//! RSK (Rootstock) Integration
//!
//! RSK is a Bitcoin sidechain that enables Ethereum-compatible smart contracts
//! with a BTC-pegged token (rBTC).
//! This module provides integration with RSK for:
//! - rBTC (BTC-pegged token) management
//! - Smart contract deployment
//! - Peg-in and peg-out operations

use crate::error::BitcoinError;
use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use uuid::Uuid;

/// RSK network type
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum RskNetwork {
    /// Mainnet
    Mainnet,
    /// Testnet
    Testnet,
    /// Regtest (local development)
    Regtest,
}

impl RskNetwork {
    /// Get the RPC URL for this network
    pub fn rpc_url(&self) -> &str {
        match self {
            RskNetwork::Mainnet => "https://public-node.rsk.co",
            RskNetwork::Testnet => "https://public-node.testnet.rsk.co",
            RskNetwork::Regtest => "http://localhost:4444",
        }
    }

    /// Get the chain ID
    pub fn chain_id(&self) -> u64 {
        match self {
            RskNetwork::Mainnet => 30,
            RskNetwork::Testnet => 31,
            RskNetwork::Regtest => 33,
        }
    }
}

/// RSK address (Ethereum-compatible)
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct RskAddress {
    /// Address string (0x-prefixed hex)
    pub address: String,
}

impl RskAddress {
    /// Create a new RSK address
    pub fn new(address: String) -> Result<Self, BitcoinError> {
        // Validate address format (0x + 40 hex chars)
        if !address.starts_with("0x") {
            return Err(BitcoinError::InvalidAddress(
                "RSK address must start with 0x".to_string(),
            ));
        }

        if address.len() != 42 {
            return Err(BitcoinError::InvalidAddress(
                "RSK address must be 42 characters (0x + 40 hex)".to_string(),
            ));
        }

        Ok(Self { address })
    }

    /// Convert to lowercase (standard format)
    pub fn to_lowercase(&self) -> String {
        self.address.to_lowercase()
    }
}

/// Peg operation type
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum PegOperation {
    /// Peg-in: Convert BTC to rBTC
    PegIn,
    /// Peg-out: Convert rBTC back to BTC
    PegOut,
}

/// Peg transaction status
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum PegStatus {
    /// Waiting for BTC transaction
    Pending,
    /// BTC transaction confirmed, waiting for RSK
    Confirming,
    /// Waiting for bridge processing
    Processing,
    /// Completed successfully
    Completed,
    /// Failed or rejected
    Failed,
    /// Refunded to sender
    Refunded,
}

/// Peg-in transaction (BTC -> rBTC)
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PegInTransaction {
    /// Transaction ID
    pub id: Uuid,
    /// BTC transaction ID
    pub btc_tx_id: String,
    /// Amount in satoshis
    pub amount: u64,
    /// Source BTC address
    pub btc_address: String,
    /// Destination RSK address
    pub rsk_address: RskAddress,
    /// RSK transaction hash (when rBTC is minted)
    pub rsk_tx_hash: Option<String>,
    /// BTC confirmations received
    pub btc_confirmations: u32,
    /// Current status
    pub status: PegStatus,
}

/// Peg-out transaction (rBTC -> BTC)
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PegOutTransaction {
    /// Transaction ID
    pub id: Uuid,
    /// RSK transaction hash
    pub rsk_tx_hash: String,
    /// Amount in satoshis (wei)
    pub amount: u64,
    /// Source RSK address
    pub rsk_address: RskAddress,
    /// Destination BTC address
    pub btc_address: String,
    /// BTC transaction ID (when released)
    pub btc_tx_id: Option<String>,
    /// RSK confirmations received
    pub rsk_confirmations: u32,
    /// Current status
    pub status: PegStatus,
}

/// Peg configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PegConfig {
    /// Minimum peg amount (in satoshis)
    pub min_amount: u64,
    /// Maximum peg amount (in satoshis)
    pub max_amount: u64,
    /// Required BTC confirmations for peg-in
    pub btc_confirmations_required: u32,
    /// Required RSK confirmations for peg-out
    pub rsk_confirmations_required: u32,
    /// Federation address (for peg-in deposits)
    pub federation_address: String,
}

impl Default for PegConfig {
    fn default() -> Self {
        Self {
            min_amount: 5_000,         // 0.00005 BTC
            max_amount: 1_000_000_000, // 10 BTC
            btc_confirmations_required: 100,
            rsk_confirmations_required: 100,
            federation_address: String::new(),
        }
    }
}

/// RSK client for interacting with RSK network
pub struct RskClient {
    /// Network configuration
    network: RskNetwork,
    /// RPC URL
    #[allow(dead_code)]
    rpc_url: String,
    /// HTTP client
    #[allow(dead_code)]
    http_client: reqwest::Client,
}

impl RskClient {
    /// Create a new RSK client
    pub fn new(network: RskNetwork) -> Self {
        Self {
            network,
            rpc_url: network.rpc_url().to_string(),
            http_client: reqwest::Client::new(),
        }
    }

    /// Get the current network
    pub fn network(&self) -> RskNetwork {
        self.network
    }

    /// Validate an RSK address
    pub fn validate_address(&self, address: &str) -> Result<RskAddress, BitcoinError> {
        RskAddress::new(address.to_string())
    }

    /// Get rBTC balance
    pub async fn get_balance(&self, address: &RskAddress) -> Result<u64, BitcoinError> {
        // In a real implementation, this would call the RSK RPC
        // eth_getBalance
        let _ = address;
        Ok(0)
    }

    /// Get transaction count (nonce)
    pub async fn get_transaction_count(&self, address: &RskAddress) -> Result<u64, BitcoinError> {
        // In a real implementation, this would call the RSK RPC
        // eth_getTransactionCount
        let _ = address;
        Ok(0)
    }

    /// Get transaction receipt
    pub async fn get_transaction_receipt(
        &self,
        tx_hash: &str,
    ) -> Result<RskTransactionReceipt, BitcoinError> {
        // In a real implementation, this would call the RSK RPC
        // eth_getTransactionReceipt
        let _ = tx_hash;
        Err(BitcoinError::TransactionNotFound(
            "Not implemented".to_string(),
        ))
    }

    /// Get current block number
    pub async fn get_block_number(&self) -> Result<u64, BitcoinError> {
        // In a real implementation, this would call the RSK RPC
        // eth_blockNumber
        Ok(0)
    }

    /// Send raw transaction
    pub async fn send_raw_transaction(&self, tx_hex: &str) -> Result<String, BitcoinError> {
        // In a real implementation, this would call the RSK RPC
        // eth_sendRawTransaction
        let _ = tx_hex;
        Err(BitcoinError::BroadcastFailed("Not implemented".to_string()))
    }
}

/// RSK transaction receipt
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RskTransactionReceipt {
    /// Transaction hash
    pub transaction_hash: String,
    /// Block number
    pub block_number: u64,
    /// Block hash
    pub block_hash: String,
    /// From address
    pub from: RskAddress,
    /// To address
    pub to: Option<RskAddress>,
    /// Gas used
    pub gas_used: u64,
    /// Status (1 = success, 0 = failure)
    pub status: u8,
}

/// Smart contract deployment on RSK
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RskContractDeployment {
    /// Deployment ID
    pub id: Uuid,
    /// Contract bytecode
    pub bytecode: String,
    /// Constructor arguments
    pub constructor_args: Vec<String>,
    /// Deployer address
    pub deployer: RskAddress,
    /// Gas limit
    pub gas_limit: u64,
    /// Gas price (in wei)
    pub gas_price: u64,
}

/// Contract deployment result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RskDeploymentResult {
    /// Deployment ID
    pub deployment_id: Uuid,
    /// Transaction hash
    pub tx_hash: Option<String>,
    /// Deployed contract address
    pub contract_address: Option<RskAddress>,
    /// Status
    pub status: DeploymentStatus,
    /// Error message (if failed)
    pub error: Option<String>,
}

/// Deployment status
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum DeploymentStatus {
    /// Pending deployment
    Pending,
    /// Transaction broadcast
    Broadcast,
    /// Confirmed on chain
    Confirmed,
    /// Failed
    Failed,
}

/// Peg manager for handling peg-in and peg-out operations
pub struct PegManager {
    /// Configuration
    config: PegConfig,
    /// RSK client
    rsk_client: RskClient,
    /// Active peg-in transactions
    peg_ins: HashMap<Uuid, PegInTransaction>,
    /// Active peg-out transactions
    peg_outs: HashMap<Uuid, PegOutTransaction>,
}

impl PegManager {
    /// Create a new peg manager
    pub fn new(config: PegConfig, rsk_client: RskClient) -> Self {
        Self {
            config,
            rsk_client,
            peg_ins: HashMap::new(),
            peg_outs: HashMap::new(),
        }
    }

    /// Initiate a peg-in operation (BTC -> rBTC)
    pub fn initiate_peg_in(
        &mut self,
        btc_tx_id: String,
        amount: u64,
        btc_address: String,
        rsk_address: RskAddress,
    ) -> Result<PegInTransaction, BitcoinError> {
        // Validate amount
        if amount < self.config.min_amount {
            return Err(BitcoinError::Validation(format!(
                "Amount {} is below minimum {}",
                amount, self.config.min_amount
            )));
        }

        if amount > self.config.max_amount {
            return Err(BitcoinError::Validation(format!(
                "Amount {} exceeds maximum {}",
                amount, self.config.max_amount
            )));
        }

        let tx = PegInTransaction {
            id: Uuid::new_v4(),
            btc_tx_id,
            amount,
            btc_address,
            rsk_address,
            rsk_tx_hash: None,
            btc_confirmations: 0,
            status: PegStatus::Pending,
        };

        self.peg_ins.insert(tx.id, tx.clone());
        Ok(tx)
    }

    /// Initiate a peg-out operation (rBTC -> BTC)
    pub fn initiate_peg_out(
        &mut self,
        rsk_tx_hash: String,
        amount: u64,
        rsk_address: RskAddress,
        btc_address: String,
    ) -> Result<PegOutTransaction, BitcoinError> {
        // Validate amount
        if amount < self.config.min_amount {
            return Err(BitcoinError::Validation(format!(
                "Amount {} is below minimum {}",
                amount, self.config.min_amount
            )));
        }

        if amount > self.config.max_amount {
            return Err(BitcoinError::Validation(format!(
                "Amount {} exceeds maximum {}",
                amount, self.config.max_amount
            )));
        }

        let tx = PegOutTransaction {
            id: Uuid::new_v4(),
            rsk_tx_hash,
            amount,
            rsk_address,
            btc_address,
            btc_tx_id: None,
            rsk_confirmations: 0,
            status: PegStatus::Pending,
        };

        self.peg_outs.insert(tx.id, tx.clone());
        Ok(tx)
    }

    /// Update peg-in transaction
    pub fn update_peg_in(
        &mut self,
        id: Uuid,
        btc_confirmations: u32,
        rsk_tx_hash: Option<String>,
    ) -> Result<(), BitcoinError> {
        let tx = self
            .peg_ins
            .get_mut(&id)
            .ok_or_else(|| BitcoinError::TransactionNotFound(id.to_string()))?;

        tx.btc_confirmations = btc_confirmations;

        if let Some(hash) = rsk_tx_hash {
            tx.rsk_tx_hash = Some(hash);
        }

        // Update status based on confirmations
        if btc_confirmations >= self.config.btc_confirmations_required {
            if tx.rsk_tx_hash.is_some() {
                tx.status = PegStatus::Completed;
            } else {
                tx.status = PegStatus::Processing;
            }
        } else {
            tx.status = PegStatus::Confirming;
        }

        Ok(())
    }

    /// Update peg-out transaction
    pub fn update_peg_out(
        &mut self,
        id: Uuid,
        rsk_confirmations: u32,
        btc_tx_id: Option<String>,
    ) -> Result<(), BitcoinError> {
        let tx = self
            .peg_outs
            .get_mut(&id)
            .ok_or_else(|| BitcoinError::TransactionNotFound(id.to_string()))?;

        tx.rsk_confirmations = rsk_confirmations;

        if let Some(txid) = btc_tx_id {
            tx.btc_tx_id = Some(txid);
        }

        // Update status based on confirmations
        if rsk_confirmations >= self.config.rsk_confirmations_required {
            if tx.btc_tx_id.is_some() {
                tx.status = PegStatus::Completed;
            } else {
                tx.status = PegStatus::Processing;
            }
        } else {
            tx.status = PegStatus::Confirming;
        }

        Ok(())
    }

    /// Get peg-in transaction
    pub fn get_peg_in(&self, id: &Uuid) -> Option<&PegInTransaction> {
        self.peg_ins.get(id)
    }

    /// Get peg-out transaction
    pub fn get_peg_out(&self, id: &Uuid) -> Option<&PegOutTransaction> {
        self.peg_outs.get(id)
    }

    /// Get the RSK client
    pub fn rsk_client(&self) -> &RskClient {
        &self.rsk_client
    }

    /// Get federation address for deposits
    pub fn federation_address(&self) -> &str {
        &self.config.federation_address
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_rsk_address_validation() {
        let addr = RskAddress::new("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb0".to_string());
        assert!(addr.is_ok());

        let invalid = RskAddress::new("742d35Cc6634C0532925a3b844Bc9e7595f0bEb0".to_string());
        assert!(invalid.is_err());

        let too_short = RskAddress::new("0x742d35Cc".to_string());
        assert!(too_short.is_err());
    }

    #[test]
    fn test_rsk_network_chain_ids() {
        assert_eq!(RskNetwork::Mainnet.chain_id(), 30);
        assert_eq!(RskNetwork::Testnet.chain_id(), 31);
        assert_eq!(RskNetwork::Regtest.chain_id(), 33);
    }

    #[test]
    fn test_peg_config_defaults() {
        let config = PegConfig::default();
        assert_eq!(config.min_amount, 5_000);
        assert_eq!(config.max_amount, 1_000_000_000);
        assert_eq!(config.btc_confirmations_required, 100);
        assert_eq!(config.rsk_confirmations_required, 100);
    }

    #[test]
    fn test_peg_manager_peg_in() {
        let config = PegConfig::default();
        let client = RskClient::new(RskNetwork::Testnet);
        let mut manager = PegManager::new(config, client);

        let rsk_addr =
            RskAddress::new("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb0".to_string()).unwrap();

        let result = manager.initiate_peg_in(
            "btc_txid".to_string(),
            100_000,
            "bc1qtest".to_string(),
            rsk_addr,
        );

        assert!(result.is_ok());
        let tx = result.unwrap();
        assert_eq!(tx.amount, 100_000);
        assert_eq!(tx.status, PegStatus::Pending);
    }

    #[test]
    fn test_peg_manager_amount_validation() {
        let config = PegConfig::default();
        let client = RskClient::new(RskNetwork::Testnet);
        let mut manager = PegManager::new(config, client);

        let rsk_addr =
            RskAddress::new("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb0".to_string()).unwrap();

        // Too small
        let result = manager.initiate_peg_in(
            "btc_txid".to_string(),
            100,
            "bc1qtest".to_string(),
            rsk_addr.clone(),
        );
        assert!(result.is_err());

        // Too large
        let result = manager.initiate_peg_in(
            "btc_txid".to_string(),
            2_000_000_000,
            "bc1qtest".to_string(),
            rsk_addr,
        );
        assert!(result.is_err());
    }

    #[test]
    fn test_peg_in_status_updates() {
        let config = PegConfig::default();
        let client = RskClient::new(RskNetwork::Testnet);
        let mut manager = PegManager::new(config, client);

        let rsk_addr =
            RskAddress::new("0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb0".to_string()).unwrap();

        let tx = manager
            .initiate_peg_in(
                "btc_txid".to_string(),
                100_000,
                "bc1qtest".to_string(),
                rsk_addr,
            )
            .unwrap();

        // Update with confirmations
        manager.update_peg_in(tx.id, 50, None).unwrap();
        let updated = manager.get_peg_in(&tx.id).unwrap();
        assert_eq!(updated.status, PegStatus::Confirming);

        // Complete the peg-in
        manager
            .update_peg_in(tx.id, 100, Some("rsk_tx_hash".to_string()))
            .unwrap();
        let completed = manager.get_peg_in(&tx.id).unwrap();
        assert_eq!(completed.status, PegStatus::Completed);
    }

    #[test]
    fn test_rsk_client_network() {
        let client = RskClient::new(RskNetwork::Mainnet);
        assert_eq!(client.network(), RskNetwork::Mainnet);
    }
}
