package com.twitter.util

import org.specs.Specification
import java.io.{File, FileOutputStream}

import com.twitter.io.TempFile

object EvalSpec extends Specification {
  "Evaluator" should {
    "apply('expression')" in {
      (new Eval).apply[Int]("1 + 1") mustEqual 2
    }

    "apply(new File(...))" in {
      (new Eval).apply[Int](TempFile.fromResourcePath("/OnePlusOne.scala")) mustEqual 2
    }

    "apply(new File(...), new File(...))" in {
      val derived = (new Eval).apply[() => String](
        TempFile.fromResourcePath("/Base.scala"),
        TempFile.fromResourcePath("/Derived.scala"))
      derived() mustEqual "hello"
    }

    "apply(new File(...) with target" in {
      val f = File.createTempFile("eval", "target")
      f.delete()
      f.mkdir()
      val e = new Eval(Some(f))
      val sourceFile = TempFile.fromResourcePath("/OnePlusOne.scala")
      val res: Int = e(sourceFile)
      res mustEqual 2

      // make sure it created a class file with the expected name
      val targetFileName = f.getAbsolutePath() + File.separator + "Evaluator__" + sourceFile.getName + ".class"
      val targetFile = new File(targetFileName)
      targetFile.exists must be_==(true)
      val targetMod = targetFile.lastModified

      // eval again, make sure it works
      val res2: Int = e(sourceFile)
      // and make sure it didn't create a new file
      f.listFiles.length mustEqual 1
      // and make sure it didn't update the file
      val targetFile2 = new File(targetFileName)
      targetFile2.lastModified mustEqual targetMod

      // touch source, ensure recompile
      sourceFile.setLastModified(System.currentTimeMillis())
      val res3: Int = e(sourceFile)
      res3 mustEqual 2
      // and make sure it didn't create a different file
      f.listFiles.length mustEqual 1
      // and make sure it updated the file
      val targetFile3 = new File(targetFileName)
      targetFile3.lastModified must be_>=(targetMod)
    }

    "apply(InputStream)" in {
      (new Eval).apply[Int](getClass.getResourceAsStream("/OnePlusOne.scala")) mustEqual 2
    }

    "inPlace('expression')" in {
      // Old object API works
      Eval.compile("object Doubler { def apply(n: Int) = n * 2 }")
      Eval.inPlace[Int]("Doubler(2)") mustEqual 4
      Eval.inPlace[Int]("Doubler(14)") mustEqual 28
      // New class API fails
      // val eval = new Eval
      // eval.compile("object Doubler { def apply(n: Int) = n * 2 }")
      // eval.inPlace[Int]("Doubler(2)") mustEqual 4
      // eval.inPlace[Int]("Doubler(14)") mustEqual 28
    }

    "check" in {
      (new Eval).check("23")      mustEqual ()
      (new Eval).check("invalid") must throwA[Eval.CompilerException]
    }

    "#include" in {
      val derived = Eval[() => String](
        TempFile.fromResourcePath("/Base.scala"),
        TempFile.fromResourcePath("/DerivedWithInclude.scala"))
      derived() mustEqual "hello"
      derived.toString mustEqual "hello, joe"
    }

    "recursive #include" in {
      val derived = Eval[() => String](
        TempFile.fromResourcePath("/Base.scala"),
        TempFile.fromResourcePath("/IncludeInclude.scala"))
      derived() mustEqual "hello"
      derived.toString mustEqual "hello, joe; hello, joe"
    }

    "toSource returns post-processed code" in {
      val derived = Eval.toSource(TempFile.fromResourcePath("/DerivedWithInclude.scala"))
      derived must include("hello, joe")
      derived must include("new Base")
    }

    "throws a compilation error when Ruby is #included" in {
      Eval[() => String](
        TempFile.fromResourcePath("RubyInclude.scala")) must throwA[Throwable]
    }
  }
}