/**
 * @file llwindowlistener.cpp
 * @brief EventAPI interface for injecting input into LLWindow
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"
#include "linden_common.h"

#include "llwindowlistener.h"

#include "llcoord.h"
#include "llfocusmgr.h"
#include "llkeyboard.h"
#include "llwindowcallbacks.h"
#include "llui.h"
#include "llview.h"
#include "llviewinject.h"
#include "llviewerwindow.h"
#include "llviewerinput.h"
#include "llrootview.h"
#include "llsdutil.h"
#include "stringize.h"
#include <typeinfo>
#include <map>
#include <boost/scoped_ptr.hpp>
#include <boost/bind.hpp>

LLWindowListener::LLWindowListener(LLViewerWindow *window, const KeyboardGetter& kbgetter)
    : LLEventAPI("LLWindow", "Inject input events into the LLWindow instance"),
      mWindow(window),
      mKbGetter(kbgetter)
{
    std::string keySomething =
        "Given [\"keysym\"], [\"keycode\"] or [\"char\"], inject the specified ";
    std::string keyExplain =
        "(integer keycode values, or keysym string from any addKeyName() call in\n"
        "https://github.com/secondlife/viewer/blob/main/indra/llwindow/llkeyboard.cpp#L68-L124)\n";
    std::string mask =
        "Specify optional [\"mask\"] as an array containing any of \"CTL\", \"ALT\",\n"
        "\"SHIFT\" or \"MAC_CONTROL\"; the corresponding modifier bits will be combined\n"
        "to form the mask used with the event.";

    std::string given = "Given ";
    std::string mouseParams =
        "optional [\"path\"], optional [\"x\"] and [\"y\"], inject the requested mouse ";
    std::string buttonParams =
        std::string("[\"button\"], ") + mouseParams;
    std::string buttonExplain =
        "(button values \"LEFT\", \"MIDDLE\", \"RIGHT\")\n";
    std::string paramsExplain =
        "[\"path\"] is as for LLUI::getInstance()->resolvePath(), described in\n"
        "http://bitbucket.org/lindenlab/viewer-release/src/tip/indra/llui/llui.h\n"
        "If you omit [\"path\"], you must specify both [\"x\"] and [\"y\"].\n"
        "If you specify [\"path\"] without both [\"x\"] and [\"y\"], will synthesize (x, y)\n"
        "in the center of the LLView selected by [\"path\"].\n"
        "You may specify [\"path\"] with both [\"x\"] and [\"y\"], will use your (x, y).\n"
        "This may cause the LLView selected by [\"path\"] to reject the event.\n"
        "Optional [\"reply\"] requests a reply event on the named LLEventPump.\n"
        "reply[\"error\"] isUndefined (None) on success, else an explanatory message.\n";

    add("getInfo",
        "Get information about the ui element specified by [\"path\"]",
        &LLWindowListener::getInfo,
        LLSDMap("reply", LLSD()));
    add("getPaths",
        "Send on [\"reply\"] an event in which [\"paths\"] is an array of valid LLView\n"
        "pathnames. Optional [\"under\"] pathname specifies the base node under which\n"
        "to list; all nodes from root if no [\"under\"].",
        &LLWindowListener::getPaths,
        LLSDMap("reply", LLSD()));
    add("keyDown",
        keySomething + "keypress event.\n" + keyExplain + mask,
        &LLWindowListener::keyDown);
    add("keyUp",
        keySomething + "key release event.\n" + keyExplain + mask,
        &LLWindowListener::keyUp);
    add("mouseDown",
        given + buttonParams + "click event.\n" + buttonExplain + paramsExplain + mask,
        &LLWindowListener::mouseDown);
    add("mouseUp",
        given + buttonParams + "release event.\n" + buttonExplain + paramsExplain + mask,
        &LLWindowListener::mouseUp);
    add("mouseMove",
        given + mouseParams + "movement event.\n" + paramsExplain + mask,
        &LLWindowListener::mouseMove);
    add("mouseScroll",
        "Given an integer number of [\"clicks\"], inject the requested mouse scroll event.\n"
        "(positive clicks moves downward through typical content)",
        &LLWindowListener::mouseScroll);
}

template <typename MAPPED>
class StringLookup
{
private:
    std::string mDesc;
    typedef std::map<std::string, MAPPED> Map;
    Map mMap;

public:
    StringLookup(const std::string& desc): mDesc(desc) {}

    MAPPED lookup(const typename Map::key_type& key) const
    {
        typename Map::const_iterator found = mMap.find(key);
        if (found == mMap.end())
        {
            LL_WARNS("LLWindowListener") << "Unknown " << mDesc << " '" << key << "'" << LL_ENDL;
            return MAPPED();
        }
        return found->second;
    }

protected:
    void add(const typename Map::key_type& key, const typename Map::mapped_type& value)
    {
        mMap.insert(typename Map::value_type(key, value));
    }
};

namespace {

// helper for getMask()
MASK lookupMask_(const std::string& maskname)
{
    // It's unclear to me whether MASK_MAC_CONTROL is important, but it's not
    // supported by maskFromString(). Handle that specially.
    if (maskname == "MAC_CONTROL")
    {
        return MASK_MAC_CONTROL;
    }
    else
    {
        // In case of lookup failure, return MASK_NONE, which won't affect our
        // caller's OR.
        MASK mask(MASK_NONE);
        LLKeyboard::maskFromString(maskname, &mask);
        return mask;
    }
}

MASK getMask(const LLSD& event)
{
    LLSD masknames(event["mask"]);
    if (! masknames.isArray())
    {
        // If event["mask"] is a single string, perform normal lookup on it.
        return lookupMask_(masknames);
    }

    // Here event["mask"] is an array of mask-name strings. OR together their
    // corresponding bits.
    MASK mask(MASK_NONE);
    for (LLSD::array_const_iterator ai(masknames.beginArray()), aend(masknames.endArray());
         ai != aend; ++ai)
    {
        mask |= lookupMask_(*ai);
    }
    return mask;
}

KEY getKEY(const LLSD& event)
{
    if (event.has("keysym"))
    {
        // Initialize to KEY_NONE; that way we can ignore the bool return from
        // keyFromString() and, in the lookup-fail case, simply return KEY_NONE.
        KEY key(KEY_NONE);
        LLKeyboard::keyFromString(event["keysym"], &key);
        return key;
    }
    else if (event.has("keycode"))
    {
        return KEY(event["keycode"].asInteger());
    }
    else
    {
        return KEY(event["char"].asString()[0]);
    }
}

} // namespace

void LLWindowListener::getInfo(LLSD const & evt)
{
    Response response(LLSD(), evt);

    if (evt.has("path"))
    {
        std::string path(evt["path"]);
        LLView * target_view = LLUI::getInstance()->resolvePath(LLUI::getInstance()->getRootView(), path);
        if (target_view != 0)
        {
            response.setResponse(target_view->getInfo());
        }
        else
        {
            response.error(STRINGIZE(evt["op"].asString() << " request "
                                            "specified invalid \"path\": '" << path << "'"));
        }
    }
    else
    {
        response.error(
            STRINGIZE(evt["op"].asString() << "request did not provide a path" ));
    }
}

void LLWindowListener::getPaths(LLSD const & request)
{
    Response response(LLSD(), request);
    LLView *root(LLUI::getInstance()->getRootView()), *base(NULL);
    // Capturing request["under"] as string means we conflate the case in
    // which there is no ["under"] key with the case in which its value is the
    // empty string. That seems to make sense to me.
    std::string under(request["under"]);

    // Deal with optional "under" parameter
    if (under.empty())
    {
        base = root;
    }
    else
    {
        base = LLUI::getInstance()->resolvePath(root, under);
        if (! base)
        {
            return response.error(STRINGIZE(request["op"].asString() << " request "
                                            "specified invalid \"under\" path: '" << under << "'"));
        }
    }

    // Traverse the entire subtree under 'base', collecting pathnames
    for (LLView::tree_iterator_t ti(base->beginTreeDFS()), tend(base->endTreeDFS());
         ti != tend; ++ti)
    {
        response["paths"].append((*ti)->getPathname());
    }
}

void LLWindowListener::keyDown(LLSD const & evt)
{
    Response response(LLSD(), evt);
    KEY key = getKEY(evt);
    MASK mask = getMask(evt);

    if (evt.has("path"))
    {
        std::string path(evt["path"]);
        LLView * target_view = LLUI::getInstance()->resolvePath(LLUI::getInstance()->getRootView(), path);
        if (target_view == 0)
        {
            response.error(STRINGIZE(evt["op"].asString() << " request "
                                            "specified invalid \"path\": '" << path << "'"));
        }
        else if(target_view->isAvailable())
        {
            response.setResponse(target_view->getInfo());

            gFocusMgr.setKeyboardFocus(target_view);
            gViewerInput.handleKey(key, mask, false);
            if(key < 0x80) mWindow->handleUnicodeChar(key, mask);
        }
        else
        {
            response.error(STRINGIZE(evt["op"].asString() << " request "
                                            "element specified by \"path\": '" << path << "'"
                                            << " is not visible"));
        }
    }
    else
    {
        gViewerInput.handleKey(key, mask, false);
        if(key < 0x80) mWindow->handleUnicodeChar(key, mask);
    }
}

void LLWindowListener::keyUp(LLSD const & evt)
{
    Response response(LLSD(), evt);

    if (evt.has("path"))
    {
        std::string path(evt["path"]);
        LLView * target_view = LLUI::getInstance()->resolvePath(LLUI::getInstance()->getRootView(), path);
        if (target_view == 0 )
        {
            response.error(STRINGIZE(evt["op"].asString() << " request "
                                            "specified invalid \"path\": '" << path << "'"));
        }
        else if (target_view->isAvailable())
        {
            response.setResponse(target_view->getInfo());

            gFocusMgr.setKeyboardFocus(target_view);
            mKbGetter()->handleTranslatedKeyUp(getKEY(evt), getMask(evt));
        }
        else
        {
            response.error(STRINGIZE(evt["op"].asString() << " request "
                                            "element specified byt \"path\": '" << path << "'"
                                            << " is not visible"));
        }
    }
    else
    {
        mKbGetter()->handleTranslatedKeyUp(getKEY(evt), getMask(evt));
    }
}

// for WhichButton
typedef BOOL (LLWindowCallbacks::*MouseMethod)(LLWindow *, LLCoordGL, MASK);
struct Actions
{
    Actions(const MouseMethod& d, const MouseMethod& u): down(d), up(u), valid(true) {}
    Actions(): valid(false) {}
    MouseMethod down, up;
    bool valid;
};

struct WhichButton: public StringLookup<Actions>
{
    WhichButton(): StringLookup<Actions>("mouse button")
    {
        add("LEFT",     Actions(&LLWindowCallbacks::handleMouseDown,
                                &LLWindowCallbacks::handleMouseUp));
        add("RIGHT",    Actions(&LLWindowCallbacks::handleRightMouseDown,
                                &LLWindowCallbacks::handleRightMouseUp));
        add("MIDDLE",   Actions(&LLWindowCallbacks::handleMiddleMouseDown,
                                &LLWindowCallbacks::handleMiddleMouseUp));
    }
};
static WhichButton buttons;

typedef boost::function<bool(LLCoordGL, MASK)> MouseFunc;

// Wrap a function returning 'void' to return 'true' instead. I'm sure there's
// a more generic way to accomplish this, but generically handling the
// arguments seems to require variadic templates and perfect forwarding. (We
// used to be able to write (boost::lambda::bind(...), true), counting on
// boost::lambda's comma operator overload, until
// https://svn.boost.org/trac/boost/ticket/10864. And boost::phoenix doesn't
// seem to overload comma the same way; or at least not with bind().)
class MouseFuncTrue
{
    typedef boost::function<void(LLCoordGL, MASK)> MouseFuncVoid;
    MouseFuncVoid mFunc;

public:
    MouseFuncTrue(const MouseFuncVoid& func):
        mFunc(func)
    {}

    bool operator()(LLCoordGL coords, MASK mask) const
    {
        mFunc(coords, mask);
        return true;
    }
};

static void mouseEvent(const MouseFunc& func, const LLSD& request)
{
    // Ensure we send response
    LLEventAPI::Response response(LLSD(), request);
    // We haven't yet established whether the incoming request has "x" and "y",
    // but capture this anyway, with 0 for omitted values.
    LLCoordGL pos(request["x"].asInteger(), request["y"].asInteger());
    bool has_pos(request.has("x") && request.has("y"));

    std::unique_ptr<LLView::TemporaryDrilldownFunc> tempfunc;

    // Documentation for mouseDown(), mouseUp() and mouseMove() claims you
    // must either specify ["path"], or both of ["x"] and ["y"]. You MAY
    // specify all. Let's say that passing "path" as an empty string is
    // equivalent to not passing it at all.
    std::string path(request["path"]);
    if (path.empty())
    {
        // Without "path", you must specify both "x" and "y".
        if (! has_pos)
        {
            return response.error(STRINGIZE(request["op"].asString() << " request "
                                            "without \"path\" must specify both \"x\" and \"y\": "
                                            << request));
        }
    }
    else // ! path.empty()
    {
        LLView* root   = LLUI::getInstance()->getRootView();
        LLView* target = LLUI::getInstance()->resolvePath(root, path);
        if (! target)
        {
            return response.error(STRINGIZE(request["op"].asString() << " request "
                                            "specified invalid \"path\": '" << path << "'"));
        }

        response.setResponse(target->getInfo());

        // The intent of this test is to prevent trying to drill down to a
        // widget in a hidden floater, or on a tab that's not current, etc.
        if (! target->isInVisibleChain())
        {
            return response.error(STRINGIZE(request["op"].asString() << " request "
                                            "specified \"path\" not currently visible: '"
                                            << path << "'"));
        }

        // This test isn't folded in with the above error case since you can
        // (e.g.) pop up a tooltip even for a disabled widget.
        if (! target->isInEnabledChain())
        {
            response.warn(STRINGIZE(request["op"].asString() << " request "
                                    "specified \"path\" not currently enabled: '"
                                    << path << "'"));
        }

        if (! has_pos)
        {
            LLRect rect(target->calcScreenRect());
            pos.set(rect.getCenterX(), rect.getCenterY());
            // nonstandard warning tactic: probably usual case; we want event
            // sender to know synthesized (x, y), but maybe don't need to log?
            response["warnings"].append(STRINGIZE("using center point ("
                                                  << pos.mX << ", " << pos.mY << ")"));
        }

/*==========================================================================*|
        // NEVER MIND: the LLView tree defines priority handler layers in
        // front of the normal widget set, so this has never yet produced
        // anything but spam warnings. (sigh)

        // recursive childFromPoint() should give us the frontmost, leafmost
        // widget at the specified (x, y).
        LLView* frontmost = root->childFromPoint(pos.mX, pos.mY, true);
        if (frontmost != target)
        {
            response.warn(STRINGIZE(request["op"].asString() << " request "
                                    "specified \"path\" = '" << path
                                    << "', but frontmost LLView at (" << pos.mX << ", " << pos.mY
                                    << ") is '" << LLView::getPathname(frontmost) << "'"));
        }
|*==========================================================================*/

        // Instantiate a TemporaryDrilldownFunc to route incoming mouse events
        // to the target LLView*. But put it on the heap since "path" is
        // optional. Nonetheless, manage it with a boost::scoped_ptr so it
        // will be destroyed when we leave.
        tempfunc.reset(new LLView::TemporaryDrilldownFunc(llview::TargetEvent(target)));
    }

    // The question of whether the requested LLView actually handled the
    // specified event is important enough, and its handling unclear enough,
    // to warrant a separate response attribute. Instead of deciding here to
    // make it a warning, or an error, let caller decide.
    response["handled"] = func(pos, getMask(request));

    // On exiting this scope, response will send, tempfunc will restore the
    // normal pointInView(x, y) containment logic, etc.
}

void LLWindowListener::mouseDown(LLSD const & request)
{
    Actions actions(buttons.lookup(request["button"]));
    if (actions.valid)
    {
        // Normally you can pass NULL to an LLWindow* without compiler
        // complaint, but going through boost::bind() evidently
        // bypasses that special case: it only knows you're trying to pass an
        // int to a pointer. Explicitly cast NULL to the desired pointer type.
        mouseEvent(boost::bind(actions.down, mWindow,
                             static_cast<LLWindow*>(NULL), _1, _2),
                   request);
    }
}

void LLWindowListener::mouseUp(LLSD const & request)
{
    Actions actions(buttons.lookup(request["button"]));
    if (actions.valid)
    {
        mouseEvent(boost::bind(actions.up, mWindow,
                             static_cast<LLWindow*>(NULL), _1, _2),
                   request);
    }
}

void LLWindowListener::mouseMove(LLSD const & request)
{
    // We want to call the same central mouseEvent() routine for
    // handleMouseMove() as for button clicks. But handleMouseMove() returns
    // void, whereas mouseEvent() accepts a function returning bool -- and
    // uses that bool return. Use MouseFuncTrue to construct a callable that
    // returns bool anyway.
    mouseEvent(MouseFuncTrue(boost::bind(&LLWindowCallbacks::handleMouseMove, mWindow,
                          static_cast<LLWindow*>(NULL), _1, _2)),
               request);
}

void LLWindowListener::mouseScroll(LLSD const & request)
{
    S32 clicks = request["clicks"].asInteger();

    mWindow->handleScrollWheel(NULL, clicks);
}