src/main.rs

   1 use anyhow::anyhow;
   2 use clap::CommandFactory;
   3 use clap::Parser;
   4 use itertools::Itertools;
   5 use serde::Deserialize;
   6 use serde_json::Value as JsonValue;
   7 use std::{
   8     collections::{BTreeMap, BTreeSet},
   9     fmt,
  10 };
  11
  12 fn main() -> anyhow::Result<()> {
  13     #[derive(Parser, Debug)]
  14     #[clap(author, version, about, long_about = None)]
  15     struct Args {
  16         /// Address of the server list
  17         #[clap(short, long, value_parser, default_value_t = String::from("https://servers.minetest.net/list"))]
  18         address: String,
  19
  20         /// List available keys
  21         #[clap(short, long, action)]
  22         show_keys: bool,
  23
  24         /// The key to look up. Use --show-keys to list available keys.
  25         key: Option<String>,
  26     }
  27     let args = Args::parse();
  28
  29     #[derive(Deserialize)]
  30     struct Payload {
  31         list: Vec<BTreeMap<String, JsonValue>>,
  32     }
  33     let payload: Payload = reqwest::blocking::get(args.address)?.json()?;
  34
  35     if args.show_keys {
  36         let keys: BTreeSet<&String> = payload.list.iter().flat_map(BTreeMap::keys).collect();
  37         println!("available keys: {}", keys.iter().format(", "));
  38     }
  39
  40     if let Some(key) = args.key {
  41         let mut iter = payload
  42             .list
  43             .iter()
  44             .flat_map(|server| server.get(&key).map(|value| (server, value)))
  45             .peekable();
  46
  47         if iter.peek().is_none() {
  48             return Err(anyhow!("invalid key"));
  49         } else {
  50             iter.for_each(|(server, value)| {
  51                 struct DisplayJson<'a>(Option<&'a JsonValue>);
  52                 impl<'a> fmt::Display for DisplayJson<'a> {
  53                     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  54                         match self.0 {
  55                             None => Ok(()),
  56                             Some(value) => match value {
  57                                 JsonValue::String(x) => write!(f, "{x}"),
  58                                 _ => write!(f, "{value}"),
  59                             },
  60                         }
  61                     }
  62                 }
  63
  64                 let address = DisplayJson(server.get("address"));
  65                 let port = DisplayJson(server.get("port"));
  66
  67                 if let JsonValue::Array(array) = value {
  68                     let prefix = format!("{address}:{port}"); // cache it
  69                     for value in array.iter() {
  70                         println!("{prefix}\t{}", DisplayJson(Some(value)));
  71                     }
  72                 } else {
  73                     println!("{address}:{port}\t{}", DisplayJson(Some(value)));
  74                 }
  75             });
  76         }
  77     } else if !args.show_keys {
  78         Args::command().print_help()?;
  79     }
  80
  81     Ok(())
  82 }