package ui

import (
	"fmt"
	"net/url"
	"strconv"

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

const appVersion = "V1.5.1"

const (
	ipPlaceholder   = "例子：\n127.0.0.1 - 单IP\n192.168.0.0/24 - 掩码IP段\n0.0.0.0-255.255.255.255 - IP段\ndomain.com - 单域名"
	portPlaceholder = "例子：\n22 - 单端口\n80;443 - 多个不连续端口\n3000-65535 - 连续的端口范围"
)

type scanForm struct {
	app fyne.App

	ipList   *widget.Entry
	portList *widget.Entry
	timeout  *widget.Entry
	threads  *widget.Entry
	output   *widget.Entry
	progress *widget.ProgressBar

	scanBtn  *widget.Button
	pingBtn  *widget.Button
	scanning bool
}

func newScanForm(app fyne.App) *scanForm {
	f := &scanForm{app: app}

	f.ipList = widget.NewMultiLineEntry()
	f.ipList.SetPlaceHolder(ipPlaceholder)
	f.ipList.SetMinRowsVisible(4)

	f.portList = widget.NewMultiLineEntry()
	f.portList.SetPlaceHolder(portPlaceholder)
	f.portList.SetMinRowsVisible(4)

	f.timeout = newIntEntry(100, 1, 10000)
	f.threads = newIntEntry(64, 1, 1024)

	f.output = widget.NewMultiLineEntry()
	f.output.SetMinRowsVisible(6)

	f.progress = widget.NewProgressBar()

	f.scanBtn = widget.NewButton("开始扫描", f.toggleScan)
	f.pingBtn = widget.NewButton("仅Ping", f.togglePing)

	return f
}

func (f *scanForm) build() fyne.CanvasObject {
	ipSection := container.NewVBox(
		widget.NewLabel("IP"),
		f.ipList,
		newIPKeypad(f.ipList),
	)
	portSection := container.NewVBox(
		widget.NewLabel("端口"),
		f.portList,
		newPortKeypad(f.portList),
	)

	topRow := container.New(layout.NewGridLayoutWithColumns(2), ipSection, portSection)
	controlRow := f.buildControlRow()
	topArea := container.NewVBox(topRow, controlRow)

	footer := container.NewHBox(
		widget.NewLabel(appVersion),
		layout.NewSpacer(),
		widget.NewButton("Blog", func() { f.openURL("https://wnfed.com/") }),
		widget.NewButton("GitLab", func() { f.openURL("https://git.lmve.net/kevin/tcp_ip_scan") }),
		widget.NewButton("GitHub", func() { f.openURL("https://github.com/wuwenfengmi1998/tcp_ip_scan") }),
	)

	return container.NewBorder(topArea, footer, nil, nil, f.output)
}

func (f *scanForm) buildControlRow() fyne.CanvasObject {
	left := container.NewHBox(
		widget.NewButton("清空输出", func() { f.output.SetText("") }),
		widget.NewButton("保存输出", f.saveOutput),
		container.NewHBox(widget.NewLabel("超时ms"), f.timeout),
		container.NewHBox(widget.NewLabel("线程"), f.threads),
		widget.NewButton("清空IP", func() { f.ipList.SetText("") }),
		f.pingBtn,
	)
	right := container.NewHBox(
		widget.NewButton("清空端口", func() { f.portList.SetText("") }),
		f.scanBtn,
	)
	return container.NewBorder(nil, nil, left, right, f.progress)
}

func (f *scanForm) toggleScan() {
	if !f.scanning {
		f.scanning = true
		f.scanBtn.SetText("停止扫描")
		f.pingBtn.Disable()
		f.setInputsEnabled(false)
		f.progress.SetValue(0)
		f.output.Append("开始扫描... (TODO: 接入扫描逻辑)\n")
	} else {
		f.scanning = false
		f.scanBtn.SetText("开始扫描")
		f.pingBtn.Enable()
		f.setInputsEnabled(true)
		f.output.Append("已停止扫描\n")
	}
}

func (f *scanForm) togglePing() {
	if !f.scanning {
		f.scanning = true
		f.pingBtn.SetText("停止Ping")
		f.scanBtn.Disable()
		f.setInputsEnabled(false)
		f.progress.SetValue(0)
		f.output.Append("开始Ping... (TODO: 接入扫描逻辑)\n")
	} else {
		f.scanning = false
		f.pingBtn.SetText("仅Ping")
		f.scanBtn.Enable()
		f.setInputsEnabled(true)
		f.output.Append("已停止Ping\n")
	}
}

func (f *scanForm) setInputsEnabled(enabled bool) {
	if enabled {
		f.ipList.Enable()
		f.portList.Enable()
		f.timeout.Enable()
		f.threads.Enable()
	} else {
		f.ipList.Disable()
		f.portList.Disable()
		f.timeout.Disable()
		f.threads.Disable()
	}
}

func (f *scanForm) saveOutput() {
	f.output.Append("(TODO: 保存输出到文件)\n")
}

func (f *scanForm) openURL(urlStr string) {
	u, err := url.Parse(urlStr)
	if err != nil {
		return
	}
	_ = f.app.OpenURL(u)
}

func newIntEntry(val, min, max int) *widget.Entry {
	e := widget.NewEntry()
	e.SetText(strconv.Itoa(val))
	e.Validator = func(s string) error {
		n, err := strconv.Atoi(s)
		if err != nil || n < min || n > max {
			return fmt.Errorf("需为 %d-%d", min, max)
		}
		return nil
	}
	return e
}