(FPS))
	e1 := &text.Editor{
		Face:       faces.For(regular, ui.Sp(24)),
		SingleLine: true,
	}
	e1.Focus()
	e1.SetText("text 1")

	e2 := &text.Editor{
		Face:       faces.For(regular, ui.Sp(24)),
		SingleLine: true,
	}
	e2.Focus()
	e2.SetText("text 2")

	btn1 := &Button{
		Face:  faces.For(regular, ui.Sp(24)),
		Label: "push1",
	}
	btn2 := &Button{
		Face:  faces.For(regular, ui.Sp(24)),
		Label: "push2",
	}

	profiled := false
	startTime := time.Now()

	for {
		select {
		case <-t.C:
			w.Invalidate()
		case e := <-w.Events():
			stime := time.Now()
			switch e := e.(type) {
			case app.DestroyEvent:
				return
			case app.UpdateEvent:
				profileNow := false
				var ms runtime.MemStats
				if Profile && time.Since(startTime) > time.Second*2 {
					profileNow = true
					startTime = time.Now()
				}
				if profileNow {
					if !profiled {
						prof(0)
					}
					runtime.ReadMemStats(&ms)
				}
				c := &e.Config
				ops.Reset()
				faces.Reset(c)
				for ev, ok := btn1.Click.Next(q); ok; ev, ok = btn1.Click.Next(q) {
					if ev.Type == gesture.TypeClick {
						log.Print("Clicked: " + e1.Text())
					}
				}
				for ev, ok := btn2.Click.Next(q); ok; ev, ok = btn2.Click.Next(q) {
					if ev.Type == gesture.TypeClick {
						log.Print("Clicked: " + e2.Text())
					}
				}

				var dims layout.Dimensions
				cs := layout.RigidConstraints(e.Size)
				{
					f1 := layout.Flex{Axis: layout.Vertical}
					ins := layout.UniformInset(ui.Dp(10))
					f1.Init(ops, ins.Begin(c, ops, cs))
					c1 := f1.End(e1.Layout(c, q, ops, f1.Rigid()))
					{
						cs = f1.Flexible(0.33)
						ins := layout.UniformInset(ui.Dp(10))
						dims = ins.End(e2.Layout(c, q, ops, ins.Begin(c, ops, cs)))
					}
					c2 := f1.End(dims)
					{
						cs = f1.Flexible(0.67)
						f2 := layout.Flex{Axis: layout.Horizontal}
						f2.Init(ops, cs)

						c1 := f2.End(btn1.Layout(c, ops, f2.Rigid()))

						c2 := f2.End(btn2.Layout(c, ops, f2.Flexible(0.5)))

						dims = f2.Layout(c1, c2)
					}
					c3 := f1.End(dims)
					dims = ins.End(f1.Layout(c1, c2, c3))
				}
				w.Update(ops)
				if profileNow {
					mallocs := ms.Mallocs
					runtime.ReadMemStats(&ms)
					mallocs = ms.Mallocs - mallocs
					log.Printf("Mallocs = %d\n", mallocs)
					if !profiled {
						prof(1)
						profiled = true
					}
				}
			}
			dur := time.Since(stime).Nanoseconds()
			mux.Lock()
			frames = frames + 1
			frametime = frametime + dur
			if dur > maxframetime {
				maxframetime = dur
			}
			mux.Unlock()
		}
	}
}

func layoutRRect(c ui.Config, ops *ui.Ops, cs layout.Constraints) layout.Dimensions {
	r := float32(c.Px(ui.Dp(4)))
	sz := image.Point{X: cs.Width.Min, Y: cs.Height.Min}
	w, h := float32(sz.X), float32(sz.Y)
	giowrap.Rrect(ops, w, h, r, r, r, r)
	paint.ColorOp{Color: color.RGBA{A: 0xff, R: 0x3c, G: 0x98, B: 0xc6}}.Add(ops)
	paint.PaintOp{Rect: f32.Rectangle{Max: f32.Point{X: w, Y: h}}}.Add(ops)
	return layout.Dimensions{Size: sz}
}

type Button struct {
	Face  text.Face
	Label string
	Click gesture.Click
}

func (b *Button) Layout(c ui.Config, ops *ui.Ops, cs layout.Constraints) layout.Dimensions {
	ins := layout.UniformInset(ui.Dp(10))
	cs = ins.Begin(c, ops, cs)
	var dims layout.Dimensions
	st := layout.Stack{}
	st.Init(ops, cs)
	{
		cs = st.Rigid()
		l := text.Label{
			Face: b.Face,
			Text: b.Label,
		}
		ins := layout.UniformInset(ui.Dp(4))
		dims = ins.End(l.Layout(ops, ins.Begin(c, ops, cs)))
		pointer.RectAreaOp{image.Rect(0, 0, dims.Size.X, dims.Size.Y)}.Add(ops)
		b.Click.Add(ops)
	}
	c2 := st.End(dims)
	c1 := st.End(layoutRRect(c, ops, st.Expand()))
	dims = st.Layout(c1, c2)
	return ins.End(dims)
}