main.rs

use std::path::PathBuf;

use anyhow::Result;
use clap::Parser;
use gix::date::Time;
use image::{GrayImage, Luma};

#[derive(Parser)]
struct Opts {
    image: PathBuf,

    #[clap(long)]
    top_left: u32,

    #[clap(long, default_value_t = 20)]
    intensity: u32,

    #[clap(long)]
    repo: PathBuf,
}

const SECONDS_PER_DAY: u32 = 86400;
const SECONDS_PER_WEEK: u32 = SECONDS_PER_DAY * 7;

fn main() -> Result<()> {
    let opts = Opts::parse();

    let image: GrayImage = image::io::Reader::open(opts.image)?.decode()?.into_luma8();
    assert!(image.height() == 7);

    let repo = gix::open(opts.repo)?;

    let committer = repo.committer().unwrap()?;
    let author = repo.author().unwrap()?;

    let tree = gix::objs::Tree::empty();

    let mut prev = repo.head_commit()?.id();

    for (x, y, &Luma([value])) in image.enumerate_pixels() {
        let repetitions = value as u32 * opts.intensity / 255;

        let mut author = author.clone();
        author.time = Time {
            seconds_since_unix_epoch: opts.top_left + SECONDS_PER_DAY * y + SECONDS_PER_WEEK * x,
            offset_in_seconds: 0,
            sign: gix::actor::Sign::Plus,
        };

        for _i in 0..repetitions {
            let tree_id = repo.write_object(&tree)?;

            prev = repo.commit_as(committer, author, "HEAD", "yoo", tree_id, [prev])?;
        }
    }

    Ok(())
}