make all packet stuff take from a file that i can update instead of it being hardcoded

Author: cyteon

Cargo.toml

@@ -30,6 +30,9 @@ lazy_static = "1.5.0"
 byteorder = "1.5.0"
 console-subscriber = { version = "0.5.0", optional = true }
 
+[build-dependencies]
+serde_json = "1.0.149"
+
 [features]
 default = []
 console = ["console-subscriber"]

build.rs

@@ -0,0 +1,66 @@
+use std::collections::HashMap;
+use std::env;
+use std::fs;
+use std::path::Path;
+
+fn main() {
+    let manifest = env::var("CARGO_MANIFEST_DIR").unwrap();
+    let json_path = Path::new(&manifest).join("src/assets/packets.json");
+    println!("cargo:rerun-if-changed={}", json_path.display());
+
+    let bytes = fs::read(&json_path).expect("Failed to read packets.json");
+
+    let json: HashMap<String, serde_json::Value> =
+        serde_json::from_slice(&bytes).expect("Failed to parse packets.json");
+    
+    let mut out = String::new();
+
+    const PATHS: &[(&str, &str)] = &[
+        ("handshake", "serverbound"),
+        ("configuration", "clientbound"),
+        ("configuration", "serverbound"),
+        ("login", "clientbound"),
+        ("login", "serverbound"),
+        ("play", "clientbound"),
+        ("play", "serverbound"),
+        ("status", "clientbound"),
+        ("status", "serverbound"),
+    ];
+
+    let mut tree: HashMap<&str, HashMap<&str, Vec<(String, i64)>>> = HashMap::new();
+    for (state, direction) in PATHS {
+        let obj = json[*state][*direction].as_object().unwrap();
+
+        for (k, v) in obj {
+            let protocol_id = v["protocol_id"].as_i64().unwrap();
+            tree.entry(state).or_default().entry(direction).or_default().push((k.clone(), protocol_id));
+        }
+    }
+
+    for (state, directions) in &tree {
+        out.push_str(&format!("pub mod {} {{\n", state));
+
+        for (direction, packets) in directions {
+            out.push_str(&format!("    pub mod {} {{\n", direction));
+
+            for (name, protocol_id) in packets {
+                out.push_str(
+                    &format!(
+                        "        pub const {}: u32 = {};\n", 
+                        name.to_uppercase().replace("MINECRAFT:", "").replace("/", "_"),
+                        protocol_id
+                    )
+                );
+            }
+
+            out.push_str("    }\n");
+        }
+
+        out.push_str("}\n");
+    }
+
+    dbg!(tree);
+
+    let out_path = Path::new(&env::var("OUT_DIR").unwrap()).join("packets.rs");
+    fs::write(out_path, out).unwrap();
+}