Complete refactor of modpacks, add modpack serialization

theseus/src/modpack/pack.rs

@@ -0,0 +1,106 @@
+use std::path::{Path, PathBuf};
+use daedalus::download_file_mirrors;
+use futures::future;
+use tokio::fs;
+
+use crate::launcher::ModLoader;
+use super::ModpackResult;
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct Modpack {
+    pub game: ModpackGame,
+    pub version: String,
+    pub name: String,
+    pub summary: Option<String>,
+    pub files: Vec<ModpackFile>,
+}
+
+impl Modpack {
+    /// Download a modpack's files for a given side to a given destination
+    /// Assumes the destination exists and is a directory
+    pub async fn download_files(&self, dest: &Path, side: ModpackSide) -> ModpackResult<()> {
+        let handles = self.files.iter().cloned().map(move |file| {
+            let (dest, side) = (dest.to_owned(), side);
+            tokio::spawn(async move { file.fetch(&dest, side).await })
+        });
+        future::try_join_all(handles)
+            .await?
+            .into_iter()
+            .collect::<ModpackResult<_>>()?;
+
+        // TODO Integrate instance format to save other metadata
+        Ok(())
+    }
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum ModpackGame {
+    // TODO: Currently, the launcher does not support specifying mod loader versions, so I just
+    // store the loader here.
+    Minecraft(String, ModLoader),
+}
+
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct ModpackFile {
+    pub path: PathBuf,
+    pub hashes: ModpackFileHashes,
+    pub env: ModpackEnv,
+    pub downloads: Vec<String>,
+}
+
+impl ModpackFile {
+    pub async fn fetch(&self, dest: &Path, side: ModpackSide) -> ModpackResult<()> {
+        if !self.env.supports(side) {
+            return Ok(());
+        }
+
+        let output = dest.join(&self.path);
+
+        // HACK: Since Daedalus appends a file name to all mirrors and the manifest supplies full
+        // URLs, I'm supplying it with an empty string to avoid reinventing the wheel.
+        let bytes = download_file_mirrors(
+            "",
+            &self
+                .downloads
+                .iter()
+                .map(|it| it.as_str())
+                .collect::<Vec<&str>>()
+                .as_slice(),
+            Some(&self.hashes.sha1),
+        )
+        .await?;
+        fs::create_dir_all(output.parent().unwrap()).await?;
+        fs::write(output, bytes).await?;
+        Ok(())
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum ModpackEnv {
+    ClientOnly,
+    ServerOnly,
+    Both,
+}
+
+impl ModpackEnv {
+    pub fn supports(&self, side: ModpackSide) -> bool {
+        match self {
+            Self::ClientOnly => side == ModpackSide::Client,
+            Self::ServerOnly => side == ModpackSide::Server,
+            Self::Both => true,
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum ModpackSide {
+    Client, Server,
+}
+
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct ModpackFileHashes {
+    pub sha1: String,
+}
+