[WIP] Version Parsing

type-map/build.rs

@@ -151,15 +151,25 @@ const RESERVED_DATA_TYPES: &[ReservedEntry] = &[
 ];
 
 fn main() {
-    let config_path = std::env::var("MTP_TYPE_MAPS").expect(
-        "MTP_TYPE_MAPS environment variable must be set to the path of a type-maps.yaml file",
-    );
-
-    let content = std::fs::read_to_string(&config_path).expect("Failed to read type-maps.yaml");
-
-    let config: Config = serde_yaml::from_str(&content).expect("Failed to parse type-maps.yaml");
-
     let out = std::path::PathBuf::from(std::env::var("OUT_DIR").unwrap());
+
+    let config = match std::env::var("MTP_TYPE_MAPS") {
+        Ok(config_path) => {
+            let content =
+                std::fs::read_to_string(&config_path).expect("Failed to read type-maps.yaml");
+            serde_yaml::from_str(&content).expect("Failed to parse type-maps.yaml")
+        }
+        Err(_) => {
+            eprintln!(
+                "warning: MTP_TYPE_MAPS not set; generating types with reserved entries only"
+            );
+            Config {
+                protocol_version: String::new(),
+                type_maps: BTreeMap::new(),
+            }
+        }
+    };
+
     let code = generate(&config);
     std::fs::write(out.join("types.rs"), code).unwrap();
 }
@@ -187,7 +197,7 @@ fn generate(config: &Config) -> String {
     let mut out = String::new();
     writeln!(
         out,
-        "// Auto-generated by type-map/build.rs, they should not be edited manually"
+        "// Auto-generated by type-map/build.rs, this file should not be edited manually"
     )
     .unwrap();
     writeln!(out).unwrap();
@@ -206,15 +216,39 @@ fn generate(config: &Config) -> String {
 
     let sorted = sorted_versions(config);
 
+    generate_protocol_version(&mut out, config);
     generate_comm_type_enum(&mut out, &all_comm_names);
     generate_data_type_enum(&mut out, &all_data_names);
     generate_type_map_constructors(&mut out, &sorted);
     generate_lookup_methods(&mut out, config, &sorted);
     generate_builtin_type_maps(&mut out, &sorted);
+    generate_enum_conversion_methods(&mut out, &sorted);
 
     out
 }
 
+fn generate_protocol_version(out: &mut String, config: &Config) {
+    let (major, minor) = if config.protocol_version.is_empty() {
+        (0, 0)
+    } else {
+        let parts: Vec<&str> = config.protocol_version.split('.').collect();
+        if parts.len() == 2 {
+            let maj = parts[0].parse::<u16>().unwrap_or(0);
+            let min = parts[1].parse::<u16>().unwrap_or(0);
+            (maj, min)
+        } else {
+            (0, 0)
+        }
+    };
+    writeln!(
+        out,
+        "pub const PROTOCOL_VERSION: Version = Version({}, {});",
+        major, minor
+    )
+    .unwrap();
+    writeln!(out).unwrap();
+}
+
 fn generate_comm_type_enum(out: &mut String, user_names: &BTreeSet<&str>) {
     writeln!(
         out,
@@ -343,6 +377,22 @@ fn generate_type_map_constructors(out: &mut String, sorted_versions: &[(String,
         writeln!(out, "}}").unwrap();
         writeln!(out).unwrap();
     }
+
+    let (latest_major, latest_minor) = match sorted_versions.last() {
+        Some((_key, major, minor)) => (*major, *minor),
+        None => (0, 0),
+    };
+    writeln!(out, "impl TypeMap {{").unwrap();
+    writeln!(out, "    pub fn latest() -> Self {{").unwrap();
+    writeln!(
+        out,
+        "        Self {{ version: Version({}, {}) }}",
+        latest_major, latest_minor
+    )
+    .unwrap();
+    writeln!(out, "    }}").unwrap();
+    writeln!(out, "}}").unwrap();
+    writeln!(out).unwrap();
 }
 
 fn generate_lookup_methods(
@@ -351,7 +401,7 @@ fn generate_lookup_methods(
     sorted_versions: &[(String, u16, u16)],
 ) {
     // comm_id_enum
-    writeln!(out, "#[allow(unreachable_patterns)]").unwrap();
+    writeln!(out, "#[allow(unreachable_patterns, unused_variables)]").unwrap();
     writeln!(out, "impl TypeMap {{").unwrap();
     writeln!(
         out,
@@ -392,6 +442,7 @@ fn generate_lookup_methods(
     writeln!(out).unwrap();
 
     // data_id_enum
+    writeln!(out, "    #[allow(unused_variables)]").unwrap();
     writeln!(
         out,
         "    pub fn data_id_enum(&self, dt: DataType) -> Option<u16> {{"
@@ -438,3 +489,27 @@ fn generate_builtin_type_maps(out: &mut String, sorted_versions: &[(String, u16,
     writeln!(out, "}}").unwrap();
     writeln!(out).unwrap();
 }
+
+fn generate_enum_conversion_methods(out: &mut String, _sorted_versions: &[(String, u16, u16)]) {
+    writeln!(out, "impl CommunicationType {{").unwrap();
+    writeln!(out, "    pub fn to_id(self, tm: &TypeMap) -> CommunicationTypeId {{").unwrap();
+    writeln!(
+        out,
+        "        CommunicationTypeId(tm.comm_id_enum(self).expect(\"CommunicationType not found in this TypeMap version\"))"
+    )
+    .unwrap();
+    writeln!(out, "    }}").unwrap();
+    writeln!(out, "}}").unwrap();
+    writeln!(out).unwrap();
+
+    writeln!(out, "impl DataType {{").unwrap();
+    writeln!(out, "    pub fn to_id(self, tm: &TypeMap) -> DataTypeId {{").unwrap();
+    writeln!(
+        out,
+        "        DataTypeId(tm.data_id_enum(self).expect(\"DataType not found in this TypeMap version\"))"
+    )
+    .unwrap();
+    writeln!(out, "    }}").unwrap();
+    writeln!(out, "}}").unwrap();
+    writeln!(out).unwrap();
+}