// package screens implements application screens (login, main menu, settings).
package screens

import (
	"fmt"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/dialog"
	"fyne.io/fyne/v2/layout"
	"fyne.io/fyne/v2/widget"

	"gitea.mrixs.me/Mrixs/MrixsCraft-launcher/internal/auth"
	"gitea.mrixs.me/Mrixs/MrixsCraft-launcher/internal/ui/components"
)

// Modpack represents a single server/modpack entry from the backend.
type Modpack struct {
	Slug string
	Name string
}

// MainScreen builds the primary launcher window content.
func MainScreen(
	w fyne.Window,
	client *auth.Client,
	session *auth.Session,
	serverList []Modpack,
	onPlay func(),
	onSettings func(),
) fyne.CanvasObject {

	// ── Sidebar (Left) ──────────────────────────────────────
	serverLabels := make([]*widget.Label, len(serverList))
	serverContainer := container.NewVBox()

	for i, sp := range serverList {
		label := widget.NewLabel(sp.Name)
		serverLabels[i] = label
		index := i
		card := components.ServerCard(sp.Name, index == 0, func() {
			for j, l := range serverLabels {
				l.TextStyle.Bold = (j == index)
				l.Refresh()
			}
		})
		serverContainer.Add(card)
	}

	sidebar := container.NewVScroll(serverContainer)

	// ── Center (background + info) ──────────────────────────
	bg := widget.NewRichTextFromMarkdown(
		"# Welcome to MrixsCraft\n\n" +
			"Select a server from the left panel and press **PLAY**.\n\n" +
			"---\n\n" +
			"*Version: dev*",
	)
	center := container.NewMax(widget.NewCard("", "", bg))

	// ── Bottom bar ──────────────────────────────────────────
	avatar := components.AvatarImage()

	displayName := "Not logged in"
	if session != nil && session.Username != "" {
		displayName = session.Username
	}
	usernameLabel := widget.NewLabel(displayName)

	logoutBtn := components.LogoutButton(func() {
		dialog.ShowConfirm(
			"Logout",
			"Are you sure you want to log out?",
			func(confirmed bool) {
				if confirmed {
					_ = auth.Delete()
					w.Close()
				}
			},
			w,
		)
	})

	bottomLeft := container.NewHBox(
		avatar,
		usernameLabel,
		layout.NewSpacer(),
		logoutBtn,
	)

	progress := components.NewProgressBar()

	playBtn := components.PlayButton(onPlay)
	settingsBtn := components.SettingsButton(onSettings)

	bottomRight := container.NewHBox(
		settingsBtn,
		widget.NewSeparator(),
		playBtn,
	)

	bottomCenter := container.NewMax(progress)

	bottom := container.NewBorder(
		nil, nil,
		bottomLeft,
		bottomRight,
		bottomCenter,
	)

	// ── Assemble ────────────────────────────────────────────
	return container.NewBorder(
		nil,
		bottom,
		sidebar,
		nil,
		center,
	)
}

// LoginScreen builds a modal login form.
func LoginScreen(w fyne.Window, client *auth.Client, onLogin func(*auth.Session)) {
	username := widget.NewEntry()
	username.SetPlaceHolder("Username or email")

	password := widget.NewPasswordEntry()
	password.SetPlaceHolder("Password")

	form := widget.NewForm(
		widget.NewFormItem("Username", username),
		widget.NewFormItem("Password", password),
	)

	dialog.ShowCustomConfirm(
		"Login — MrixsCraft",
		"Login",
		"Cancel",
		form,
		func(confirmed bool) {
			if !confirmed {
				return
			}
			sess, err := client.Authenticate(username.Text, password.Text)
			if err != nil {
				dialog.ShowError(err, w)
				return
			}
			if err := sess.Save(); err != nil {
				dialog.ShowError(err, w)
				return
			}
			onLogin(sess)
		},
		w,
	)
}

// SettingsScreen builds the settings modal.
func SettingsScreen(w fyne.Window, onSave func(memoryMB int, extraArgs string)) {
	memorySlider := widget.NewSlider(1024, 16384)
	memorySlider.Step = 512
	memorySlider.Value = 4096

	memLabel := widget.NewLabel("4096 MB")
	memorySlider.OnChanged = func(v float64) {
		memLabel.SetText(fmt.Sprintf("%.0f MB", v))
	}

	extraArgs := widget.NewMultiLineEntry()
	extraArgs.SetPlaceHolder("e.g. -XX:+UseG1GC -XX:MaxGCPauseMillis=50")

	content := container.NewVBox(
		widget.NewLabelWithStyle("Memory (RAM)", fyne.TextAlignLeading, fyne.TextStyle{Bold: true}),
		memLabel,
		memorySlider,
		widget.NewSeparator(),
		widget.NewLabelWithStyle("Extra JVM arguments", fyne.TextAlignLeading, fyne.TextStyle{}),
		extraArgs,
	)

	dialog.ShowCustomConfirm(
		"Settings",
		"Save",
		"Cancel",
		content,
		func(confirmed bool) {
			if confirmed {
				onSave(int(memorySlider.Value), extraArgs.Text)
			}
		},
		w,
	)
}