/*
 * Copyright (c) 2023 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import type {
  Expression,
  Identifier,
  Node,
  ObjectBindingPattern,
  SourceFile,
  TypeChecker,
  TransformationContext,
  TransformerFactory
} from 'typescript';
import {
  Symbol,
  SyntaxKind,
  getModifiers,
  isBinaryExpression,
  isBindingElement,
  isCallExpression,
  isClassDeclaration,
  isClassExpression,
  isComputedPropertyName,
  isConstructorDeclaration,
  isElementAccessExpression,
  isEnumMember,
  isGetAccessor,
  isIdentifier,
  isMetaProperty,
  isMethodDeclaration,
  isMethodSignature,
  isParameter,
  isPrivateIdentifier,
  isPropertyAccessExpression,
  isPropertyAssignment,
  isPropertyDeclaration,
  isPropertySignature,
  isQualifiedName,
  isSetAccessor,
  isVariableDeclaration,
  visitEachChild
} from 'typescript';
import {
  getViewPUClassProperties,
  isParameterPropertyModifier,
  isViewPUBasedClass,
  visitEnumInitializer
} from './OhsUtil';
import { Extension } from '../common/type';
import { MergedConfig } from '../initialization/ConfigResolver';

export class NodeUtils {
  public static isPropertyDeclarationNode(node: Node): boolean {
    let parent: Node | undefined = node.parent;
    if (!parent) {
      return false;
    }

    /** eg: { 'name'' : 'akira' }, pass */
    if (isPropertyAssignment(parent)) {
      return parent.name === node;
    }

    if (isComputedPropertyName(parent) && parent.expression === node) {
      return true;
    }

    /** object binding pattern */
    if (isBindingElement(parent) && parent.propertyName === node) {
      return true;
    }

    /** eg: interface/type inf { 'name' : string}, pass */
    if (isPropertySignature(parent) && parent.name === node) {
      return true;
    }

    /** eg: interface/type T1 { func(arg: string): number;} */
    if (isMethodSignature(parent) && parent.name === node) {
      return true;
    }

    /** eg: enum { xxx = 1}; */
    if (isEnumMember(parent) && parent.name === node) {
      return true;
    }

    /** class { private name= 1}; */
    if (isPropertyDeclaration(parent) && parent.name === node) {
      return true;
    }

    /** class {'getName': function() {}} let _ = { getName() [}} */
    if (isMethodDeclaration(parent) && parent.name === node) {
      return true;
    }

    if (isSetAccessor(parent) && parent.name === node) {
      return true;
    }

    return isGetAccessor(parent) && parent.name === node;
  }

  public static isPropertyOrElementAccessNode(node: Node): boolean {
    return this.isPropertyAccessNode(node) || this.isElementAccessNode(node) || false;
  }

  public static isPropertyAccessNode(node: Node): boolean {
    let parent: Node | undefined = node.parent;
    if (!parent) {
      return false;
    }

    /** eg: a.b = 1 */
    if (isPropertyAccessExpression(parent) && parent.name === node) {
      return true;
    }
    if (isPrivateIdentifier(node) && NodeUtils.isInClassDeclaration(parent)) {
      return NodeUtils.isInExpression(parent);
    }
    return isQualifiedName(parent) && parent.right === node;
  }

  private static isInClassDeclaration(node: Node | undefined): boolean {
    if (!node) {
      return false;
    }

    if (isClassDeclaration(node) || isClassExpression(node)) {
      return true;
    }

    return NodeUtils.isInClassDeclaration(node.parent);
  }
  
  public static isInClassDeclarationForTest(node: Node | undefined): boolean {
    return NodeUtils.isInClassDeclaration(node);
  }

  private static isInExpression(node: Node | undefined): boolean {
    return !!node && NodeUtils.isInOperator(node);
  }

  public static isInExpressionForTest(node: Node | undefined): boolean {
    return NodeUtils.isInExpression(node);
  }

  private static isInOperator(node: Node): boolean {
    return isBinaryExpression(node) && node.operatorToken.kind === SyntaxKind.InKeyword;
  }

  public static isInOperatorForTest(node: Node | undefined): boolean {
    return NodeUtils.isInOperator(node);
  }

  public static isElementAccessNode(node: Node): boolean {
    let parent: Node | undefined = node.parent;
    if (!parent) {
      return false;
    }

    return isElementAccessExpression(parent) && parent.argumentExpression === node;
  }

  public static isClassPropertyInConstructorParams(node: Node): boolean {
    if (!isIdentifier(node)) {
      return false;
    }

    if (!node.parent || !isParameter(node.parent)) {
      return false;
    }

    const modifiers = getModifiers(node.parent);
    if (!modifiers || modifiers.length === 0 || !modifiers.find(modifier => isParameterPropertyModifier(modifier))) {
      return false;
    }

    return node.parent.parent && isConstructorDeclaration(node.parent.parent);
  }

  public static isClassPropertyInConstructorBody(node: Node, constructorParams: Set<string>): boolean {
    if (!isIdentifier(node)) {
      return false;
    }

    const id: string = node.escapedText.toString();
    let curNode: Node = node.parent;
    while (curNode) {
      if (isConstructorDeclaration(curNode) && constructorParams.has(id)) {
        return true;
      }

      curNode = curNode.parent;
    }

    return false;
  }

  public static isPropertyNode(node: Node): boolean {
    if (this.isPropertyOrElementAccessNode(node)) {
      return true;
    }

    return this.isPropertyDeclarationNode(node);
  }

  public static isObjectBindingPatternAssignment(node: ObjectBindingPattern): boolean {
    if (!node || !node.parent || !isVariableDeclaration(node.parent)) {
      return false;
    }

    const initializer: Expression = node.parent.initializer;
    return initializer && isCallExpression(initializer);
  }

  public static isDeclarationFile(node: SourceFile): boolean {
    return node.isDeclarationFile;
  }

  public static getSourceFileOfNode(node: Node): SourceFile {
    while (node && node.kind !== SyntaxKind.SourceFile) {
      node = node.parent;
    }
    return <SourceFile>node;
  }

  public static isDETSFile(node: Node | undefined): boolean {
    return !!node && NodeUtils.getSourceFileOfNode(node).fileName.endsWith(Extension.DETS);
  }

  public static isNewTargetNode(node: Identifier): boolean {
    if (isMetaProperty(node.parent) && node.parent.keywordToken === SyntaxKind.NewKeyword && node.escapedText === 'target') {
      return true;
    }
    return false;
  }

  public static findSymbolOfIdentifier(checker: TypeChecker, node: Identifier): Symbol | undefined {
    let sym: Symbol | undefined = checker.getSymbolAtLocation(node);
    if (!sym || (sym && sym.name !== 'default')) {
      return sym;
    }
    /* Handle default exports, eg. export default class Ability {};
       The expected symbol we want to find to obfuscate is named "Ability",
       but `getSymbolAtLocation` will return the symbol named "default", so we need to continue to search.
    */
    let localSyms: Symbol[] = checker.getSymbolsInScope(node, sym.flags);
    for (let i = 0; i < localSyms.length; i++) {
      const localSym = localSyms[i];
      // `localSym` named "Ability" has property `exportSymbol` named "default" that we find by `getSymbolAtLocation`,
      // So the `localSym` is what we want to obfuscate.
      if (localSym && localSym.name === node.text && localSym.exportSymbol === sym) {
        sym = localSym;
        break;
      }
    }
    return sym;
  }
}

/**
 * When enabling property obfuscation, collect the properties of struct.
 * When enabling property obfuscation and the compilation output is a TS file,
 * collect the Identifier names in the initialization expressions of enum members.
 */
export function collectReservedNameForObf(obfuscationConfig: MergedConfig | undefined, shouldTransformToJs: boolean): TransformerFactory<SourceFile> {
  const disableObf = obfuscationConfig?.options === undefined || obfuscationConfig.options.disableObfuscation;
  const enablePropertyObf = obfuscationConfig?.options.enablePropertyObfuscation;
  // process.env.compiler === 'on': indicates that during the Webpack packaging process,
  // the code is executed here for the first time.
  // During the Webpack packaging process, this step will be executed twice,
  // but only the first time will it perform subsequent operations to prevent repetition.
  const shouldCollect = (process.env.compiler === 'on' || process.env.compileTool === 'rollup') &&
                        !disableObf && enablePropertyObf;

  return (context: TransformationContext) => {
    return (node: SourceFile) => {
      if (shouldCollect) {
        node = visitEachChild(node, collectReservedNames, context);
      }
      return node;
    };

    function collectReservedNames(node: Node): Node {
      // collect properties of struct
      if (isClassDeclaration(node) && isViewPUBasedClass(node)) {
        getViewPUClassProperties(node);
      }

      // collect enum properties
      if (!shouldTransformToJs && isEnumMember(node) && node.initializer) {
        node.initializer.forEachChild(visitEnumInitializer);
        return node;
      }

      return visitEachChild(node, collectReservedNames, context);
    }
  };
}