Add tests and example for modpack support

theseus/src/modpack/mod.rs

@@ -1,12 +1,15 @@
 //! Provides utilties for downloading and parsing modpacks
 
-use std::{convert::TryFrom, io, path::Path};
+use daedalus::download_file;
 use fs_extra::dir::CopyOptions;
+use std::{borrow::Borrow, convert::TryFrom, env, io, path::Path};
 use tokio::fs;
+use uuid::Uuid;
+use zip::ZipArchive;
 
 use self::manifest::Manifest;
 
-mod manifest;
+pub mod manifest;
 
 pub const MANIFEST_PATH: &'static str = "index.json";
 pub const OVERRIDES_PATH: &'static str = "overrides/";
@@ -19,6 +22,12 @@ pub enum ModpackError {
     #[error("I/O error while reading modpack: {0}")]
     FSExtraError(#[from] fs_extra::error::Error),
 
+    #[error("Error extracting archive: {0}")]
+    ZipError(#[from] zip::result::ZipError),
+
+    #[error("Invalid modpack format: {0}")]
+    FormatError(String),
+
     #[error("Invalid output directory: {0}")]
     InvalidDirectory(String),
 
@@ -35,13 +44,44 @@ pub enum ModpackError {
     JoinError(#[from] tokio::task::JoinError),
 }
 
+/// Realise a modpack from a given URL
+pub async fn fetch_modpack(
+    url: &str,
+    sha1: Option<&str>,
+    dest: &Path,
+    side: manifest::ModpackSide,
+) -> Result<(), ModpackError> {
+    let bytes = download_file(url, sha1).await?;
+    let mut archive = ZipArchive::new(io::Cursor::new(&bytes as &[u8]))?;
+    realise_modpack_zip(&mut archive, dest, side).await
+}
+
+/// Realise a given modpack from a zip archive
+pub async fn realise_modpack_zip(
+    archive: &mut ZipArchive<impl io::Read + io::Seek>,
+    dest: &Path,
+    side: manifest::ModpackSide,
+) -> Result<(), ModpackError> {
+    let tmp = env::temp_dir().join(format!("theseus-{}/", Uuid::new_v4()));
+    archive.extract(&tmp)?;
+    realise_modpack(&tmp, dest, side).await
+}
+
 /// Realise a given modpack into an instance
-pub async fn realise_modpack(dir: &Path, dest: &Path, side: &manifest::ModpackSide) -> Result<(), ModpackError> {
+pub async fn realise_modpack(
+    dir: &Path,
+    dest: &Path,
+    side: manifest::ModpackSide,
+) -> Result<(), ModpackError> {
     if dest.is_file() {
-        return Err(ModpackError::InvalidDirectory(String::from("Output is not a directory")));
+        return Err(ModpackError::InvalidDirectory(String::from(
+            "Output is not a directory",
+        )));
     }
     if dest.exists() && std::fs::read_dir(dest).map_or(false, |it| it.count() != 0) {
-        return Err(ModpackError::InvalidDirectory(String::from("Output directory is non-empty")));
+        return Err(ModpackError::InvalidDirectory(String::from(
+            "Output directory is non-empty",
+        )));
     }
     if !dest.exists() {
         fs::create_dir_all(dest).await?;
@@ -57,9 +97,12 @@ pub async fn realise_modpack(dir: &Path, dest: &Path, side: &manifest::ModpackSi
     // NOTE: I'm using standard files here, since Serde does not support async readers
     let manifest_path = Some(dir.join(MANIFEST_PATH))
         .filter(|it| it.exists() && it.is_file())
-        .ok_or(ModpackError::ManifestError(String::from("Manifest missing or is not a file")))?;
+        .ok_or(ModpackError::ManifestError(String::from(
+            "Manifest missing or is not a file",
+        )))?;
     let manifest_file = std::fs::File::open(manifest_path)?;
-    let manifest_json: serde_json::Value = serde_json::from_reader(io::BufReader::new(manifest_file))?;
+    let manifest_json: serde_json::Value =
+        serde_json::from_reader(io::BufReader::new(manifest_file))?;
     let manifest = Manifest::try_from(manifest_json)?;
 
     // Realise manifest