refactoring to library

src/drivers.rs

@@ -0,0 +1,80 @@
+
+use std::time::Duration;
+use std::path::{Path, PathBuf};
+
+use log::{debug, error};
+
+use crates_io_api::AsyncClient;
+use semver::Version;
+
+use crate::PkgFmt;
+use crate::helpers::*;
+
+/// Fetch a crate by name and version from crates.io
+pub async fn fetch_crate_cratesio(name: &str, version: Option<&str>, temp_dir: &Path) -> Result<PathBuf, anyhow::Error> {
+    // Build crates.io api client and fetch info
+    // TODO: support git-based fetches (whole repo name rather than just crate name)
+    let api_client = AsyncClient::new("cargo-binstall (https://github.com/ryankurte/cargo-binstall)", Duration::from_millis(100))?;
+
+    debug!("Fetching information for crate: '{}'", name);
+
+    // Fetch overall crate info
+    let info = match api_client.get_crate(name.as_ref()).await {
+        Ok(i) => i,
+        Err(e) => {
+            error!("Error fetching information for crate {}: {}", name, e);
+            return Err(e.into())
+        }
+    };
+
+    // Use specified or latest version
+    let version_num = match version {
+        Some(v) => v.to_string(),
+        None => info.crate_data.max_version,
+    };
+
+    // Fetch crates.io information for the specified version
+    // TODO: Filter by semver matches instead of literal match
+    let mut versions = info.versions.clone();
+    versions.sort_by(|a, b| {
+        let ver_a = Version::parse(&a.num).unwrap();
+        let ver_b = Version::parse(&b.num).unwrap();
+
+        ver_a.partial_cmp(&ver_b).unwrap()
+    } );    
+
+    let version = match versions.iter().find(|v| v.num == version_num) {
+        Some(v) => v,
+        None => {
+            error!("No crates.io information found for crate: '{}' version: '{}'", 
+                    name, version_num);
+            return Err(anyhow::anyhow!("No crate information found"));
+        }
+    };
+
+    debug!("Found information for crate version: '{}'", version.num);
+    
+    // Download crate to temporary dir (crates.io or git?)
+    let crate_url = format!("https://crates.io/{}", version.dl_path);
+    let tgz_path = temp_dir.join(format!("{}.tgz", name));
+
+    debug!("Fetching crate from: {}", crate_url);    
+
+    // Download crate
+    download(&crate_url, &tgz_path).await?;
+
+    // Decompress downloaded tgz
+    debug!("Decompressing crate archive");
+    extract(&tgz_path, PkgFmt::Tgz, &temp_dir)?;
+    let crate_path = temp_dir.join(format!("{}-{}", name, version_num));
+
+    // Return crate directory
+    Ok(crate_path)
+}
+
+/// Fetch a crate by name and version from github
+/// TODO: implement this
+pub async fn fetch_crate_gh_releases(_name: &str, _version: Option<&str>, _temp_dir: &Path) -> Result<PathBuf, anyhow::Error> {
+
+    unimplemented!();
+}