chore: extract jc2m into multiple files (#171)

* chore: extract jc2m into multiple files

* docs: add jc2m fields public

crates/lib/src/games/jc2m/protocol.rs

@@ -0,0 +1,75 @@
+use crate::buffer::{Buffer, Utf8Decoder};
+use crate::jc2m::{Player, Response};
+use crate::protocols::gamespy::common::has_password;
+use crate::protocols::gamespy::three::{data_to_map, GameSpy3};
+use crate::protocols::types::TimeoutSettings;
+use crate::GDErrorKind::{PacketBad, TypeParse};
+use crate::GDResult;
+use byteorder::BigEndian;
+use std::net::{IpAddr, SocketAddr};
+
+fn parse_players_and_teams(packet: &[u8]) -> GDResult<Vec<Player>> {
+    let mut buf = Buffer::<BigEndian>::new(packet);
+
+    let count = buf.read::<u16>()?;
+    let mut players = Vec::with_capacity(count as usize);
+
+    while buf.remaining_length() != 0 {
+        players.push(Player {
+            name: buf.read_string::<Utf8Decoder>(None)?,
+            steam_id: buf.read_string::<Utf8Decoder>(None)?,
+            ping: buf.read::<u16>()?,
+        });
+    }
+
+    Ok(players)
+}
+
+pub fn query(address: &IpAddr, port: Option<u16>) -> GDResult<Response> { query_with_timeout(address, port, None) }
+
+pub fn query_with_timeout(
+    address: &IpAddr,
+    port: Option<u16>,
+    timeout_settings: Option<TimeoutSettings>,
+) -> GDResult<Response> {
+    let mut client = GameSpy3::new_custom(
+        &SocketAddr::new(*address, port.unwrap_or(7777)),
+        timeout_settings,
+        [0xFF, 0xFF, 0xFF, 0x02],
+        true,
+    )?;
+
+    let packets = client.get_server_packets()?;
+    let data = packets
+        .get(0)
+        .ok_or_else(|| PacketBad.context("First packet missing"))?;
+
+    let (mut server_vars, remaining_data) = data_to_map(data)?;
+    let players = parse_players_and_teams(&remaining_data)?;
+
+    let players_maximum = server_vars
+        .remove("maxplayers")
+        .ok_or_else(|| PacketBad.context("Server variables missing maxplayers"))?
+        .parse()
+        .map_err(|e| TypeParse.context(e))?;
+    let players_online = match server_vars.remove("numplayers") {
+        None => players.len(),
+        Some(v) => {
+            let reported_players = v.parse().map_err(|e| TypeParse.context(e))?;
+            match reported_players < players.len() {
+                true => players.len(),
+                false => reported_players,
+            }
+        }
+    } as u32;
+
+    Ok(Response {
+        game_version: server_vars.remove("version").ok_or(PacketBad)?,
+        description: server_vars.remove("description").ok_or(PacketBad)?,
+        name: server_vars.remove("hostname").ok_or(PacketBad)?,
+        has_password: has_password(&mut server_vars)?,
+        players,
+        players_maximum,
+        players_online,
+    })
+}