/*                     __                                               *\
**     ________ ___   / /  ___      __ ____  Scala.js Test Suite        **
**    / __/ __// _ | / /  / _ | __ / // __/  (c) 2013, LAMP/EPFL        **
**  __\ \/ /__/ __ |/ /__/ __ |/_// /_\ \    http://scala-js.org/       **
** /____/\___/_/ |_/____/_/ | |__/ /____/                               **
**                          |/____/                                     **
\*                                                                      */
package scala.scalajs.testsuite.niocharset

import java.nio._
import java.nio.charset._

import scala.scalajs.niocharset.StandardCharsets

import BaseCharsetTest._

abstract class BaseUTF16Test(charset: Charset) extends BaseCharsetTest(charset) {
  describe(charset.name) {
    it("decode") {
      // ASCII characters
      testDecode(bb"0042 006f 006e 006a 006f 0075 0072")(cb"Bonjour")

      // Other characters without surrogate pairs
      testDecode(bb"0047 0072 00fc 00df 0020 0047 006f 0074 0074")(cb"Grüß Gott")
      testDecode(bb"039a 03b1 03bb 03b7 03bc 03ad 03c1 03b1")(cb"Καλημέρα")
      testDecode(bb"0635 0628 0627 062d 0020 0627 0644 062e 064a 0631")(cb"صباح الخير")
      testDecode(bb"3053 3093 306b 3061 306f")(cb"こんにちは")
      testDecode(bb"0414 043e 0431 0440 044b 0439 0020 0434 0435 043d 044c")(cb"Добрый день")
      testDecode(bb"4f60 597d")(cb"你好")

      // 4-byte characters
      testDecode(bb"d835 dcd7 d835 dcee d835 dcf5 d835 dcf5 d835 dcf8")(
          cb"\ud835\udcd7\ud835\udcee\ud835\udcf5\ud835\udcf5\ud835\udcf8")

      testDecode(bb"")(cb"")

      // Here begin the sequences with at least one error

      // Single UTF-16 surrogates
      testDecode(bb"d800")(Malformed(2))
      testDecode(bb"daff")(Malformed(2))
      testDecode(bb"db80")(Malformed(2))
      testDecode(bb"dbff")(Malformed(2))
      testDecode(bb"dc00")(Malformed(2))
      testDecode(bb"df80")(Malformed(2))
      testDecode(bb"dfff")(Malformed(2))

      // High UTF-16 surrogates not followed by low surrogates
      testDecode(bb"d800 0041")(Malformed(2), cb"A")
      testDecode(bb"d800 d800")(Malformed(2), Malformed(2))
      testDecode(bb"d800 d835 dcd7")(Malformed(2), cb"\ud835\udcd7")
      testDecode(bb"dbff 0041")(Malformed(2), cb"A")
      testDecode(bb"dbff db8f")(Malformed(2), Malformed(2))
      testDecode(bb"dbff d835 dcd7")(Malformed(2), cb"\ud835\udcd7")

      // Lonely byte at the end
      testDecode(bb"0041 41")(cb"A", Malformed(1))
    }

    it("encode") {
      // ASCII characters
      testEncode(cb"Bonjour")(bb"0042 006f 006e 006a 006f 0075 0072")

      // Other characters without surrogate pairs
      testEncode(cb"Grüß Gott")(bb"0047 0072 00fc 00df 0020 0047 006f 0074 0074")
      testEncode(cb"Καλημέρα")(bb"039a 03b1 03bb 03b7 03bc 03ad 03c1 03b1")
      testEncode(cb"صباح الخير")(bb"0635 0628 0627 062d 0020 0627 0644 062e 064a 0631")
      testEncode(cb"こんにちは")(bb"3053 3093 306b 3061 306f")
      testEncode(cb"Добрый день")(bb"0414 043e 0431 0440 044b 0439 0020 0434 0435 043d 044c")
      testEncode(cb"你好")(bb"4f60 597d")

      // 4-byte characters
      testEncode(cb"\ud835\udcd7\ud835\udcee\ud835\udcf5\ud835\udcf5\ud835\udcf8")(
          bb"d835 dcd7 d835 dcee d835 dcf5 d835 dcf5 d835 dcf8")

      testEncode(cb"")(bb"")

      // Here begin the sequences with at least one error

      // Single UTF-16 surrogates
      testEncode(cb"\ud800")(Malformed(1))
      testEncode(cb"\udaff")(Malformed(1))
      testEncode(cb"\udb80")(Malformed(1))
      testEncode(cb"\udbff")(Malformed(1))
      testEncode(cb"\udc00")(Malformed(1))
      testEncode(cb"\udf80")(Malformed(1))
      testEncode(cb"\udfff")(Malformed(1))

      // High UTF-16 surrogates not followed by low surrogates
      testEncode(cb"\ud800A")(Malformed(1), bb"0041")
      testEncode(cb"\ud800\ud800")(Malformed(1), Malformed(1))
      testEncode(cb"\ud800\ud835\udcd7")(Malformed(1), bb"d835 dcd7")
      testEncode(cb"\udbffA")(Malformed(1), bb"0041")
      testEncode(cb"\udbff\udb8f")(Malformed(1), Malformed(1))
      testEncode(cb"\udbff\ud835\udcd7")(Malformed(1), bb"d835 dcd7")
    }
  }
}

object UTF16BETest extends BaseUTF16Test(StandardCharsets.UTF_16BE)

object UTF16LETest extends BaseUTF16Test(StandardCharsets.UTF_16LE) {
  override protected def testDecode(in: ByteBuffer)(
      outParts: OutPart[CharBuffer]*): Unit = {
    flipByteBuffer(in)
    super.testDecode(in)(outParts: _*)
  }

  override protected def testEncode(in: CharBuffer)(
      outParts: OutPart[ByteBuffer]*): Unit = {
    for (BufferPart(buf) <- outParts)
      flipByteBuffer(buf)
    super.testEncode(in)(outParts: _*)
  }

  /** Flips all pairs of bytes in a byte buffer, except a potential lonely
   *  last byte.
   */
  def flipByteBuffer(buf: ByteBuffer): Unit = {
    buf.mark()
    while (buf.remaining() >= 2) {
      val high = buf.get()
      val low = buf.get()
      buf.position(buf.position - 2)
      buf.put(low)
      buf.put(high)
    }
    buf.reset()
  }
}

object UTF16Test extends BaseUTF16Test(StandardCharsets.UTF_16) {
  def BigEndianBOM = ByteBuffer.wrap(Array(0xfe.toByte, 0xff.toByte))

  override protected def testDecode(in: ByteBuffer)(
      outParts: OutPart[CharBuffer]*): Unit = {
    // Without BOM, big endian is assumed
    super.testDecode(in)(outParts: _*)

    // With BOM, big endian
    val inWithBOM = ByteBuffer.allocate(2+in.remaining)
    inWithBOM.put(BigEndianBOM).put(in).flip()
    super.testDecode(inWithBOM)(outParts: _*)

    // With BOM, little endian
    UTF16LETest.flipByteBuffer(inWithBOM)
    super.testDecode(inWithBOM)(outParts: _*)
  }

  override protected def testEncode(in: CharBuffer)(
      outParts: OutPart[ByteBuffer]*): Unit = {
    if (in.remaining == 0) super.testEncode(in)(outParts: _*)
    else super.testEncode(in)(BufferPart(BigEndianBOM) +: outParts: _*)
  }
}