tools: Migrate to Protobuf RPC sessions

.gitattributes

@@ -0,0 +1 @@
+tools/src/proto/gen/* linguist-generated=true

tools/.gitignore

@@ -4,3 +4,6 @@
 
 # These are backup files generated by rustfmt
 **/*.rs.bk
+
+# Local folder or symlink created to regenerate Protobuf files
+/flipperzero-protobuf

tools/Cargo.toml

@@ -15,6 +15,7 @@ elf = "0.7"
 hex = "0.4"
 md-5 = "0.10"
 once_cell = "1.17.1"
+prost = "0.12"
 rand = "0.8"
 regex = "1.7.1"
 serde = { version = "1.0.152", features = ["derive"] }
@@ -23,3 +24,7 @@ serialport = "4.2.0"
 shlex = "1.1.0"
 tempfile = "3"
 which = "4"
+
+[build-dependencies]
+prost-build = "0.12"
+which = "4"

tools/build.rs

@@ -0,0 +1,69 @@
+use std::env;
+use std::fs;
+use std::io;
+use std::path::{Path, PathBuf};
+
+macro_rules! flipper_proto {
+    ($name:literal) => {
+        concat!("flipperzero-protobuf/", $name, ".proto")
+    };
+}
+
+macro_rules! stage_generated_proto {
+    ($from:ident, $name:literal) => {
+        fs::copy($from.join($name), concat!("src/proto/gen/", $name))
+    };
+}
+
+const FLIPPER_PROTO_DIR: &str = "flipperzero-protobuf/";
+const FLIPPER_PROTO: &str = flipper_proto!("flipper");
+
+fn main() -> io::Result<()> {
+    // - We don't include the proto files in the repository so that downstreams do not
+    //   need to regenerate the bindings even if protoc is present.
+    // - We check for the existence of protoc in the same way as prost-build, so that
+    //   people building from source do not need to have protoc installed.
+    if Path::new(FLIPPER_PROTO).exists()
+        && env::var_os("PROTOC")
+            .map(PathBuf::from)
+            .or_else(|| which::which("protoc").ok())
+            .is_some()
+    {
+        gen_protobufs()?;
+    }
+
+    Ok(())
+}
+
+fn gen_protobufs() -> io::Result<()> {
+    let out: PathBuf = env::var_os("OUT_DIR")
+        .expect("Cannot find OUT_DIR environment variable")
+        .into();
+
+    // Build the compact format types.
+    prost_build::compile_protos(
+        &[
+            FLIPPER_PROTO,
+            flipper_proto!("application"),
+            flipper_proto!("desktop"),
+            flipper_proto!("gpio"),
+            flipper_proto!("gui"),
+            flipper_proto!("property"),
+            flipper_proto!("storage"),
+            flipper_proto!("system"),
+        ],
+        &[FLIPPER_PROTO_DIR],
+    )?;
+
+    // Copy the generated types into the source tree so changes can be committed.
+    stage_generated_proto!(out, "pb.rs")?;
+    stage_generated_proto!(out, "pb_app.rs")?;
+    stage_generated_proto!(out, "pb_desktop.rs")?;
+    stage_generated_proto!(out, "pb_gpio.rs")?;
+    stage_generated_proto!(out, "pb_gui.rs")?;
+    stage_generated_proto!(out, "pb_property.rs")?;
+    stage_generated_proto!(out, "pb_storage.rs")?;
+    stage_generated_proto!(out, "pb_system.rs")?;
+
+    Ok(())
+}