package component

import (
	"bytes"
	"fmt"
	"strings"
	"time"

	"fyne.io/fyne/v2"
	"fyne.io/fyne/v2/container"
	"fyne.io/fyne/v2/widget"
	"github.com/starlight-go/starlight"
	"github.com/theriault/maths/combinatorics"
	"github.com/theriault/maths/numbertheory"
)

func StarLight() fyne.CanvasObject {
	input := widget.NewMultiLineEntry()
	result := widget.NewMultiLineEntry()
	lblMsg := widget.NewLabel("")
	buf := bytes.NewBuffer(nil)
	p := &Page{
		Name:     "a story about nate",
		Date:     time.Now(),
		Contents: "I like to write go code.",
		IsDraft:  true,
	}
	fns := []string{
		"aliquotSum:和",
		"numberOfDivisors:因数个数",
		"primeFactorization:分解质因数",
		"politeness:礼貌数",
		"factorial:阶乘",
	}
	globals := map[string]interface{}{
		"println":            fmt.Fprintln,
		"buf":                buf,
		"page":               p,
		"aliquotSum":         numbertheory.AliquotSum[int],
		"numberOfDivisors":   numbertheory.NumberOfDivisors[int],
		"primeFactorization": numbertheory.PrimeFactorization[int],
		"politeness":         numbertheory.Politeness[int],
		"factorial":         combinatorics.Factorial[int],
	}
	reset := func() {
		buf.Reset()
		lblMsg.SetText("")
		result.SetText("")
	}
	input1 := widget.NewEntry()
	input1.SetText("9")
	selFn := widget.NewSelect(fns, func(s string) {
		reset()
		fn := strings.Split(s, ":")[0]
		input.SetText(`println(buf,` + fn + `(` + input1.Text + `))`)
		_, err := starlight.Eval([]byte(input.Text), globals, nil)
		if err != nil {
			lblMsg.SetText(err.Error())
			return
		}
		result.SetText(buf.String())
	})
	btnDoo := widget.NewButton("Do", func() {
		reset()
		_, err := starlight.Eval([]byte(input.Text), globals, nil)
		if err != nil {
			lblMsg.SetText(err.Error())
			return
		}
		result.SetText(buf.String())

	})
	btnDo := widget.NewButton("Eval", func() {
		reset()
		input.SetText(code)
		_, err := starlight.Eval([]byte(input.Text), globals, nil)
		if err != nil {
			lblMsg.SetText(err.Error())
			return
		}
		// buf.WriteString(fmt.Sprintf("%v is draft: %v\n", p.Name, p.IsDraft))
		result.SetText(buf.String())
	})

	split := container.NewHSplit(input, result)
	topbtns := container.NewHBox(btnDoo, btnDo)
	topInputs := container.NewGridWithColumns(3, input1,selFn)
	top := container.NewVBox(topInputs, topbtns)
	return container.NewBorder(top, lblMsg, nil, nil, split)
}

// Starlight makes it easy to get values in and out of your starlark scripts.
// Just pass in pointers to values that you want changed, or callback functions
// that propagate data.

// In theory, starlight also returns all global variables set by the script, but
// in real programs, you need well-defined outputs for your calling code to act on.
// If I write a script that creates a variable called nate_is_awesome = 1337 ... your
// go code probably isn't going to care that the variable exists.

// The best way to do it is to write a "results" struct that you pass in, just
// as you would for any other function.

type Page struct {
	Name     string
	Date     time.Time
	Contents string
	IsDraft  bool
}

const code = `
def run():
  if "nate" in page.Name:
	  # capitalize words
	  page.Name = page.Name.title()
  page.Name += " " + page.Date.Format("2006/01/02")
  page.IsDraft = False
run()
println(buf,page)
println(buf,page.Contents)
println(buf, "github.com/starlight-go/starlight")
println(buf,1+5.9)
def sum(a,b):
	return a+b

println(buf,sum(6.6,5.5))

def fibonacci(num):
    fibs = [0,1]
    for i in range(num-2):
        fibs.append(fibs[-2]+fibs[-1])   #倒数第二个+倒数第一个数的结果，追加到列表
    return(fibs)
println(buf,fibonacci(5))
`

// func main() {
// 	p := &Page{
// 		Name:     "a story about nate",
// 		Date:     time.Now(),
// 		Contents: "I like to write go code.",
// 		IsDraft:  true,
// 	}
// 	globals := map[string]interface{}{
// 		"page": p,
// 	}
// 	_, err := starlight.Eval([]byte(code), globals, nil)
// 	if err != nil {
// 		log.Fatal(err)
// 	}
// 	fmt.Printf("%v is draft: %v\n", p.Name, p.IsDraft)
// }

// Running it:
// $ go run inout.go
// A Story About Nate 2018/12/07 is draft: false