// SPDX-License-Identifier: Apache-2.0

package firrtl.transforms

import firrtl._

import firrtl.Utils.v_keywords
import firrtl.options.Dependency

/** Transform that removes collisions with reserved keywords
  * @param keywords a set of reserved words
  */
class RemoveKeywordCollisions(keywords: Set[String]) extends ManipulateNames {

  private val inlineDelim = "_"

  /** Generate a new name, by appending underscores, that will not conflict with the existing namespace
    * @param n a name
    * @param ns a [[Namespace]]
    * @return Some name if a rename occurred, None otherwise
    * @note prefix uniqueness is not respected
    */
  override def manipulate = (n: String, ns: Namespace) =>
    keywords.contains(n) match {
      case true  => Some(Namespace.findValidPrefix(n + inlineDelim, Seq(""), ns.cloneUnderlying ++ keywords))
      case false => None
    }

}

/** Transform that removes collisions with Verilog keywords */
class VerilogRename extends RemoveKeywordCollisions(v_keywords) {

  override def prerequisites = firrtl.stage.Forms.LowFormMinimumOptimized ++
    Seq(
      Dependency[BlackBoxSourceHelper],
      Dependency[FixAddingNegativeLiterals],
      Dependency[ReplaceTruncatingArithmetic],
      Dependency[InlineBitExtractionsTransform],
      Dependency[InlineAcrossCastsTransform],
      Dependency[LegalizeClocksAndAsyncResetsTransform],
      Dependency[FlattenRegUpdate],
      Dependency(passes.VerilogModulusCleanup)
    )

  override def optionalPrerequisites = firrtl.stage.Forms.LowFormOptimized

  override def optionalPrerequisiteOf = Seq.empty

}