Add web modules (crypto, wiki, define, urban, tinyurl, down) + shared http/json

README.md

@@ -55,10 +55,13 @@ pub fn all() -> Vec<Box<dyn Module>> {
 
 Shipped modules: **`builtins`** (`ping`, `echo`, `hello`), **`dice`**
 (`roll [NdM]`), **`hash`** (`md5`/`sha1`/`sha256`/`hash <text>`, hand-rolled),
-and **`weather`** (`add <location>` then `w [location]` via wttr.in; per-user
-locations saved to a per-network JSON file, path from `RUSTBOT_DATA_DIR`).
-Module tests live in `tests/` — construct a module and assert on the `Action`s
-it returns, no network required.
+**`weather`** (`add <location>` then `w [location]` via wttr.in; per-user
+locations saved to a per-network JSON file, path from `RUSTBOT_DATA_DIR`), and
+web lookups over the shared `http`/`json` helpers: **`crypto <sym>`** (Bitstamp),
+**`wiki <term>`**, **`define <word>`**, **`urban <term>`**, **`tinyurl <url>`**,
+**`down <host>`**. Module tests live in `tests/` — construct a module (or call
+its pure formatter with a canned API body) and assert on the result, no network
+required.
 
 ## Build & run
 

src/bot/modules/crypto.rs

@@ -0,0 +1,63 @@
+use crate::bot::module::{Action, Command, CommandSpec, Module};
+use crate::json::Json;
+
+pub struct Crypto;
+
+const COMMANDS: &[CommandSpec] = &[CommandSpec {
+    name: "crypto",
+    usage: "crypto <symbol>",
+    about: "USD price of a coin (e.g. crypto btc), via Bitstamp",
+}];
+
+impl Module for Crypto {
+    fn name(&self) -> &'static str {
+        "crypto"
+    }
+
+    fn commands(&self) -> &'static [CommandSpec] {
+        COMMANDS
+    }
+
+    fn on_command(&mut self, cmd: &Command) -> Vec<Action> {
+        let Some(sym) = cmd.args.first() else {
+            return vec![Action::reply(format!(
+                "usage: {}crypto <symbol>",
+                cmd.prefix
+            ))];
+        };
+        let sym = sym.to_lowercase();
+        if sym.is_empty() || !sym.chars().all(|c| c.is_ascii_alphanumeric()) {
+            return vec![Action::reply("invalid symbol".to_string())];
+        }
+        let path = format!("/api/v2/ticker/{sym}usd");
+        match crate::http::get("www.bitstamp.net", &path) {
+            Ok(body) => vec![Action::reply(format_ticker(&sym, &body))],
+            Err(e) => {
+                let msg = if e.contains("404") {
+                    format!("no such pair '{}usd'", sym.to_uppercase())
+                } else {
+                    format!("crypto unavailable: {e}")
+                };
+                vec![Action::reply(msg)]
+            }
+        }
+    }
+}
+
+pub fn format_ticker(sym: &str, body: &str) -> String {
+    let up = sym.to_uppercase();
+    let Some(j) = Json::parse(body) else {
+        return format!("no data for {up}");
+    };
+    let num = |k: &str| {
+        j.get(k)
+            .and_then(Json::as_str)
+            .and_then(|s| s.parse::<f64>().ok())
+    };
+    match (num("last"), num("high"), num("low")) {
+        (Some(last), Some(high), Some(low)) => {
+            format!("{up}/USD: ${last:.2} (high ${high:.2} / low ${low:.2})")
+        }
+        _ => format!("no data for {up}"),
+    }
+}

src/bot/modules/define.rs

@@ -0,0 +1,73 @@
+use crate::bot::module::{Action, Command, CommandSpec, Module};
+use crate::json::Json;
+
+pub struct Define;
+
+const COMMANDS: &[CommandSpec] = &[CommandSpec {
+    name: "define",
+    usage: "define <word>",
+    about: "dictionary definition of a word",
+}];
+
+impl Module for Define {
+    fn name(&self) -> &'static str {
+        "define"
+    }
+
+    fn commands(&self) -> &'static [CommandSpec] {
+        COMMANDS
+    }
+
+    fn on_command(&mut self, cmd: &Command) -> Vec<Action> {
+        let Some(word) = cmd.args.first() else {
+            return vec![Action::reply(format!("usage: {}define <word>", cmd.prefix))];
+        };
+        let word = word.to_lowercase();
+        let path = format!("/api/v2/entries/en/{}", crate::http::url_encode(&word));
+        match crate::http::get("api.dictionaryapi.dev", &path) {
+            Ok(body) => vec![Action::reply(format_define(&word, &body))],
+            Err(e) => {
+                let msg = if e.contains("404") {
+                    format!("no definition for '{word}'")
+                } else {
+                    format!("define unavailable: {e}")
+                };
+                vec![Action::reply(msg)]
+            }
+        }
+    }
+}
+
+pub fn format_define(word: &str, body: &str) -> String {
+    let Some(j) = Json::parse(body) else {
+        return format!("no definition for '{word}'");
+    };
+    let meaning = j
+        .idx(0)
+        .and_then(|e| e.get("meanings"))
+        .and_then(|m| m.idx(0));
+    let pos = meaning
+        .and_then(|m| m.get("partOfSpeech"))
+        .and_then(Json::as_str)
+        .unwrap_or("");
+    let def = meaning
+        .and_then(|m| m.get("definitions"))
+        .and_then(|d| d.idx(0))
+        .and_then(|d| d.get("definition"))
+        .and_then(Json::as_str);
+    match def {
+        Some(d) => {
+            let mut out = if pos.is_empty() {
+                format!("{word}: {d}")
+            } else {
+                format!("{word} ({pos}): {d}")
+            };
+            if out.chars().count() > 300 {
+                out = out.chars().take(300).collect::<String>();
+                out.push('…');
+            }
+            out
+        }
+        None => format!("no definition for '{word}'"),
+    }
+}

src/bot/modules/down.rs

@@ -0,0 +1,64 @@
+use std::net::{TcpStream, ToSocketAddrs};
+use std::time::Duration;
+
+use crate::bot::module::{Action, Command, CommandSpec, Module};
+
+pub struct Down;
+
+const COMMANDS: &[CommandSpec] = &[CommandSpec {
+    name: "down",
+    usage: "down <host>",
+    about: "check whether a site is reachable",
+}];
+
+impl Module for Down {
+    fn name(&self) -> &'static str {
+        "down"
+    }
+
+    fn commands(&self) -> &'static [CommandSpec] {
+        COMMANDS
+    }
+
+    fn on_command(&mut self, cmd: &Command) -> Vec<Action> {
+        let Some(arg) = cmd.args.first() else {
+            return vec![Action::reply(format!("usage: {}down <host>", cmd.prefix))];
+        };
+        let host = host_of(arg);
+        if host.is_empty() {
+            return vec![Action::reply(format!("usage: {}down <host>", cmd.prefix))];
+        }
+        let up = reachable(&host, 443) || reachable(&host, 80);
+        let msg = if up {
+            format!("{host} looks up 👍")
+        } else {
+            format!("{host} looks down 👎")
+        };
+        vec![Action::reply(msg)]
+    }
+}
+
+pub fn host_of(input: &str) -> String {
+    let mut s = input.trim();
+    for p in ["https://", "http://", "//"] {
+        if let Some(rest) = s.strip_prefix(p) {
+            s = rest;
+            break;
+        }
+    }
+    s = s.split(['/', '?', '#']).next().unwrap_or("");
+    if let Some((_, after)) = s.rsplit_once('@') {
+        s = after;
+    }
+    s.split(':').next().unwrap_or("").to_string()
+}
+
+fn reachable(host: &str, port: u16) -> bool {
+    let Ok(mut addrs) = (host, port).to_socket_addrs() else {
+        return false;
+    };
+    let Some(addr) = addrs.next() else {
+        return false;
+    };
+    TcpStream::connect_timeout(&addr, Duration::from_secs(4)).is_ok()
+}

src/bot/modules/mod.rs

@@ -1,7 +1,13 @@
 pub mod builtins;
+pub mod crypto;
+pub mod define;
 pub mod dice;
+pub mod down;
 pub mod hash;
+pub mod tinyurl;
+pub mod urban;
 pub mod weather;
+pub mod wiki;
 
 use super::module::Module;
 
@@ -10,6 +16,12 @@ pub fn all(network: &str) -> Vec<Box<dyn Module>> {
         Box::new(builtins::Builtins),
         Box::new(dice::Dice::new()),
         Box::new(hash::Hash),
+        Box::new(crypto::Crypto),
+        Box::new(define::Define),
+        Box::new(down::Down),
+        Box::new(tinyurl::Tinyurl),
+        Box::new(urban::Urban),
         Box::new(weather::Weather::new(network)),
+        Box::new(wiki::Wiki),
     ]
 }

src/bot/modules/tinyurl.rs

@@ -0,0 +1,37 @@
+use crate::bot::module::{Action, Command, CommandSpec, Module};
+
+pub struct Tinyurl;
+
+const COMMANDS: &[CommandSpec] = &[CommandSpec {
+    name: "tinyurl",
+    usage: "tinyurl <url>",
+    about: "shorten a URL via tinyurl.com",
+}];
+
+impl Module for Tinyurl {
+    fn name(&self) -> &'static str {
+        "tinyurl"
+    }
+
+    fn commands(&self) -> &'static [CommandSpec] {
+        COMMANDS
+    }
+
+    fn on_command(&mut self, cmd: &Command) -> Vec<Action> {
+        let Some(url) = cmd.args.first() else {
+            return vec![Action::reply(format!("usage: {}tinyurl <url>", cmd.prefix))];
+        };
+        let path = format!("/api-create.php?url={}", crate::http::url_encode(url));
+        match crate::http::get("tinyurl.com", &path) {
+            Ok(body) => {
+                let short = body.trim();
+                if short.starts_with("http") {
+                    vec![Action::reply(short.to_string())]
+                } else {
+                    vec![Action::reply("couldn't shorten that URL".to_string())]
+                }
+            }
+            Err(e) => vec![Action::reply(format!("tinyurl unavailable: {e}"))],
+        }
+    }
+}

src/bot/modules/urban.rs

@@ -0,0 +1,58 @@
+use crate::bot::module::{Action, Command, CommandSpec, Module};
+use crate::json::Json;
+
+pub struct Urban;
+
+const COMMANDS: &[CommandSpec] = &[CommandSpec {
+    name: "urban",
+    usage: "urban <term>",
+    about: "urban dictionary definition",
+}];
+
+impl Module for Urban {
+    fn name(&self) -> &'static str {
+        "urban"
+    }
+
+    fn commands(&self) -> &'static [CommandSpec] {
+        COMMANDS
+    }
+
+    fn on_command(&mut self, cmd: &Command) -> Vec<Action> {
+        let term = cmd.args.join(" ");
+        if term.is_empty() {
+            return vec![Action::reply(format!("usage: {}urban <term>", cmd.prefix))];
+        }
+        let path = format!("/v0/define?term={}", crate::http::url_encode(&term));
+        match crate::http::get("api.urbandictionary.com", &path) {
+            Ok(body) => vec![Action::reply(format_urban(&term, &body))],
+            Err(e) => vec![Action::reply(format!("urban unavailable: {e}"))],
+        }
+    }
+}
+
+pub fn format_urban(term: &str, body: &str) -> String {
+    let Some(j) = Json::parse(body) else {
+        return format!("no results for '{term}'");
+    };
+    let first = j.get("list").and_then(|l| l.idx(0));
+    let word = first
+        .and_then(|d| d.get("word"))
+        .and_then(Json::as_str)
+        .unwrap_or(term);
+    let def = first
+        .and_then(|d| d.get("definition"))
+        .and_then(Json::as_str);
+    match def {
+        Some(d) => {
+            let clean = d.replace(['\r', '\n'], " ").replace(['[', ']'], "");
+            let mut out = format!("{word}: {clean}");
+            if out.chars().count() > 320 {
+                out = out.chars().take(320).collect::<String>();
+                out.push('…');
+            }
+            out
+        }
+        None => format!("no results for '{term}'"),
+    }
+}

src/bot/modules/weather.rs

@@ -1,14 +1,11 @@
 use std::collections::{BTreeMap, HashMap};
 use std::fs;
-use std::io::{self, Read, Write};
+use std::io;
 use std::iter::Peekable;
-use std::net::{TcpStream, ToSocketAddrs};
 use std::path::{Path, PathBuf};
 use std::str::Chars;
 use std::time::{Duration, Instant};
 
-use native_tls::TlsConnector;
-
 use crate::bot::module::{Action, Command, CommandSpec, Module};
 
 const CACHE_TTL: Duration = Duration::from_secs(600);
@@ -148,34 +145,20 @@ impl Store {
 }
 
 fn fetch_weather(location: &str) -> Result<String, String> {
-    let path = format!("/{}?format=%l|%c|%C|%t|%f|%w|%h&m", url_encode(location));
-    let mut last = "no response".to_string();
-    for attempt in 0..3 {
-        if attempt > 0 {
-            std::thread::sleep(Duration::from_millis(250));
-        }
-        match https_get("wttr.in", &path) {
-            Ok(body) => {
+    let path = format!(
+        "/{}?format=%l|%c|%C|%t|%f|%w|%h&m",
+        crate::http::url_encode(location)
+    );
+    let body = crate::http::get("wttr.in", &path)?;
     let raw = body
         .lines()
         .map(str::trim)
         .find(|l| !l.is_empty())
         .unwrap_or("");
-                if !raw.is_empty() {
-                    return Ok(format_weather(raw, location));
+    if raw.is_empty() {
+        return Err("no data".to_string());
     }
-                last = "empty response".to_string();
-            }
-            Err(e) => {
-                let retry = e.retry;
-                last = e.msg;
-                if !retry {
-                    break;
-                }
-            }
-        }
-    }
-    Err(last)
+    Ok(format_weather(raw, location))
 }
 
 pub fn format_weather(raw: &str, location: &str) -> String {
@@ -196,101 +179,6 @@ pub fn format_weather(raw: &str, location: &str) -> String {
     raw.chars().take(250).collect()
 }
 
-struct HttpErr {
-    msg: String,
-    retry: bool,
-}
-
-fn https_get(host: &str, path: &str) -> Result<String, HttpErr> {
-    let addr = (host, 443)
-        .to_socket_addrs()
-        .map_err(|e| HttpErr {
-            msg: e.to_string(),
-            retry: false,
-        })?
-        .next()
-        .ok_or(HttpErr {
-            msg: "dns lookup failed".to_string(),
-            retry: false,
-        })?;
-    let stream =
-        TcpStream::connect_timeout(&addr, Duration::from_secs(4)).map_err(|e| HttpErr {
-            retry: retryable_io(&e),
-            msg: e.to_string(),
-        })?;
-    stream.set_read_timeout(Some(Duration::from_secs(5))).ok();
-    stream.set_write_timeout(Some(Duration::from_secs(5))).ok();
-
-    let connector = TlsConnector::new().map_err(|e| HttpErr {
-        msg: e.to_string(),
-        retry: false,
-    })?;
-    let mut tls = connector.connect(host, stream).map_err(|e| HttpErr {
-        msg: e.to_string(),
-        retry: true,
-    })?;
-
-    let req = format!(
-        "GET {path} HTTP/1.0\r\nHost: {host}\r\nUser-Agent: curl/rubot\r\nAccept: text/plain\r\nConnection: close\r\n\r\n"
-    );
-    tls.write_all(req.as_bytes()).map_err(|e| HttpErr {
-        retry: retryable_io(&e),
-        msg: e.to_string(),
-    })?;
-
-    let mut buf = Vec::new();
-    tls.read_to_end(&mut buf).map_err(|e| HttpErr {
-        retry: retryable_io(&e),
-        msg: e.to_string(),
-    })?;
-
-    let text = String::from_utf8_lossy(&buf);
-    let Some((head, body)) = text.split_once("\r\n\r\n") else {
-        return Err(HttpErr {
-            msg: "malformed response".to_string(),
-            retry: true,
-        });
-    };
-    let code = head
-        .lines()
-        .next()
-        .unwrap_or("")
-        .split_whitespace()
-        .nth(1)
-        .and_then(|c| c.parse::<u16>().ok())
-        .unwrap_or(0);
-    if !(200..300).contains(&code) {
-        return Err(HttpErr {
-            retry: code == 429 || code >= 500,
-            msg: format!("http {code}"),
-        });
-    }
-    Ok(body.to_string())
-}
-
-fn retryable_io(e: &io::Error) -> bool {
-    use io::ErrorKind::{
-        BrokenPipe, ConnectionAborted, ConnectionRefused, ConnectionReset, UnexpectedEof,
-    };
-    matches!(
-        e.kind(),
-        ConnectionReset | ConnectionAborted | ConnectionRefused | BrokenPipe | UnexpectedEof
-    )
-}
-
-fn url_encode(s: &str) -> String {
-    let mut out = String::new();
-    for b in s.bytes() {
-        match b {
-            b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => {
-                out.push(b as char)
-            }
-            _ => out.push_str(&format!("%{b:02X}")),
-        }
-    }
-    out
-}
-
 pub fn to_json(map: &BTreeMap<String, String>) -> String {
     let items: Vec<String> = map
         .iter()

src/bot/modules/wiki.rs

@@ -0,0 +1,72 @@
+use crate::bot::module::{Action, Command, CommandSpec, Module};
+use crate::json::Json;
+
+pub struct Wiki;
+
+const COMMANDS: &[CommandSpec] = &[CommandSpec {
+    name: "wiki",
+    usage: "wiki <term>",
+    about: "summary of a Wikipedia article",
+}];
+
+impl Module for Wiki {
+    fn name(&self) -> &'static str {
+        "wiki"
+    }
+
+    fn commands(&self) -> &'static [CommandSpec] {
+        COMMANDS
+    }
+
+    fn on_command(&mut self, cmd: &Command) -> Vec<Action> {
+        let term = cmd.args.join(" ");
+        if term.is_empty() {
+            return vec![Action::reply(format!("usage: {}wiki <term>", cmd.prefix))];
+        }
+        let search = format!(
+            "/w/api.php?action=opensearch&format=json&limit=1&search={}",
+            crate::http::url_encode(&term)
+        );
+        let title = match crate::http::get("en.wikipedia.org", &search) {
+            Ok(body) => match pick_title(&body) {
+                Some(t) => t,
+                None => return vec![Action::reply(format!("no wikipedia article for '{term}'"))],
+            },
+            Err(e) => return vec![Action::reply(format!("wiki unavailable: {e}"))],
+        };
+        let path = format!(
+            "/api/rest_v1/page/summary/{}",
+            crate::http::url_encode(&title.replace(' ', "_"))
+        );
+        match crate::http::get("en.wikipedia.org", &path) {
+            Ok(body) => vec![Action::reply(format_summary(&body))],
+            Err(e) => vec![Action::reply(format!("wiki unavailable: {e}"))],
+        }
+    }
+}
+
+pub fn pick_title(opensearch_body: &str) -> Option<String> {
+    let j = Json::parse(opensearch_body)?;
+    Some(j.idx(1)?.idx(0)?.as_str()?.to_string())
+}
+
+pub fn format_summary(body: &str) -> String {
+    let Some(j) = Json::parse(body) else {
+        return "no data".to_string();
+    };
+    let title = j.get("title").and_then(Json::as_str).unwrap_or("");
+    let extract = j.get("extract").and_then(Json::as_str).unwrap_or("");
+    if extract.is_empty() {
+        return "no summary available".to_string();
+    }
+    let mut out = if title.is_empty() {
+        extract.to_string()
+    } else {
+        format!("{title} — {extract}")
+    };
+    if out.chars().count() > 300 {
+        out = out.chars().take(300).collect::<String>();
+        out.push('…');
+    }
+    out
+}

src/http.rs

@@ -0,0 +1,120 @@
+use std::io::{self, Read, Write};
+use std::net::{TcpStream, ToSocketAddrs};
+use std::time::Duration;
+
+use native_tls::TlsConnector;
+
+pub fn get(host: &str, path: &str) -> Result<String, String> {
+    let mut last = "no response".to_string();
+    for attempt in 0..3 {
+        if attempt > 0 {
+            std::thread::sleep(Duration::from_millis(250));
+        }
+        match try_get(host, path) {
+            Ok(body) => return Ok(body),
+            Err(e) => {
+                let retry = e.retry;
+                last = e.msg;
+                if !retry {
+                    break;
+                }
+            }
+        }
+    }
+    Err(last)
+}
+
+pub fn url_encode(s: &str) -> String {
+    let mut out = String::new();
+    for b in s.bytes() {
+        match b {
+            b'A'..=b'Z' | b'a'..=b'z' | b'0'..=b'9' | b'-' | b'_' | b'.' | b'~' => {
+                out.push(b as char)
+            }
+            _ => out.push_str(&format!("%{b:02X}")),
+        }
+    }
+    out
+}
+
+struct HttpErr {
+    msg: String,
+    retry: bool,
+}
+
+fn try_get(host: &str, path: &str) -> Result<String, HttpErr> {
+    let addr = (host, 443)
+        .to_socket_addrs()
+        .map_err(|e| HttpErr {
+            msg: e.to_string(),
+            retry: false,
+        })?
+        .next()
+        .ok_or(HttpErr {
+            msg: "dns lookup failed".to_string(),
+            retry: false,
+        })?;
+    let stream =
+        TcpStream::connect_timeout(&addr, Duration::from_secs(4)).map_err(|e| HttpErr {
+            retry: retryable_io(&e),
+            msg: e.to_string(),
+        })?;
+    stream.set_read_timeout(Some(Duration::from_secs(5))).ok();
+    stream.set_write_timeout(Some(Duration::from_secs(5))).ok();
+
+    let connector = TlsConnector::new().map_err(|e| HttpErr {
+        msg: e.to_string(),
+        retry: false,
+    })?;
+    let mut tls = connector.connect(host, stream).map_err(|e| HttpErr {
+        msg: e.to_string(),
+        retry: true,
+    })?;
+
+    let req = format!(
+        "GET {path} HTTP/1.0\r\nHost: {host}\r\nUser-Agent: curl/rubot\r\nAccept: */*\r\nConnection: close\r\n\r\n"
+    );
+    tls.write_all(req.as_bytes()).map_err(|e| HttpErr {
+        retry: retryable_io(&e),
+        msg: e.to_string(),
+    })?;
+
+    let mut buf = Vec::new();
+    tls.read_to_end(&mut buf).map_err(|e| HttpErr {
+        retry: retryable_io(&e),
+        msg: e.to_string(),
+    })?;
+
+    let text = String::from_utf8_lossy(&buf);
+    let Some((head, body)) = text.split_once("\r\n\r\n") else {
+        return Err(HttpErr {
+            msg: "malformed response".to_string(),
+            retry: true,
+        });
+    };
+    let code = head
+        .lines()
+        .next()
+        .unwrap_or("")
+        .split_whitespace()
+        .nth(1)
+        .and_then(|c| c.parse::<u16>().ok())
+        .unwrap_or(0);
+    if !(200..300).contains(&code) {
+        return Err(HttpErr {
+            retry: code == 429 || code >= 500,
+            msg: format!("http {code}"),
+        });
+    }
+    Ok(body.to_string())
+}
+
+fn retryable_io(e: &io::Error) -> bool {
+    use io::ErrorKind::{
+        BrokenPipe, ConnectionAborted, ConnectionRefused, ConnectionReset, UnexpectedEof,
+    };
+    matches!(
+        e.kind(),
+        ConnectionReset | ConnectionAborted | ConnectionRefused | BrokenPipe | UnexpectedEof
+    )
+}

src/json.rs

@@ -0,0 +1,184 @@
+use std::iter::Peekable;
+use std::str::Chars;
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum Json {
+    Null,
+    Bool(bool),
+    Num(f64),
+    Str(String),
+    Arr(Vec<Json>),
+    Obj(Vec<(String, Json)>),
+}
+
+impl Json {
+    pub fn parse(s: &str) -> Option<Json> {
+        let mut p = Parser {
+            it: s.chars().peekable(),
+        };
+        p.ws();
+        let v = p.value()?;
+        Some(v)
+    }
+
+    pub fn get(&self, key: &str) -> Option<&Json> {
+        match self {
+            Json::Obj(m) => m.iter().find(|(k, _)| k == key).map(|(_, v)| v),
+            _ => None,
+        }
+    }
+
+    pub fn idx(&self, i: usize) -> Option<&Json> {
+        match self {
+            Json::Arr(a) => a.get(i),
+            _ => None,
+        }
+    }
+
+    pub fn as_str(&self) -> Option<&str> {
+        match self {
+            Json::Str(s) => Some(s),
+            _ => None,
+        }
+    }
+
+    pub fn as_f64(&self) -> Option<f64> {
+        match self {
+            Json::Num(n) => Some(*n),
+            _ => None,
+        }
+    }
+}
+
+struct Parser<'a> {
+    it: Peekable<Chars<'a>>,
+}
+
+impl Parser<'_> {
+    fn ws(&mut self) {
+        while matches!(self.it.peek(), Some(c) if c.is_whitespace()) {
+            self.it.next();
+        }
+    }
+
+    fn value(&mut self) -> Option<Json> {
+        self.ws();
+        match self.it.peek()? {
+            '{' => self.object(),
+            '[' => self.array(),
+            '"' => Some(Json::Str(self.string()?)),
+            't' | 'f' => self.boolean(),
+            'n' => self.consume("null").then_some(Json::Null),
+            _ => self.number(),
+        }
+    }
+
+    fn object(&mut self) -> Option<Json> {
+        self.it.next();
+        let mut m = Vec::new();
+        self.ws();
+        if self.it.peek() == Some(&'}') {
+            self.it.next();
+            return Some(Json::Obj(m));
+        }
+        loop {
+            self.ws();
+            let k = self.string()?;
+            self.ws();
+            if self.it.next()? != ':' {
+                return None;
+            }
+            let v = self.value()?;
+            m.push((k, v));
+            self.ws();
+            match self.it.next()? {
+                ',' => continue,
+                '}' => break,
+                _ => return None,
+            }
+        }
+        Some(Json::Obj(m))
+    }
+
+    fn array(&mut self) -> Option<Json> {
+        self.it.next();
+        let mut a = Vec::new();
+        self.ws();
+        if self.it.peek() == Some(&']') {
+            self.it.next();
+            return Some(Json::Arr(a));
+        }
+        loop {
+            a.push(self.value()?);
+            self.ws();
+            match self.it.next()? {
+                ',' => continue,
+                ']' => break,
+                _ => return None,
+            }
+        }
+        Some(Json::Arr(a))
+    }
+
+    fn string(&mut self) -> Option<String> {
+        self.ws();
+        if self.it.next()? != '"' {
+            return None;
+        }
+        let mut out = String::new();
+        loop {
+            match self.it.next()? {
+                '"' => return Some(out),
+                '\\' => match self.it.next()? {
+                    '"' => out.push('"'),
+                    '\\' => out.push('\\'),
+                    '/' => out.push('/'),
+                    'n' => out.push('\n'),
+                    't' => out.push('\t'),
+                    'r' => out.push('\r'),
+                    'b' => out.push('\u{08}'),
+                    'f' => out.push('\u{0C}'),
+                    'u' => {
+                        let mut code = 0u32;
+                        for _ in 0..4 {
+                            code = code * 16 + self.it.next()?.to_digit(16)?;
+                        }
+                        if let Some(c) = char::from_u32(code) {
+                            out.push(c);
+                        }
+                    }
+                    other => out.push(other),
+                },
+                c => out.push(c),
+            }
+        }
+    }
+
+    fn number(&mut self) -> Option<Json> {
+        let mut s = String::new();
+        while matches!(self.it.peek(), Some(c) if c.is_ascii_digit() || matches!(c, '-' | '+' | '.' | 'e' | 'E'))
+        {
+            s.push(self.it.next()?);
+        }
+        s.parse::<f64>().ok().map(Json::Num)
+    }
+
+    fn boolean(&mut self) -> Option<Json> {
+        if self.consume("true") {
+            Some(Json::Bool(true))
+        } else if self.consume("false") {
+            Some(Json::Bool(false))
+        } else {
+            None
+        }
+    }
+
+    fn consume(&mut self, word: &str) -> bool {
+        for ch in word.chars() {
+            if self.it.next() != Some(ch) {
+                return false;
+            }
+        }
+        true
+    }
+}

src/lib.rs

@@ -2,7 +2,9 @@
 
 pub mod bot;
 pub mod config;
+pub mod http;
 pub mod irc;
+pub mod json;
 
 pub fn log(msg: &str) {
     eprintln!("[rustbot] {msg}");

tests/json.rs

@@ -0,0 +1,38 @@
+use rustbot::json::Json;
+
+#[test]
+fn parses_object_and_navigates() {
+    let j = Json::parse(r#"{"a":"x","b":{"c":42}}"#).unwrap();
+    assert_eq!(j.get("a").and_then(Json::as_str), Some("x"));
+    assert_eq!(
+        j.get("b").and_then(|v| v.get("c")).and_then(Json::as_f64),
+        Some(42.0)
+    );
+    assert!(j.get("missing").is_none());
+}
+
+#[test]
+fn parses_nested_arrays() {
+    let j = Json::parse(r#"["q",["t1","t2"],[""],["u1"]]"#).unwrap();
+    assert_eq!(j.idx(0).and_then(Json::as_str), Some("q"));
+    assert_eq!(
+        j.idx(1).and_then(|v| v.idx(1)).and_then(Json::as_str),
+        Some("t2")
+    );
+}
+
+#[test]
+fn parses_scalars_and_escapes() {
+    assert_eq!(Json::parse("true"), Some(Json::Bool(true)));
+    assert_eq!(Json::parse("null"), Some(Json::Null));
+    assert_eq!(Json::parse("-3.5e2").and_then(|j| j.as_f64()), Some(-350.0));
+    let s = Json::parse(r#""a\"bé""#).unwrap();
+    assert_eq!(s.as_str(), Some("a\"bé"));
+}
+
+#[test]
+fn rejects_garbage() {
+    assert!(Json::parse("{oops").is_none());
+    assert!(Json::parse("").is_none());
+    assert!(Json::parse("[1,2").is_none());
+}

tests/tier4.rs

@@ -0,0 +1,50 @@
+use rustbot::bot::modules::crypto::format_ticker;
+use rustbot::bot::modules::define::format_define;
+use rustbot::bot::modules::down::host_of;
+use rustbot::bot::modules::urban::format_urban;
+use rustbot::bot::modules::wiki::{format_summary, pick_title};
+
+#[test]
+fn crypto_formats_ticker() {
+    let body = r#"{"last":"63836.11","high":"64658.00","low":"63477.46","volume":"1032.2"}"#;
+    let out = format_ticker("btc", body);
+    assert!(out.contains("BTC/USD: $63836.11"), "{out}");
+    assert!(out.contains("high $64658.00"), "{out}");
+    assert!(out.contains("low $63477.46"), "{out}");
+}
+
+#[test]
+fn wiki_picks_title_and_formats_summary() {
+    let os = r#"["Rust programming",["Rust (programming language)"],[""],["https://en.wikipedia.org/wiki/Rust_(programming_language)"]]"#;
+    assert_eq!(
+        pick_title(os).as_deref(),
+        Some("Rust (programming language)")
+    );
+    let sum = r#"{"title":"Rust (programming language)","extract":"Rust is a language."}"#;
+    assert_eq!(
+        format_summary(sum),
+        "Rust (programming language) — Rust is a language."
+    );
+}
+
+#[test]
+fn define_formats_first_meaning() {
+    let body = r#"[{"word":"hello","meanings":[{"partOfSpeech":"noun","definitions":[{"definition":"a greeting"}]}]}]"#;
+    assert_eq!(format_define("hello", body), "hello (noun): a greeting");
+}
+
+#[test]
+fn urban_formats_and_strips_brackets() {
+    let body = "{\"list\":[{\"word\":\"irc\",\"definition\":\"[Internet] Relay\\r\\nChat\"}]}";
+    let out = format_urban("irc", body);
+    assert!(out.starts_with("irc: Internet Relay"), "{out}");
+    assert!(!out.contains('['), "{out}");
+}
+
+#[test]
+fn down_parses_host() {
+    assert_eq!(host_of("https://example.com/path?x=1"), "example.com");
+    assert_eq!(host_of("example.com:8080"), "example.com");
+    assert_eq!(host_of("user@host.net"), "host.net");
+    assert_eq!(host_of("//foo.org/"), "foo.org");
+}