Initial commitHEADmain

1 files changed, 134 insertions, 0 deletions

diff --git a/src/repl.rs b/src/repl.rs
new file mode 100644
index 0000000..339405e
--- /dev/null
+++ b/src/repl.rs
@@ -0,0 +1,134 @@
+use crate::common::expr::Error as ProtoError;
+use crate::common::expr::Expr;
+use crate::common::term::Term;
+use std::io::BufReader;
+use std::io::Write;
+use std::net::TcpStream;
+use std::process::ExitCode;
+
+pub const USAGE: &str = "
+Usage: blom start
+
+ Starts the blom repl.
+
+ -b, --bind               Bind to the given ADDRESS:PORT. Default is
+                          0.0.0.0:4902
+
+";
+
+enum Error {
+    Connect,
+}
+
+pub fn cmd(args: &[String]) -> ExitCode {
+    let mut addr = "0.0.0.0:4902";
+
+    let mut arg_index: usize = 0;
+    while arg_index < args.len() {
+        match args[arg_index].as_str() {
+            "--addr" | "-a" => {
+                addr = args
+                    .get(arg_index + 1)
+                    .expect("Missing address after --addr.")
+                    .as_str();
+                arg_index += 1;
+            }
+            _ => {
+                println!("Too many arguments.");
+                return ExitCode::FAILURE;
+            }
+        }
+
+        arg_index += 1;
+    }
+
+    match start(addr) {
+        Ok(()) => ExitCode::SUCCESS,
+        Err(_) => ExitCode::FAILURE,
+    }
+}
+
+fn start(addr: &str) -> Result<(), Error> {
+    let mut term = Term::new();
+
+    term.setup_prompt(format!("{addr}> ").as_bytes());
+    term.setup_hints(hints);
+
+    while let Some(query) = input(&mut term) {
+        if query.is_empty() {
+            continue;
+        }
+
+        let mut stream = match try_connect(addr) {
+            Ok(stream) => stream,
+            Err(_) => continue,
+        };
+
+        let expr = Expr::from_query(&query);
+
+        if stream.write(&expr.encode()).is_err() {
+            println!("Couldn't connect to blom at {addr}");
+            continue;
+        }
+
+        let mut resp = BufReader::new(&stream);
+
+        match Expr::from_bytes(&mut resp) {
+            Ok(resp) => println!("{resp}"),
+            Err(ProtoError::ConnectionClosed) => {
+                println!("Couldn't connect to blom at {addr}");
+                continue;
+            }
+            Err(e) => {
+                println!("{e}");
+                break;
+            }
+        }
+    }
+
+    Ok(())
+}
+
+fn try_connect(addr: &str) -> Result<TcpStream, Error> {
+    match TcpStream::connect(addr) {
+        Ok(stream) => Ok(stream),
+        Err(_) => {
+            println!("Couldn't connect to blom at {addr}.");
+            Err(Error::Connect)
+        }
+    }
+}
+
+fn input(term: &mut Term) -> Option<String> {
+    let line = term.edit()?;
+    let query = std::str::from_utf8(&line).unwrap().trim();
+
+    if query == "exit" {
+        return None;
+    }
+
+    Some(query.to_string())
+}
+
+// TODO: Refactor
+fn hints(line: &[u8]) -> &[u8] {
+    match line {
+        b"ECHO" | b"echo" => b" MESSAGE",
+        b"SET" | b"set" => b" BLOCK META",
+        b"GET" | b"get" => b" BLOCK",
+        b"DEL" | b"del" => b" BLOCK",
+        b"EXISTS" | b"exists" => b" BLOCK",
+        b"INFO" | b"info" => b" BLOCK",
+        b"PARENT" | b"parent" => b" BLOCK",
+        b"CHILDREN" | b"children" => b" BLOCK",
+        b"ECHO " | b"echo " => b"MESSAGE",
+        b"SET " | b"set " => b"BLOCK META",
+        b"GET " | b"get " => b"BLOCK",
+        b"DEL " | b"del " => b"BLOCK",
+        b"EXISTS " | b"exists " => b"BLOCK",
+        b"INFO " | b"info " => b"BLOCK",
+        b"PARENT " | b"parent " => b"BLOCK",
+        b"CHILDREN " | b"children " => b"BLOCK",
+        _ => b"",
+    }
+}