use crate::swqos::common::{
    default_http_client_builder, poll_transaction_confirmation, serialize_transaction_and_encode,
};
use rand::seq::IndexedRandom;
use reqwest::Client;
use serde_json::json;
use std::{sync::Arc, time::Instant};

use solana_transaction_status::UiTransactionEncoding;

use crate::swqos::SwqosClientTrait;
use crate::swqos::{SwqosType, TradeType};
use anyhow::Result;
use solana_sdk::transaction::VersionedTransaction;

use crate::{common::SolanaRpcClient, constants::swqos::ZEROSLOT_TIP_ACCOUNTS};

#[derive(Clone)]
pub struct ZeroSlotClient {
    pub endpoint: String,
    pub auth_token: String,
    pub rpc_client: Arc<SolanaRpcClient>,
    pub http_client: Client,
}

#[async_trait::async_trait]
impl SwqosClientTrait for ZeroSlotClient {
    async fn send_transaction(
        &self,
        trade_type: TradeType,
        transaction: &VersionedTransaction,
        wait_confirmation: bool,
    ) -> Result<()> {
        self.send_transaction(trade_type, transaction, wait_confirmation).await
    }

    async fn send_transactions(
        &self,
        trade_type: TradeType,
        transactions: &Vec<VersionedTransaction>,
        wait_confirmation: bool,
    ) -> Result<()> {
        self.send_transactions(trade_type, transactions, wait_confirmation).await
    }

    fn get_tip_account(&self) -> Result<String> {
        let tip_account = *ZEROSLOT_TIP_ACCOUNTS
            .choose(&mut rand::rng())
            .or_else(|| ZEROSLOT_TIP_ACCOUNTS.first())
            .unwrap();
        Ok(tip_account.to_string())
    }

    fn get_swqos_type(&self) -> SwqosType {
        SwqosType::ZeroSlot
    }
}

impl ZeroSlotClient {
    pub fn new(rpc_url: String, endpoint: String, auth_token: String) -> Self {
        let rpc_client = SolanaRpcClient::new(rpc_url);
        let http_client = default_http_client_builder().build().unwrap();
        Self { rpc_client: Arc::new(rpc_client), endpoint, auth_token, http_client }
    }

    pub async fn send_transaction(
        &self,
        trade_type: TradeType,
        transaction: &VersionedTransaction,
        wait_confirmation: bool,
    ) -> Result<()> {
        let start_time = Instant::now();
        let (content, signature) =
            serialize_transaction_and_encode(transaction, UiTransactionEncoding::Base64)?;

        let request_body = serde_json::to_string(&json!({
            "jsonrpc": "2.0",
            "id": 1,
            "method": "sendTransaction",
            "params": [
                content,
                { "encoding": "base64", "skipPreflight": true }
            ]
        }))?;

        let mut url = String::with_capacity(self.endpoint.len() + self.auth_token.len() + 20);
        url.push_str(&self.endpoint);
        url.push_str("/?api-key=");
        url.push_str(&self.auth_token);

        // 4. Use `text().await?` directly, avoiding async JSON parsing from `json().await?`
        let response_text = self
            .http_client
            .post(&url)
            .body(request_body) // Pass string directly, avoiding `json()` overhead
            .header("Content-Type", "application/json") // Explicitly specify JSON header
            .send()
            .await?
            .text()
            .await?;

        // 5. Use `serde_json::from_str()` to parse JSON, reducing extra wait from `.json().await?`
        if let Ok(response_json) = serde_json::from_str::<serde_json::Value>(&response_text) {
            if response_json.get("result").is_some() {
                println!(" [0slot] {} submitted: {:?}", trade_type, start_time.elapsed());
            } else if let Some(_error) = response_json.get("error") {
                eprintln!(" [0slot] {} submission failed: {:?}", trade_type, _error);
            }
        } else {
            eprintln!(" [0slot] {} submission failed: {:?}", trade_type, response_text);
        }

        let start_time: Instant = Instant::now();
        match poll_transaction_confirmation(&self.rpc_client, signature, wait_confirmation).await {
            Ok(_) => (),
            Err(e) => {
                println!(" signature: {:?}", signature);
                println!(" [0slot] {} confirmation failed: {:?}", trade_type, start_time.elapsed());
                return Err(e);
            }
        }
        if wait_confirmation {
            println!(" signature: {:?}", signature);
            println!(" [0slot] {} confirmed: {:?}", trade_type, start_time.elapsed());
        }

        Ok(())
    }

    pub async fn send_transactions(
        &self,
        trade_type: TradeType,
        transactions: &Vec<VersionedTransaction>,
        wait_confirmation: bool,
    ) -> Result<()> {
        for transaction in transactions {
            self.send_transaction(trade_type, transaction, wait_confirmation).await?;
        }
        Ok(())
    }
}