package ui

import (
	"gioui.org/layout"
	"gioui.org/unit"
	"gioui.org/widget"
	"gioui.org/widget/material"

	"git.wxccs.org/iceking2nd/winauth-go/internal/i18n"
)

// preferencesDialog edits the persistent UI prefs: UI language and
// theme. Auto-lock and minimize-to-tray live in their own bucket and
// will appear here later.
type preferencesDialog struct {
	lang  string
	theme themeMode

	// Theme selection — three "radio" buttons.
	themeSystemBt widget.Clickable
	themeLightBt  widget.Clickable
	themeDarkBt   widget.Clickable

	// Language selection — one button per supported locale. Cheap
	// substitute for a dropdown until Gio gains a native one.
	langEnBt   widget.Clickable
	langZhCNBt widget.Clickable
	langDeBt   widget.Clickable

	okBt     widget.Clickable
	cancelBt widget.Clickable
}

// preferencesResult is what Layout's callback receives. cancel skips
// any persistence.
type preferencesResult struct {
	cancel   bool
	language string
	theme    themeMode
}

// supportedLanguages is the closed set the prefs dialog exposes. Keep
// in sync with internal/i18n/locales/*.toml.
var supportedLanguages = []struct {
	tag   string
	label string
}{
	{"en", "English"},
	{"zh-CN", "中文 (简体)"},
	{"de", "Deutsch"},
}

func newPreferencesDialog(currentLang string, currentTheme themeMode) *preferencesDialog {
	if currentLang == "" {
		currentLang = "en"
	}
	if currentTheme == "" {
		currentTheme = themeSystem
	}
	return &preferencesDialog{lang: currentLang, theme: currentTheme}
}

func (d *preferencesDialog) Layout(
	gtx layout.Context, th *material.Theme,
	onDone func(preferencesResult),
) layout.Dimensions {
	if d.cancelBt.Clicked(gtx) {
		onDone(preferencesResult{cancel: true})
		return layout.Dimensions{Size: gtx.Constraints.Max}
	}
	if d.okBt.Clicked(gtx) {
		onDone(preferencesResult{language: d.lang, theme: d.theme})
		return layout.Dimensions{Size: gtx.Constraints.Max}
	}

	// Map button clicks to model updates before the next layout.
	switch {
	case d.themeSystemBt.Clicked(gtx):
		d.theme = themeSystem
	case d.themeLightBt.Clicked(gtx):
		d.theme = themeLight
	case d.themeDarkBt.Clicked(gtx):
		d.theme = themeDark
	case d.langEnBt.Clicked(gtx):
		d.lang = "en"
	case d.langZhCNBt.Clicked(gtx):
		d.lang = "zh-CN"
	case d.langDeBt.Clicked(gtx):
		d.lang = "de"
	}

	// Render one labeled "chip" — emphasised when selected, regular
	// otherwise. Implemented as a material.Button so the click target
	// stays generous without us hand-rolling a Pointer area.
	chip := func(btn *widget.Clickable, label string, selected bool) layout.FlexChild {
		return layout.Rigid(func(gtx layout.Context) layout.Dimensions {
			return layout.Inset{Right: unit.Dp(8), Bottom: unit.Dp(4)}.Layout(gtx,
				func(gtx layout.Context) layout.Dimensions {
					b := material.Button(th, btn, label)
					if !selected {
						b.Background = activePalette.RingBg
						b.Color = activePalette.OnBackground
					}
					return b.Layout(gtx)
				})
		})
	}

	body := func(gtx layout.Context) layout.Dimensions {
		return layout.Flex{Axis: layout.Vertical}.Layout(gtx,
			layout.Rigid(material.Body1(th, i18n.T("label_theme")).Layout),
			layout.Rigid(layout.Spacer{Height: unit.Dp(6)}.Layout),
			layout.Rigid(func(gtx layout.Context) layout.Dimensions {
				return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
					chip(&d.themeSystemBt, i18n.T("theme_system"), d.theme == themeSystem),
					chip(&d.themeLightBt, i18n.T("theme_light"), d.theme == themeLight),
					chip(&d.themeDarkBt, i18n.T("theme_dark"), d.theme == themeDark),
				)
			}),
			layout.Rigid(layout.Spacer{Height: unit.Dp(12)}.Layout),
			layout.Rigid(material.Body1(th, i18n.T("label_language")).Layout),
			layout.Rigid(layout.Spacer{Height: unit.Dp(6)}.Layout),
			layout.Rigid(func(gtx layout.Context) layout.Dimensions {
				return layout.Flex{Axis: layout.Horizontal}.Layout(gtx,
					chip(&d.langEnBt, supportedLanguages[0].label, d.lang == "en"),
					chip(&d.langZhCNBt, supportedLanguages[1].label, d.lang == "zh-CN"),
					chip(&d.langDeBt, supportedLanguages[2].label, d.lang == "de"),
				)
			}),
		)
	}

	return modalCard(gtx, th, i18n.T("dialog_preferences_title"),
		i18n.T("btn_ok"), i18n.T("btn_cancel"),
		&d.okBt, &d.cancelBt, body)
}