// SPDX-License-Identifier: Apache-2.0

package chiselTests

import chisel3._
import chisel3.experimental.{DataMirror, FixedPoint, ChiselEnum}
import chisel3.testers.BasicTester

class AsTypeOfBundleTester extends BasicTester {
  class MultiTypeBundle extends Bundle {
    val u  = UInt(4.W)
    val s  = SInt(4.W)
    val fp = FixedPoint(4.W, 3.BP)
  }

  val bun = new MultiTypeBundle

  val bunAsTypeOf = ((4 << 8) + (15 << 4) + (12 << 0)).U.asTypeOf(bun)

  assert(bunAsTypeOf.u === 4.U)
  assert(bunAsTypeOf.s === -1.S)
  assert(bunAsTypeOf.fp === FixedPoint.fromDouble(-0.5, 4.W, 3.BP))

  stop()
}

class AsTypeOfBundleZeroWidthTester extends BasicTester {
  class ZeroWidthBundle extends Bundle {
    val a = UInt(0.W)
    val b = UInt(1.W)
    val c = UInt(0.W)
  }

  val bun = new ZeroWidthBundle

  val bunAsTypeOf = 1.U.asTypeOf(bun)

  assert(bunAsTypeOf.a === 0.U)
  assert(bunAsTypeOf.b === 1.U)
  assert(bunAsTypeOf.c === 0.U)

  stop()
}

class AsTypeOfVecTester extends BasicTester {
  val vec = ((15 << 12) + (0 << 8) + (1 << 4) + (2 << 0)).U.asTypeOf(Vec(4, SInt(4.W)))

  assert(vec(0) === 2.S)
  assert(vec(1) === 1.S)
  assert(vec(2) === 0.S)
  assert(vec(3) === -1.S)

  stop()
}

class AsTypeOfTruncationTester extends BasicTester {
  val truncate = (64 + 3).U.asTypeOf(UInt(3.W))
  val expand   = 1.U.asTypeOf(UInt(3.W))

  assert( DataMirror.widthOf(truncate).get == 3 )
  assert( truncate === 3.U )
  assert( DataMirror.widthOf(expand).get == 3 )
  assert( expand === 1.U )

  stop()
}

class ResetAsTypeOfBoolTester extends BasicTester {
  assert(reset.asTypeOf(Bool()) === reset.asBool)
  stop()
}

class AsTypeOfClockTester extends BasicTester {
  class MyBundle extends Bundle {
    val x = UInt(4.W)
    val y = Clock()
  }
  assert(true.B.asTypeOf(Clock()).asUInt.asBool === true.B)

  assert(0x1f.U.asTypeOf(new MyBundle).asUInt === 0x1f.U)
  stop()
}

class AsChiselEnumTester extends BasicTester {
  object MyEnum extends ChiselEnum {
    val foo, bar = Value
    val fizz = Value(2.U)
  }
  class MyBundle extends Bundle {
    val a = Bool()
    val b = Bool()
  }

  // To
  assert(2.U.asTypeOf(MyEnum()) === MyEnum.fizz)
  assert(VecInit(2.U.asBools).asTypeOf(MyEnum()) === MyEnum.fizz)
  assert(2.U.asTypeOf(new MyBundle).asTypeOf(MyEnum()) === MyEnum.fizz)

  // From
  assert(MyEnum.foo.asUInt === 0.U)
  val vec = MyEnum.bar.asTypeOf(Vec(2, Bool()))
  assert(vec(0) === 1.U)
  assert(vec(1) === 0.U)
  val bun = MyEnum.fizz.asTypeOf(new MyBundle)
  assert(bun.b === 0.U)
  assert(bun.a === 1.U)

  // In aggregate
  class OtherBundle extends Bundle {
    val enum = MyEnum()
    val foo = Bool()
  }
  val wire = Wire(new OtherBundle)
  wire.enum := MyEnum.fizz
  wire.foo := true.B

  assert(wire.asUInt === 5.U)
  val other = 5.U.asTypeOf(new OtherBundle)
  assert(other.enum === MyEnum.fizz)
  assert(other.foo === true.B)

  stop()
}

class AsTypeOfSpec extends ChiselFlatSpec {
  behavior of "asTypeOf"

  it should "work with Bundles containing Bits Types" in {
    assertTesterPasses{ new AsTypeOfBundleTester }
  }

  it should "work with Bundles that have fields of zero width" in {
    assertTesterPasses{ new AsTypeOfBundleZeroWidthTester }
  }

  it should "work with Vecs containing Bits Types" in {
    assertTesterPasses{ new AsTypeOfVecTester }
  }

  it should "expand and truncate UInts of different width" in {
    assertTesterPasses{ new AsTypeOfTruncationTester }
  }

  it should "work for casting implicit Reset to Bool" in {
    assertTesterPasses{ new ResetAsTypeOfBoolTester  }
  }

  it should "work for casting to and from ChiselEnums" in {
    assertTesterPasses(new AsChiselEnumTester)
  }

  it should "work for casting to and from Clock" in {
    assertTesterPasses(new AsTypeOfClockTester)
  }
}
