//
// Camera - pan, zoom, and window resizing
//
#include <algorithm>
#include <SDL.h>
#include <SDL_opengles2.h>
#include "camera.h"

bool Camera::updated()
{
    bool updated = mCameraUpdated;
    mCameraUpdated = false;
    return updated;
}

bool Camera::windowResized()
{
    bool resized = mWindowResized;
    mWindowResized = false;
    return resized;
}

void Camera::setWindowSize(int width, int height)
{
    if (mWindowSize.width != width || mWindowSize.height != height)
    {
        mWindowResized = true;
        mWindowSize = {width, height};
        mViewport = {(float)width, (float)height};
        //setAspect((float)width / (float)height);
        setAspect(1.0);

        printf("setWindowSize: %d, %d, %f\n", width, height, (float)width/(float)height);
    }
}

// Clamp val between lo and hi
float Camera::clamp (float val, float lo, float hi) 
{ 
    return std::max(lo, std::min(val, hi)); 
}

// Convert from normalized window coords (x,y) in ([0.0, 1.0], [1.0, 0.0]) to device coords ([-1.0, 1.0], [-1.0,1.0])
void Camera::normWindowToDeviceCoords (float normWinX, float normWinY, float& deviceX, float& deviceY)
{
    deviceX = (normWinX - 0.5f) * 2.0f;
    deviceY = (1.0f - normWinY - 0.5f) * 2.0f;
}

// Convert from window coords (x,y) in ([0, mWindowWidth], [mWindowHeight, 0]) to device coords ([-1.0, 1.0], [-1.0,1.0])
void Camera::windowToDeviceCoords (int winX, int winY, float& deviceX, float& deviceY)
{
    normWindowToDeviceCoords(winX / (float)mWindowSize.width,  winY / (float)mWindowSize.height, deviceX, deviceY);
}

// Convert from device coords ([-1.0, 1.0], [-1.0,1.0]) to world coords ([-inf, inf], [-inf, inf])
void Camera::deviceToWorldCoords (float deviceX, float deviceY, float& worldX, float& worldY)
{
    worldX = deviceX / mZoom - mPan.x;
    worldY = deviceY / mAspect / mZoom - mPan.y;
}

// Convert from window coords (x,y) in ([0, windowWidth], [windowHeight, 0]) to world coords ([-inf, inf], [-inf, inf])
void Camera::windowToWorldCoords(int winX, int winY, float& worldX, float& worldY)
{
    float deviceX, deviceY;
    windowToDeviceCoords(winX, winY, deviceX, deviceY);   
    deviceToWorldCoords(deviceX, deviceY, worldX, worldY);
}

// Convert from normalized window coords (x,y) in in ([0.0, 1.0], [1.0, 0.0]) to world coords ([-inf, inf], [-inf, inf])
void Camera::normWindowToWorldCoords(float normWinX, float normWinY, float& worldX, float& worldY)
{
    float deviceX, deviceY;
    normWindowToDeviceCoords(normWinX, normWinY, deviceX, deviceY);
    deviceToWorldCoords(deviceX, deviceY, worldX, worldY);
}

void Camera::reset()
{
    mZoom = 1.0f;
    mPan = Vec2{0.0f, 0.0f};
    mBasePan = Vec2{0.0f, 0.0f};
    mAspect = 1.0f;

    mCameraUpdated = true;

}

void Camera::toJson(nlohmann::json& json_obj) const
{
    printf("1");
    json_obj["camera"]["cameraUpdated"] = mCameraUpdated;
    json_obj["camera"]["windowResized"] = mWindowResized;

    printf("2");
    json_obj["camera"]["width"] = mWindowSize.width;
    json_obj["camera"]["height"] = mWindowSize.height;

    printf("3");
    json_obj["camera"]["viewport_x"] = mViewport.x;
    json_obj["camera"]["viewport_y"] = mViewport.y;

    printf("4");
    json_obj["camera"]["pan_x"] = mPan.x;
    json_obj["camera"]["pan_y"] = mPan.y;

    printf("5");
    json_obj["camera"]["zoom"] = mZoom;
    json_obj["camera"]["aspect"] = mAspect;

    printf("6");
    json_obj["camera"]["basepan_x"] = mBasePan.x;
    json_obj["camera"]["basepan_y"] = mBasePan.y;

    printf("exit toJson");
}

void Camera::fromString(const char* pStrDumpJson)
{
    printf("Camera::fromString enter!%s\n", pStrDumpJson);

    try 
    {
        nlohmann::json json_obj = nlohmann::json::parse(pStrDumpJson);

        printf("1");
        const auto& camera_data = json_obj["camera"];
        mCameraUpdated = camera_data["cameraUpdated"];
        mWindowResized = camera_data["windowResized"];
        mWindowSize.width = camera_data["width"];
        mWindowSize.height = camera_data["height"];
        mViewport.x = camera_data["viewport_x"];
        mViewport.y = camera_data["viewport_y"];
        mPan.x = camera_data["pan_x"];
        mPan.y = camera_data["pan_y"];
        mZoom = camera_data["zoom"];
        mAspect = camera_data["aspect"];
        mBasePan.x = camera_data["basepan_x"];
        mBasePan.y = camera_data["basepan_y"];
     

    } 
    catch (const nlohmann::json::exception& e) 
    {
        // It's good practice to catch potential errors
        printf("JSON parsing error: %s\n", e.what());
    }

}