package timer

import (
	"image"
	"sync"
	"time"

	"gioui.org/app"
	"gioui.org/io/event"
	"gioui.org/op"
	"gioui.org/op/clip"
	"gioui.org/op/paint"
	"gioui.org/text"
	"gioui.org/widget/material"
	"git.mstar.dev/mstar/timer/shared"
	"github.com/rs/zerolog/log"
)

type StateCountdown struct {
	initialSetupDone bool
	TargetTime       time.Time
	ops              op.Ops
}

func (s *StateCountdown) Run(globalState *shared.GlobalState, event event.Event) shared.NewState {
	if !s.initialSetupDone {
		s.initialSetup(globalState)
	}
	switch event := event.(type) {
	case app.FrameEvent:
		return s.handleFrameEvent(globalState, &event)
	case app.DestroyEvent:
		return s.handleQuitEvent()
	case app.WaylandViewEvent, app.X11ViewEvent:
		return shared.EmptyEvent()
	default:
		log.Debug().Any("event", event).Type("type", event).Msg("Unknown event")
		return shared.NewState{}
	}
}

func (s *StateCountdown) Exit(globalState *shared.GlobalState, wg *sync.WaitGroup) {
	wg.Done()
}

func (s *StateCountdown) initialSetup(globalState *shared.GlobalState) {
	s.initialSetupDone = true
	go func(window *app.Window) {
		t := time.NewTicker(time.Second)
		for range t.C {
			window.Invalidate()
		}
	}(globalState.Window)
}

func (s *StateCountdown) handleQuitEvent() shared.NewState {
	return shared.NewState{ExitCode: shared.ErrExitOk}
}

func (s *StateCountdown) handleFrameEvent(
	globalState *shared.GlobalState,
	frameEvent *app.FrameEvent,
) shared.NewState {
	gtx := app.NewContext(&s.ops, *frameEvent)
	paint.FillShape(
		gtx.Ops,
		globalState.Theme.Bg,
		clip.Rect(image.Rect(0, 0, gtx.Constraints.Max.X, gtx.Constraints.Max.Y)).Op(),
	)
	diff := frameEvent.Now.Sub(s.TargetTime)
	diff *= -1
	title := material.H1(
		globalState.Theme,
		diff.Round(time.Second).String(),
	)
	// //
	// // // Change the color of the label.
	title.Color = shared.TextColor
	// //
	// // // Change the position of the label.
	title.Alignment = text.Middle
	//
	// // Draw the label to the graphics context.
	title.Layout(gtx)
	// // Pass the drawing operations to the GPU.
	frameEvent.Frame(&s.ops)
	return shared.NewState{}
}