path: root/common/natspec/natspec.go

package natspec

import (
    "fmt"
    "github.com/robertkrimen/otto"
)

type NatSpec struct {
    jsvm *otto.Otto
}

// TODO: should initialise with abi and userdoc jsons
func New() (self *NatSpec, err error) {

    self = new(NatSpec)
    self.jsvm = otto.New()

    _, err = self.jsvm.Run(natspecJS)
    if err != nil {
        return
    }
    _, err = self.jsvm.Run("var natspec = require('natspec');")
    if err != nil {
        return
    }

    return
}

func (self *NatSpec) Notice(transaction, abi, method, expression string) (string, error) {
    var err error
    if _, err = self.jsvm.Run("var transaction = " + transaction + ";"); err != nil {
        return "", fmt.Errorf("natspec.js error setting transaction: %v", err)
    }

    if _, err = self.jsvm.Run("var abi = " + abi + ";"); err != nil {
        return "", fmt.Errorf("natspec.js error setting abi: %v", err)
    }

    if _, err = self.jsvm.Run("var method = '" + method + "';"); err != nil {
        return "", fmt.Errorf("natspec.js error setting method: %v", err)
    }

    if _, err = self.jsvm.Run("var expression = \"" + expression + "\";"); err != nil {
        return "", fmt.Errorf("natspec.js error setting expression: %v", err)
    }

    self.jsvm.Run("var call = {method: method,abi: abi,transaction: transaction};")
    value, err := self.jsvm.Run("natspec.evaluateExpression(expression, call);")
    if err != nil {
        return "", fmt.Errorf("natspec.js error evaluating expression: %v", err)
    }
    evalError := "Natspec evaluation failed, wrong input params"
    if value.String() == evalError {
        return "", fmt.Errorf("natspec.js error evaluating expression: wrong input params in expression '%s'", expression)
    }
    if len(value.String()) == 0 {
        return "", fmt.Errorf("natspec.js error evaluating expression")
    }

    return value.String(), nil

}