package game

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

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

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

// EndingScene är storyns slut: sällskapet flyger hem, resan summeras och
// eftertexterna rullar. Enter går vidare mellan delarna, Esc hoppar till
// bankartan.
type EndingScene struct {
	t     float64 // sekunder i aktuell del
	phase int     // 0 flyget, 1 summeringen, 2 eftertexterna
	lines []string
}

const (
	endingFlightSec  = 7.0  // flyget innan summeringen kommer av sig själv
	endingCreditsPxS = 14.0 // eftertexternas rullhastighet
)

// NewEndingScene startar hemresan.
func NewEndingScene(g *Game) *EndingScene {
	return &EndingScene{lines: strings.Split(g.Assets.T("ending.credits"), "\n")}
}

func (e *EndingScene) Update(g *Game) error {
	e.t += dt
	switch {
	case backJustPressed():
		g.SetScene(NewMapScene(g))
		return nil
	case confirmJustPressed():
		e.phase++
		e.t = 0
	}
	if e.phase == 0 && e.t > endingFlightSec {
		e.phase, e.t = 1, 0
	}
	if e.phase == 2 && e.t*endingCreditsPxS > float64(len(e.lines)*LineH+ScreenH) {
		e.phase++ // eftertexterna har rullat förbi
	}
	if e.phase > 2 {
		g.SetScene(NewMapScene(g))
	}
	return nil
}

func (e *EndingScene) Draw(g *Game, screen *ebiten.Image) {
	a := g.Assets
	e.drawSky(screen)
	switch e.phase {
	case 0:
		e.drawFlight(g, screen)
		a.DrawBig(screen, a.T("ending.title"), 24, 20, colText)
		a.Draw(screen, a.T("ending.sub"), 24, 44, colDim)
	case 1:
		e.drawSummary(g, screen)
	default:
		e.drawCredits(g, screen)
	}
	a.Draw(screen, a.T("ending.hint"), 8, ScreenH-12, colDim)
}

// drawSky är en skymningshimmel i band, från mörkblått upptill till orange
// vid horisonten, med långsamt drivande moln.
func (e *EndingScene) drawSky(screen *ebiten.Image) {
	top, bottom := [3]float64{30, 32, 80}, [3]float64{230, 120, 70}
	const bands = 12
	for i := 0; i < bands; i++ {
		f := float64(i) / float64(bands-1)
		col := color.RGBA{uint8(top[0] + (bottom[0]-top[0])*f), uint8(top[1] + (bottom[1]-top[1])*f), uint8(top[2] + (bottom[2]-top[2])*f), 255}
		vector.DrawFilledRect(screen, 0, float32(i*ScreenH/bands), ScreenW, float32(ScreenH/bands+1), col, false)
	}
	cloud := color.RGBA{250, 220, 200, 120}
	for i := 0; i < 5; i++ {
		x := math.Mod(float64(i)*73+e.t*(4+float64(i)), ScreenW+60) - 30
		y := float64(40 + i*22)
		vector.DrawFilledRect(screen, float32(x), float32(y), 28, 6, cloud, false)
		vector.DrawFilledRect(screen, float32(x+6), float32(y-4), 14, 5, cloud, false)
	}
	vector.DrawFilledRect(screen, 0, ScreenH-20, ScreenW, 20, color.RGBA{24, 20, 37, 255}, false) // marken
}

// drawFlight: planet lyfter åt höger medan sällskapet vinkar på marken.
func (e *EndingScene) drawFlight(g *Game, screen *ebiten.Image) {
	a := g.Assets
	f := min(1, e.t/endingFlightSec)
	px := -40 + f*(ScreenW+80)
	py := 120 - f*80 + 3*math.Sin(e.t*2)
	var op ebiten.DrawImageOptions
	op.GeoM.Scale(2, 2)
	op.GeoM.Translate(px, py)
	screen.DrawImage(a.Plane, &op)
	for i := range memberTints {
		var o ebiten.DrawImageOptions
		t := memberTints[i]
		o.ColorScale.Scale(t[0], t[1], t[2], 1)
		o.GeoM.Translate(float64(ScreenW/2-50+i*20), ScreenH-20-TileSize+math.Abs(2*math.Sin(e.t*3+float64(i))))
		screen.DrawImage(a.PlayerFrame(sim.Up, true, e.t+float64(i)*0.3), &o)
	}
}

// drawSummary är resan i siffror: banor, stjärnor, poäng, ord och souvenirer.
func (e *EndingScene) drawSummary(g *Game, screen *ebiten.Image) {
	a := g.Assets
	p := g.Progress
	vector.DrawFilledRect(screen, 16, 14, ScreenW-32, ScreenH-40, colPanel, false)
	vector.DrawFilledRect(screen, 16, 14, ScreenW-32, 2, colGood, false)
	a.DrawBig(screen, a.T("ending.summary"), 24, 20, colGood)
	levels, cleared, score := 0, 0, 0
	for _, l := range g.Levels {
		if l.IsLeg() {
			continue
		}
		levels++
		if r := p.Levels[l.ID]; r != nil && r.Cleared {
			cleared++
			score += r.Score
		}
	}
	y := 44
	rows := []string{
		fmt.Sprintf("%s: %d/%d", a.T("ending.levels"), cleared, levels),
		fmt.Sprintf("%s: %d/%d", a.T("ending.stars"), p.TotalStars(), 3*levels),
		fmt.Sprintf("%s: %d", a.T("ending.score"), score),
		fmt.Sprintf("%s: %d", a.T("ending.words"), g.Know.Count()),
	}
	for _, r := range rows {
		a.Draw(screen, r, 24, y, colText)
		y += LineH
	}
	var items []string
	for id := range p.Items {
		if it := g.Catalog.Item(id); it != nil {
			items = append(items, it.Name.Get(UILang))
		}
	}
	sort.Strings(items)
	souvenirs := a.T("ending.none")
	if len(items) > 0 {
		souvenirs = strings.Join(items, ", ")
	}
	for _, l := range a.wrapLine(plainLine(a.T("ending.items")+": "+souvenirs, colKnown), ScreenW-48) {
		a.drawLines(screen, []line{l}, 24, y)
		y += LineH
	}
	y += 4
	for _, l := range a.wrapLine(plainLine(a.T("ending.story_done"), colWarn), ScreenW-48) {
		a.drawLines(screen, []line{l}, 24, y)
		y += LineH
	}
}

// drawCredits rullar eftertexterna nerifrån och upp.
func (e *EndingScene) drawCredits(g *Game, screen *ebiten.Image) {
	a := g.Assets
	y0 := ScreenH - int(e.t*endingCreditsPxS)
	for i, l := range e.lines {
		y := y0 + i*LineH
		if y < -LineH || y > ScreenH {
			continue
		}
		col := colDim
		if i == 0 || (i > 0 && e.lines[i-1] == "" && i+1 < len(e.lines) && e.lines[i+1] != "") {
			col = colText // rubriker
		}
		a.Draw(screen, l, (ScreenW-a.Width(l))/2, y, col)
	}
}