/*
 * Copyright (C) 2011 The Android Open Source Project
 *
 * Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php
 *
 * 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 com.android.ide.eclipse.ndk.internal.discovery;

import com.android.ide.eclipse.ndk.internal.Activator;
import com.android.ide.eclipse.ndk.internal.build.NdkCommandLauncher;

import org.eclipse.cdt.core.CCorePlugin;
import org.eclipse.cdt.core.envvar.IEnvironmentVariable;
import org.eclipse.cdt.core.envvar.IEnvironmentVariableManager;
import org.eclipse.cdt.core.settings.model.ICConfigurationDescription;
import org.eclipse.cdt.managedbuilder.core.IBuilder;
import org.eclipse.cdt.managedbuilder.core.IManagedBuildInfo;
import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.FileLocator;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Path;

import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

public class NdkDiscoveryUpdater {
    private final NdkDiscoveredPathInfo mPathInfo;
    private final IProject mProject;

    private boolean mCPlusPlus = false;
    private String mCommand;
    private List<String> mArguments = new ArrayList<String>();

    public NdkDiscoveryUpdater(NdkDiscoveredPathInfo pathInfo) {
        mPathInfo = pathInfo;
        mProject = pathInfo.getProject();
    }

    public void runUpdate(IProgressMonitor monitor) throws CoreException {
        try {
            // Run ndk-build -nB to get the list of commands
            IPath commandPath = new Path("ndk-build"); //$NON-NLS-1$
            String[] args = {
                "-nB"}; //$NON-NLS-1$
            String[] env = calcEnvironment();
            File projectDir = new File(mProject.getLocationURI());
            IPath changeToDirectory = new Path(projectDir.getAbsolutePath());
            Process proc = new NdkCommandLauncher().execute(commandPath, args, env,
                    changeToDirectory, monitor);
            if (proc == null)
                // proc failed to start
                return;
            BufferedReader reader = new BufferedReader(new InputStreamReader(proc.getInputStream()));
            String line = reader.readLine();
            while (line != null) {
                checkBuildLine(line);
                line = reader.readLine();
            }

            if (mCommand == null) {
                return;
            }

            // Run the unique commands with special gcc options to extract the
            // symbols and paths
            // -E -P -v -dD
            mArguments.add("-E"); //$NON-NLS-1$
            mArguments.add("-P"); //$NON-NLS-1$
            mArguments.add("-v"); //$NON-NLS-1$
            mArguments.add("-dD"); //$NON-NLS-1$

            URL url = Activator.findFile(new Path(
                    "discovery/" + (mCPlusPlus ? "test.cpp" : "test.c"))); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
            File testFile = new File(FileLocator.toFileURL(url).toURI());
            String testFileName = testFile.getAbsolutePath().replace('\\', '/');
            mArguments.add(testFileName);

            args = mArguments.toArray(new String[mArguments.size()]);
            proc = new NdkCommandLauncher().execute(new Path(mCommand), args, env,
                    changeToDirectory, monitor);
            // Error stream has the includes
            final InputStream errStream = proc.getErrorStream();
            new Thread() {
                @Override
                public void run() {
                    checkIncludes(errStream);
                };
            }.start();

            // Input stream has the defines
            checkDefines(proc.getInputStream());
        } catch (IOException e) {
            throw new CoreException(Activator.newStatus(e));
        } catch (URISyntaxException e) {
            throw new CoreException(Activator.newStatus(e));
        }
    }

    private String[] calcEnvironment() throws CoreException {
        IManagedBuildInfo info = ManagedBuildManager.getBuildInfo(mProject);
        IBuilder builder = info.getDefaultConfiguration().getBuilder();
        HashMap<String, String> envMap = new HashMap<String, String>();
        if (builder.appendEnvironment()) {
            ICConfigurationDescription cfgDes = ManagedBuildManager
                    .getDescriptionForConfiguration(builder.getParent().getParent());
            IEnvironmentVariableManager mngr = CCorePlugin.getDefault()
                    .getBuildEnvironmentManager();
            IEnvironmentVariable[] vars = mngr.getVariables(cfgDes, true);
            for (IEnvironmentVariable var : vars) {
                envMap.put(var.getName(), var.getValue());
            }
        }
        // Add variables from build info
        Map<String, String> builderEnv = builder.getExpandedEnvironment();
        if (builderEnv != null)
            envMap.putAll(builderEnv);
        List<String> strings = new ArrayList<String>(envMap.size());
        for (Entry<String, String> entry : envMap.entrySet()) {
            StringBuffer buffer = new StringBuffer(entry.getKey());
            buffer.append('=').append(entry.getValue());
            strings.add(buffer.toString());
        }
        return strings.toArray(new String[strings.size()]);
    }

    private static class Line {
        private final String line;
        private int pos;

        public Line(String line) {
            this.line = line;
        }

        public Line(String line, int pos) {
            this(line);
            this.pos = pos;
        }

        public String getToken() {
            skipWhiteSpace();
            if (pos == line.length())
                return null;

            int start = pos;
            boolean inQuote = false;

            while (true) {
                char c = line.charAt(pos);
                if (c == ' ') {
                    if (!inQuote)
                        return line.substring(start, pos);
                } else if (c == '"') {
                    inQuote = !inQuote;
                }

                if (++pos == line.length())
                    return null;
            }

        }

        private String getRemaining() {
            if (pos == line.length())
                return null;

            skipWhiteSpace();
            String rc = line.substring(pos);
            pos = line.length();
            return rc;
        }

        private void skipWhiteSpace() {
            while (true) {
                if (pos == line.length())
                    return;
                char c = line.charAt(pos);
                if (c == ' ')
                    pos++;
                else
                    return;
            }
        }
    }

    private void checkBuildLine(String text) {
        Line line = new Line(text);
        String cmd = line.getToken();
        if (cmd == null) {
            return;
        } else if (cmd.endsWith("g++")) {           //$NON-NLS-1$
            if (mCommand == null || !mCPlusPlus) {
                mCommand = cmd;
                mCPlusPlus = true;
            }
            gatherOptions(line);
        } else if (cmd.endsWith("gcc")) {   //$NON-NLS-1$
            if (mCommand == null)
                mCommand = cmd;
            gatherOptions(line);
        }
    }

    private void gatherOptions(Line line) {
        for (String option = line.getToken(); option != null; option = line.getToken()) {
            if (option.startsWith("-")) { //$NON-NLS-1$
                // only look at options
                if (option.equals("-I")) { //$NON-NLS-1$
                    String dir = line.getToken();
                    if (dir != null)
                        addArg(option + dir);
                } else if (option.startsWith("-I")) { //$NON-NLS-1$
                    addArg(option);
                } else if (option.equals("-D")) { //$NON-NLS-1$
                    String def = line.getToken();
                    if (def != null)
                        addArg(option + def);
                } else if (option.startsWith("-D")) { //$NON-NLS-1$
                    addArg(option);
                } else if (option.startsWith("-f")) { //$NON-NLS-1$
                    addArg(option);
                } else if (option.startsWith("-m")) { //$NON-NLS-1$
                    addArg(option);
                } else if (option.startsWith("--sysroot")) { //$NON-NLS-1$
                    addArg(option);
                }
            }
        }
    }

    private void addArg(String arg) {
        if (!mArguments.contains(arg))
            mArguments.add(arg);
    }

    private void checkIncludes(InputStream in) {
        try {
            List<String> includes = new ArrayList<String>();
            boolean inIncludes1 = false;
            boolean inIncludes2 = false;
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            String line = reader.readLine();
            while (line != null) {
                if (!inIncludes1) {
                    if (line.equals("#include \"...\" search starts here:")) //$NON-NLS-1$
                        inIncludes1 = true;
                } else {
                    if (!inIncludes2) {
                        if (line.equals("#include <...> search starts here:")) //$NON-NLS-1$
                            inIncludes2 = true;
                        else
                            includes.add(line.trim());
                    } else {
                        if (line.equals("End of search list.")) { //$NON-NLS-1$
                            mPathInfo.setIncludePaths(includes);
                        } else {
                            includes.add(line.trim());
                        }
                    }
                }
                line = reader.readLine();
            }
        } catch (IOException e) {
            Activator.log(e);
        }
    }

    private void checkDefines(InputStream in) {
        try {
            Map<String, String> defines = new HashMap<String, String>();
            BufferedReader reader = new BufferedReader(new InputStreamReader(in));
            String line = reader.readLine();
            while (line != null) {
                if (line.startsWith("#define")) { //$NON-NLS-1$
                    Line l = new Line(line, 7);
                    String var = l.getToken();
                    if (var == null)
                        continue;
                    String value = l.getRemaining();
                    if (value == null)
                        value = ""; //$NON-NLS-1$
                    defines.put(var, value);
                }
                line = reader.readLine();
            }
            mPathInfo.setSymbols(defines);
        } catch (IOException e) {
            Activator.log(e);
        }
    }

}