convertis/plugins/png_to_jpeg.rs

// Copyright (C) 2026 Elias Wendland <eliaswendland@pm.me>
//
// 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, version 3 exclusively.
//
// 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/>.

use crate::plugin::Plugin;

pub struct PluginImpl;

impl Plugin for PluginImpl {
    #[tracing::instrument(skip(self))]
    fn is_available(&self) -> bool {
        tracing::trace!("Checking availability for png_to_jpeg plugin (always true)");
        true
    }
    fn name(&self) -> &'static str {
        "png_to_jpeg"
    }
    fn from_formats(&self) -> Vec<&'static str> {
        vec!["png"]
    }
    fn to_formats(&self) -> Vec<&'static str> {
        vec!["jpeg"]
    }
    fn familiarity(&self, _from: &str, _to: &str) -> u8 {
        255
    }
    fn quality(&self, _from: &str, _to: &str) -> u8 {
        200
    } // JPEG has some compression loss
    fn speed(&self, _from: &str, _to: &str) -> u8 {
        220
    }

    #[tracing::instrument(skip(self, input, _temp_dir))]
    fn convert(
        &self,
        input: &[u8],
        _from: &str,
        _to: &str,
        _temp_dir: &std::path::Path,
    ) -> Result<Vec<u8>, String> {
        tracing::debug!("png_to_jpeg starting conversion");
        tracing::trace!("Loading PNG image from memory ({} bytes)", input.len());
        let img = image::load_from_memory_with_format(input, image::ImageFormat::Png)
            .map_err(|e| {
                tracing::error!("Failed to decode PNG image: {}", e);
                e.to_string()
            })?;

        tracing::trace!("PNG image loaded successfully. Dimensions: {}x{}", img.width(), img.height());

        let mut output = std::io::Cursor::new(Vec::new());
        tracing::trace!("Encoding image as JPEG");
        img.write_to(&mut output, image::ImageFormat::Jpeg)
            .map_err(|e| {
                tracing::error!("Failed to encode image as JPEG: {}", e);
                e.to_string()
            })?;

        let out_bytes = output.into_inner();
        tracing::debug!("png_to_jpeg conversion completed. Output size: {} bytes", out_bytes.len());
        Ok(out_bytes)
    }
}