// Copyright (C) 2024 Riften Labs AS
//
// This software is licensed under the GNU Affero General Public License (AGPL), version 3.0 or later.
// A copy of the license can be found in the LICENSE file or at https://www.gnu.org/licenses/agpl-3.0.html

use std::{collections::HashSet, str::FromStr};

use anyhow::{Context, Result};
use bitcoin_hashes::hex::ToHex;
use bitcoincash::{consensus::deserialize, BlockHeader, Transaction, Txid};
use electrum_client_netagnostic::{Client, ElectrumApi, Param};
use log::info;
use riftenlabs_defi::cauldron::V2_CONTRACT_TEMPLATE;
use serde_json::{json, Value};

/// Fetch blockchain tip from electrum server
pub fn electrum_get_tip(client: &Client) -> Result<(BlockHeader, u64)> {
    let tip: Value =
        serde_json::from_str(&client.raw_call("blockchain.headers.tip", [])?.to_string())?;

    let height = tip
        .get("height")
        .context("no height")?
        .as_i64()
        .context("no int")?;

    let header = tip
        .get("hex")
        .context("no hex in header")?
        .as_str()
        .context("hex not str")?;

    Ok((deserialize(&hex::decode(header)?)?, height as u64))
}

/// Fetch cauldron mempool transactions
pub fn electrum_fetch_mempool(client: &Client) -> Result<HashSet<Txid>> {
    let filter = json!({
        "scriptsig": hex::encode(&V2_CONTRACT_TEMPLATE[(V2_CONTRACT_TEMPLATE.len() - 43)..])
    });

    let response = client.raw_call("mempool.get", [Param::Value(filter)])?;

    let txs = response
        .get("transactions")
        .context("no txs in mempool get")?
        .as_array()
        .context("txs not array")?;
    Ok(txs
        .iter()
        .filter_map(|txid| match txid.as_str() {
            Some(txid_hex) => match Txid::from_str(txid_hex) {
                Ok(txid) => Some(txid),
                Err(e) => {
                    info!("Txid not hex: {}", e);
                    None
                }
            },
            None => {
                info!("Failed to read txid from electrum response {:?}", txid);
                None
            }
        })
        .collect())
}

/// Fetch blockchain tip from electrum server
pub fn electrum_get_tx(client: &Client, txid: &Txid) -> Result<Transaction> {
    let tx: Value = serde_json::from_str(
        &client
            .raw_call("blockchain.transaction.get", [Param::String(txid.to_hex())])?
            .to_string(),
    )?;

    let tx: Transaction = deserialize(
        &hex::decode(tx.as_str().context("no tx in response")?).context("failed to decode tx")?,
    )?;

    Ok(tx)
}