ptprnt/src/graphics/Label.cpp

/* 
    ptrnt - print labels on linux
    Copyright (C) 2025  Moritz Martinius

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.

 */

#include "graphics/Label.hpp"

#include <algorithm>
#include <spdlog/spdlog.h>

#include <cassert>
#include <cstddef>
#include <cstdint>
#include <memory>
#include <string>
#include <vector>

#include "cairo.h"
#include "graphics/CairoWrapper.hpp"
#include "graphics/interface/ICairoWrapper.hpp"
#include "graphics/interface/ILabel.hpp"
#include "pango/pango-font.h"
#include "pango/pango-layout.h"
#include "pango/pango-types.h"

namespace ptprnt::graphics {

// Deleter implementations
void CairoSurfaceDeleter::operator()(cairo_surface_t* surface) const {
    if (surface && wrapper)
        wrapper->cairo_surface_destroy(surface);
}

void CairoDeleter::operator()(cairo_t* cr) const {
    if (cr && wrapper)
        wrapper->cairo_destroy(cr);
}

void GObjectDeleter::operator()(gpointer obj) const {
    if (obj && wrapper)
        wrapper->g_object_unref(obj);
}

// Default constructor - creates real Cairo/Pango wrapper
Label::Label(const uint16_t heightPixel) : Label(heightPixel, std::make_shared<CairoWrapper>()) {}

// Constructor with dependency injection
Label::Label(const uint16_t heightPixel, std::shared_ptr<ICairoWrapper> cairoWrapper)
    : mCairoWrapper(std::move(cairoWrapper)), mPrinterHeight(heightPixel) {
    // Initialize resources in correct order with RAII
    // Pass wrapper to deleter so cleanup uses the wrapper
    GObjectDeleter deleter;
    deleter.wrapper = mCairoWrapper;
    mFontMap        = std::unique_ptr<PangoFontMap, GObjectDeleter>(mCairoWrapper->pango_cairo_font_map_new(), deleter);
}

std::vector<uint8_t> Label::getRaw() const {
    assert(mSurface != nullptr);
    auto* surface = mSurface.get();

    mCairoWrapper->cairo_surface_flush(surface);
    assert(mCairoWrapper->cairo_image_surface_get_format(surface) == CAIRO_FORMAT_A8);

    int width  = mCairoWrapper->cairo_image_surface_get_width(surface);
    int height = mCairoWrapper->cairo_image_surface_get_height(surface);
    int stride = mCairoWrapper->cairo_image_surface_get_stride(surface);

    spdlog::debug("Cairo Surface data: W: {}; H: {}; S:{}", width, height, stride);

    auto data = mCairoWrapper->cairo_image_surface_get_data(surface);

    // If stride equals width, we can return data directly
    if (stride == width) {
        size_t len = height * stride;
        return {data, data + len};
    }

    // Otherwise, we need to copy row by row, removing stride padding
    std::vector<uint8_t> result;
    result.reserve(width * height);

    for (int y = 0; y < height; ++y) {
        uint8_t* row_start = data + (y * stride);
        result.insert(result.end(), row_start, row_start + width);
    }

    spdlog::debug("getRaw: Removed stride padding, returning {} bytes ({}x{})", result.size(), width, height);
    return result;
}

uint8_t Label::getNumLines(std::string_view strv) {
    return std::count(strv.begin(), strv.end(), '\n');
}

int Label::getWidth() const {
    // Return the actual Cairo surface width (which is the layout width)
    return mLayoutWidth;
}

int Label::getHeight() const {
    // Return the actual Cairo surface height (which is the printer height)
    return mPrinterHeight;
}

void Label::configureLayout(PangoLayout* layout, const std::string& text, PangoFontDescription* fontDesc) {
    mCairoWrapper->pango_layout_set_font_description(layout, fontDesc);
    mCairoWrapper->pango_layout_set_text(layout, text.c_str(), static_cast<int>(text.length()));
    mCairoWrapper->pango_layout_set_height(layout, getNumLines(text) * -1);
}

void Label::applyHorizontalAlignment(PangoLayout* layout) {
    switch (mHAlign) {
        case HAlignPosition::LEFT:
            mCairoWrapper->pango_layout_set_alignment(layout, PANGO_ALIGN_LEFT);
            break;
        case HAlignPosition::RIGHT:
            mCairoWrapper->pango_layout_set_alignment(layout, PANGO_ALIGN_RIGHT);
            break;
        case HAlignPosition::JUSTIFY:
            mCairoWrapper->pango_layout_set_alignment(layout, PANGO_ALIGN_LEFT);
            mCairoWrapper->pango_layout_set_justify(layout, true);
#if PANGO_VERSION_MAJOR >= 1 && PANGO_VERSION_MINOR >= 50
            mCairoWrapper->pango_layout_set_justify_last_line(layout, true);
#endif
            break;
        case HAlignPosition::CENTER:
            [[fallthrough]];
        default:
            mCairoWrapper->pango_layout_set_alignment(layout, PANGO_ALIGN_CENTER);
            break;
    }
}

bool Label::create(PrintableText printableText) {
    setFontFamily(printableText.fontFamily);
    setFontSize(printableText.fontSize);

    return create(printableText.text);
}

bool Label::create(const std::string& labelText) {
    // TODO: we need to create a custom font config here so that Noto Emoji does not load the systems default
    // font config here. For this, we need to create a PangoFcFontMap and a custom FcConfig
    // see: https://docs.gtk.org/PangoFc/method.FontMap.set_config.html
    // see: https://gist.github.com/CallumDev/7c66b3f9cf7a876ef75f

    // Create a temporary surface for layout size calculations
    auto* tempSurface  = mCairoWrapper->cairo_image_surface_create(CAIRO_FORMAT_A8, 1, 1);
    auto* tempCr       = mCairoWrapper->cairo_create(tempSurface);
    auto* tempPangoCtx = mCairoWrapper->pango_cairo_create_context(tempCr);
    auto* tempPangoLyt = mCairoWrapper->pango_layout_new(tempPangoCtx);

    PangoFontDescription* regularFont = mCairoWrapper->pango_font_description_new();
    mCairoWrapper->pango_font_description_set_size(regularFont, static_cast<int>(mFontSize * PANGO_SCALE));
    mCairoWrapper->pango_font_description_set_family(regularFont, mFontFamily.c_str());

    // Configure temporary layout for size calculation
    configureLayout(tempPangoLyt, labelText, regularFont);
    applyHorizontalAlignment(tempPangoLyt);

    // Calculate label size from temporary layout
    mCairoWrapper->pango_layout_get_size(tempPangoLyt, &mLayoutWidth, &mLayoutHeight);
    mLayoutWidth /= PANGO_SCALE;
    mLayoutHeight /= PANGO_SCALE;

    spdlog::debug("Layout width: {}, height: {}", mLayoutWidth, mLayoutHeight);

    // Clean up temporary resources
    mCairoWrapper->g_object_unref(tempPangoLyt);
    mCairoWrapper->g_object_unref(tempPangoCtx);
    mCairoWrapper->cairo_destroy(tempCr);
    mCairoWrapper->cairo_surface_destroy(tempSurface);

    // Now create the final surface and Pango context for actual rendering
    // Create deleters with wrapper reference
    CairoSurfaceDeleter surfaceDeleter;
    surfaceDeleter.wrapper = mCairoWrapper;
    CairoDeleter cairoDeleter;
    cairoDeleter.wrapper = mCairoWrapper;
    GObjectDeleter gobjectDeleter;
    gobjectDeleter.wrapper = mCairoWrapper;

    mSurface = std::unique_ptr<cairo_surface_t, CairoSurfaceDeleter>(
        mCairoWrapper->cairo_image_surface_create(CAIRO_FORMAT_A8, mLayoutWidth, mPrinterHeight), surfaceDeleter);
    cairo_t* cr = mCairoWrapper->cairo_create(mSurface.get());
    mCairoCtx   = std::unique_ptr<cairo_t, CairoDeleter>(cr, cairoDeleter);
    mPangoCtx =
        std::unique_ptr<PangoContext, GObjectDeleter>(mCairoWrapper->pango_cairo_create_context(cr), gobjectDeleter);
    mPangoLyt =
        std::unique_ptr<PangoLayout, GObjectDeleter>(mCairoWrapper->pango_layout_new(mPangoCtx.get()), gobjectDeleter);

    // Configure final layout with same settings
    configureLayout(mPangoLyt.get(), labelText, regularFont);
    applyHorizontalAlignment(mPangoLyt.get());

    // Adjust Cairo cursor position to respect the vertical alignment
    switch (mVAlign) {
        case VAlignPosition::TOP:
            break;
        case VAlignPosition::BOTTOM:
            mCairoWrapper->cairo_move_to(mCairoCtx.get(), 0.0, mPrinterHeight - mLayoutHeight);
            break;
        case VAlignPosition::MIDDLE:
            mCairoWrapper->cairo_move_to(mCairoCtx.get(), 0.0, (mPrinterHeight - mLayoutHeight) / 2);
            break;
        default:
            break;
    }

    // Finally show the layout on the Cairo surface
    mCairoWrapper->pango_cairo_show_layout(mCairoCtx.get(), mPangoLyt.get());

    mCairoWrapper->cairo_set_source_rgb(mCairoCtx.get(), 0.0, 0.0, 0.0);
    mCairoWrapper->cairo_surface_flush(mSurface.get());
    // mCairoCtx smart pointer will handle cleanup
    return true;
}

void Label::writeToPng(const std::string& file) {
    if (mSurface) {
        mCairoWrapper->cairo_surface_flush(mSurface.get());
        mCairoWrapper->cairo_surface_write_to_png(mSurface.get(), file.c_str());
    }
}

bool Label::append(const ILabel& other, uint32_t spacingPx) {
    // Check that heights match
    if (getHeight() != other.getHeight()) {
        spdlog::error("Cannot append labels with different heights: {} vs {}", getHeight(), other.getHeight());
        return false;
    }

    int currentWidth = getWidth();
    int otherWidth   = other.getWidth();
    int height       = getHeight();
    int spacing      = static_cast<int>(spacingPx);
    int newWidth     = currentWidth + spacing + otherWidth;

    spdlog::debug("Appending label: current={}x{}, other={}x{}, spacing={}, new={}x{}", currentWidth, height,
                  otherWidth, height, spacing, newWidth, height);

    // Get current and other label data
    auto currentData = getRaw();
    auto otherData   = other.getRaw();

    // Create new surface with extended width
    CairoSurfaceDeleter surfaceDeleter;
    surfaceDeleter.wrapper = mCairoWrapper;
    auto newSurface        = std::unique_ptr<cairo_surface_t, CairoSurfaceDeleter>(
        mCairoWrapper->cairo_image_surface_create(CAIRO_FORMAT_A8, newWidth, height), surfaceDeleter);

    if (mCairoWrapper->cairo_surface_status(newSurface.get()) != CAIRO_STATUS_SUCCESS) {
        spdlog::error("Failed to create new surface for appended label");
        return false;
    }

    // Get data pointer and stride
    mCairoWrapper->cairo_surface_flush(newSurface.get());
    unsigned char* newData = mCairoWrapper->cairo_image_surface_get_data(newSurface.get());
    int newStride          = mCairoWrapper->cairo_image_surface_get_stride(newSurface.get());

    // Clear the new surface (set to transparent/white)
    std::memset(newData, 0x00, newStride * height);

    // Copy current label data
    for (int y = 0; y < height; ++y) {
        for (int x = 0; x < currentWidth; ++x) {
            size_t srcIdx = y * currentWidth + x;
            size_t dstIdx = y * newStride + x;
            if (srcIdx < currentData.size()) {
                newData[dstIdx] = currentData[srcIdx];
            }
        }
    }

    // Copy other label data (with spacing offset)
    int xOffset = currentWidth + spacing;
    for (int y = 0; y < height; ++y) {
        for (int x = 0; x < otherWidth; ++x) {
            size_t srcIdx = y * otherWidth + x;
            size_t dstIdx = y * newStride + (xOffset + x);
            if (srcIdx < otherData.size()) {
                newData[dstIdx] = otherData[srcIdx];
            }
        }
    }

    mCairoWrapper->cairo_surface_mark_dirty(newSurface.get());

    // Replace current surface with new one
    mSurface = std::move(newSurface);

    // Update layout dimensions
    mLayoutWidth = newWidth;

    return true;
}

void Label::setFontSize(const double fontSize) {
    mFontSize = fontSize;
}

void Label::setFontFamily(const std::string& fontFamily) {
    mFontFamily = fontFamily;
}

void Label::setHAlign(HAlignPosition hAlign) {
    mHAlign = hAlign;
}

void Label::setVAlign(VAlignPosition vAlign) {
    mVAlign = vAlign;
}

void Label::setText(const std::string& text) {
    mText = text;
}

Label::~Label() {
    spdlog::debug("Image dtor...");
    // RAII smart pointers handle cleanup automatically
}
}  // namespace ptprnt::graphics