/**
 * @license
 * Copyright Google Inc. All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */
import { constructorParametersDownlevelTransform } from '@angular/compiler-cli';
import * as ts from 'typescript';
import { elideImports } from '../transformers/elide_imports';
import { removeIvyJitSupportCalls } from '../transformers/remove-ivy-jit-support-calls';
import { replaceResources } from '../transformers/replace_resources';

export function createAotTransformers(
  builder: ts.BuilderProgram,
  options: { emitClassMetadata?: boolean; emitNgModuleScope?: boolean },
): ts.CustomTransformers {
  const getTypeChecker = () => builder.getProgram().getTypeChecker();
  const transformers: ts.CustomTransformers = {
    before: [replaceBootstrap(getTypeChecker)],
    after: [],
  };

  const removeClassMetadata = !options.emitClassMetadata;
  const removeNgModuleScope = !options.emitNgModuleScope;
  if (removeClassMetadata || removeNgModuleScope) {
    // tslint:disable-next-line: no-non-null-assertion
    transformers.before!.push(
      removeIvyJitSupportCalls(removeClassMetadata, removeNgModuleScope, getTypeChecker),
    );
  }

  return transformers;
}

export function createJitTransformers(
  builder: ts.BuilderProgram,
  options: { directTemplateLoading?: boolean },
): ts.CustomTransformers {
  const getTypeChecker = () => builder.getProgram().getTypeChecker();

  return {
    before: [
      replaceResources(() => true, getTypeChecker, options.directTemplateLoading),
      constructorParametersDownlevelTransform(builder.getProgram()),
    ],
  };
}

export function mergeTransformers(
  first: ts.CustomTransformers,
  second: ts.CustomTransformers,
): ts.CustomTransformers {
  const result: ts.CustomTransformers = {};

  if (first.before || second.before) {
    result.before = [...(first.before || []), ...(second.before || [])];
  }

  if (first.after || second.after) {
    result.after = [...(first.after || []), ...(second.after || [])];
  }

  if (first.afterDeclarations || second.afterDeclarations) {
    result.afterDeclarations = [
      ...(first.afterDeclarations || []),
      ...(second.afterDeclarations || []),
    ];
  }

  return result;
}

export function replaceBootstrap(
  getTypeChecker: () => ts.TypeChecker,
): ts.TransformerFactory<ts.SourceFile> {
  return (context: ts.TransformationContext) => {
    let bootstrapImport: ts.ImportDeclaration | undefined;
    let bootstrapNamespace: ts.Identifier | undefined;
    const replacedNodes: ts.Node[] = [];

    const visitNode: ts.Visitor = (node: ts.Node) => {
      if (ts.isCallExpression(node) && ts.isIdentifier(node.expression)) {
        const target = node.expression;
        if (target.text === 'platformBrowserDynamic') {
          if (!bootstrapNamespace) {
            bootstrapNamespace = ts.createUniqueName('__NgCli_bootstrap_');
            bootstrapImport = ts.createImportDeclaration(
              undefined,
              undefined,
              ts.createImportClause(undefined, ts.createNamespaceImport(bootstrapNamespace)),
              ts.createLiteral('@angular/platform-browser'),
            );
          }
          replacedNodes.push(target);

          return ts.updateCall(
            node,
            ts.createPropertyAccess(bootstrapNamespace, 'platformBrowser'),
            node.typeArguments,
            node.arguments,
          );
        }
      }

      return ts.visitEachChild(node, visitNode, context);
    };

    return (sourceFile: ts.SourceFile) => {
      let updatedSourceFile = ts.visitEachChild(sourceFile, visitNode, context);

      if (bootstrapImport) {
        // Remove any unused platform browser dynamic imports
        const removals = elideImports(
          updatedSourceFile,
          replacedNodes,
          getTypeChecker,
          context.getCompilerOptions(),
        ).map((op) => op.target);
        if (removals.length > 0) {
          updatedSourceFile = ts.visitEachChild(
            updatedSourceFile,
            (node) => (removals.includes(node) ? undefined : node),
            context,
          );
        }

        // Add new platform browser import
        return ts.updateSourceFileNode(
          updatedSourceFile,
          ts.setTextRange(
            ts.createNodeArray([bootstrapImport, ...updatedSourceFile.statements]),
            sourceFile.statements,
          ),
        );
      } else {
        return updatedSourceFile;
      }
    };
  };
}
