package game

import (
	"image/color"
	"time"

	"github.com/hajimehoshi/ebiten/v2"

	"github.com/atridad/BigFeelings/internal/hero"
	"github.com/atridad/BigFeelings/internal/status"
	"github.com/atridad/BigFeelings/internal/ui/hud"
)

const (
	ScreenWidth  = 960
	ScreenHeight = 540

	TargetTPS   = 60
	WindowTitle = "Big Feelings"
)

var (
	backgroundColor = color.NRGBA{R: 0, G: 0, B: 0, A: 255}
)

type controls struct {
	Left  bool
	Right bool
	Up    bool
	Down  bool
}

func readControls() controls {
	return controls{
		Left:  ebiten.IsKeyPressed(ebiten.KeyArrowLeft) || ebiten.IsKeyPressed(ebiten.KeyA),
		Right: ebiten.IsKeyPressed(ebiten.KeyArrowRight) || ebiten.IsKeyPressed(ebiten.KeyD),
		Up:    ebiten.IsKeyPressed(ebiten.KeyArrowUp) || ebiten.IsKeyPressed(ebiten.KeyW),
		Down:  ebiten.IsKeyPressed(ebiten.KeyArrowDown) || ebiten.IsKeyPressed(ebiten.KeyS),
	}
}

type Game struct {
	state *state
}

func New() *Game {
	return &Game{state: newState()}
}

func (g *Game) Update() error {
	g.state.update(readControls())
	return nil
}

func (g *Game) Draw(screen *ebiten.Image) {
	g.state.draw(screen)
}

func (g *Game) Layout(outsideWidth, outsideHeight int) (int, int) {
	return ScreenWidth, ScreenHeight
}

type state struct {
	hero     *hero.Hero
	status   *status.Manager
	hud      hud.Overlay
	bounds   hero.Bounds
	lastTick time.Time
}

func newState() *state {
	now := time.Now()
	return &state{
		hero: hero.New(hero.Config{
			StartX: ScreenWidth / 2,
			StartY: ScreenHeight / 2,
			Radius: 28,
			Speed:  180,
			Color:  color.NRGBA{R: 210, G: 220, B: 255, A: 255},
		}),
		status: status.NewManager([]status.Config{
			{Label: "Core", Base: 60, Color: color.NRGBA{R: 255, G: 208, B: 0, A: 255}},
			{Label: "Drive", Base: 45, Color: color.NRGBA{R: 0, G: 190, B: 255, A: 255}},
			{Label: "Flux", Base: 30, Color: color.NRGBA{R: 255, G: 92, B: 120, A: 255}},
		}),
		hud: hud.Overlay{
			X:     ScreenWidth - 220,
			Y:     20,
			Color: color.White,
		},
		bounds: hero.Bounds{
			Width:  ScreenWidth,
			Height: ScreenHeight,
		},
		lastTick: now,
	}
}

func (s *state) update(input controls) {
	now := time.Now()
	dt := now.Sub(s.lastTick).Seconds()
	s.lastTick = now

	s.hero.Update(hero.Input{
		Left:  input.Left,
		Right: input.Right,
		Up:    input.Up,
		Down:  input.Down,
	}, dt, s.bounds)

	s.status.Update()
}

func (s *state) draw(screen *ebiten.Image) {
	screen.Fill(backgroundColor)
	s.hero.Draw(screen)
	s.hud.Draw(screen, s.status.Meters())
}