package game

import (
	"fmt"
	"image/color"
	"math"

	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/vector"

	"gitea.brasse-pc.eu/brasse/metro-puzzle-jp/internal/buildinfo"
)

// TitleScene är titelskärmen: premissen i text och menyn Fortsätt/Starta,
// Tutorial, Inställningar, Avsluta (Enter två gånger).
type TitleScene struct {
	sel     int
	t       float64
	confirm bool // Avsluta valt en gång
}

// NewTitleScene öppnar titelskärmen.
func NewTitleScene() *TitleScene { return &TitleScene{} }

const titleItems = 4

func (s *TitleScene) Update(g *Game) error {
	s.t += dt
	if mv := menuMove(); mv != 0 {
		s.sel = (s.sel + mv + titleItems) % titleItems
		s.confirm = false
	}
	if backJustPressed() {
		s.confirm = false
	}
	if !confirmJustPressed() {
		return nil
	}
	g.Audio.Play(SoundConfirm, 0.6)
	switch s.sel {
	case 0:
		g.SetScene(NewMapScene(g))
	case 1:
		g.SetScene(NewTutorialScene(s))
	case 2:
		g.SetScene(NewSettingsScene(s))
	case 3:
		if s.confirm {
			return ebiten.Termination
		}
		s.confirm = true
	}
	return nil
}

func (s *TitleScene) Draw(g *Game, screen *ebiten.Image) {
	a := g.Assets
	screen.Fill(color.RGBA{24, 20, 37, 255})
	// Räls längs nederkanten med ett tåg som rullar förbi.
	railY := ScreenH - 28
	for x := 0; x < ScreenW; x += TileSize {
		var op ebiten.DrawImageOptions
		op.GeoM.Translate(float64(x), float64(railY))
		screen.DrawImage(a.Rails, &op)
	}
	tx := math.Mod(s.t*40, float64(ScreenW+6*TileSize)) - 3*TileSize
	for i := 0; i < 3; i++ {
		var op ebiten.DrawImageOptions
		op.GeoM.Translate(tx+float64(i*TileSize), float64(railY-TileSize+4))
		screen.DrawImage(a.Train, &op)
	}
	a.DrawBig(screen, a.T("game.title"), 16, 8, colKnown)
	ver := fmt.Sprintf("%s (%s)", buildinfo.Version, buildinfo.Mode)
	a.Draw(screen, ver, ScreenW-8-a.Width(ver), 10, colDim)
	y := 30
	for _, l := range a.wrapLine(plainLine(a.T("title.premise"), colText), ScreenW-32) {
		a.drawLines(screen, []line{l}, 16, y)
		y += LineH
	}
	start := a.T("menu.continue")
	if g.Progress.TotalStars() == 0 && len(g.Progress.Levels) == 0 {
		start = a.T("menu.start")
	}
	items := [titleItems]string{start, a.T("title.tutorial"), a.T("menu.settings"), a.T("menu.quit")}
	y += 6
	for i, it := range items {
		col := colText
		if i == s.sel {
			vector.DrawFilledRect(screen, 12, float32(y-2), 130, LineH, colBar, false)
			col = colKnown
			a.Draw(screen, "▶", 14, y, colKnown)
		}
		a.Draw(screen, it, 26, y, col)
		y += LineH
	}
	if s.confirm {
		a.Draw(screen, a.T("title.quit_confirm"), 16, y+2, colWarn)
	}
	a.Draw(screen, a.T("title.hint"), 8, ScreenH-12, colDim)
}

// LangScene visas första gången spelet startar: välj språk.
type LangScene struct{ sel int }

var langChoices = []string{"sv", "en"}

func (s *LangScene) Update(g *Game) error {
	if mv := menuMove(); mv != 0 {
		s.sel = (s.sel + mv + len(langChoices)) % len(langChoices)
	}
	if confirmJustPressed() {
		g.State.Settings.Lang = langChoices[s.sel]
		g.applySettings()
		g.Save()
		g.Audio.Play(SoundConfirm, 0.6)
		g.SetScene(NewTitleScene())
	}
	return nil
}

func (s *LangScene) Draw(g *Game, screen *ebiten.Image) {
	a := g.Assets
	screen.Fill(color.RGBA{24, 20, 37, 255})
	a.DrawBig(screen, a.T("game.title"), 16, 10, colKnown)
	a.Draw(screen, "Välj språk  /  Choose language", 16, 50, colText)
	y := 72
	for i, l := range langChoices {
		col := colText
		if i == s.sel {
			vector.DrawFilledRect(screen, 12, float32(y-2), 130, LineH+2, colBar, false)
			col = colKnown
			a.Draw(screen, "▶", 14, y, colKnown)
		}
		a.Draw(screen, a.T("lang."+l), 26, y, col)
		y += LineH + 1
	}
	a.Draw(screen, "Pilar + Enter  /  Arrows + Enter", 16, y+8, colDim)
}

// PauseScene är pausmenyn i en bana (Esc): Fortsätt, Lämna banan,
// Inställningar, Avsluta spelet (Enter två gånger). Esc igen fortsätter.
type PauseScene struct {
	from    *LevelScene
	sel     int
	confirm bool
}

const pauseItems = 4

// NewPauseScene pausar banan.
func NewPauseScene(from *LevelScene) *PauseScene { return &PauseScene{from: from} }

func (s *PauseScene) Update(g *Game) error {
	if backJustPressed() {
		g.SetScene(s.from)
		return nil
	}
	if mv := menuMove(); mv != 0 {
		s.sel = (s.sel + mv + pauseItems) % pauseItems
		s.confirm = false
	}
	if !confirmJustPressed() {
		return nil
	}
	g.Audio.Play(SoundConfirm, 0.6)
	switch s.sel {
	case 0:
		g.SetScene(s.from)
	case 1:
		if s.from.endless {
			g.endEndless()
		}
		g.SetScene(NewMapScene(g))
	case 2:
		g.SetScene(NewSettingsScene(s))
	case 3:
		if s.confirm {
			return ebiten.Termination
		}
		s.confirm = true
	}
	return nil
}

func (s *PauseScene) Draw(g *Game, screen *ebiten.Image) {
	s.from.Draw(g, screen)
	a := g.Assets
	vector.DrawFilledRect(screen, 0, 0, ScreenW, ScreenH, color.RGBA{0, 0, 0, 120}, false)
	vector.DrawFilledRect(screen, 40, 40, ScreenW-80, 104, colPanel, false)
	vector.DrawFilledRect(screen, 40, 40, ScreenW-80, 2, colWarn, false)
	a.DrawBig(screen, a.T("pause.title"), 48, 46, colText)
	items := [pauseItems]string{a.T("pause.resume"), a.T("pause.leave"), a.T("menu.settings"), a.T("pause.quit")}
	y := 68
	for i, it := range items {
		col := colText
		if i == s.sel {
			vector.DrawFilledRect(screen, 44, float32(y-2), ScreenW-88, LineH+2, colBar, false)
			col = colKnown
		}
		a.Draw(screen, it, 50, y, col)
		y += LineH + 2
	}
	msg := a.T("pause.hint")
	if s.confirm {
		msg = a.T("pause.quit_confirm")
	}
	for _, l := range a.wrapLine(plainLine(msg, colDim), ScreenW-96) {
		a.drawLines(screen, []line{l}, 48, y+2)
		y += LineH
	}
}