package game

import (
	"fmt"
	"image/color"
	"strings"

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

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

// TutorialScene är genomgången av grundmekaniken i fem sidor: målet och
// stationen, hur man läser en skylt (med resmålet markerat och resten
// nedtonat), kort/biljetter/spärrar, sällskapet och tåget, lägen och
// tangenter. ←/→ bläddrar, Esc går tillbaka.
type TutorialScene struct {
	back Scene
	page int
}

const tutorialPages = 5

// NewTutorialScene öppnar tutorialen.
func NewTutorialScene(back Scene) *TutorialScene { return &TutorialScene{back: back} }

func (s *TutorialScene) Update(g *Game) error {
	if backJustPressed() {
		g.SetScene(s.back)
		return nil
	}
	dx, _ := miniMoveXY()
	if confirmJustPressed() {
		dx = 1
	}
	if dx != 0 {
		s.page += dx
		if s.page >= tutorialPages {
			g.SetScene(s.back)
			return nil
		}
		if s.page < 0 {
			s.page = 0
		}
		g.Audio.Play(SoundConfirm, 0.4)
	}
	return nil
}

func (s *TutorialScene) Draw(g *Game, screen *ebiten.Image) {
	a := g.Assets
	screen.Fill(color.RGBA{24, 20, 37, 255})
	vector.DrawFilledRect(screen, 0, 0, ScreenW, 22, color.RGBA{38, 43, 68, 255}, false)
	key := fmt.Sprintf("tutorial.p%d", s.page+1)
	a.DrawBig(screen, a.T(key+".title"), 8, 5, colText)
	a.Draw(screen, fmt.Sprintf(a.T("tutorial.page"), s.page+1, tutorialPages), ScreenW-70, 8, colDim)
	y := 28
	for _, para := range strings.Split(a.T(key), "\n") {
		for _, l := range a.wrapLine(plainLine(para, colText), ScreenW-16) {
			a.drawLines(screen, []line{l}, 8, y)
			y += LineH
		}
		y += 3
	}
	switch s.page {
	case 0: // rutlegend med riktiga sprites
		x := 12
		for _, t := range []struct {
			tile level.Tile
			key  string
		}{{level.Sign, "tile.sign"}, {level.Gate, "tile.gate"}, {level.TicketMachine, "tile.machine"}, {level.Toilet, "tile.toilet"}, {level.Kiosk, "tile.kiosk"}, {level.Platform, "tile.platform"}} {
			var op ebiten.DrawImageOptions
			op.GeoM.Scale(2, 2)
			op.GeoM.Translate(float64(x), float64(y))
			screen.DrawImage(a.Tiles[t.tile], &op)
			a.Draw(screen, a.T(t.key), x, y+2*TileSize+2, colDim)
			x += 52
		}
	case 1: // exempelskylten: resmålet markerat, resten nedtonat
		sample := "14番線 山手線 渋谷方面 → 南東口 改札"
		body := append([]line{highlightLine(sample, "渋谷", colGood, colDim)}, a.wrapLine(line{{"→ ", colDim}, {a.T("tutorial.p2.sample"), colText}}, ScreenW-28)...)
		vector.DrawFilledRect(screen, 8, float32(y), ScreenW-16, float32(LineH*len(body)+8), colPanel, false)
		a.drawLines(screen, body, 14, y+4)
		y += LineH*len(body) + 12
		for _, l := range a.wrapLine(plainLine(a.T("tutorial.p2b"), colText), ScreenW-16) {
			a.drawLines(screen, []line{l}, 8, y)
			y += LineH
		}
	}
	a.Draw(screen, a.T("tutorial.hint"), 8, ScreenH-12, colDim)
}