package controllers

import play.api._
import play.api.data.Form
import play.api.mvc._

import lila.api.Context
import lila.app._
import lila.qa.{ QuestionId, Question, AnswerId, Answer, QaAuth }

trait QaController extends LilaController {

  protected def api = Env.qa.api
  protected def forms = Env.qa.forms

  protected def renderQuestion(q: Question, answerForm: Option[Form[_]] = None)(implicit ctx: Context): Fu[Result] =
    (api.answer popular q.id) zip
      fetchPopular zip
      api.relation.questions(q, 10) zip
      (QaAuth.canAsk ?? { forms.anyCaptcha map (_.some) }) flatMap {
        case (((answers, popular), related), captcha) => fuccess {
          Ok(views.html.qa.questionShow(q, answers, popular, related,
            answerForm = if (QaAuth canAnswer q) answerForm orElse Some(forms.answer) else None,
            captcha = captcha))
        }
        case _ => notFound
      }

  protected def renderN00b(implicit ctx: Context) = fetchPopular map { popular =>
    Forbidden(views.html.qa.n00b(popular))
  }

  protected def WithQuestion(id: QuestionId)(block: Question => Fu[Result])(implicit ctx: Context): Fu[Result] =
    OptionFuResult(api.question findById id)(block)

  protected def WithQuestion(id: QuestionId, slug: String)(block: Question => Fu[Result])(implicit ctx: Context): Fu[Result] =
    WithQuestion(id) { q =>
      if (slug != q.slug) fuccess(Redirect {
        controllers.routes.QaQuestion.show(id, q.slug)
      })
      else block(q)
    }

  protected def WithOwnQuestion(id: QuestionId)(block: Question => Fu[Result])(implicit ctx: Context): Fu[Result] =
    WithQuestion(id) { q =>
      if (QaAuth canEdit q) block(q)
      else fuccess(Unauthorized)
    }
  protected def WithOwnQuestion(id: QuestionId, slug: String)(block: Question => Fu[Result])(implicit ctx: Context): Fu[Result] =
    WithQuestion(id, slug) { q =>
      if (QaAuth canEdit q) block(q)
      else fuccess(Unauthorized)
    }

  protected def WithOwnAnswer(questionId: QuestionId, answerId: AnswerId)(block: Question => Answer => Fu[Result])(implicit ctx: Context): Fu[Result] =
    api.question findById questionId zip (api.answer findById answerId) flatMap {
      case (Some(q), Some(a)) if (QaAuth canEdit a) => block(q)(a)
      case (Some(q), Some(a))                       => fuccess(Unauthorized)
      case _                                        => notFound
    }

  protected def fetchPopular = api.question popular 20
}