package termui

import (
	"bufio"
	"fmt"
	"os"
	"strings"
	"syscall"
	"unsafe"

	"hub.gaomia.site/titor/YunShu/pkg/style"
)

const (
	stdInputHandle     = ^uintptr(9)
	stdOutputHandle    = ^uintptr(10)
	enableProcessed    = 0x0001
	enableLineInput    = 0x0002
	enableEchoInput    = 0x0004
	enableVtProcessing = 0x0004
)

var (
	kernel32          = syscall.NewLazyDLL("kernel32.dll")
	procGetStdHandle  = kernel32.NewProc("GetStdHandle")
	procGetConsoleMode = kernel32.NewProc("GetConsoleMode")
	procSetConsoleMode = kernel32.NewProc("SetConsoleMode")
)

func ensureLineMode() {
	h, _, _ := procGetStdHandle.Call(stdInputHandle)
	if h == 0 || h == uintptr(syscall.InvalidHandle) {
		return
	}
	var mode uint32
	ret, _, _ := procGetConsoleMode.Call(h, uintptr(unsafe.Pointer(&mode)))
	if ret == 0 {
		return
	}
	need := uint32(enableProcessed | enableLineInput | enableEchoInput)
	if mode&need != need {
		procSetConsoleMode.Call(h, uintptr(need))
	}
}

type InputConfig struct {
	Label     string
	Help      string
	Default   string
	Required  bool
	Validator Validator
}

type InputOption func(*InputConfig)

func WithDefault(v string) InputOption {
	return func(c *InputConfig) { c.Default = v }
}

func WithHelp(v string) InputOption {
	return func(c *InputConfig) { c.Help = v }
}

func WithRequired(v bool) InputOption {
	return func(c *InputConfig) { c.Required = v }
}

func WithValidator(v Validator) InputOption {
	return func(c *InputConfig) { c.Validator = v }
}

func applyOpts(opts []InputOption) InputConfig {
	c := InputConfig{}
	for _, o := range opts {
		o(&c)
	}
	return c
}

func printLabel(label string, required bool) {
	s := style.New().Bold().Render(label)
	if required {
		s += "（必填）"
	}
	fmt.Println(s)
}

func ReadLine() string {
	ensureLineMode()
	r := bufio.NewReader(os.Stdin)
	s, err := r.ReadString('\n')
	if err != nil {
		return ""
	}
	return strings.TrimRight(s, "\r\n")
}

func TextInput(label string, opts ...InputOption) string {
	cfg := applyOpts(opts)
	printLabel(label, cfg.Required)

	for {
		fmt.Print(style.Cyan.Render("? "))

		line := ReadLine()

		if line == "" {
			line = cfg.Default
		}

		var err error
		if cfg.Required && line == "" {
			err = fmt.Errorf("不能为空")
		} else if cfg.Validator != nil {
			err = cfg.Validator(line)
		}

		if err != nil {
			fmt.Println(style.Red.Render("⚠ " + err.Error()))
			continue
		}

		fmt.Println(style.Green.Render("✔ " + line))
		return line
	}
}

func PasswordInput(label string, opts ...InputOption) string {
	cfg := applyOpts(opts)
	printLabel(label, cfg.Required)

	for {
		fmt.Print(style.Cyan.Render("? "))

		line := ReadLine()

		fmt.Print("\033[A\r\033[K")

		if line == "" {
			line = cfg.Default
		}

		var err error
		if cfg.Required && line == "" {
			err = fmt.Errorf("不能为空")
		} else if cfg.Validator != nil {
			err = cfg.Validator(line)
		}

		if err != nil {
			fmt.Println(style.Red.Render("⚠ " + err.Error()))
			continue
		}

		masked := strings.Repeat("*", len(line))
		fmt.Println(style.Green.Render("✔ " + masked))
		return line
	}
}

func Confirm(label string, defaultValue bool) bool {
	hint := "Y/n"
	if !defaultValue {
		hint = "y/N"
	}

	fmt.Print(style.Cyan.Render("?"), label, "（", hint, "）")

	line := ReadLine()
	line = strings.ToLower(line)

	fmt.Print("\033[A\r\033[K")

	ok := defaultValue
	if line == "y" || line == "yes" {
		ok = true
	} else if line == "n" || line == "no" {
		ok = false
	} else if line != "" {
		ok = false
	}

	if ok {
		fmt.Println(style.Green.Render("✔ " + label))
	} else {
		fmt.Println(style.Red.Render("✘ " + label))
	}
	return ok
}