agent-image-diff 0.2.4

use crate::region::DiffResult;
use anyhow::Result;
use std::io::Write;

pub fn write_summary(result: &DiffResult, writer: &mut impl Write) -> Result<()> {
    if result.is_match {
        writeln!(writer, "Images are identical.")?;
        return Ok(());
    }

    writeln!(writer, "Images differ.")?;
    writeln!(
        writer,
        "  Dimensions: {}x{}",
        result.dimensions.width, result.dimensions.height
    )?;
    writeln!(
        writer,
        "  Changed pixels: {} ({:.2}%)",
        result.stats.changed_pixels, result.stats.diff_percentage
    )?;
    if result.stats.antialiased_pixels > 0 {
        writeln!(
            writer,
            "  Anti-aliased pixels (excluded): {}",
            result.stats.antialiased_pixels
        )?;
    }
    writeln!(writer, "  Regions: {}", result.stats.region_count)?;

    if let Some(mismatch) = &result.dimension_mismatch {
        writeln!(
            writer,
            "  Dimension mismatch: baseline={}x{}, candidate={}x{}",
            mismatch.baseline.width,
            mismatch.baseline.height,
            mismatch.candidate.width,
            mismatch.candidate.height
        )?;
    }

    writeln!(writer)?;
    for region in &result.regions {
        writeln!(
            writer,
            "  Region #{} [{}]: {}x{} at ({},{}) — {} pixels, avg delta {:.3}, max delta {:.3}",
            region.id,
            region.label,
            region.bounding_box.width,
            region.bounding_box.height,
            region.bounding_box.x,
            region.bounding_box.y,
            region.pixel_count,
            region.avg_delta,
            region.max_delta
        )?;
    }

    Ok(())
}