import PathKit


class IncludeNode : NodeType {
  let templateName: Variable

  class func parse(_ parser: TokenParser, token: Token) throws -> NodeType {
    let bits = token.components()

    guard bits.count == 2 else {
      throw TemplateSyntaxError("'include' tag takes one argument, the template file to be included")
    }

    return IncludeNode(templateName: Variable(bits[1]))
  }

  init(templateName: Variable) {
    self.templateName = templateName
  }

  func render(_ context: Context) throws -> String {
    guard let templateName = try self.templateName.resolve(context) as? String else {
      throw TemplateSyntaxError("'\(self.templateName)' could not be resolved as a string")
    }

    let template = try context.environment.loadTemplate(name: templateName)

    return try context.push {
      return try template.render(context)
    }
  }
}