package main

import (
	"fmt"
	"image/color"
	"log"
	"os"

	"gioui.org/app"
	"gioui.org/font/gofont"
	"gioui.org/layout"
	"gioui.org/op"
	"gioui.org/op/clip"
	"gioui.org/op/paint"
	"gioui.org/text"
	"gioui.org/unit"
	"gioui.org/widget"
	"gioui.org/widget/material"
)

// 定义侧边栏项目
type SidebarItem struct {
	Text string
	Btn  widget.Clickable // 处理点击事件
	ID   int              // 用于唯一标识每个项目
}

// 应用状态
type AppState struct {
	SidebarItems    []SidebarItem
	SelectedItemID  int // 当前选中的项目ID
	SelectedItemID2 int
}

func main() {
	go func() {
		window := new(app.Window)
		window.Option(app.Title("Go Desk"), app.Size(unit.Dp(1200), unit.Dp(800)))

		err := run(window)
		if err != nil {
			log.Fatal(err)
		}
		os.Exit(0)
	}()
	app.Main()
}

func run(window *app.Window) error {
	theme := material.NewTheme()
	theme.Shaper = text.NewShaper(text.WithCollection(gofont.Collection()))
	// 初始化应用状态
	var state AppState
	state.SelectedItemID = 1 // 默认选中第一个项目
	// 初始化侧边栏项目
	state.SidebarItems = []SidebarItem{
		{Text: "仪表盘", ID: 1},
		{Text: "文件", ID: 2},
		{Text: "设置", ID: 3},
		{Text: "帮助", ID: 4},
	}

	// 初始化一个按钮组件
	var btn widget.Clickable
	var ops op.Ops
	for {
		switch e := window.Event().(type) {
		case app.DestroyEvent:
			return e.Err
		case app.FrameEvent:
			// This graphics context is used for managing the rendering state.
			gtx := app.NewContext(&ops, e)

			// Define an large label with an appropriate text:
			title := material.H1(theme, "Hello, Gio")

			// Change the color of the label.
			maroon := color.NRGBA{R: 127, G: 0, B: 0, A: 255}
			title.Color = maroon

			// Change the position of the label.
			title.Alignment = text.Middle
			// 处理侧边栏按钮点击
			for i := range state.SidebarItems {
				if state.SidebarItems[i].Btn.Clicked(gtx) {
					fmt.Printf("Item %d clicked\n", state.SidebarItems[i].ID)
					state.SelectedItemID = state.SidebarItems[i].ID // 更新选中状态
					// 这里可以触发其他操作，如加载新的内容页面
				}
			}
			// 开始绘制界面
			layout.Flex{
				Axis: layout.Horizontal,
			}.Layout(gtx,
				// 侧边栏
				layout.Rigid(func(gtx layout.Context) layout.Dimensions {
					return drawSidebar(gtx, theme, &state)
				}),
				// 主内容区 (此处简化，仅显示文本)
				layout.Flexed(1, func(gtx layout.Context) layout.Dimensions {
					return material.Body1(theme, fmt.Sprintf("当前显示的内容: Item %d", state.SelectedItemID)).Layout(gtx)
				}),
			)
			// Draw the label to the graphics context.
			title.Layout(gtx)
			// 监听按钮点击事件
			for btn.Clicked(gtx) {
				fmt.Println("按钮被点击了！")
			}

			// 使用布局中心化内容
			layout.Center.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
				// 创建按钮并使用Material Design样式
				return material.Button(theme, &btn, "点我").Layout(gtx)
			})
			// Pass the drawing operations to the GPU.
			e.Frame(gtx.Ops)
		}
	}
}

// drawSidebar 绘制侧边栏
func drawSidebar(gtx layout.Context, th *material.Theme, state *AppState) layout.Dimensions {
	// 侧边栏背景和样式
	sidebarBackground := func(gtx layout.Context, w layout.Widget) layout.Dimensions {
		return material.Background(gtx, "", w) /* 设置背景颜色 */
	}

	return layout.Stack{}.Layout(gtx,
		layout.Expanded(sidebarBackground),
		layout.Stacked(func(gtx layout.Context) layout.Dimensions {
			// 使用列表布局排列侧边栏项目
			list := layout.List{
				Axis: layout.Vertical,
			}
			return list.Layout(gtx, len(state.SidebarItems), func(gtx layout.Context, index int) layout.Dimensions {
				item := &state.SidebarItems[index]
				// 根据是否选中决定样式
				bgColor := ""   /* 默认背景色 */
				textColor := "" /* 默认文字颜色 */
				if item.ID == state.SelectedItemID {
					bgColor = ""   /* 选中时的背景色，例如 primary color */
					textColor = "" /* 选中时的文字颜色，例如 on primary color */
				}

				// 绘制可点击的按钮，应用选中的样式
				return material.Clickable(gtx, &item.Btn, func(gtx layout.Context) layout.Dimensions {
					// 填充背景色 (选中与否颜色不同)
					return layout.Background{}.Layout(gtx,
						func(gtx layout.Context) layout.Dimensions {
							return fill(gtx, bgColor)
						},
						func(gtx layout.Context) layout.Dimensions {
							// 添加边距和布局
							return layout.Inset{Top: unit.Dp(5), Bottom: unit.Dp(5), Left: unit.Dp(10), Right: unit.Dp(10)}.Layout(gtx, func(gtx layout.Context) layout.Dimensions {
								// 显示文字
								label := material.Body1(th, item.Text)
								label.Color = textColor
								return label.Layout(gtx)
							})
						},
					)
				})
			})
		}),
	)
}

// fill 用指定颜色填充区域
func fill(gtx layout.Context, color color.NRGBA) layout.Dimensions {
	defer clip.Rect{Max: gtx.Constraints.Max}.Push(gtx.Ops).Pop()
	paint.ColorOp{Color: color}.Add(gtx.Ops)
	paint.PaintOp{}.Add(gtx.Ops)
	return layout.Dimensions{Size: gtx.Constraints.Max}
}