/*
 * Copyright  2001-2004 The Apache Software Foundation
 *
 *  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.
 *
 */

package org.drools.contrib;

import java.io.File;
import java.io.PrintStream;
import java.net.URL;

import junit.framework.TestCase;

import org.apache.tools.ant.BuildEvent;
import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.BuildListener;
import org.apache.tools.ant.Project;
import org.apache.tools.ant.ProjectHelper;

/**
 * A BuildFileTest is a TestCase which executes targets from an Ant buildfile
 * for testing.
 *
 * This class provides a number of utility methods for particular build file
 * tests which extend this class.
 *
 */
public abstract class BuildFileTest extends TestCase {

    protected Project project;

    private StringBuffer logBuffer;
    private StringBuffer fullLogBuffer;
    private StringBuffer outBuffer;
    private StringBuffer errBuffer;
    private BuildException buildException;

    /**
     *  Constructor for the BuildFileTest object
     *
     *@param  name string to pass up to TestCase constructor
     */
    public BuildFileTest(String name) {
        super(name);
    }

    /**
     *  run a target, expect for any build exception
     *
     *@param  target target to run
     *@param  cause  information string to reader of report
     */
    protected void expectBuildException(String target, String cause) {
        expectSpecificBuildException(target, cause, null);
    }

    /**
     * Assert that only the given message has been logged with a
     * priority &gt;= INFO when running the given target.
     */
    protected void expectLog(String target, String log) {
        executeTarget(target);
        String realLog = getLog();
        assertEquals(log, realLog);
    }

    /**
     * Assert that the given substring is in the log messages
     */

    protected void assertLogContaining(String substring) {
        String realLog = getLog();
        assertTrue("expecting log to contain \"" + substring + "\" log was \""
                   + realLog + "\"",
                   realLog.indexOf(substring) >= 0);
    }

    /**
     * Assert that the given message has been logged with a priority
     * &gt;= INFO when running the given target.
     */
    protected void expectLogContaining(String target, String log) {
        executeTarget(target);
        assertLogContaining(log);
    }

    /**
     *  Gets the log the BuildFileTest object.
     *  only valid if configureProject() has
     *  been called.
     * @pre logBuffer!=null
     * @return    The log value
     */
    protected String getLog() {
        return logBuffer.toString();
    }

    /**
     * Assert that the given message has been logged with a priority
     * &gt;= DEBUG when running the given target.
     */
    protected void expectDebuglog(String target, String log) {
        executeTarget(target);
        String realLog = getFullLog();
        assertEquals(log, realLog);
    }

    /**
     *  Gets the log the BuildFileTest object.
     *  only valid if configureProject() has
     *  been called.
     * @pre fullLogBuffer!=null
     * @return    The log value
     */
    protected String getFullLog() {
        return fullLogBuffer.toString();
    }

    /**
     *  execute the target, verify output matches expectations
     *
     *@param  target  target to execute
     *@param  output  output to look for
     */

    protected void expectOutput(String target, String output) {
        executeTarget(target);
        String realOutput = getOutput();
        assertEquals(output, realOutput.trim());
    }

    /**
     *  execute the target, verify output matches expectations
     *  and that we got the named error at the end
     *@param  target  target to execute
     *@param  output  output to look for
     *@param  error   Description of Parameter
     */

    protected void expectOutputAndError(String target, String output, String error) {
        executeTarget(target);
        String realOutput = getOutput();
        assertEquals(output, realOutput);
        String realError = getError();
        assertEquals(error, realError);
    }

    protected String getOutput() {
        return cleanBuffer(outBuffer);
    }

    protected String getError() {
        return cleanBuffer(errBuffer);
    }

    protected BuildException getBuildException() {
        return buildException;
    }

    private String cleanBuffer(StringBuffer buffer) {
        StringBuffer cleanedBuffer = new StringBuffer();
        boolean cr = false;
        for (int i = 0; i < buffer.length(); i++) {
            char ch = buffer.charAt(i);
            if (ch == '\r') {
                cr = true;
                continue;
            }

            if (!cr) {
                cleanedBuffer.append(ch);
            } else {
                cleanedBuffer.append(ch);
            }
        }
        return cleanedBuffer.toString();
    }

    /**
     *  set up to run the named project
     *
     * @param  filename name of project file to run
     */
    protected void configureProject(String filename) throws BuildException {
        configureProject(filename, Project.MSG_DEBUG);
    }

    /**
     *  set up to run the named project
     *
     * @param  filename name of project file to run
     */
    protected void configureProject(String filename, int logLevel)
        throws BuildException {
        logBuffer = new StringBuffer();
        fullLogBuffer = new StringBuffer();
        project = new Project();
        project.init();
        project.setUserProperty( "ant.file" , new File(filename).getAbsolutePath() );
        project.addBuildListener(new AntTestListener(logLevel));
        ProjectHelper.configureProject(project, new File(filename));
    }

    /**
     *  execute a target we have set up
     * @pre configureProject has been called
     * @param  targetName  target to run
     */
    protected void executeTarget(String targetName) {
        PrintStream sysOut = System.out;
        PrintStream sysErr = System.err;
        try {
            sysOut.flush();
            sysErr.flush();
            outBuffer = new StringBuffer();
            PrintStream out = new PrintStream(new AntOutputStream(outBuffer));
            System.setOut(out);
            errBuffer = new StringBuffer();
            PrintStream err = new PrintStream(new AntOutputStream(errBuffer));
            System.setErr(err);
            logBuffer = new StringBuffer();
            fullLogBuffer = new StringBuffer();
            buildException = null;
            project.executeTarget(targetName);
        } finally {
            System.setOut(sysOut);
            System.setErr(sysErr);
        }

    }

    /**
     * Get the project which has been configured for a test.
     *
     * @return the Project instance for this test.
     */
    protected Project getProject() {
        return project;
    }

    /**
     * get the directory of the project
     * @return the base dir of the project
     */
    protected File getProjectDir() {
        return project.getBaseDir();
    }

    /**
     *  run a target, wait for a build exception
     *
     *@param  target target to run
     *@param  cause  information string to reader of report
     *@param  msg    the message value of the build exception we are waiting for
              set to null for any build exception to be valid
     */
    protected void expectSpecificBuildException(String target, String cause, String msg) {
        try {
            executeTarget(target);
        } catch (org.apache.tools.ant.BuildException ex) {
            buildException = ex;
            if ((null != msg) && (!ex.getMessage().equals(msg))) {
                fail("Should throw BuildException because '" + cause
                        + "' with message '" + msg
                        + "' (actual message '" + ex.getMessage() + "' instead)");
            }
            return;
        }
        fail("Should throw BuildException because: " + cause);
    }

    /**
     *  run a target, expect an exception string
     *  containing the substring we look for (case sensitive match)
     *
     *@param  target target to run
     *@param  cause  information string to reader of report
     *@param  contains  substring of the build exception to look for
     */
    protected void expectBuildExceptionContaining(String target, String cause, String contains) {
        try {
            executeTarget(target);
        } catch (org.apache.tools.ant.BuildException ex) {
            buildException = ex;
            if ((null != contains) && (ex.getMessage().indexOf(contains) == -1)) {
                fail("Should throw BuildException because '" + cause + "' with message containing '" + contains + "' (actual message '" + ex.getMessage() + "' instead)");
            }
            return;
        }
        fail("Should throw BuildException because: " + cause);
    }


    /**
     * call a target, verify property is as expected
     *
     * @param target build file target
     * @param property property name
     * @param value expected value
     */

    protected void expectPropertySet(String target, String property, String value) {
        executeTarget(target);
        assertPropertyEquals(property, value);
    }

    /**
     * assert that a property equals a value; comparison is case sensitive.
     * @param property property name
     * @param value expected value
     */
    protected void assertPropertyEquals(String property, String value) {
        String result = project.getProperty(property);
        assertEquals("property " + property,value,result);
    }

    /**
     * assert that a property equals &quot;true&quot;
     * @param property property name
     */
    protected void assertPropertySet(String property) {
        assertPropertyEquals(property, "true");
    }

    /**
     * assert that a property is null
     * @param property property name
     */
    protected void assertPropertyUnset(String property) {
        assertPropertyEquals(property, null);
    }


    /**
     * call a target, verify named property is "true".
     *
     * @param target build file target
     * @param property property name
     */
    protected void expectPropertySet(String target, String property) {
        expectPropertySet(target, property, "true");
    }


    /**
     * call a target, verify property is null
     * @param target build file target
     * @param property property name
     */
    protected void expectPropertyUnset(String target, String property) {
        expectPropertySet(target, property, null);
    }

    /**
     * Retrieve a resource from the caller classloader to avoid
     * assuming a vm working directory. The resource path must be
     * relative to the package name or absolute from the root path.
     * @param resource the resource to retrieve its url.
     */
    protected URL getResource(String resource){
        URL url = getClass().getResource(resource);
        assertNotNull("Could not find resource :" + resource, url);
        return url;
    }

    /**
     * an output stream which saves stuff to our buffer.
     */
    private static class AntOutputStream extends java.io.OutputStream {
        private StringBuffer buffer;

        public AntOutputStream( StringBuffer buffer ) {
            this.buffer = buffer;
        }

        public void write(int b) {
            buffer.append((char)b);
        }
    }

    /**
     * our own personal build listener
     */
    private class AntTestListener implements BuildListener {
        private int logLevel;

        /**
         * Constructs a test listener which will ignore log events
         * above the given level
         */
        public AntTestListener(int logLevel) {
            this.logLevel = logLevel;
        }

        /**
         *  Fired before any targets are started.
         */
        public void buildStarted(BuildEvent event) {
        }

        /**
         *  Fired after the last target has finished. This event
         *  will still be thrown if an error occured during the build.
         *
         *  @see BuildEvent#getException()
         */
        public void buildFinished(BuildEvent event) {
        }

        /**
         *  Fired when a target is started.
         *
         *  @see BuildEvent#getTarget()
         */
        public void targetStarted(BuildEvent event) {
            //System.out.println("targetStarted " + event.getTarget().getName());
        }

        /**
         *  Fired when a target has finished. This event will
         *  still be thrown if an error occured during the build.
         *
         *  @see BuildEvent#getException()
         */
        public void targetFinished(BuildEvent event) {
            //System.out.println("targetFinished " + event.getTarget().getName());
        }

        /**
         *  Fired when a task is started.
         *
         *  @see BuildEvent#getTask()
         */
        public void taskStarted(BuildEvent event) {
            //System.out.println("taskStarted " + event.getTask().getTaskName());
        }

        /**
         *  Fired when a task has finished. This event will still
         *  be throw if an error occured during the build.
         *
         *  @see BuildEvent#getException()
         */
        public void taskFinished(BuildEvent event) {
            //System.out.println("taskFinished " + event.getTask().getTaskName());
        }

        /**
         *  Fired whenever a message is logged.
         *
         *  @see BuildEvent#getMessage()
         *  @see BuildEvent#getPriority()
         */
        public void messageLogged(BuildEvent event) {
            if (event.getPriority() > logLevel) {
                // ignore event
                return;
            }

            if (event.getPriority() == Project.MSG_INFO ||
                event.getPriority() == Project.MSG_WARN ||
                event.getPriority() == Project.MSG_ERR) {
                logBuffer.append(event.getMessage());
            }
            fullLogBuffer.append(event.getMessage());

        }
    }


}
