// SPDX-License-Identifier: Apache-2.0

package chisel3

import scala.language.experimental.macros
import scala.reflect.macros.blackbox.Context

trait CompileOptions {

  /** Should Record connections require a strict match of fields.
    *
    * If true and the same fields aren't present in both source and sink, a MissingFieldException,
    * MissingLeftFieldException, or MissingRightFieldException will be thrown.
    */
  val connectFieldsMustMatch: Boolean

  /** When creating an object that takes a type argument, the argument must be unbound (a pure type). */
  val declaredTypeMustBeUnbound: Boolean

  /** If a connection operator fails, don't try the connection with the operands (source and sink) reversed. */
  val dontTryConnectionsSwapped: Boolean

  /** If connection directionality is not explicit, do not use heuristics to attempt to determine it. */
  val dontAssumeDirectionality: Boolean

  /** Check that referenced Data have actually been declared. */
  val checkSynthesizable: Boolean

  /** Require explicit assignment of DontCare to generate "x is invalid" */
  val explicitInvalidate: Boolean

  /** Should the reset type of Module be a Bool or a Reset */
  val inferModuleReset: Boolean

  /** If marked true, then any Module which consumes `inferModuleReset=false` must also mix in [[RequireSyncReset]] */
  def migrateInferModuleReset: Boolean = false

  /** Should connects emit as firrtl <= instead of <- */
  def emitStrictConnects: Boolean = true
}

object CompileOptions {
  // Provides a low priority Strict default. Can be overridden by importing the NotStrict option.
  // Implemented as a macro to prevent this from being used inside chisel core.
  implicit def materialize: CompileOptions = macro materialize_impl

  def materialize_impl(c: Context): c.Tree = {
    import c.universe._
    q"_root_.chisel3.ExplicitCompileOptions.Strict"
  }
}

object ExplicitCompileOptions {

  case class CompileOptionsClass(
    // Should Record connections require a strict match of fields.
    // If true and the same fields aren't present in both source and sink, a MissingFieldException,
    // MissingLeftFieldException, or MissingRightFieldException will be thrown.
    val connectFieldsMustMatch: Boolean,
    // When creating an object that takes a type argument, the argument must be unbound (a pure type).
    val declaredTypeMustBeUnbound: Boolean,
    // If a connection operator fails, don't try the connection with the operands (source and sink) reversed.
    val dontTryConnectionsSwapped: Boolean,
    // If connection directionality is not explicit, do not use heuristics to attempt to determine it.
    val dontAssumeDirectionality: Boolean,
    // Check that referenced Data have actually been declared.
    val checkSynthesizable: Boolean,
    // Require an explicit DontCare assignment to generate a firrtl DefInvalid
    val explicitInvalidate: Boolean,
    // Should the reset type of Module be a Bool or a Reset
    val inferModuleReset: Boolean)
      extends CompileOptions

  // Collection of "not strict" connection compile options.
  // These provide compatibility with existing code.
  implicit val NotStrict = new CompileOptionsClass(
    connectFieldsMustMatch = false,
    declaredTypeMustBeUnbound = false,
    dontTryConnectionsSwapped = false,
    dontAssumeDirectionality = false,
    checkSynthesizable = false,
    explicitInvalidate = false,
    inferModuleReset = false
  ) {
    override def migrateInferModuleReset = false
    override def emitStrictConnects = false
    override def copy(
      connectFieldsMustMatch:    Boolean = false,
      declaredTypeMustBeUnbound: Boolean = false,
      dontTryConnectionsSwapped: Boolean = false,
      dontAssumeDirectionality:  Boolean = false,
      checkSynthesizable:        Boolean = false,
      explicitInvalidate:        Boolean = false,
      inferModuleReset:          Boolean = false
    ) = new CompileOptionsClass(
      connectFieldsMustMatch,
      declaredTypeMustBeUnbound,
      dontTryConnectionsSwapped,
      dontAssumeDirectionality,
      checkSynthesizable,
      explicitInvalidate,
      inferModuleReset
    ) {
      override def migrateInferModuleReset = false
      override def emitStrictConnects = false
    }
  }

  // Collection of "strict" connection compile options, preferred for new code.
  implicit val Strict = new CompileOptionsClass(
    connectFieldsMustMatch = true,
    declaredTypeMustBeUnbound = true,
    dontTryConnectionsSwapped = true,
    dontAssumeDirectionality = true,
    checkSynthesizable = true,
    explicitInvalidate = true,
    inferModuleReset = true
  ) {

    override def migrateInferModuleReset = false
    override def emitStrictConnects = true

    override def copy(
      connectFieldsMustMatch:    Boolean = true,
      declaredTypeMustBeUnbound: Boolean = true,
      dontTryConnectionsSwapped: Boolean = true,
      dontAssumeDirectionality:  Boolean = true,
      checkSynthesizable:        Boolean = true,
      explicitInvalidate:        Boolean = true,
      inferModuleReset:          Boolean = true
    ) = new CompileOptionsClass(
      connectFieldsMustMatch,
      declaredTypeMustBeUnbound,
      dontTryConnectionsSwapped,
      dontAssumeDirectionality,
      checkSynthesizable,
      explicitInvalidate,
      inferModuleReset
    ) {
      override def migrateInferModuleReset = false
      override def emitStrictConnects = true
    }
  }
}
