/*
  ==============================================================================

   This file is part of the JUCE framework.
   Copyright (c) Raw Material Software Limited

   JUCE is an open source framework subject to commercial or open source
   licensing.

   By downloading, installing, or using the JUCE framework, or combining the
   JUCE framework with any other source code, object code, content or any other
   copyrightable work, you agree to the terms of the JUCE End User Licence
   Agreement, and all incorporated terms including the JUCE Privacy Policy and
   the JUCE Website Terms of Service, as applicable, which will bind you. If you
   do not agree to the terms of these agreements, we will not license the JUCE
   framework to you, and you must discontinue the installation or download
   process and cease use of the JUCE framework.

   JUCE End User Licence Agreement: https://juce.com/legal/juce-9-licence/
   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/

   Or:

   You may also use this code under the terms of the AGPLv3:
   https://www.gnu.org/licenses/agpl-3.0.en.html

   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.

  ==============================================================================
*/

namespace juce
{

//==============================================================================
/**
    Launches and monitors a child process.

    This class lets you launch an executable, and read its output. You can also
    use it to check whether the child process has finished.

    @tags{Core}
*/
class JUCE_API  ChildProcess
{
public:
    //==============================================================================
    /** Creates a process object.
        To actually launch the process, use start().
    */
    ChildProcess();

    /** Destructor.
        Note that deleting this object won't terminate the child process.
    */
    ~ChildProcess();

    /** These flags are used by the start() methods. */
    enum StreamFlags
    {
        wantStdOut = 1,
        wantStdErr = 2
    };

    /** Attempts to launch a child process command.

        The command should be the name of the executable file, followed by any arguments
        that are required.
        If the process has already been launched, this will launch it again. If a problem
        occurs, the method will return false.
        The streamFlags is a combinations of values to indicate which of the child's output
        streams should be read and returned by readProcessOutput().
    */
    bool start (const String& command, int streamFlags = wantStdOut | wantStdErr);

    /** Attempts to launch a child process command.

        The first argument should be the name of the executable file, followed by any other
        arguments that are needed.
        If the process has already been launched, this will launch it again. If a problem
        occurs, the method will return false.
        The streamFlags is a combinations of values to indicate which of the child's output
        streams should be read and returned by readProcessOutput().
    */
    bool start (const StringArray& arguments, int streamFlags = wantStdOut | wantStdErr);

    /** Returns true if the child process is alive. */
    bool isRunning() const;

    /** Attempts to read some output from the child process.
        This will attempt to read up to the given number of bytes of data from the
        process. It returns the number of bytes that were actually read.
    */
    int readProcessOutput (void* destBuffer, int numBytesToRead);

    /** Blocks until the process has finished, and then returns its complete output
        as a string.
    */
    String readAllProcessOutput();

    /** Blocks until the process is no longer running. */
    bool waitForProcessToFinish (int timeoutMs) const;

    /** If the process has finished, this returns its exit code. */
    uint32 getExitCode() const;

    /** Attempts to kill the child process.
        Returns true if it succeeded. Trying to read from the process after calling this may
        result in undefined behaviour.
    */
    bool kill();

private:
    //==============================================================================
    class ActiveProcess;
    std::unique_ptr<ActiveProcess> activeProcess;

    JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (ChildProcess)
};

} // namespace juce
