use std, jdbc, functional, server

class Phrases {
  def Phrases(database) {
    conn = getConnection("jdbc:sqlite:" + database)
    statement = conn.createStatement()
    this.queryByWordsLength = conn.prepareStatement("
        SELECT * FROM phrases
        WHERE words BETWEEN ? AND ?
        ORDER BY RANDOM()
        LIMIT 1")
    this.wordsByGroup = this.getWordsCountByGroup()
  }
  
  def getRandomPhrase() = this.readPhrase(
    this.statement.executeQuery("SELECT * FROM phrases ORDER BY RANDOM() LIMIT 1")
  )
  
  def getRandomPhrase(minWords, maxWords = minWords) {
    this.queryByWordsLength.setInt(1, minWords)
    this.queryByWordsLength.setInt(2, maxWords)
    return this.readPhrase(this.queryByWordsLength.executeQuery())
  }
  
  def readPhrase(rs) {
    if (!rs.next()) {
      return "Can't find any phrase"
    }
    words = rs.getInt("words")
    return {
      "id": rs.getInt("id"),
      "words": words,
      "en": rs.getString("en"),
      "ru": rs.getString("ru"),
      "countInGroup": this.wordsByGroup[words]
    }
  }
  
  def getWordsCountByGroup() {
    rs = statement.executeQuery(
        "SELECT words, COUNT(*) FROM phrases GROUP BY words")
    result = {}
    while (rs.next()) {
        result[rs.getInt(1)] = rs.getInt(2)
    }
    return result
  }
}

db = new Phrases("phrases-easy.db")

server = newServer({"externalDirs": ["public"]})
server
  .get("/shutdown", def(ctx) = server.stop().close())
  .get("/phrase", def(ctx) = ctx.json(db.getRandomPhrase()))
  .get("/phrase/{words}", def(ctx) {
    words = parseInt(ctx.pathParam("words"))
    ctx.json(db.getRandomPhrase(words))
  })
  .error(404, def(ctx) = ctx.result("Phrases not found"))
  .start(8081)