anya-core 1.2.0

use std::error::Error;
// Migrated from OPSource to anya-core
// This file was automatically migrated as part of the Rust-only implementation
// Original file: C:\Users\bmokoka\Downloads\OPSource\src\bitcoin\cross_chain\mod.rs
// Cross-Chain Module
// Implements unified cross-chain bridge functionality for Bitcoin sidechains
//
// [AIR-3][AIS-3][AIT-3][AIM-2][AIP-2][BPC-3][PFM-2][RES-3][SCL-2]
// This module provides a unified interface for cross-chain operations
// with high security and resilience ratings for multi-chain support.

// Re-export modules
pub mod liquid;
pub mod rsk;

use crate::bitcoin::interface::BlockHeader;
use bitcoin::{Block, Transaction};
use bitcoin::hashes::Hash;
use std::collections::HashMap;
use hex;
use bitcoin::blockdata::transaction::{Transaction, TxIn, TxOut};
use bitcoin::key::{PublicKey, WPubkeyHash};
use thiserror::Error;

/// Cross-Chain Transaction Status
/// 
/// Represents the status of a cross-chain transaction.
#[derive(Debug, Clone, PartialEq)]
pub enum CrossChainStatus {
    /// Transaction is pending confirmation on the source chain
    PendingSource,
    /// Transaction is confirmed on the source chain, waiting for target chain processing
    ConfirmedSource,
    /// Transaction is being processed by the cross-chain bridge
    ProcessingBridge,
    /// Transaction is being processed on the target chain
    ProcessingTarget,
    /// Transaction is completed on both chains
    Completed,
    /// Transaction failed
    Failed(String),
}

/// Bridge error type
#[derive(Debug, thiserror::Error)]
pub enum BridgeError {
    /// Invalid transaction
    #[error("Invalid transaction: {0}")]
    InvalidTransaction(String),
    
    /// Bridge execution error
    #[error("Bridge execution error: {0}")]
    ExecutionError(String),
    
    /// Insufficient funds
    #[error("Insufficient funds: {0}")]
    InsufficientFunds(String),
    
    /// Bridge not supported
    #[error("Bridge not supported: {0}")]
    NotSupported(String),
    
    /// Bitcoin error
    #[error("Bitcoin error: {0}")]
    BitcoinError(#[from] crate::bitcoin::error::BitcoinError),
    
    /// RSK bridge error
    #[error("RSK bridge error: {0}")]
    RskError(#[from] crate::bitcoin::cross_chain::rsk::BridgeError),
}

/// Cross-Chain Bridge
/// 
/// Represents a bridge between Bitcoin and another blockchain.
#[derive(Debug, Clone)]
pub struct CrossChainBridge {
    /// Bridge name
    pub name: String,
    /// Source chain (e.g., "Bitcoin")
    pub source_chain: String,
    /// Target chain (e.g., "RSK", "Ethereum", "Liquid")
    pub target_chain: String,
    /// Minimum amount for bridge transactions
    pub min_amount: u64,
    /// Maximum amount for bridge transactions
    pub max_amount: Option<u64>,
    /// Required confirmations on source chain
    pub required_confirmations: u32,
    /// Bridge fee percentage (basis points, e.g., 25 = 0.25%)
    pub fee_bps: u16,
    /// Bridge transactions
    pub transactions: HashMap<String, CrossChainTransaction>,
}

impl CrossChainBridge {
    fn create_bridge_output(&self, bridge_tx: &BridgeTx) -> Result<ScriptBuf, BridgeError> {
        // Placeholder implementation for now
        Err(BridgeError::NotSupported("Method requires additional development".to_string()))
    }
}

/// Cross-Chain Transaction
/// 
/// Represents a transaction between Bitcoin and another blockchain.
#[derive(Debug, Clone)]
pub struct CrossChainTransaction {
    /// Transaction ID on source chain
    pub source_txid: String,
    /// Transaction ID on target chain (if available)
    pub target_txid: Option<String>,
    /// Amount being transferred
    pub amount: u64,
    /// Fee amount
    pub fee: u64,
    /// Sender address on source chain
    pub source_sender: String,
    /// Recipient address on target chain
    pub target_recipient: String,
    /// Transaction status
    pub status: CrossChainStatus,
    /// Timestamp of creation
    pub timestamp: u64,
    /// Number of confirmations on source chain
    pub source_confirmations: u32,
}

/// Bridge transaction
/// 
/// Represents a cross-chain bridge transaction.
#[derive(Debug, Clone)]
pub struct BridgeTx {
    /// Transaction ID
    pub tx_id: String,
    
    /// Sender address
    pub sender: String,
    
    /// Sender public key
    pub sender_pubkey: bitcoin::PublicKey,
    
    /// Recipient address
    pub recipient: String,
    
    /// Amount to transfer
    pub amount: u64,
    
    /// Fee amount
    pub fee: u64,
    
    /// Bridge type
    pub bridge_type: BridgeType,
    
    /// Transaction status
    pub status: CrossChainStatus,
}

/// Bridge type
/// 
/// Represents the type of cross-chain bridge.
#[derive(Debug, Clone, PartialEq)]
pub enum BridgeType {
    /// RSK federation bridge
    RSK,
    
    /// Liquid federated sidechain
    Liquid,
    
    /// Other bridge type
    Other(String),
}

/// Create a new cross-chain bridge
/// 
/// Creates a new bridge between Bitcoin and another blockchain.
pub fn create_bridge(
    name: &str,
    target_chain: &str,
    min_amount: u64,
    max_amount: Option<u64>,
    required_confirmations: u32,
    fee_bps: u16,
) -> CrossChainBridge {
    CrossChainBridge {
        name: name.to_string(),
        source_chain: "Bitcoin".to_string(),
        target_chain: target_chain.to_string(),
        min_amount,
        max_amount,
        required_confirmations,
        fee_bps,
        transactions: HashMap::new(),
    }
}

/// Create a new cross-chain transaction
/// 
/// Creates a new transaction between Bitcoin and another blockchain.
pub fn create_transaction(
    bridge: &mut CrossChainBridge,
    source_sender: &str,
    target_recipient: &str,
    amount: u64,
) -> Result<CrossChainTransaction, &'static str> {
    // Validate inputs
    if source_sender.is_empty() {
        return Err("Source sender address cannot be empty");
    }
    
    if target_recipient.is_empty() {
        return Err("Target recipient address cannot be empty");
    }
    
    if amount < bridge.min_amount {
        return Err("Amount is below minimum bridge amount");
    }
    
    if let Some(max_amount) = bridge.max_amount {
        if amount > max_amount {
            return Err("Amount exceeds maximum bridge amount");
        }
    }
    
    // Calculate fee
    let fee = (amount as u128 * bridge.fee_bps as u128 / 10000) as u64;
    
    // Create the transaction
    let transaction = CrossChainTransaction {
        source_txid: String::new(), // Will be set when the transaction is created
        target_txid: None,
        amount,
        fee,
        source_sender: source_sender.to_string(),
        target_recipient: target_recipient.to_string(),
        status: CrossChainStatus::PendingSource,
        timestamp: std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .unwrap_or_default()
            .as_secs(),
        source_confirmations: 0,
    };
    
    Ok(transaction)
}

/// Execute a cross-chain transaction
/// 
/// Executes a transaction between Bitcoin and another blockchain.
pub fn execute_transaction(
    bridge: &mut CrossChainBridge,
    transaction: &mut CrossChainTransaction,
) -> Result<String, BitcoinError> {
    // Execute the transaction based on the target chain
    match bridge.target_chain.as_str() {
        "RSK" => {
            // Create an RSK bridge transaction
            let bridge_tx = rsk::RSKBridgeTransaction {
                prev_tx_id: transaction.source_txid.clone(),
                prev_vout: 0, // This would be set properly in a real implementation
                sender_pubkey: bitcoin::PublicKey::from_slice(&hex::decode(&transaction.source_sender)?)?,
                amount: transaction.amount,
                change_amount: 0, // This would be calculated in a real implementation
                status: rsk::RSKBridgeStatus::PendingBitcoin,
                btc_inputs: vec![],
                btc_sender: transaction.source_sender.clone(),
                btc_txid: None,
                rsk_recipient: transaction.target_recipient.clone(),
            };

            // Create federation script (in a real implementation, this would be the RSK federation's script)
            let federation_script = bitcoin::ScriptBuf::new_p2wpkh(&bridge_tx.sender_pubkey.pubkey_hash());

            // Create the RSK bridge transaction
            let rsk_tx = rsk::create_rsk_bridge_transaction(&bridge_tx, federation_script)?;
            
            // For this example, we're just setting the transaction ID
            // In a real implementation, this would execute the transaction
            let txid = rsk_tx.compute_txid().to_string();
            
            // Update the transaction
            transaction.source_txid = txid.clone();
            transaction.status = CrossChainStatus::PendingSource;
            
            Ok(txid)
        },
        "Liquid" => {
            // Create a Liquid bridge transaction
            let mut liquid_tx = liquid::create_liquid_bridge_transaction(
                &transaction.source_sender,
                &transaction.target_recipient,
                transaction.amount,
                liquid::LiquidAssetType::LBTC,
            )?;
            
            // For this example, we're just setting the transaction ID
            // In a real implementation, this would execute the transaction
            let txid = format!("{}:{}", bridge.source_chain, transaction.timestamp);
            
            // Update the transaction
            transaction.source_txid = txid.clone();
            transaction.status = CrossChainStatus::PendingSource;
            
            // Add the transaction to the bridge
            bridge.transactions.insert(txid.clone(), transaction.clone());
            
            Ok(txid)
        },
        _ => Err("Unsupported target chain"),
    }
}

/// Update the status of a cross-chain transaction
/// 
/// Updates the status of a transaction between Bitcoin and another blockchain.
pub fn update_transaction_status(
    bridge: &mut CrossChainBridge,
    txid: &str,
    source_confirmations: u32,
) -> Result<CrossChainStatus, &'static str> {
    // Get the transaction
    let transaction = bridge.transactions.get_mut(txid)
        .ok_or("Transaction not found")?;
    
    // Update the confirmations
    transaction.source_confirmations = source_confirmations;
    
    // Update the status based on confirmations and target chain
    match bridge.target_chain.as_str() {
        "RSK" => {
            if source_confirmations == 0 {
                transaction.status = CrossChainStatus::PendingSource;
            } else if source_confirmations < bridge.required_confirmations {
                transaction.status = CrossChainStatus::ConfirmedSource;
            } else if transaction.target_txid.is_none() {
                transaction.status = CrossChainStatus::ProcessingTarget;
                
                // In a real implementation, this would check the RSK chain
                // For this example, we're simulating RSK processing
                
                // Simulate RSK transaction creation
                transaction.target_txid = Some(format!("0x{}", hex::encode(&[0u8; 32])));
                transaction.status = CrossChainStatus::Completed;
            }
        },
        "Liquid" => {
            if source_confirmations == 0 {
                transaction.status = CrossChainStatus::PendingSource;
            } else if source_confirmations < 102 { // Liquid requires 102 confirmations
                transaction.status = CrossChainStatus::ConfirmedSource;
            } else if transaction.target_txid.is_none() {
                transaction.status = CrossChainStatus::ProcessingTarget;
                
                // In a real implementation, this would check the Liquid chain
                // For this example, we're simulating Liquid processing
                
                // Simulate Liquid transaction creation
                transaction.target_txid = Some(format!("0x{}", hex::encode(&[0u8; 32])));
                transaction.status = CrossChainStatus::Completed;
            }
        },
        _ => {
            transaction.status = CrossChainStatus::Failed("Unsupported target chain".to_string());
        }
    }
    
    Ok(transaction.status.clone())
}

/// Common interface for cross-chain SPV proofs
pub trait SPVProof {
    /// Get the transaction hash
    fn tx_hash(&self) -> &[u8; 32];
    
    /// Verify the proof
    fn verify(&self) -> bool;
    
    /// Get the confirmation count
    fn confirmations(&self) -> u32;
}

// Implement SPVProof for LiquidSPV
impl SPVProof for liquid::LiquidSPV {
    fn tx_hash(&self) -> &[u8; 32] {
        &self.tx_hash
    }
    
    fn verify(&self) -> bool {
        // In a real implementation, this would verify the merkle proof
        true
    }
    
    fn confirmations(&self) -> u32 {
        self.confirmations
    }
}

// Implement SPVProof for BitcoinSPV
impl SPVProof for rsk::BitcoinSPV {
    fn tx_hash(&self) -> &[u8; 32] {
        &self.tx_hash
    }
    
    fn verify(&self) -> bool {
        // In a real implementation, this would verify the merkle proof
        true
    }
    
    fn confirmations(&self) -> u32 {
        self.confirmations
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    
    #[test]
    fn test_create_bridge() {
        let bridge = create_bridge(
            "Bitcoin-RSK Bridge",
            "RSK",
            100000, // 0.001 BTC
            Some(1000000000), // 10 BTC
            6,
            25, // 0.25%
        );
        
        assert_eq!(bridge.name, "Bitcoin-RSK Bridge");
        assert_eq!(bridge.source_chain, "Bitcoin");
        assert_eq!(bridge.target_chain, "RSK");
        assert_eq!(bridge.min_amount, 100000);
        assert_eq!(bridge.max_amount, Some(1000000000));
        assert_eq!(bridge.required_confirmations, 6);
        assert_eq!(bridge.fee_bps, 25);
    }
    
    #[test]
    fn test_create_transaction() {
        let mut bridge = create_bridge(
            "Bitcoin-RSK Bridge",
            "RSK",
            100000, // 0.001 BTC
            Some(1000000000), // 10 BTC
            6,
            25, // 0.25%
        );
        
        let transaction = create_transaction(
            &mut bridge,
            "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4",
            "0x71C7656EC7ab88b098defB751B7401B5f6d8976F",
            1000000, // 0.01 BTC
        )?;
        
        assert_eq!(transaction.source_sender, "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4");
        assert_eq!(transaction.target_recipient, "0x71C7656EC7ab88b098defB751B7401B5f6d8976F");
        assert_eq!(transaction.amount, 1000000);
        assert_eq!(transaction.fee, 250); // 0.25% of 1000000
        assert_eq!(transaction.status, CrossChainStatus::PendingSource);
    }
    
    #[test]
    fn test_liquid_bridge() {
        let mut bridge = create_bridge(
            "Bitcoin-Liquid Bridge",
            "Liquid",
            100000, // 0.001 BTC
            Some(1000000000), // 10 BTC
            102, // Liquid requires 102 confirmations
            10, // 0.1%
        );
        
        let transaction = create_transaction(
            &mut bridge,
            "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4",
            "VJL7xGMPkX4BoKYvCBNqYUNLd3UcguxHyA",
            1000000, // 0.01 BTC
        )?;
        
        assert_eq!(transaction.source_sender, "bc1qw508d6qejxtdg4y5r3zarvary0c5xw7kv8f3t4");
        assert_eq!(transaction.target_recipient, "VJL7xGMPkX4BoKYvCBNqYUNLd3UcguxHyA");
        assert_eq!(transaction.amount, 1000000);
        assert_eq!(transaction.fee, 100); // 0.1% of 1000000
        assert_eq!(transaction.status, CrossChainStatus::PendingSource);
    }
}