// SPDX-License-Identifier: Apache-2.0

package chiselTests

import chisel3._
import circt.stage.ChiselStage
import org.scalatest.matchers.should.Matchers

import java.io.File

class SimpleTest extends Module {
  val io = IO(new Bundle {
    val in = Input(UInt(8.W))
    val out = Output(UInt(8.W))
  })
  io.out := io.in
  cover(io.in === 3.U)
  when(io.in === 3.U) {
    assume(io.in =/= 2.U)
    assert(io.out === io.in)
  }
}

class VerificationSpec extends ChiselPropSpec with Matchers {

  def assertContains(s: Seq[String], x: String): Unit = {
    val containsLine = s.map(_.contains(x)).reduce(_ || _)
    assert(containsLine, s"\n  $x\nwas not found in`\n  ${s.mkString("\n  ")}``")
  }

  property("basic equality check should work") {
    val fir = ChiselStage.emitCHIRRTL(new SimpleTest)
    val lines = fir.split("\n").map(_.trim).toIndexedSeq

    // reset guard around the verification statement
    assertContains(lines, "when _T_2 : ")
    assertContains(lines, "cover(clock, _T, UInt<1>(\"h1\"), \"\")")

    assertContains(lines, "when _T_6 : ")
    assertContains(lines, "assume(clock, _T_4, UInt<1>(\"h1\"), \"\")")

    assertContains(lines, "when _T_10 : ")
    assertContains(lines, "assert(clock, _T_8, UInt<1>(\"h1\"), \"\")")
  }

  property("annotation of verification constructs should work") {

    /** Circuit that contains and annotates verification nodes. */
    class AnnotationTest extends Module {
      val io = IO(new Bundle {
        val in = Input(UInt(8.W))
        val out = Output(UInt(8.W))
      })
      io.out := io.in
      val cov = cover(io.in === 3.U)
      val assm = chisel3.assume(io.in =/= 2.U)
      val asst = chisel3.assert(io.out === io.in)
    }

    // compile circuit
    val testDir = new File("test_run_dir", "VerificationAnnotationTests")
    ChiselStage.emitSystemVerilogFile(gen = new AnnotationTest, args = Array("-td", testDir.getPath))

    // read in FIRRTL file
    val svFile = new File(testDir, "AnnotationTest.sv")
    svFile should exist
    val svLines = scala.io.Source.fromFile(svFile).getLines().toList

    // check that verification appear in verilog output
    exactly(1, svLines) should include("cover__cov: cov")
    exactly(1, svLines) should include("assume__assm: assume")
  }
}
