//
//  inspect.js
//  examples
//
//  Created by Clément Brisset on March 20, 2014
//  Copyright 2014 High Fidelity, Inc.
//
//  Allows you to inspect non moving objects (Voxels or Avatars) using Atl, Control (Command on Mac) and Shift
//
//  radial mode = hold ALT
//  orbit mode  = hold ALT + CONTROL
//  pan mode    = hold ALT + CONTROL + SHIFT
//  Once you are in a mode left click on the object to inspect and hold the click
//  Dragging the mouse will move your camera according to the mode you are in.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

var PI = Math.PI;
var RAD_TO_DEG = 180.0 / PI;

var AZIMUTH_RATE = 90.0;
var ALTITUDE_RATE = 200.0;
var RADIUS_RATE = 1.0 / 100.0;
var PAN_RATE = 250.0;

var Y_AXIS = {
    x: 0,
    y: 1,
    z: 0
};
var X_AXIS = {
    x: 1,
    y: 0,
    z: 0
};

var LOOK_AT_TIME = 500;

var alt = false;
var shift = false;
var control = false;

var isActive = false;

var oldMode = Camera.mode;
var noMode = 0;
var orbitMode = 1;
var radialMode = 2;
var panningMode = 3;
var detachedMode = 4;

var mode = noMode;

var mouseLastX = 0;
var mouseLastY = 0;

var center = {
    x: 0,
    y: 0,
    z: 0
};
var position = {
    x: 0,
    y: 0,
    z: 0
};
var vector = {
    x: 0,
    y: 0,
    z: 0
};
var radius = 0.0;
var azimuth = 0.0;
var altitude = 0.0;

var avatarPosition;
var avatarOrientation;

var rotatingTowardsTarget = false;
var targetCamOrientation;
var oldPosition, oldOrientation;

function orientationOf(vector) {
    var direction,
        yaw,
        pitch;

    direction = Vec3.normalize(vector);
    yaw = Quat.angleAxis(Math.atan2(direction.x, direction.z) * RAD_TO_DEG, Y_AXIS);
    pitch = Quat.angleAxis(Math.asin(-direction.y) * RAD_TO_DEG, X_AXIS);
    return Quat.multiply(yaw, pitch);
}

function handleRadialMode(dx, dy) {
    azimuth += dx / AZIMUTH_RATE;
    radius += radius * dy * RADIUS_RATE;
    if (radius < 1) {
        radius = 1;
    }

    vector = {
        x: (Math.cos(altitude) * Math.cos(azimuth)) * radius,
        y: Math.sin(altitude) * radius,
        z: (Math.cos(altitude) * Math.sin(azimuth)) * radius
    };
    position = Vec3.sum(center, vector);
    Camera.setPosition(position);
    Camera.setOrientation(orientationOf(vector));
}

function handleOrbitMode(dx, dy) {
    azimuth += dx / AZIMUTH_RATE;
    altitude += dy / ALTITUDE_RATE;
    if (altitude > PI / 2.0) {
        altitude = PI / 2.0;
    }
    if (altitude < -PI / 2.0) {
        altitude = -PI / 2.0;
    }

    vector = {
        x: (Math.cos(altitude) * Math.cos(azimuth)) * radius,
        y: Math.sin(altitude) * radius,
        z: (Math.cos(altitude) * Math.sin(azimuth)) * radius
    };
    position = Vec3.sum(center, vector);
    Camera.setPosition(position);
    Camera.setOrientation(orientationOf(vector));
}

function handlePanMode(dx, dy) {
    var up = Quat.getUp(Camera.getOrientation());
    var right = Quat.getRight(Camera.getOrientation());
    var distance = Vec3.length(vector);

    var dv = Vec3.sum(Vec3.multiply(up, distance * dy / PAN_RATE), Vec3.multiply(right, -distance * dx / PAN_RATE));

    center = Vec3.sum(center, dv);
    position = Vec3.sum(position, dv);

    Camera.setPosition(position);
    Camera.setOrientation(orientationOf(vector));
}

function saveCameraState() {
    oldMode = Camera.mode;
    oldPosition = Camera.getPosition();
    oldOrientation = Camera.getOrientation();

    Camera.mode = "independent";
    Camera.setPosition(oldPosition);
}

function restoreCameraState() {
    Camera.mode = oldMode;
    Camera.setPosition(oldPosition);
    Camera.setOrientation(oldOrientation);
}

function handleModes() {
    var newMode = (mode == noMode) ? noMode : detachedMode;
    if (alt) {
        if (control) {
            if (shift) {
                newMode = panningMode;
            } else {
                newMode = orbitMode;
            }
        } else {
            newMode = radialMode;
        }
    }

    // if entering detachMode
    if (newMode == detachedMode && mode != detachedMode) {
        avatarPosition = MyAvatar.position;
        avatarOrientation = MyAvatar.orientation;
    }
    // if leaving detachMode
    if (mode == detachedMode && newMode == detachedMode &&
        (avatarPosition.x != MyAvatar.position.x ||
            avatarPosition.y != MyAvatar.position.y ||
            avatarPosition.z != MyAvatar.position.z ||
            avatarOrientation.x != MyAvatar.orientation.x ||
            avatarOrientation.y != MyAvatar.orientation.y ||
            avatarOrientation.z != MyAvatar.orientation.z ||
            avatarOrientation.w != MyAvatar.orientation.w)) {
        newMode = noMode;
    }

    if (mode == noMode && newMode != noMode && Camera.mode == "independent") {
        newMode = noMode;
    }

    // if leaving noMode
    if (mode == noMode && newMode != noMode) {
        saveCameraState();
    }
    // if entering noMode
    if (newMode == noMode && mode != noMode) {
        restoreCameraState();
    }

    mode = newMode;
}

function keyPressEvent(event) {
    var changed = false;

    if (event.text == "ALT") {
        alt = true;
        changed = true;
    }
    if (event.text == "CONTROL") {
        control = true;
        changed = true;
    }
    if (event.text == "SHIFT") {
        shift = true;
        changed = true;
    }

    if (changed) {
        handleModes();
    }
}

function keyReleaseEvent(event) {
    var changed = false;

    if (event.text == "ALT") {
        alt = false;
        changed = true;
        mode = noMode;
        restoreCameraState();
    }
    if (event.text == "CONTROL") {
        control = false;
        changed = true;
    }
    if (event.text == "SHIFT") {
        shift = false;
        changed = true;
    }

    if (changed) {
        handleModes();
    }
}

function mousePressEvent(event) {
    if (alt && !isActive) {
        mouseLastX = event.x;
        mouseLastY = event.y;

        // Compute trajectories related values
        var pickRay = Camera.computePickRay(mouseLastX, mouseLastY);
        var modelIntersection = Entities.findRayIntersection(pickRay, true);
        var avatarIntersection = AvatarList.findRayIntersection(pickRay);

        position = Camera.getPosition();

        if (avatarIntersection.intersects || (modelIntersection.intersects && modelIntersection.accurate)) {
            if (avatarIntersection.intersects) {
                center = avatarIntersection.intersection;
            } else {
                center = modelIntersection.intersection;
            }
            // We've selected our target, now orbit towards it automatically
            rotatingTowardsTarget = true;
            // calculate our target cam rotation
            Script.setTimeout(function () {
                rotatingTowardsTarget = false;
            }, LOOK_AT_TIME);

            vector = Vec3.subtract(position, center);
            targetCamOrientation = orientationOf(vector);
            radius = Vec3.length(vector);
            azimuth = Math.atan2(vector.z, vector.x);
            altitude = Math.asin(vector.y / Vec3.length(vector));

            isActive = true;
        }
    }
}

function mouseReleaseEvent(event) {
    if (isActive) {
        isActive = false;
    }
}

function mouseMoveEvent(event) {
    if (isActive && mode != noMode && !rotatingTowardsTarget) {
        if (mode == radialMode) {
            handleRadialMode(event.x - mouseLastX, event.y - mouseLastY);
        }
        if (mode == orbitMode) {
            handleOrbitMode(event.x - mouseLastX, event.y - mouseLastY);
        }
        if (mode == panningMode) {
            handlePanMode(event.x - mouseLastX, event.y - mouseLastY);
        }
    }
    mouseLastX = event.x;
    mouseLastY = event.y;
}

function update() {
    handleModes();
    if (rotatingTowardsTarget) {
        rotateTowardsTarget();
    }
}

function rotateTowardsTarget() {
    var newOrientation = Quat.mix(Camera.getOrientation(), targetCamOrientation, 0.1);
    Camera.setOrientation(newOrientation);
}

function scriptEnding() {
    if (mode != noMode) {
        restoreCameraState();
    }
}

Controller.keyPressEvent.connect(keyPressEvent);
Controller.keyReleaseEvent.connect(keyReleaseEvent);

Controller.mousePressEvent.connect(mousePressEvent);
Controller.mouseReleaseEvent.connect(mouseReleaseEvent);
Controller.mouseMoveEvent.connect(mouseMoveEvent);

Script.update.connect(update);
Script.scriptEnding.connect(scriptEnding);