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

   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
{

ApplicationCommandManager::ApplicationCommandManager()
{
    keyMappings.reset (new KeyPressMappingSet (*this));
    Desktop::getInstance().addFocusChangeListener (this);
}

ApplicationCommandManager::~ApplicationCommandManager()
{
    Desktop::getInstance().removeFocusChangeListener (this);
    keyMappings.reset();
}

//==============================================================================
void ApplicationCommandManager::clearCommands()
{
    commands.clear();
    keyMappings->clearAllKeyPresses();
    triggerAsyncUpdate();
}

void ApplicationCommandManager::registerCommand (const ApplicationCommandInfo& newCommand)
{
    // zero isn't a valid command ID!
    jassert (newCommand.commandID != 0);

    // the name isn't optional!
    jassert (newCommand.shortName.isNotEmpty());

    if (auto* command = getMutableCommandForID (newCommand.commandID))
    {
        // Trying to re-register the same command ID with different parameters can often indicate a typo.
        // This assertion is here because I've found it useful catching some mistakes, but it may also cause
        // false alarms if you're deliberately updating some flags for a command.
        jassert (newCommand.shortName == getCommandForID (newCommand.commandID)->shortName
                  && newCommand.categoryName == getCommandForID (newCommand.commandID)->categoryName
                  && newCommand.defaultKeypresses == getCommandForID (newCommand.commandID)->defaultKeypresses
                  && (newCommand.flags & (ApplicationCommandInfo::wantsKeyUpDownCallbacks | ApplicationCommandInfo::hiddenFromKeyEditor | ApplicationCommandInfo::readOnlyInKeyEditor))
                       == (getCommandForID (newCommand.commandID)->flags & (ApplicationCommandInfo::wantsKeyUpDownCallbacks | ApplicationCommandInfo::hiddenFromKeyEditor | ApplicationCommandInfo::readOnlyInKeyEditor)));

        *command = newCommand;
    }
    else
    {
        auto* newInfo = new ApplicationCommandInfo (newCommand);
        newInfo->flags &= ~ApplicationCommandInfo::isTicked;
        commands.add (newInfo);

        keyMappings->resetToDefaultMapping (newCommand.commandID);

        triggerAsyncUpdate();
    }
}

void ApplicationCommandManager::registerAllCommandsForTarget (ApplicationCommandTarget* target)
{
    if (target != nullptr)
    {
        Array<CommandID> commandIDs;
        target->getAllCommands (commandIDs);

        for (int i = 0; i < commandIDs.size(); ++i)
        {
            ApplicationCommandInfo info (commandIDs.getUnchecked(i));
            target->getCommandInfo (info.commandID, info);

            registerCommand (info);
        }
    }
}

void ApplicationCommandManager::removeCommand (const CommandID commandID)
{
    for (int i = commands.size(); --i >= 0;)
    {
        if (commands.getUnchecked (i)->commandID == commandID)
        {
            commands.remove (i);
            triggerAsyncUpdate();

            const Array<KeyPress> keys (keyMappings->getKeyPressesAssignedToCommand (commandID));

            for (int j = keys.size(); --j >= 0;)
                keyMappings->removeKeyPress (keys.getReference (j));
        }
    }
}

void ApplicationCommandManager::commandStatusChanged()
{
    triggerAsyncUpdate();
}

//==============================================================================
ApplicationCommandInfo* ApplicationCommandManager::getMutableCommandForID (CommandID commandID) const noexcept
{
    for (int i = commands.size(); --i >= 0;)
        if (commands.getUnchecked(i)->commandID == commandID)
            return commands.getUnchecked(i);

    return nullptr;
}

const ApplicationCommandInfo* ApplicationCommandManager::getCommandForID (CommandID commandID) const noexcept
{
    return getMutableCommandForID (commandID);
}

String ApplicationCommandManager::getNameOfCommand (CommandID commandID) const noexcept
{
    if (auto* ci = getCommandForID (commandID))
        return ci->shortName;

    return {};
}

String ApplicationCommandManager::getDescriptionOfCommand (CommandID commandID) const noexcept
{
    if (auto* ci = getCommandForID (commandID))
        return ci->description.isNotEmpty() ? ci->description
                                            : ci->shortName;

    return {};
}

StringArray ApplicationCommandManager::getCommandCategories() const
{
    StringArray s;

    for (int i = 0; i < commands.size(); ++i)
        s.addIfNotAlreadyThere (commands.getUnchecked(i)->categoryName, false);

    return s;
}

Array<CommandID> ApplicationCommandManager::getCommandsInCategory (const String& categoryName) const
{
    Array<CommandID> results;

    for (int i = 0; i < commands.size(); ++i)
        if (commands.getUnchecked(i)->categoryName == categoryName)
            results.add (commands.getUnchecked(i)->commandID);

    return results;
}

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

    return invoke (info, asynchronously);
}

bool ApplicationCommandManager::invoke (const ApplicationCommandTarget::InvocationInfo& inf, bool asynchronously)
{
    // This call isn't thread-safe for use from a non-UI thread without locking the message
    // manager first..
    JUCE_ASSERT_MESSAGE_MANAGER_IS_LOCKED

    bool ok = false;
    ApplicationCommandInfo commandInfo (0);

    if (auto* target = getTargetForCommand (inf.commandID, commandInfo))
    {
        ApplicationCommandTarget::InvocationInfo info (inf);
        info.commandFlags = commandInfo.flags;

        sendListenerInvokeCallback (info);
        ok = target->invoke (info, asynchronously);
        commandStatusChanged();
    }

    return ok;
}

//==============================================================================
ApplicationCommandTarget* ApplicationCommandManager::getFirstCommandTarget (CommandID)
{
    return firstTarget != nullptr ? firstTarget
                                  : findDefaultComponentTarget();
}

void ApplicationCommandManager::setFirstCommandTarget (ApplicationCommandTarget* newTarget) noexcept
{
    firstTarget = newTarget;
}

ApplicationCommandTarget* ApplicationCommandManager::getTargetForCommand (CommandID commandID,
                                                                          ApplicationCommandInfo& upToDateInfo)
{
    auto* target = getFirstCommandTarget (commandID);

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

    if (target != nullptr)
        target = target->getTargetForCommand (commandID);

    if (target != nullptr)
    {
        upToDateInfo.commandID = commandID;
        target->getCommandInfo (commandID, upToDateInfo);
    }

    return target;
}

//==============================================================================
ApplicationCommandTarget* ApplicationCommandManager::findTargetForComponent (Component* c)
{
    auto* target = dynamic_cast<ApplicationCommandTarget*> (c);

    if (target == nullptr && c != nullptr)
        target = c->findParentComponentOfClass<ApplicationCommandTarget>();

    return target;
}

ApplicationCommandTarget* ApplicationCommandManager::findDefaultComponentTarget()
{
    auto* c = Component::getCurrentlyFocusedComponent();

    if (c == nullptr)
    {
        if (auto* activeWindow = TopLevelWindow::getActiveTopLevelWindow())
        {
            if (auto* peer = activeWindow->getPeer())
            {
                c = peer->getLastFocusedSubcomponent();

                if (c == nullptr)
                    c = activeWindow;
            }
        }
    }

    if (c == nullptr && Process::isForegroundProcess())
    {
        auto& desktop = Desktop::getInstance();

        // getting a bit desperate now: try all desktop comps..
        for (int i = desktop.getNumComponents(); --i >= 0;)
            if (auto* peer = desktop.getComponent(i)->getPeer())
                if (auto* target = findTargetForComponent (peer->getLastFocusedSubcomponent()))
                    return target;
    }

    if (c != nullptr)
    {
        // if we're focused on a ResizableWindow, chances are that it's the content
        // component that really should get the event. And if not, the event will
        // still be passed up to the top level window anyway, so let's send it to the
        // content comp.
        if (auto* resizableWindow = dynamic_cast<ResizableWindow*> (c))
            if (auto* content = resizableWindow->getContentComponent())
                c = content;

        if (auto* target = findTargetForComponent (c))
            return target;
    }

    return JUCEApplication::getInstance();
}

//==============================================================================
void ApplicationCommandManager::addListener (ApplicationCommandManagerListener* listener)
{
    listeners.add (listener);
}

void ApplicationCommandManager::removeListener (ApplicationCommandManagerListener* listener)
{
    listeners.remove (listener);
}

void ApplicationCommandManager::sendListenerInvokeCallback (const ApplicationCommandTarget::InvocationInfo& info)
{
    listeners.call ([&] (ApplicationCommandManagerListener& l) { l.applicationCommandInvoked (info); });
}

void ApplicationCommandManager::handleAsyncUpdate()
{
    listeners.call ([] (ApplicationCommandManagerListener& l) { l.applicationCommandListChanged(); });
}

void ApplicationCommandManager::globalFocusChanged (Component*)
{
    commandStatusChanged();
}

} // namespace juce