#if os(Linux)

import CJavaScriptCore

#else

import JavaScriptCore

#endif

public class JSContext {

let group: JSContextGroupRef

let context: JSGlobalContextRef

var exception: JSObjectRef? = nil

var global: JSObjectRef {

return JSContextGetGlobalObject(context)!

}

public init() {

guard let group = JSContextGroupCreate(),

let context = JSGlobalContextCreateInGroup(group, nil) else {

fatalError("can't create context")

}

self.group = group

self.context = context

}

deinit {

JSGlobalContextRelease(context)

JSContextGroupRelease(group)

}

@discardableResult

public func evaluate(

_ script: String,

source: String? = nil

) throws -> JSValue {

let file = JSStringCreateWithUTF8CString(source)

let script = JSStringCreateWithUTF8CString(script)

defer {

JSStringRelease(file)

JSStringRelease(script)

}

let result = try JSEvaluateScript(context, script, global, file, 0)

return JSValue(context: context, pointer: result)

}

@discardableResult

public func createFunction(

name: String,

callback: @escaping JSObjectCallAsFunctionCallback

) throws -> JSObjectRef {

let name = JSStringCreateWithUTF8CString(name)

defer { JSStringRelease(name) }

let function = JSObjectMakeFunctionWithCallback(context, name, callback)

try JSObjectSetProperty(context, global, name, function, .none)

return function!

}

}