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use std::io::Read;
extern crate serde;
#[macro_use]
extern crate serde_derive;
extern crate serde_json;
use serde::Deserialize;
use serde::de::{self, Deserializer, Unexpected};
extern crate reqwest;
#[derive(Debug, Deserialize)]
pub struct Symbol {
id: String,
name: String,
symbol: String,
#[serde(deserialize_with = "string_as_u32")] rank: u32,
#[serde(deserialize_with = "string_as_f64")] price_usd: f64,
#[serde(deserialize_with = "string_as_f64")] price_btc: f64,
#[serde(deserialize_with = "string_as_f64")] price_eur: f64,
#[serde(deserialize_with = "string_as_f64")] market_cap_usd: f64,
#[serde(deserialize_with = "string_as_f64")] market_cap_eur: f64,
}
#[derive(Debug, Deserialize)]
pub struct Global {
active_assets: u32,
active_currencies: u32,
active_markets: u32,
bitcoin_percentage_of_market_cap: f64,
total_24h_volume_eur: f64,
total_24h_volume_usd: f64,
total_market_cap_eur: f64,
total_market_cap_usd: f64,
}
fn string_as_f64<'de, D>(deserializer: D) -> Result<f64, D::Error>
where
D: Deserializer<'de>,
{
let s = String::deserialize(deserializer)?;
s.parse::<f64>().map_err(|_err| {
de::Error::invalid_value(Unexpected::Str(&s), &"a string representation of a f64")
})
}
fn string_as_u32<'de, D>(deserializer: D) -> Result<u32, D::Error>
where
D: Deserializer<'de>,
{
let s = String::deserialize(deserializer)?;
s.parse::<u32>().map_err(|_err| {
de::Error::invalid_value(Unexpected::Str(&s), &"a string representation of a u32")
})
}
fn parse_ticker_result_to_symbols(json: String) -> Result<Vec<Symbol>, serde_json::Error> {
serde_json::from_str(&json)
}
fn parse_global_result(json: String) -> Result<Global, serde_json::Error> {
serde_json::from_str(&json)
}
fn fetch(url: &str) -> Result<String, reqwest::Error> {
let mut result: reqwest::Response = match reqwest::get(url) {
Ok(result) => result,
Err(err) => return Err(err),
};
let mut content = String::new();
let _ = result.read_to_string(&mut content);
Ok(content)
}
pub fn ticker() -> Vec<Symbol> {
let content = match fetch("https://api.coinmarketcap.com/v1/ticker/?convert=EUR") {
Ok(content) => content,
Err(err) => panic!("{}", err),
};
match parse_ticker_result_to_symbols(content) {
Ok(symbols) => symbols,
Err(e) => panic!("{}", e),
}
}
pub fn global() -> Global {
let content = match fetch("https://api.coinmarketcap.com/v1/global/?convert=EUR") {
Ok(content) => content,
Err(err) => panic!("{}", err),
};
match parse_global_result(content) {
Ok(global) => global,
Err(e) => panic!("{}", e),
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
pub fn parsing_ticker_example_should_work() {
let example_content = r#"[
{
"id": "bitcoin",
"name": "Bitcoin",
"symbol": "BTC",
"rank": "1",
"price_usd": "8667.49",
"price_btc": "1.0",
"24h_volume_usd": "4899070000.0",
"market_cap_usd": "146819479859",
"available_supply": "16939100.0",
"total_supply": "16939100.0",
"max_supply": "21000000.0",
"percent_change_1h": "1.07",
"percent_change_24h": "-3.06",
"percent_change_7d": "12.03",
"last_updated": "1522004666",
"price_eur": "7013.94959525",
"24h_volume_eur": "3964449920.75",
"market_cap_eur": "118809993589"
},
{
"id": "ethereum",
"name": "Ethereum",
"symbol": "ETH",
"rank": "2",
"price_usd": "529.528",
"price_btc": "0.0613264",
"24h_volume_usd": "1182010000.0",
"market_cap_usd": "52111526356.0",
"available_supply": "98411276.0",
"total_supply": "98411276.0",
"max_supply": null,
"percent_change_1h": "1.31",
"percent_change_24h": "-1.53",
"percent_change_7d": "5.64",
"last_updated": "1522004652",
"price_eur": "428.5072958",
"24h_volume_eur": "956512042.25",
"market_cap_eur": "42169949915.0"
}
]
"#;
match parse_ticker_result_to_symbols(String::from(example_content)) {
Ok(symbols) => {
assert_eq!(2, symbols.len());
}
Err(e) => {
panic!("{}", e);
}
};
}
#[test]
pub fn parsing_global_example_should_work() {
let example_content = r#"
{
"active_assets": 677,
"active_currencies": 919,
"active_markets": 9914,
"bitcoin_percentage_of_market_cap": 45.41,
"last_updated": 1522597167,
"total_24h_volume_eur": 8326584597.0,
"total_24h_volume_usd": 10267058689.0,
"total_market_cap_eur": 198469129734.0,
"total_market_cap_usd": 244721491658.0
}"#;
match parse_global_result(String::from(example_content)) {
Ok(global) => {
assert_eq!(677, global.active_assets);
}
Err(e) => {
panic!("{}", e);
}
};
}
}