Implement basic game files download logic

Implement core clap arguments

Respect XDG_BASE_DIR

Currently library extraction is broken because it assumes every instace has it's own library folder. This should be refactored so instances share libraries

Signed-off-by: Filip Wandzio <contact@philw.dev>

1 files changed, 66 insertions, 0 deletions

diff --git a/src/minecraft/downloads.rs b/src/minecraft/downloads.rs
new file mode 100644
index 0000000..5be5a05
--- /dev/null
+++ b/src/minecraft/downloads.rs
@@ -0,0 +1,66 @@
+use log::{debug, info};
+use tokio::{fs, io::AsyncWriteExt};
+
+use crate::{
+    config::Config,
+    errors::McError,
+    minecraft::manifests::{Library, Version},
+    platform::paths,
+};
+
+/// Download everything required to launch:
+/// - client jar
+/// - libraries
+pub async fn download_all(config: &Config, version: &Version) -> Result<(), McError> {
+    download_client(config, version).await?;
+    download_libraries(config, &version.libraries).await?;
+    Ok(())
+}
+
+async fn download_client(config: &Config, version: &Version) -> Result<(), McError> {
+    let jar_path = paths::client_jar(config, &version.id)?;
+
+    if jar_path.exists() {
+        debug!("Client jar already exists");
+        return Ok(());
+    }
+
+    info!("Downloading client {}", version.id);
+
+    download_file(&version.downloads.client.url, &jar_path).await
+}
+
+async fn download_libraries(config: &Config, libraries: &[Library]) -> Result<(), McError> {
+    for lib in libraries {
+        let Some(artifact) = &lib.downloads.artifact else {
+            continue;
+        };
+
+        let lib_path = paths::library_file(config, &artifact.path)?;
+
+        if lib_path.exists() {
+            continue;
+        }
+
+        info!("Downloading library {}", artifact.path);
+        download_file(&artifact.url, &lib_path).await?;
+    }
+
+    Ok(())
+}
+
+/* ---------------- helper ---------------- */
+
+async fn download_file(url: &str, path: &std::path::Path) -> Result<(), McError> {
+    if let Some(parent) = path.parent() {
+        fs::create_dir_all(parent).await?;
+    }
+
+    let response = reqwest::get(url).await?;
+    let bytes = response.bytes().await?;
+
+    let mut file = fs::File::create(path).await?;
+    file.write_all(&bytes).await?;
+
+    Ok(())
+}