// Copyright 2022 Google LLC

//

// 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

//

// https://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.

package codelab;

import dev.cel.common.CelAbstractSyntaxTree;

import dev.cel.common.CelValidationException;

import dev.cel.common.types.SimpleType;

import dev.cel.compiler.CelCompiler;

import dev.cel.compiler.CelCompilerFactory;

import dev.cel.runtime.CelEvaluationException;

import dev.cel.runtime.CelRuntime;

import dev.cel.runtime.CelRuntimeFactory;

final class Exercise3 {

private static final CelCompiler CEL_COMPILER =

CelCompilerFactory.standardCelCompilerBuilder().setResultType(SimpleType.BOOL).build();

private static final CelRuntime CEL_RUNTIME =

CelRuntimeFactory.standardCelRuntimeBuilder().build();

/**

* Compiles the given expression and evaluates it.

*

* @throws IllegalArgumentException If the expression fails to compile or evaluate

*/

Object compileAndEvaluate(String expression) {

CelAbstractSyntaxTree ast;

try {

ast = CEL_COMPILER.compile(expression).getAst();

} catch (CelValidationException e) {

throw new IllegalArgumentException("Failed to compile expression.", e);

}

try {

CelRuntime.Program program = CEL_RUNTIME.createProgram(ast);

return program.eval();

} catch (CelEvaluationException e) {

throw new IllegalArgumentException("Evaluation error has occurred.", e);

}

}

}