package gio

import (
	"image/color"

	"gioui.org/layout"
	"gioui.org/op/paint"
	"gioui.org/unit"
	"gioui.org/widget/material"
)

var shellColors = struct {
	background color.NRGBA
	foreground color.NRGBA
	primary    color.NRGBA
	onPrimary  color.NRGBA
	secondary  color.NRGBA
}{
	background: color.NRGBA{R: 248, G: 250, B: 252, A: 255},
	foreground: color.NRGBA{R: 15, G: 23, B: 42, A: 255},
	primary:    color.NRGBA{R: 13, G: 148, B: 136, A: 255},
	onPrimary:  color.NRGBA{R: 255, G: 255, B: 255, A: 255},
	secondary:  color.NRGBA{R: 71, G: 85, B: 105, A: 255},
}

// AppShell is the modern window frame. Feature views are added in later tasks.
type AppShell struct {
	edition string
}

// NewAppShell creates an empty shell for the supplied build edition.
func NewAppShell(edition string) *AppShell {
	return &AppShell{edition: edition}
}

// NewTheme creates the semantic palette shared by the modern shell.
func NewTheme() *material.Theme {
	theme := material.NewTheme()
	theme.Palette = material.Palette{
		Bg:         shellColors.background,
		Fg:         shellColors.foreground,
		ContrastBg: shellColors.primary,
		ContrastFg: shellColors.onPrimary,
	}
	theme.FingerSize = unit.Dp(44)
	return theme
}

// Layout renders the shell without performing IO or submitting use cases.
func (shell *AppShell) Layout(context layout.Context, theme *material.Theme) layout.Dimensions {
	paint.Fill(context.Ops, theme.Bg)

	return layout.UniformInset(unit.Dp(32)).Layout(context, func(context layout.Context) layout.Dimensions {
		return layout.Flex{Axis: layout.Vertical}.Layout(
			context,
			layout.Rigid(func(context layout.Context) layout.Dimensions {
				return layout.Flex{Alignment: layout.Middle}.Layout(
					context,
					layout.Rigid(material.H5(theme, "SoftBox").Layout),
					layout.Rigid(layout.Spacer{Width: unit.Dp(16)}.Layout),
					layout.Rigid(func(context layout.Context) layout.Dimensions {
						label := material.Body2(theme, shell.edition)
						label.Color = shellColors.primary
						return label.Layout(context)
					}),
				)
			}),
			layout.Rigid(layout.Spacer{Height: unit.Dp(24)}.Layout),
			layout.Flexed(1, func(context layout.Context) layout.Dimensions {
				return layout.Center.Layout(context, func(context layout.Context) layout.Dimensions {
					return layout.Flex{Axis: layout.Vertical, Alignment: layout.Middle}.Layout(
						context,
						layout.Rigid(material.H6(theme, "软件目录准备中").Layout),
						layout.Rigid(layout.Spacer{Height: unit.Dp(8)}.Layout),
						layout.Rigid(func(context layout.Context) layout.Dimensions {
							label := material.Body1(theme, "当前窗口仅验证 Gio AppShell 与双构建链路。")
							label.Color = shellColors.secondary
							return label.Layout(context)
						}),
					)
				})
			}),
			layout.Rigid(func(context layout.Context) layout.Dimensions {
				label := material.Body2(theme, "Modern · Windows 10/11 x64")
				label.Color = shellColors.secondary
				return label.Layout(context)
			}),
		)
	})
}