import {
  Expression,
  Joinpoint,
  ParenType,
  PointerType,
  Scope,
  Statement,
  Type,
  VariableArrayType,
  Varref,
} from "../Joinpoints.js";
import ClavaJoinPoints from "./ClavaJoinPoints.js";
import ClavaJavaTypes from "./ClavaJavaTypes.js";

/**
 * Utility methods related with the type join points.
 *
 */
export default class ClavaType {
  /**
   * @param type - The type to visit
   * @param exprFunction - A function that receives an $expr join point
   *
   * @returns The $type after applying the given exprFunction to its $expr nodes. If any of the fields of the type is visited, a copy of the type is returned.
   */
  static visitExprInTypeCopy(
    $type: Type,
    exprFunction: (expr: Expression) => void
  ): Type {
    if ($type instanceof PointerType) {
      const $typeCopy = $type.copy() as PointerType;
      $typeCopy.setPointee(
        ClavaType.visitExprInTypeCopy($typeCopy.pointee, exprFunction)
      );
      return $typeCopy;
    }

    if ($type instanceof ParenType) {
      const $typeCopy = $type.copy() as ParenType;
      $typeCopy.setDesugar(
        ClavaType.visitExprInTypeCopy($typeCopy.desugar, exprFunction)
      );
      return $typeCopy;
    }

    if ($type instanceof VariableArrayType) {
      const $typeCopy = $type.copy() as VariableArrayType;
      $typeCopy.setSizeExpr($typeCopy.sizeExpr.copy() as Expression);
      exprFunction($typeCopy.sizeExpr);
      return $typeCopy;
    }

    return $type;
  }

  /**
   * @param type - A type join point that will be visited looking for $expr join points. Any visited nodes in the type (e.g., desugar) will be copied, so that the returned varrefs can be safely modified.
   * @param varrefs - An array (possibly empty) where the $varref join points found in the given type will be stored
   *
   * @returns A copy of the given $type, to which the varrefs refer to
   */
  static getVarrefsInTypeCopy($type: Type, varrefs: Varref[]) {
    const exprFunction = function ($expr: Expression) {
      for (const $varref of $expr.getDescendantsAndSelf("varref") as Varref[]) {
        varrefs.push($varref);
      }
    };

    return ClavaType.visitExprInTypeCopy($type, exprFunction);
  }

  /**
   * Makes sure the given parameter is an expression join point.
   *
   * @param $expression - If a string, returns a literal expression with the code of the string. Otherwise, returns $expression
   * @param isOptional - If false and $expression is undefined, throws an exception. Otherwise, returns undefined if $expression is undefined.
   */
  static asExpression(
    $expression: Expression | undefined,
    isOptional = false
  ): Expression | undefined {
    if ($expression === undefined) {
      if (isOptional) {
        return undefined;
      } else {
        throw "ClavaType.asExpression: $expression is undefined. If this is allowed, set 'isOptional' to true.";
      }
    }

    return $expression;
  }

  /**
   * Makes sure the given parameter is a statement join point.
   *
   * @param code - If a string, returns a literal statement with the code of the string. Otherwise, tries to transform the given node to a $statement
   * @param isOptional - If false and code is undefined, throws an exception. Otherwise, returns undefined if code is undefined.
   */
  static asStatement(
    code: Joinpoint | undefined,
    isOptional = false
  ): Statement | undefined {
    if (code === undefined) {
      if (isOptional) {
        return undefined;
      } else {
        throw "ClavaType.asStatement: code is undefined. If this is allowed, set 'isOptional' to true.";
      }
    }

    const newStmtNode = ClavaJavaTypes.ClavaNodes.toStmt(code.node);

    return ClavaJoinPoints.toJoinPoint(newStmtNode) as Statement;
  }

  /**
   * Makes sure the given parameter is a type join point.
   *
   * @param $type - If a string, returns a literal type with the code of the string. Otherwise, returns $type
   *
   * @deprecated This method does not do anything, it is only kept for compatibility with the old API
   */
  static asType($type: Type): Type {
    return $type;
  }

  /**
   *  Makes sure the given parameter is a scope join point.
   *
   * @param code - If a string, returns a literal statement with the code of the string. Otherwise, returns $statement
   */
  static asScope(code: Joinpoint | undefined): Scope {
    const $newStmt = ClavaType.asStatement(code);

    const newScopeNode = ClavaJavaTypes.ClavaNodes.toCompoundStmt(
      $newStmt?.node
    );

    return ClavaJoinPoints.toJoinPoint(newScopeNode) as Scope;
  }
}