use pathdiff::diff_paths;
use sha2::{Digest, Sha256};
use std::fs::File;
use std::io::Read;
use std::path::{Path, PathBuf};

fn get_hash(fname: &str) -> Vec<u8> {
    let result1 = File::open(fname);
    if result1.is_err() {
        return vec![];
    }
    let mut result = result1.unwrap();
    let mut hasher = Sha256::new();
    loop {
        let mut bif = [0; 1024];
        let ur = result.read(&mut bif);
        if ur.is_err() {
            return vec![];
        }
        hasher.update(&bif);
        if ur.unwrap() < 1024 {
            break;
        }
    }

    hasher.finalize().to_vec()
}

fn find_files(path: &Path) -> Vec<PathBuf> {
    let mut ret = vec![];
    let fss = std::fs::read_dir(path).unwrap();
    for fs in fss {
        let fs = fs.unwrap();
        if fs.file_type().unwrap().is_file() {
            ret.push(fs.path());
        } else if fs.file_type().unwrap().is_dir() {
            let mut p = PathBuf::from(path);
            p.push(fs.file_name().to_str().unwrap());
            ret.extend(find_files(p.as_path()));
        }
    }
    ret
}

fn linkdup(path: &Path) {
    let mut fhtable = vec![];
    for z in find_files(path) {
        let pth = z;
        let hsh = get_hash(pth.to_str().unwrap());
        fhtable.push((pth.to_str().unwrap().to_string(), hsh));
    }
    fhtable.sort_by(|x, y| Ord::cmp(&x.0, &y.0));
    let mut fable: Vec<(String, Vec<u8>)> = vec![];
    for f in fhtable {
        let prstr = fable
            .iter()
            .filter_map(|x| if x.1 == f.1 { Some(x.0.clone()) } else { None })
            .next();
        if prstr.is_some() {
            // let f2m = std::fs::metadata(f.0.clone()).unwrap();
            std::fs::remove_file(f.0.clone()).unwrap();
            let mut zz = PathBuf::from(f.0.clone());
            zz.pop();
            std::os::unix::fs::symlink(diff_paths(prstr.unwrap(), zz).unwrap(), f.0.clone())
                .unwrap();
        } else {
            fable.push(f);
        }
    }
}

fn main() {
    linkdup(PathBuf::from(".").as_path());
}