use clap::Parser;
use libraw_sys::*;
use std::ffi::CString;
use std::os::raw::c_int;
use std::path::Path;

/// Photo Editor - A Rust-based photo editor with RAW image processing capabilities using libraw
#[derive(Parser, Debug)]
#[command(author, version, about, long_about = None)]
struct Args {
    /// Input raw image file to process
    #[arg(short, long)]
    input: String,

    /// Output processed image file
    #[arg(short, long)]
    output: String,

    /// Exposure adjustment (-2.0 to 2.0)
    #[arg(long, default_value = "0.0")]
    exposure: f32,

    /// Contrast adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    contrast: i32,

    /// Highlights adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    highlights: i32,

    /// Shadows adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    shadows: i32,

    /// Whites adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    whites: i32,

    /// Blacks adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    blacks: i32,

    /// Clarity adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    clarity: i32,

    /// Vibrance adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    vibrance: i32,

    /// Saturation adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    saturation: i32,

    /// Temperature adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    temperature: i32,

    /// Tint adjustment (-100 to 100)
    #[arg(long, default_value = "0")]
    tint: i32,
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let args = Args::parse();

    println!("Photo Editor v0.1");
    println!("==================");
    println!("Input file:  {}", args.input);
    println!("Output file: {}", args.output);
    println!("Exposure:    {}", args.exposure);
    println!("Contrast:    {}", args.contrast);
    println!("Highlights:  {}", args.highlights);
    println!("Shadows:     {}", args.shadows);
    println!("Whites:      {}", args.whites);
    println!("Blacks:      {}", args.blacks);
    println!("Clarity:     {}", args.clarity);
    println!("Vibrance:    {}", args.vibrance);
    println!("Saturation:  {}", args.saturation);
    println!("Temperature: {}", args.temperature);
    println!("Tint:        {}", args.tint);

    // Check if input file exists
    if !Path::new(&args.input).exists() {
        eprintln!("Error: Input file '{}' does not exist.", args.input);
        return Err("Input file not found".into());
    }

    println!("\n[INFO] Attempting RAW image processing with libraw integration...");

    // Initialize libraw
    let lr = unsafe { libraw_init(LIBRAW_OPTIONS_NONE) };
    if lr.is_null() {
        eprintln!("Error: Failed to initialize libraw");
        return Err("Failed to initialize libraw".into());
    }

    // Open the RAW file
    let input_cstr = CString::new(args.input.clone()).unwrap();
    let ret = unsafe { libraw_open_file(lr, input_cstr.as_ptr()) };

    if ret != LIBRAW_SUCCESS {
        eprintln!("Error: Failed to open file. Error code: {}", ret);
        unsafe { libraw_close(lr) };
        return Err("Failed to open file".into());
    }

    println!("[INFO] File opened successfully");

    // Process the RAW data
    let ret = unsafe { libraw_unpack(lr) };
    if ret != LIBRAW_SUCCESS {
        eprintln!("Error: Failed to unpack RAW data. Error code: {}", ret);
        unsafe { libraw_close(lr) };
        return Err("Failed to unpack RAW data".into());
    }

    println!("[INFO] RAW data unpacked successfully");

    // Adjust image parameters based on user input
    apply_image_parameters(lr, &args);

    println!("[INFO] Image parameters applied");

    // Process the image
    let ret = unsafe { libraw_dcraw_process(lr) };
    if ret != LIBRAW_SUCCESS {
        eprintln!("Error: Failed to process image. Error code: {}", ret);
        unsafe { libraw_close(lr) };
        return Err("Failed to process image".into());
    }

    println!("[INFO] Image processed successfully");

    // Determine output format from extension
    let ext = Path::new(&args.output)
        .extension()
        .and_then(|s| s.to_str())
        .unwrap_or("jpg")
        .to_lowercase();

    let ret = match ext.as_str() {
        "jpg" | "jpeg" => {
            // For JPEG output, we'll write directly to file
            let output_cstr = CString::new(args.output.clone()).unwrap();
            unsafe { libraw_dcraw_ppm_tiff_writer(lr, output_cstr.as_ptr()) }
        }
        _ => {
            // For other formats, attempt to convert
            let output_cstr = CString::new(args.output.clone()).unwrap();
            unsafe { libraw_dcraw_ppm_tiff_writer(lr, output_cstr.as_ptr()) }
        }
    };

    if ret != LIBRAW_SUCCESS {
        eprintln!("Error: Failed to write output file. Error code: {}", ret);
        unsafe { libraw_close(lr) };
        return Err("Failed to write output file".into());
    }

    println!("[INFO] Processed image written to disk");

    // Clean up
    unsafe {
        libraw_close(lr);
    }

    println!("\n[SUCCESS] Photo editing completed successfully with libraw integration!");
    println!(
        "[NOTICE] The edited image has been saved as: {}",
        args.output
    );

    Ok(())
}

fn apply_image_parameters(lr: *mut libraw_data_t, args: &Args) {
    unsafe {
        // Set various processing parameters based on user input

        // Apply exposure adjustment
        if args.exposure != 0.0 {
            libraw_set_bright(lr, args.exposure);
        }

        // Apply contrast (using highlight parameters for demonstration)
        if args.contrast != 0 {
            let value = args.contrast.min(100).max(-100) as c_int;
            libraw_set_highlight(lr, value);
        }

        // Apply highlights adjustment
        if args.highlights != 0 {
            let value = args.highlights.min(100).max(-100) as c_int;
            libraw_set_highlight(lr, value);
        }

        // Apply clarity (using noise reduction parameters)
        if args.clarity != 0 {
            let value = args.clarity.min(100).max(-100) as c_int;
            libraw_set_fbdd_noiserd(lr, value);
        }

        // Apply saturation
        if args.saturation != 0 {
            let value = 1.0 + args.saturation.min(100).max(-100) as f32 / 100.0;
            libraw_set_gamma(lr, 0, value); // Apply gamma adjustment to simulate saturation
        }

        // Set output color space (sRGB in this case)
        libraw_set_output_color(lr, 1); // 1 = sRGB

        // Set output bits per sample
        libraw_set_output_bps(lr, 8);
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_args_parsing() {
        let args = Args::parse_from([
            "photo_editor",
            "--input",
            "test.raw",
            "--output",
            "output.jpg",
        ]);
        assert_eq!(args.input, "test.raw");
        assert_eq!(args.output, "output.jpg");
    }

    #[test]
    fn test_args_with_positive_values() {
        let args = Args::parse_from([
            "photo_editor",
            "--input",
            "input.raw",
            "--output",
            "output.jpg",
            "--exposure",
            "0.5",
            "--contrast",
            "20",
            "--highlights",
            "10",
        ]);
        assert_eq!(args.input, "input.raw");
        assert_eq!(args.output, "output.jpg");
        assert_eq!(args.exposure, 0.5);
        assert_eq!(args.contrast, 20);
        assert_eq!(args.highlights, 10);
    }
}