extern crate regex;
extern crate num_bigint;
extern crate num_traits;


use regex::Regex;
use reqwest;
use serde_json::{json, Value};
use std::{error::Error};
use num_bigint::BigUint;
use num_traits::{One, ToPrimitive};

#[derive(Clone)]
pub struct Client {
    project_id: String,
    inner_client: reqwest::blocking::Client,
}

impl Client {

    pub fn new(project_id: String) -> Self {
        Client {
            project_id: project_id,
            inner_client: reqwest::blocking::Client::new(),
        }
    }

    pub fn get_price_in_pool(&self /*, pool_address: String, func_hash: String */) -> Result<(), Box<dyn Error>> {
        let url = format!("https://mainnet.infura.io/v3/{}", self.project_id);

        let client = &self.inner_client;

        let body = json!({
            "jsonrpc": "2.0",
            "method": "eth_call",
            "params": [{
                "to": "0x88e6A0c2dDD26FEEb64F039a2c41296FcB3f5640",
                "data": "0x3850c7bd"
            }, "latest"],
            "id": 1
        });

        let response = client
            .post(url.as_str())
            .header("Content-Type", "application/json")
            .json(&body) // Automatically serializes the body to JSON
            .send()?;

        let json: Value = response.json()?;
        let result = json.get("result").unwrap().as_str().unwrap();

        let re_prefix = Regex::new(r"0x0*([a-fA-F0-9]+)").unwrap();

        let mut s = String::new();

        for cap in re_prefix.captures_iter(result) {
            s = cap[1].to_string();
        }

        let mut ans = String::new();
        let re_suffix = Regex::new(r"^(.*?)(?:0000|$)").unwrap();

        for cap in re_suffix.captures_iter(&s) {
            ans = cap[1].to_string();
            println!("{}", &cap[1]);
        }

        // Используем BigUint для больших чисел.
        let num = BigUint::parse_bytes(ans.as_bytes(), 16).unwrap();

        // Используем BigUint для вычислений.
        let base: BigUint = BigUint::one() << 192;
        let price = num.pow(2).to_f64().unwrap() / base.to_f64().unwrap();
        println!("{:.2}", (1.0 / price) * 10f64.powi(12));

        Ok(())
    }

}

fn main() {
    let _= Client::new("ab65c51db1f44b23a92b3426161e8c1d".into()).get_price_in_pool();
}