package backend

import (
	"binaryserver/app/db"
	"fmt"
	"net/http"
	"strconv"
	"strings"

	"github.com/go-rod/rod"
	"github.com/go-rod/rod/lib/launcher"
)

var browser *rod.Browser

func asciiToBinary(text string) string {
	var result []string
	for _, char := range text {
		binary := fmt.Sprintf("%08b", char) // 8-bit binary format
		result = append(result, binary)
	}
	return strings.Join(result, " ")
}

func binaryToASCII(binary string) (string, error) {
	// Ensure the length of the binary string is a multiple of 8
	if len(binary)%8 != 0 {
		return "", fmt.Errorf("binary string length must be a multiple of 8")
	}

	var sb strings.Builder
	for i := 0; i < len(binary); i += 8 {
		byteStr := binary[i : i+8]
		b, err := strconv.ParseUint(byteStr, 2, 8)
		if err != nil {
			return "", fmt.Errorf("invalid binary sequence at position %d: %v", i, err)
		}
		sb.WriteByte(byte(b))
	}
	return sb.String(), nil
}

func instagramHandleExists(username string, bypass ...bool) string {
	records, _ := db.GetRecords(db.QueryOptions{Where: fmt.Sprintf(`handle='%v'`, username)})
	if len(records) > 0 && len(bypass) == 0 {
		return records[0].URL
	}
	url := fmt.Sprintf("https://www.instagram.com/%s/", username)

	page := browser.MustPage(url)

	// Wait until body is loaded
	page.MustWaitLoad().MustWaitIdle()

	body := page.MustElement("body").MustText()

	record := db.NewRecord(username, url)

	// Instagram shows this for non-existent users
	if strings.Contains(body, "Sorry, this page isn't available") {
		record.URL = ""
		db.SaveRecord(record)
		return ""
	}
	db.SaveRecord(record)
	return url
}

func BinaryHandler(w http.ResponseWriter, req *http.Request) {
	binaryInput := strings.ReplaceAll(req.URL.Query().Get("binary"), " ", "")
	var text string
	var handle string
	var err error
	if binaryInput == "" {
		asciiInput := req.URL.Query().Get("text")
		if asciiInput == "" {
			fmt.Fprintf(w, "Could not encode or decode!\n")
			return
		}
		text = asciiToBinary(asciiInput)
		fmt.Fprintf(w, "%v\n", GetFancyResponse(`<center><p>`+text+`</p></center>`, ""))
		return
	} else {
		text, err = binaryToASCII(binaryInput)
		text = strings.ReplaceAll(text, "@", "")
		handle = text
	}

	if err != nil {
		fmt.Fprintf(w, "Could not decode!\n")
		return
	}

	var url string
	if url = instagramHandleExists(text); url != "" {
		text = `<center><a href="` + url + `">` + text + `</a></center>`
	} else {
		text = `<center><p>` + text + `</p></center>`
	}
	if url == "" {
		handle = ""
	}

	fmt.Fprintf(w, "%v\n", GetFancyResponse(text, handle))
}

func init() {
	path, _ := launcher.New().
		Headless(true).
		NoSandbox(true).
		// Uncomment below to see browser
		// Set("headless", "false").
		Launch()
	browser = rod.New().ControlURL(path).MustConnect()
}