package walletconnect

import (
	"encoding/json"
	"errors"
	"fmt"
	"regexp"
	"strconv"
	"strings"
)

// Returns namspace name, chainID and error
func parseCaip2ChainID(str string) (string, uint64, error) {
	caip2 := strings.Split(str, ":")
	if len(caip2) != 2 {
		return "", 0, errors.New("CAIP-2 string is not valid")
	}

	chainIDStr := caip2[1]
	chainID, err := strconv.ParseUint(chainIDStr, 10, 64)
	if err != nil {
		return "", 0, fmt.Errorf("CAIP-2 second value not valid Chain ID: %w", err)
	}
	return caip2[0], chainID, nil
}

// JSONProxyType provides a generic way of changing the JSON value before unmarshalling it into the target.
// transform function is called before unmarshalling.
type JSONProxyType struct {
	target    interface{}
	transform func([]byte) ([]byte, error)
}

func (b *JSONProxyType) UnmarshalJSON(input []byte) error {
	if b.transform == nil {
		return errors.New("transform function is not set")
	}

	output, err := b.transform(input)
	if err != nil {
		return err
	}

	return json.Unmarshal(output, b.target)
}

func isValidNamespaceName(namespaceName string) bool {
	pattern := "^[a-z0-9-]{3,8}$"

	regex := regexp.MustCompile(pattern)

	return regex.MatchString(namespaceName)
}