package game

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

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

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

type menuEntry struct {
	id    string
	name  string
	dest  string
	stars string
}

// MenuScene listar banorna och låter spelaren välja.
type MenuScene struct {
	entries []menuEntry
	sel     int
	err     error
}

// NewMenuScene läser in banlistan.
func NewMenuScene(a *Assets) (*MenuScene, error) {
	ids, err := level.List(a.LevelsDir)
	if err != nil {
		return nil, err
	}
	m := &MenuScene{}
	for _, id := range ids {
		l, err := level.LoadFile(filepath.Join(a.LevelsDir, id+".json"))
		if err != nil {
			m.err = err
			continue
		}
		m.entries = append(m.entries, menuEntry{
			id:    id,
			name:  l.Name.Get(UILang) + "  " + l.Name.Get("ja"),
			dest:  l.Destination.Get("ja") + " " + l.Destination.Get("romaji"),
			stars: strings.Repeat("★", l.Difficulty) + strings.Repeat("☆", 5-l.Difficulty),
		})
	}
	return m, nil
}

func (m *MenuScene) Update(g *Game) error {
	if backJustPressed() {
		return ebiten.Termination
	}
	if wordsJustPressed() {
		g.SetScene(NewWordsScene(g.Assets, m))
		return nil
	}
	if n := len(m.entries); n > 0 {
		m.sel = (m.sel + menuMove() + n) % n
		if confirmJustPressed() {
			s, err := NewLevelScene(g.Assets, m.entries[m.sel].id, g.Know, g.seed())
			if err != nil {
				m.err = err
				return nil
			}
			g.SetScene(s)
		}
	}
	return nil
}

func (m *MenuScene) 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)
	a.DrawBig(screen, a.T("game.title"), 8, 5, colText)
	a.Draw(screen, a.T("menu.choose_level"), 8, 30, colDim)

	for i, e := range m.entries {
		y := 46 + i*14
		if i == m.sel {
			vector.DrawFilledRect(screen, 6, float32(y-2), ScreenW-12, 13, colBar, false)
		}
		a.Draw(screen, e.name, 12, y, colText)
		a.Draw(screen, "→ "+e.dest, 150, y, colKnown)
		a.Draw(screen, e.stars, ScreenW-62, y, colWarn)
	}
	if m.err != nil {
		a.Draw(screen, "FEL: "+m.err.Error(), 8, ScreenH-40, colBad)
	}
	a.Draw(screen, fmt.Sprintf("%s  Lv%d  %d %s  %s %d", a.T("hud.japanese"), g.Know.Level(), g.Know.Count(), a.T("hud.words"),
		a.T("words.points"), g.Know.Points), 8, ScreenH-38, colDim)
	a.Draw(screen, a.T("menu.hint"), 8, ScreenH-26, colDim)
	a.Draw(screen, fmt.Sprintf("%s (%s)", buildinfo.Version, buildinfo.Mode), 8, ScreenH-13, colDim)
}