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

   This file is part of the JUCE 6 technical preview.
   Copyright (c) 2017 - ROLI Ltd.

   You may use this code under the terms of the GPL v3
   (see www.gnu.org/licenses).

   For this technical preview, this file is not subject to commercial licensing.

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

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

namespace juce
{

class ApplicationCommandTarget::CommandMessage  : public MessageManager::MessageBase
{
public:
    CommandMessage (ApplicationCommandTarget* const target, const InvocationInfo& inf)
        : owner (target), info (inf)
    {
    }

    void messageCallback() override
    {
        if (ApplicationCommandTarget* const target = owner)
            target->tryToInvoke (info, false);
    }

private:
    WeakReference<ApplicationCommandTarget> owner;
    const InvocationInfo info;

    JUCE_DECLARE_NON_COPYABLE (CommandMessage)
};

//==============================================================================
ApplicationCommandTarget::ApplicationCommandTarget() {}
ApplicationCommandTarget::~ApplicationCommandTarget() {}

//==============================================================================
bool ApplicationCommandTarget::tryToInvoke (const InvocationInfo& info, const bool async)
{
    if (isCommandActive (info.commandID))
    {
        if (async)
        {
            (new CommandMessage (this, info))->post();
            return true;
        }

        if (perform (info))
            return true;

        // Hmm.. your target claimed that it could perform this command, but failed to do so.
        // If it can't do it at the moment for some reason, it should clear the 'isActive' flag
        // when it returns the command's info.
        jassertfalse;
    }

    return false;
}

ApplicationCommandTarget* ApplicationCommandTarget::findFirstTargetParentComponent()
{
    if (Component* const c = dynamic_cast<Component*> (this))
        return c->findParentComponentOfClass<ApplicationCommandTarget>();

    return nullptr;
}

ApplicationCommandTarget* ApplicationCommandTarget::getTargetForCommand (const CommandID commandID)
{
    ApplicationCommandTarget* target = this;
    int depth = 0;

    while (target != nullptr)
    {
        Array<CommandID> commandIDs;
        target->getAllCommands (commandIDs);

        if (commandIDs.contains (commandID))
            return target;

        target = target->getNextCommandTarget();

        ++depth;
        jassert (depth < 100); // could be a recursive command chain??
        jassert (target != this); // definitely a recursive command chain!

        if (depth > 100 || target == this)
            break;
    }

    if (target == nullptr)
    {
        target = JUCEApplication::getInstance();

        if (target != nullptr)
        {
            Array<CommandID> commandIDs;
            target->getAllCommands (commandIDs);

            if (commandIDs.contains (commandID))
                return target;
        }
    }

    return nullptr;
}

bool ApplicationCommandTarget::isCommandActive (const CommandID commandID)
{
    ApplicationCommandInfo info (commandID);
    info.flags = ApplicationCommandInfo::isDisabled;

    getCommandInfo (commandID, info);

    return (info.flags & ApplicationCommandInfo::isDisabled) == 0;
}

//==============================================================================
bool ApplicationCommandTarget::invoke (const InvocationInfo& info, const bool async)
{
    ApplicationCommandTarget* target = this;
    int depth = 0;

    while (target != nullptr)
    {
        if (target->tryToInvoke (info, async))
            return true;

        target = target->getNextCommandTarget();

        ++depth;
        jassert (depth < 100); // could be a recursive command chain??
        jassert (target != this); // definitely a recursive command chain!

        if (depth > 100 || target == this)
            break;
    }

    if (target == nullptr)
    {
        target = JUCEApplication::getInstance();

        if (target != nullptr)
            return target->tryToInvoke (info, async);
    }

    return false;
}

bool ApplicationCommandTarget::invokeDirectly (const CommandID commandID, const bool asynchronously)
{
    ApplicationCommandTarget::InvocationInfo info (commandID);
    info.invocationMethod = ApplicationCommandTarget::InvocationInfo::direct;

    return invoke (info, asynchronously);
}

//==============================================================================
ApplicationCommandTarget::InvocationInfo::InvocationInfo (const CommandID command)
    : commandID (command),
      commandFlags (0),
      invocationMethod (direct),
      originatingComponent (nullptr),
      isKeyDown (false),
      millisecsSinceKeyPressed (0)
{
}

} // namespace juce