Allow direct joining servers on old instances (#4094)

* Implement direct server joining for 1.6.2 through 1.19.4

* Implement direct server joining for versions before 1.6.2

* Ignore methods with a $ in them

* Run intl:extract

* Improve code of MinecraftTransformer

* Support showing last played time for profiles before 1.7

* Reorganize QuickPlayVersion a bit to prepare for singleplayer

* Only inject quick play checking in versions where it's needed

* Optimize agent some and fix error on NeoForge

* Remove some code for quickplay singleplayer support before 1.20, as we can't reasonably support that with an agent

* Invert the default hasServerQuickPlaySupport return value

* Remove Play Anyway button

* Fix "Server couldn't be contacted" on singleplayer worlds

* Fix "Jump back in" section not working

packages/app-lib/src/api/server_address.rs

@@ -0,0 +1,166 @@
+use crate::{Error, ErrorKind, Result};
+use std::fmt::Display;
+use std::mem;
+use std::net::{Ipv4Addr, Ipv6Addr};
+use tokio::sync::Semaphore;
+
+#[derive(Debug, Clone)]
+pub enum ServerAddress {
+    Unresolved(String),
+    Resolved {
+        original_host: String,
+        original_port: u16,
+        resolved_host: String,
+        resolved_port: u16,
+    },
+}
+
+impl ServerAddress {
+    pub async fn resolve(&mut self) -> Result<()> {
+        match self {
+            Self::Unresolved(address) => {
+                let (host, port) = parse_server_address(address)?;
+                let (resolved_host, resolved_port) =
+                    resolve_server_address(host, port).await?;
+                *self = Self::Resolved {
+                    original_host: if host.len() == address.len() {
+                        mem::take(address)
+                    } else {
+                        host.to_owned()
+                    },
+                    original_port: port,
+                    resolved_host,
+                    resolved_port,
+                }
+            }
+            Self::Resolved { .. } => {}
+        }
+        Ok(())
+    }
+
+    pub fn require_resolved(&self) -> Result<(&str, u16)> {
+        match self {
+            Self::Resolved {
+                resolved_host,
+                resolved_port,
+                ..
+            } => Ok((resolved_host, *resolved_port)),
+            Self::Unresolved(address) => Err(ErrorKind::InputError(format!(
+                "Unexpected unresolved server address: {address}"
+            ))
+            .into()),
+        }
+    }
+}
+
+impl Display for ServerAddress {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Unresolved(address) => write!(f, "{address}"),
+            Self::Resolved {
+                resolved_host,
+                resolved_port,
+                ..
+            } => {
+                if resolved_host.contains(':') {
+                    write!(f, "[{resolved_host}]:{resolved_port}")
+                } else {
+                    write!(f, "{resolved_host}:{resolved_port}")
+                }
+            }
+        }
+    }
+}
+
+pub fn parse_server_address(address: &str) -> Result<(&str, u16)> {
+    parse_server_address_inner(address)
+        .map_err(|e| Error::from(ErrorKind::InputError(e)))
+}
+
+// Reimplementation of Guava's HostAndPort#fromString with a default port of 25565
+fn parse_server_address_inner(
+    address: &str,
+) -> std::result::Result<(&str, u16), String> {
+    let (host, port_str) = if address.starts_with("[") {
+        let colon_index = address.find(':');
+        let close_bracket_index = address.rfind(']');
+        if colon_index.is_none() || close_bracket_index.is_none() {
+            return Err(format!("Invalid bracketed host/port: {address}"));
+        }
+        let close_bracket_index = close_bracket_index.unwrap();
+
+        let host = &address[1..close_bracket_index];
+        if close_bracket_index + 1 == address.len() {
+            (host, "")
+        } else {
+            if address.as_bytes().get(close_bracket_index).copied()
+                != Some(b':')
+            {
+                return Err(format!(
+                    "Only a colon may follow a close bracket: {address}"
+                ));
+            }
+            let port_str = &address[close_bracket_index + 2..];
+            for c in port_str.chars() {
+                if !c.is_ascii_digit() {
+                    return Err(format!("Port must be numeric: {address}"));
+                }
+            }
+            (host, port_str)
+        }
+    } else {
+        let colon_pos = address.find(':');
+        if let Some(colon_pos) = colon_pos {
+            (&address[..colon_pos], &address[colon_pos + 1..])
+        } else {
+            (address, "")
+        }
+    };
+
+    let mut port = None;
+    if !port_str.is_empty() {
+        if port_str.starts_with('+') {
+            return Err(format!("Unparseable port number: {port_str}"));
+        }
+        port = port_str.parse::<u16>().ok();
+        if port.is_none() {
+            return Err(format!("Unparseable port number: {port_str}"));
+        }
+    }
+
+    Ok((host, port.unwrap_or(25565)))
+}
+
+pub async fn resolve_server_address(
+    host: &str,
+    port: u16,
+) -> Result<(String, u16)> {
+    static SIMULTANEOUS_DNS_QUERIES: Semaphore = Semaphore::const_new(24);
+
+    if port != 25565
+        || host.parse::<Ipv4Addr>().is_ok()
+        || host.parse::<Ipv6Addr>().is_ok()
+    {
+        return Ok((host.to_owned(), port));
+    }
+
+    let _permit = SIMULTANEOUS_DNS_QUERIES.acquire().await?;
+    let resolver = hickory_resolver::TokioResolver::builder_tokio()?.build();
+    Ok(
+        match resolver.srv_lookup(format!("_minecraft._tcp.{host}")).await {
+            Err(e)
+                if e.proto()
+                    .filter(|x| x.kind().is_no_records_found())
+                    .is_some() =>
+            {
+                None
+            }
+            Err(e) => return Err(e.into()),
+            Ok(lookup) => lookup
+                .into_iter()
+                .next()
+                .map(|r| (r.target().to_string(), r.port())),
+        }
+        .unwrap_or_else(|| (host.to_owned(), port)),
+    )
+}