First public commit (i had some old stuff i cant publish)

src/download.rs

@@ -0,0 +1,93 @@
+use crate::meta::{AssetObjects, VersionDetail, wanted};
+use indicatif::{ParallelProgressIterator, ProgressBar, ProgressStyle};
+use rayon::prelude::*;
+use sha2::Digest;
+use std::fs::{File, create_dir_all};
+use std::io::copy;
+use std::path::Path;
+use ureq::get;
+pub fn download(url: &str, path: &Path) -> anyhow::Result<()> {
+    if let Some(parent) = path.parent() {
+        create_dir_all(parent)?;
+    }
+    let mut res = get(url).call()?;
+    let mut file = File::create(path)?;
+    copy(&mut res.body_mut().as_reader(), &mut file)?;
+    Ok(())
+}
+
+pub fn client(detail: &VersionDetail, shared_dir: &Path, version_id: &str) -> anyhow::Result<()> {
+    let out = shared_dir
+        .join("versions")
+        .join(version_id)
+        .join(format!("{version_id}.jar"));
+    if !out.exists() {
+        println!("Downloading client: {}...", detail.downloads.client.url);
+        download(&detail.downloads.client.url, &out)?;
+    }
+    Ok(())
+}
+pub fn libraries(detail: &VersionDetail, shared_dir: &Path) -> anyhow::Result<()> {
+    println!("Downloading libraries...");
+    let libs_dir = shared_dir.join("libraries");
+    let needed: Vec<_> = detail
+        .libraries
+        .iter()
+        .filter(|l| wanted(l))
+        .filter(|l| !libs_dir.join(&l.downloads.artifact.path).exists())
+        .collect();
+
+    if !needed.is_empty() {
+        let pb = ProgressBar::new(needed.len() as u64);
+        pb.set_style(ProgressStyle::with_template("{bar:40} {pos}/{len} {msg}").unwrap());
+        for lib in &needed {
+            let a = &lib.downloads.artifact;
+            pb.set_message(a.path.clone());
+            download(&a.url, &libs_dir.join(&a.path))?;
+            pb.inc(1);
+        }
+        pb.finish_and_clear();
+    }
+    Ok(())
+}
+pub fn assets(detail: &VersionDetail, shared_dir: &Path) -> anyhow::Result<()> {
+    println!("Downloading assets...");
+    let index: AssetObjects = get(&detail.asset_index.url)
+        .call()?
+        .body_mut()
+        .read_json()?;
+
+    let index_path = shared_dir
+        .join("assets")
+        .join("indexes")
+        .join(format!("{}.json", detail.asset_index.id));
+    if !index_path.exists() {
+        download(&detail.asset_index.url, &index_path)?;
+    }
+
+    let objects_dir = shared_dir.join("assets").join("objects");
+    let pb = ProgressBar::new(index.objects.len() as u64);
+    pb.set_style(ProgressStyle::with_template("{bar:40} {pos}/{len} ({eta})").unwrap());
+    index
+        .objects
+        .par_iter()
+        .progress_with(pb)
+        .try_for_each(|(_, obj)| -> anyhow::Result<()> {
+            let sub = &obj.hash[..2];
+            let url = format!(
+                "https://resources.download.minecraft.net/{sub}/{}",
+                obj.hash
+            );
+            let path = objects_dir.join(sub).join(&obj.hash);
+            if !path.exists() {
+                download(&url, &path)?;
+            }
+            Ok(())
+        })?;
+    Ok(())
+}
+pub fn verify_sha512(path: &Path, expected: &str) -> anyhow::Result<bool> {
+    let mut hasher = sha2::Sha512::new();
+    std::io::copy(&mut File::open(path)?, &mut hasher)?;
+    Ok(format!("{:x}", hasher.finalize()) == expected)
+}