/*
Crafter®.Graphics
Copyright (C) 2025 Catcrafts®
Catcrafts.net

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; either
version 3.0 of the License, or (at your option) any later version.

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
*/

module Crafter.Graphics:RenderingElementScalingRotating2D_impl;
import :RenderingElement;
import :Window;
import :Types;
import :Font;
import std;

using namespace Crafter;

RenderingElementScalingRotating2D::RenderingElementScalingRotating2D(OpaqueType opaque) : RenderingElement(opaque), rotation(0) {

}

RenderingElementScalingRotating2D::RenderingElementScalingRotating2D(OpaqueType opaque, std::int_fast32_t anchorX, std::int_fast32_t anchorY, std::uint_fast32_t relativeWidth, std::uint_fast32_t relativeHeight, std::int_fast32_t anchorOffsetX, std::int_fast32_t anchorOffsetY, std::int_fast32_t z, bool ignoreScaling) : RenderingElement(opaque, anchorX, anchorY, relativeWidth, relativeHeight, anchorOffsetX, anchorOffsetY, z, ignoreScaling), rotation(0) {

}

RenderingElementScalingRotating2D::RenderingElementScalingRotating2D(OpaqueType opaque, std::uint_fast32_t bufferWidth, std::uint_fast32_t bufferHeight, std::uint_fast32_t rotation, std::int_fast32_t anchorX, std::int_fast32_t anchorY, std::uint_fast32_t relativeWidth, std::uint_fast32_t relativeHeight, std::int_fast32_t anchorOffsetX, std::int_fast32_t anchorOffsetY, std::int_fast32_t z, bool ignoreScaling) 
    : bufferWidth(bufferWidth), bufferHeight(bufferHeight), buffer(bufferWidth*bufferHeight), 
      rotation(rotation),
      RenderingElement(opaque, anchorX, anchorY, relativeWidth, relativeHeight, anchorOffsetX, anchorOffsetY, z, ignoreScaling) {
}

void RenderingElementScalingRotating2D::ResizeBuffer(std::uint_fast32_t width, std::uint_fast32_t height) {
    this->bufferWidth = width;
    this->bufferHeight = height;
    buffer.resize(width * height);
}

void RenderingElementScalingRotating2D::UpdateRotation(std::uint_fast32_t rotation) {
    rotationUpdated = true;
    this->rotation = rotation;
}

void RenderingElementScalingRotating2D::UpdateScaledBuffer(ScaleData& scaled) {
    // Rotation
    const double rad = (static_cast<double>(rotation) / static_cast<double>(std::numeric_limits<std::uint_fast32_t>::max())) * 2.0 * std::numbers::pi;

    const std::uint_fast32_t dstWidth  = scaled.width;
    const std::uint_fast32_t dstHeight = scaled.height;

    const double rotatedWidth = scaled.width  * (std::abs(std::cos(rad)) + std::abs(std::sin(rad)));
    const double rotatedHeight = scaled.height * (std::abs(std::cos(rad)) + std::abs(std::sin(rad)));

    const std::uint_fast32_t diffX = std::ceil((rotatedWidth - scaled.width)/2);
    const std::uint_fast32_t diffY = std::ceil((rotatedHeight - scaled.height)/2);

    scaled.width += diffX + diffX;
    scaled.height += diffY + diffY;

    scaled.x -= diffX;
    scaled.y -= diffY;

    bufferScaled.clear();
    bufferScaled.resize(scaled.width * scaled.height);

    // Destination center
    const double dstCx = (static_cast<double>(scaled.width)  - 1.0) * 0.5;
    const double dstCy = (static_cast<double>(scaled.height) - 1.0) * 0.5;

    // Source center
    const double srcCx = (static_cast<double>(bufferWidth)  - 1.0) * 0.5;
    const double srcCy = (static_cast<double>(bufferHeight) - 1.0) * 0.5;

    const double c = std::cos(rad);
    const double s = std::sin(rad);

    // Scale factors (destination → source)
    const double scaleX = static_cast<double>(bufferWidth)  / dstWidth;
    const double scaleY = static_cast<double>(bufferHeight) / dstHeight;

    for (std::uint_fast32_t yB = 0; yB < scaled.height; ++yB) {
        for (std::uint_fast32_t xB = 0; xB < scaled.width; ++xB) {

            // ---- Destination pixel relative to center ----
            const double dx = (static_cast<double>(xB) - dstCx) * scaleX;
            const double dy = (static_cast<double>(yB) - dstCy) * scaleY;

            // ---- Inverse rotation ----
            const double sx =  (c * dx - s * dy) + srcCx;
            const double sy =  (s * dx + c * dy) + srcCy;

            // ---- Nearest neighbour sampling ----
            const std::int_fast32_t srcX = static_cast<std::int_fast32_t>(std::round(sx));
            const std::int_fast32_t srcY = static_cast<std::int_fast32_t>(std::round(sy));

            if (srcX >= 0 && srcX < bufferWidth && srcY >= 0 && srcY < bufferHeight) {
                bufferScaled[yB * scaled.width + xB] = buffer[srcY * bufferWidth + srcX];
            }
        }
    }
}






void RenderingElementScalingRotating2D::UpdatePosition(Window& window) {
    ScaleData oldScale = scaled;
    window.ScaleElement(*this);

    if(oldScale.width != scaled.width || oldScale.height != scaled.height || rotationUpdated) {
        UpdateScaledBuffer(scaled);
        window.AddDirtyRect(oldScale);
        window.AddDirtyRect(scaled);
        rotationUpdated = false;
    } else if(oldScale.x != scaled.x || oldScale.y != scaled.y) {

        const double rad = (static_cast<double>(rotation) / static_cast<double>(std::numeric_limits<std::uint_fast32_t>::max())) * 2.0 * std::numbers::pi;

        const double rotatedWidth  = scaled.width  * (std::abs(std::cos(rad)) + std::abs(std::sin(rad)));
        const double rotatedHeight = scaled.height * (std::abs(std::cos(rad)) + std::abs(std::sin(rad)));

        scaled.width = static_cast<std::uint_fast32_t>(std::ceil(rotatedWidth));
        scaled.height = static_cast<std::uint_fast32_t>(std::ceil(rotatedHeight));

        window.AddDirtyRect(oldScale);
        window.AddDirtyRect(scaled);
    }

    for(Transform* child : children) {
        child->UpdatePosition(window, *this);
    }
}

void RenderingElementScalingRotating2D::UpdatePosition(Window& window, Transform& parent) {
    ScaleData oldScale = scaled;
    window.ScaleElement(*this, parent);

    if(oldScale.width != scaled.width || oldScale.height != scaled.height || rotationUpdated) {
        UpdateScaledBuffer(scaled);
        window.AddDirtyRect(oldScale);
        window.AddDirtyRect(scaled);
        rotationUpdated = false;
    } else if(oldScale.x != scaled.x || oldScale.y != scaled.y) {
        const double rad = (static_cast<double>(rotation) / static_cast<double>(std::numeric_limits<std::uint_fast32_t>::max())) * 2.0 * std::numbers::pi;

        const double rotatedWidth  = scaled.width  * (std::abs(std::cos(rad)) + std::abs(std::sin(rad)));
        const double rotatedHeight = scaled.height * (std::abs(std::cos(rad)) + std::abs(std::sin(rad)));

        scaled.width = static_cast<std::uint_fast32_t>(std::ceil(rotatedWidth));
        scaled.height = static_cast<std::uint_fast32_t>(std::ceil(rotatedHeight));

        window.AddDirtyRect(oldScale);
        window.AddDirtyRect(scaled);
    }

    for(Transform* child : children) {
        child->UpdatePosition(window, *this);
    }
}