package org.checkerframework.framework.test;

import java.io.File;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.List;
import javax.tools.DiagnosticCollector;
import javax.tools.JavaCompiler;
import javax.tools.JavaFileObject;
import javax.tools.StandardJavaFileManager;
import javax.tools.ToolProvider;
import org.checkerframework.framework.test.diagnostics.JavaDiagnosticReader;
import org.checkerframework.framework.test.diagnostics.TestDiagnostic;
import org.checkerframework.framework.util.PluginUtil;

/** Used by the Checker Framework test suite to run the framework and generate a test result. */
public class TypecheckExecutor {

    public TypecheckExecutor() {}

    /** Runs a typechecking test using the given configuration and returns the test result */
    public TypecheckResult runTest(TestConfiguration configuration) {
        CompilationResult result = compile(configuration);
        return interpretResults(configuration, result);
    }

    /**
     * Using the settings from the input configuration, compile all source files in the
     * configuration, and return place the result in a CompilationResult
     */
    public CompilationResult compile(TestConfiguration configuration) {
        TestUtilities.ensureDirectoryExists(new File(configuration.getOptions().get("-d")));

        final StringWriter javacOutput = new StringWriter();
        DiagnosticCollector<JavaFileObject> diagnostics = new DiagnosticCollector<JavaFileObject>();

        JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
        StandardJavaFileManager fileManager = compiler.getStandardFileManager(null, null, null);
        Iterable<? extends JavaFileObject> javaFiles =
                fileManager.getJavaFileObjects(
                        configuration.getTestSourceFiles().toArray(new File[] {}));

        // Even though the method compiler.getTask takes a list of processors, it fails if processors are passed this way
        // with the message:
        // error: Class names, 'org.checkerframework.checker.interning.InterningChecker', are only accepted if
        // annotation processing is explicitly requested
        // Therefore, we now add them to the beginning of the options list
        final List<String> options = new ArrayList<String>();
        options.add("-processor");
        options.add(PluginUtil.join(",", configuration.getProcessors()));
        List<String> nonJvmOptions = new ArrayList<String>();
        for (String option : configuration.getFlatOptions()) {
            if (!option.startsWith("-J-")) {
                nonJvmOptions.add(option);
            }
        }
        nonJvmOptions.add("-Xmaxerrs");
        nonJvmOptions.add("100000");
        nonJvmOptions.add("-Xmaxwarns");
        nonJvmOptions.add("100000");
        options.addAll(nonJvmOptions);

        if (configuration.shouldEmitDebugInfo()) {
            System.out.println("Running test using the following invocation:");
            System.out.println(
                    "javac "
                            + PluginUtil.join(" ", options)
                            + " "
                            + PluginUtil.join(" ", configuration.getTestSourceFiles()));
        }

        JavaCompiler.CompilationTask task =
                compiler.getTask(
                        javacOutput,
                        fileManager,
                        diagnostics,
                        options,
                        new ArrayList<String>(),
                        javaFiles);

        /*
         * In Eclipse, std out and std err for multiple tests appear as one
         * long stream. When selecting a specific failed test, one sees the
         * expected/unexpected messages, but not the std out/err messages from
         * that particular test. Can we improve this somehow?
         */
        final Boolean compiledWithoutError = task.call();
        javacOutput.flush();
        return new CompilationResult(
                compiledWithoutError,
                javacOutput.toString(),
                javaFiles,
                diagnostics.getDiagnostics());
    }

    /**
     * Reads the expected diagnostics for the given configuration and creates a TypecheckResult
     * which contains all of the missing and expected diagnostics
     */
    public TypecheckResult interpretResults(
            TestConfiguration config, CompilationResult compilationResult) {
        List<TestDiagnostic> expectedDiagnostics = readDiagnostics(config, compilationResult);
        return TypecheckResult.fromCompilationResults(
                config, compilationResult, expectedDiagnostics);
    }

    /**
     * Added in case a subclass wishes to filter out errors or add new expected errors. This method
     * is called immediately before results are checked.
     */
    protected List<TestDiagnostic> readDiagnostics(
            TestConfiguration config, CompilationResult compilationResult) {
        List<TestDiagnostic> expectedDiagnostics;
        if (config.getDiagnosticFiles() == null || config.getDiagnosticFiles().isEmpty()) {
            expectedDiagnostics =
                    JavaDiagnosticReader.readExpectedDiagnosticsJfo(
                            compilationResult.getJavaFileObjects(), true);
        } else {
            expectedDiagnostics =
                    JavaDiagnosticReader.readDiagnosticFiles(config.getDiagnosticFiles(), true);
        }

        return expectedDiagnostics;
    }
}