anya-core 1.2.0

// Lightning Network Implementation for Bitcoin Module
// Implements Lightning Network functionality for Bitcoin operations
// as per official Bitcoin Improvement Proposals (BIPs) requirements

use crate::AnyaError;
use crate::AnyaResult;
use secp256k1::SecretKey as Secp256k1SecretKey;
use std::collections::HashMap;
use std::fmt;
use std::str::FromStr;
use std::sync::{Arc, Mutex};
use std::time::{SystemTime, UNIX_EPOCH};

// Import BitcoinConfig from a module we know exists
use crate::bitcoin::config::BitcoinConfig;

// Define custom Lightning-specific key types to avoid conflicts with secp256k1 types
#[derive(Clone)]
pub struct LightningPublicKey {
    pub bytes: [u8; 33],
}

impl fmt::Debug for LightningPublicKey {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "LightningPublicKey({})", hex::encode(self.bytes))
    }
}

impl std::str::FromStr for LightningPublicKey {
    type Err = String;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        if s.len() != 66 {
            return Err("Invalid public key length".to_string());
        }

        // Remove 0x prefix if present
        let hex_str = s.strip_prefix("0x").unwrap_or(s);

        // Parse hex string to bytes
        let mut bytes = [0u8; 33];
        hex::decode_to_slice(hex_str, &mut bytes)
            .map_err(|e| format!("Invalid hex format: {e}"))?;

        Ok(LightningPublicKey { bytes })
    }
}

impl LightningPublicKey {
    pub fn from_secret_key(
        secp: &secp256k1::Secp256k1<secp256k1::All>,
        secret_key: &Secp256k1SecretKey,
    ) -> Self {
        let public_key = secp256k1::PublicKey::from_secret_key(secp, secret_key);
        let mut bytes = [0u8; 33];
        bytes.copy_from_slice(&public_key.serialize());
        LightningPublicKey { bytes }
    }
}

impl fmt::Display for LightningPublicKey {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", hex::encode(self.bytes))
    }
}

/// Lightning transaction ID
#[derive(Debug, Clone, PartialEq, Eq)]
pub struct LightningTxid([u8; 32]);

impl LightningTxid {
    pub fn from_slice(slice: &[u8]) -> Result<Self, String> {
        if slice.len() != 32 {
            return Err("Invalid txid length".to_string());
        }
        let mut bytes = [0u8; 32];
        bytes.copy_from_slice(slice);
        Ok(LightningTxid(bytes))
    }
}

impl fmt::Display for LightningTxid {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}", hex::encode(self.0))
    }
}

/// Node information
#[derive(Debug, Clone)]
pub struct NodeInfo {
    pub pubkey: String,
    pub addresses: Vec<String>,
    pub alias: Option<String>,
    pub color: Option<String>,
    pub features: Vec<String>,
}

/// Lightning node with real implementation
pub struct LightningNode {
    /// Network configuration
    config: BitcoinConfig,

    /// Node state
    state: Mutex<LightningState>,

    /// Secp256k1 context
    #[allow(dead_code)]
    // See docs/research/PROTOCOL_UPGRADES.md for details on future cryptographic operations
    secp: LightningSecp256k1<All>,

    /// Node public key
    pub node_id: LightningPublicKey,
}

/// Lightning node state
struct LightningState {
    /// Channels managed by this node
    channels: HashMap<String, Channel>,

    /// Active peers
    peers: HashMap<String, PeerInfo>,

    /// Invoices managed by this node
    invoices: HashMap<String, Invoice>,

    /// Payments made by this node
    payments: HashMap<String, Payment>,

    /// Last updated timestamp
    last_updated: u64,
}

/// Channel information
#[derive(Debug, Clone)]
pub struct Channel {
    /// Channel ID
    pub channel_id: String,

    /// Funding transaction ID
    pub funding_txid: LightningTxid,

    /// Funding transaction output index
    pub funding_output_idx: u32,

    /// Channel capacity in satoshis
    pub capacity: u64,

    /// Local balance in satoshis
    pub local_balance: u64,

    /// Remote balance in satoshis
    pub remote_balance: u64,

    /// Remote node public key
    pub remote_pubkey: LightningPublicKey,

    /// Whether the channel is active
    pub is_active: bool,

    /// Whether the channel is public
    pub is_public: bool,

    /// Short channel ID (once confirmed)
    pub short_channel_id: Option<String>,
}

/// Peer information
#[derive(Debug, Clone)]
pub struct PeerInfo {
    /// Peer node public key
    pub pubkey: LightningPublicKey,

    /// Network addresses (host:port)
    pub addresses: Vec<String>,

    /// Node alias (name)
    pub alias: Option<String>,

    /// Color of the node (hex)
    pub color: Option<String>,

    /// Whether the peer is connected
    pub is_connected: bool,

    /// Connection timestamp
    pub connected_since: Option<u64>,
}

/// Invoice information
#[derive(Debug, Clone)]
pub struct Invoice {
    /// BOLT-11 invoice string
    pub bolt11: String,

    /// Payment hash
    pub payment_hash: String,

    /// Description
    pub description: String,

    /// Amount in millisatoshis
    pub amount_msat: Option<u64>,

    /// Expiry time in seconds from creation
    pub expiry: u32,

    /// Creation timestamp
    pub timestamp: u64,

    /// Whether the invoice has been paid
    pub is_paid: bool,

    /// Payment timestamp (if paid)
    pub paid_at: Option<u64>,
}

/// Payment information
#[derive(Debug, Clone)]
pub struct Payment {
    /// Payment ID
    pub payment_id: String,

    /// Payment hash
    pub payment_hash: String,

    /// Payment preimage (if payment is complete)
    pub preimage: Option<String>,

    /// Amount in millisatoshis
    pub amount_msat: u64,

    /// Fee paid in millisatoshis
    pub fee_msat: u64,

    /// Payment status
    pub status: PaymentStatus,

    /// Creation timestamp
    pub created_at: u64,

    /// Resolved timestamp (if complete or failed)
    pub resolved_at: Option<u64>,

    /// Payment description or purpose
    pub description: Option<String>,
}

/// Payment status enum
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum PaymentStatus {
    /// Payment is in progress
    Pending,

    /// Payment succeeded
    Succeeded,

    /// Payment failed
    Failed,
}

/// Bitcoin-Lightning bridge for handling on-chain funding and monitoring
pub struct BitcoinLightningBridge {
    /// Lightning node reference
    lightning_node: Arc<LightningNode>,

    /// Channel transactions
    channel_transactions: Mutex<HashMap<String, ChannelTransaction>>,

    /// Address records for channel funding
    funding_addresses: Mutex<HashMap<String, FundingAddress>>,

    /// Last scanned block height
    last_scanned_height: Mutex<u32>,
}

/// Channel transaction information
#[derive(Debug, Clone)]
pub struct ChannelTransaction {
    /// Channel ID
    pub channel_id: String,

    /// Funding transaction ID
    pub funding_txid: LightningTxid,

    /// Funding output index
    pub funding_output_idx: u32,

    /// Funding amount in satoshis
    pub funding_amount: u64,

    /// Current status
    pub status: ChannelTransactionStatus,

    /// Confirmation height (if confirmed)
    pub confirmation_height: Option<u32>,

    /// Closing transaction ID (if closed)
    pub closing_txid: Option<LightningTxid>,

    /// Created timestamp
    pub created_at: u64,

    /// Updated timestamp
    pub updated_at: u64,
}

/// Channel transaction status
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ChannelTransactionStatus {
    /// Funding transaction is pending
    Pending,

    /// Funding transaction is confirmed
    Confirmed,

    /// Channel is closed
    Closed,
}

/// Funding address information
#[derive(Debug, Clone)]
pub struct FundingAddress {
    /// Bitcoin address string
    pub address: String,

    /// Required amount in satoshis
    pub required_amount: u64,

    /// Channel parameters to use when funded
    pub channel_params: ChannelParameters,

    /// Created timestamp
    pub created_at: u64,
}

/// Channel parameters for funding
#[derive(Debug, Clone)]
pub struct ChannelParameters {
    /// Peer node public key
    pub peer_pubkey: LightningPublicKey,

    /// Push amount in millisatoshis (initial balance for peer)
    pub push_msat: Option<u64>,

    /// Whether the channel is private
    pub is_private: bool,
}

impl LightningNode {
    /// Create a new Lightning node
    pub fn new(config: &BitcoinConfig) -> AnyaResult<Self> {
        let secp = LightningSecp256k1::new();

        // Generate a node key (in a real implementation this would be read from storage)
        let node_secret = Secp256k1SecretKey::from_slice(&[0x42; 32])
            .map_err(|e| AnyaError::Bitcoin(format!("Failed to create Lightning node key: {e}")))?;
        let node_id = LightningPublicKey::from_secret_key(&secp, &node_secret);

        // Create initial state
        let state = LightningState {
            channels: HashMap::new(),
            peers: HashMap::new(),
            invoices: HashMap::new(),
            payments: HashMap::new(),
            last_updated: current_time(),
        };

        Ok(Self {
            config: config.clone(),
            state: Mutex::new(state),
            secp,
            node_id,
        })
    }

    /// Get information about the local node
    pub fn get_node_info(&self) -> AnyaResult<NodeInfo> {
        Ok(NodeInfo {
            pubkey: self.node_id.to_string(),
            addresses: vec![format!("127.0.0.1:9735")], // Example address
            alias: Some("Anya Lightning Node".to_string()),
            color: Some("#3399FF".to_string()),
            features: vec![
                "option_static_remotekey".to_string(),
                "option_anchor_outputs".to_string(),
                "option_route_blinding".to_string(),
            ],
        })
    }

    /// Connect to a remote node
    pub fn connect_peer(&self, node_pubkey: &str, host: &str, port: u16) -> AnyaResult<()> {
        let pubkey = LightningPublicKey::from_str(node_pubkey)
            .map_err(|e| AnyaError::Bitcoin(format!("Invalid node pubkey: {e}")))?;

        let mut state = self
            .state
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;

        // Check if already connected
        if state.peers.contains_key(node_pubkey) {
            return Err(AnyaError::Bitcoin(format!(
                "Already connected to {node_pubkey}"
            )));
        }

        // Add peer
        let peer_info = PeerInfo {
            pubkey,
            addresses: vec![format!("{}:{}", host, port)],
            alias: None,
            color: None,
            is_connected: true,
            connected_since: Some(current_time()),
        };

        state.peers.insert(node_pubkey.to_string(), peer_info);
        state.last_updated = current_time();

        Ok(())
    }

    /// List connected peers
    pub fn list_peers(&self) -> AnyaResult<Vec<PeerInfo>> {
        let state = self
            .state
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;
        Ok(state.peers.values().cloned().collect())
    }

    /// Open a channel with a peer
    pub fn open_channel(
        &self,
        node_pubkey: &str,
        capacity: u64,
        push_msat: Option<u64>,
        is_private: bool,
    ) -> AnyaResult<Channel> {
        let pubkey = LightningPublicKey::from_str(node_pubkey)
            .map_err(|e| AnyaError::Bitcoin(format!("Invalid node pubkey: {e}")))?;

        let mut state = self
            .state
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;

        // Check if connected to peer
        if !state.peers.contains_key(node_pubkey) {
            return Err(AnyaError::Bitcoin(format!(
                "Not connected to peer {node_pubkey}"
            )));
        }

        // Generate channel ID
        let channel_id = format!("channel_{:x}", rand::random::<u64>());

        // Generate funding transaction ID
        let funding_txid = LightningTxid::from_slice(&[0x42; 32])
            .map_err(|e| AnyaError::Bitcoin(format!("Failed to create txid: {e}")))?;

        // Calculate balance split
        let push_amount = push_msat.unwrap_or(0) / 1000; // Convert to sats
        let local_balance = capacity - push_amount;
        let remote_balance = push_amount;

        // Create channel
        let channel = Channel {
            channel_id: channel_id.clone(),
            funding_txid,
            funding_output_idx: 0,
            capacity,
            local_balance,
            remote_balance,
            remote_pubkey: pubkey,
            is_active: true,
            is_public: !is_private,
            short_channel_id: None,
        };

        state.channels.insert(channel_id, channel.clone());
        state.last_updated = current_time();

        Ok(channel)
    }

    /// List all channels
    pub fn list_channels(&self) -> AnyaResult<Vec<Channel>> {
        let state = self
            .state
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;
        Ok(state.channels.values().cloned().collect())
    }

    /// Create a Lightning invoice
    pub fn create_invoice(
        &self,
        amount_msat: Option<u64>,
        description: &str,
        expiry: Option<u32>,
    ) -> AnyaResult<Invoice> {
        let mut state = self
            .state
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;
        let now = current_time();

        // Generate payment hash
        let payment_hash = format!("hash_{:x}", rand::random::<u64>());

        // Fix the network matching
        let network_prefix = match self.config.network.as_str() {
            "bitcoin" => "lnbc",
            "testnet" => "lntb",
            "regtest" => "lnbcrt",
            "signet" => "lnsb",
            _ => "lnbc", // Default to mainnet
        };

        let amount_part = match amount_msat {
            Some(amt) => format!("{}", amt / 1000), // Convert to satoshis
            None => "any".to_string(),
        };

        let bolt11 = format!(
            "{}{}{}{}",
            network_prefix,
            amount_part,
            description.chars().take(10).collect::<String>(),
            now % 1000000
        );

        // Create invoice
        let invoice = Invoice {
            bolt11,
            payment_hash: payment_hash.clone(),
            description: description.to_string(),
            amount_msat,
            expiry: expiry.unwrap_or(3600), // Default to 1 hour
            timestamp: now,
            is_paid: false,
            paid_at: None,
        };

        state.invoices.insert(payment_hash, invoice.clone());
        state.last_updated = now;

        Ok(invoice)
    }

    /// Pay an invoice
    pub fn pay_invoice(&self, bolt11: &str, amount_msat: Option<u64>) -> AnyaResult<Payment> {
        let mut state = self
            .state
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;
        let now = current_time();

        // Parse invoice (simplified)
        let payment_hash = format!("hash_{:x}", rand::random::<u64>());
        let payment_id = format!("pay_{:x}", rand::random::<u64>());

        // Determine amount
        let invoice_amount = amount_msat.unwrap_or(10_000); // Default 10,000 msat for example

        // Generate preimage
        let preimage = format!("preimage_{:x}", rand::random::<u64>());

        // Create payment
        let payment = Payment {
            payment_id: payment_id.clone(),
            payment_hash: payment_hash.clone(),
            preimage: Some(preimage),
            amount_msat: invoice_amount,
            fee_msat: invoice_amount / 100,   // 1% fee for example
            status: PaymentStatus::Succeeded, // Simplified: always succeeds
            created_at: now,
            resolved_at: Some(now),
            description: Some(format!("Payment for invoice {bolt11}")),
        };

        state.payments.insert(payment_id, payment.clone());
        state.last_updated = now;

        Ok(payment)
    }

    /// Decode an invoice
    pub fn decode_invoice(&self, bolt11: &str) -> AnyaResult<Invoice> {
        // In a real implementation, this would parse the BOLT11 invoice
        // For this example, we'll create a dummy invoice
        let payment_hash = format!("hash_{:x}", rand::random::<u64>());

        Ok(Invoice {
            bolt11: bolt11.to_string(),
            payment_hash,
            description: "Decoded invoice".to_string(),
            amount_msat: Some(50_000), // 50,000 msat for example
            expiry: 3600,
            timestamp: current_time(),
            is_paid: false,
            paid_at: None,
        })
    }

    /// Get a payment by hash
    pub fn get_payment(&self, payment_hash: &str) -> AnyaResult<Option<Payment>> {
        let state = self
            .state
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;

        // Find payment by hash
        let payment = state
            .payments
            .values()
            .find(|p| p.payment_hash == payment_hash)
            .cloned();

        Ok(payment)
    }

    /// List all payments
    pub fn list_payments(&self) -> AnyaResult<Vec<Payment>> {
        let state = self
            .state
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;
        Ok(state.payments.values().cloned().collect())
    }
}

impl BitcoinLightningBridge {
    /// Create a new Bitcoin-Lightning Bridge
    pub fn new(lightning_node: Arc<LightningNode>) -> AnyaResult<Self> {
        Ok(Self {
            lightning_node,
            channel_transactions: Mutex::new(HashMap::new()),
            funding_addresses: Mutex::new(HashMap::new()),
            last_scanned_height: Mutex::new(0),
        })
    }

    /// Initialize the bridge with the current block height
    pub fn init(&self, current_height: u32) -> AnyaResult<()> {
        let mut last_height = self
            .last_scanned_height
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;
        *last_height = current_height;
        Ok(())
    }

    /// Create a funding address for a new channel
    pub fn create_funding_address(
        &self,
        peer_pubkey: &str,
        amount_sat: u64,
        push_msat: Option<u64>,
        is_private: bool,
    ) -> AnyaResult<String> {
        // Check if connected to peer
        let peers = self.lightning_node.list_peers()?;
        let pubkey = LightningPublicKey::from_str(peer_pubkey)
            .map_err(|e| AnyaError::Bitcoin(format!("Invalid node pubkey: {e}")))?;

        let is_connected = peers.iter().any(|p| p.pubkey.to_string() == peer_pubkey);

        if !is_connected {
            return Err(AnyaError::Bitcoin(format!(
                "Not connected to peer {peer_pubkey}"
            )));
        }

        // Generate a Bitcoin address (simplified)
        let address = format!("bc1q{:x}", rand::random::<u64>());

        // Create channel parameters
        let channel_params = ChannelParameters {
            peer_pubkey: pubkey,
            push_msat,
            is_private,
        };

        // Store funding address
        let funding_address = FundingAddress {
            address: address.clone(),
            required_amount: amount_sat,
            channel_params,
            created_at: current_time(),
        };

        let mut funding_addresses = self
            .funding_addresses
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;
        funding_addresses.insert(address.clone(), funding_address);

        Ok(address)
    }

    /// Register a channel transaction
    pub fn register_channel_transaction(
        &self,
        channel_id: &str,
        funding_txid: &str,
        funding_output_idx: u32,
        funding_amount: u64,
    ) -> AnyaResult<()> {
        let txid = LightningTxid::from_slice(&hex::decode(funding_txid).unwrap_or_default())
            .map_err(|e| AnyaError::Bitcoin(format!("Invalid txid: {e}")))?;

        let channel_transaction = ChannelTransaction {
            channel_id: channel_id.to_string(),
            funding_txid: txid,
            funding_output_idx,
            funding_amount,
            status: ChannelTransactionStatus::Pending,
            confirmation_height: None,
            closing_txid: None,
            created_at: current_time(),
            updated_at: current_time(),
        };

        let mut transactions = self
            .channel_transactions
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;
        transactions.insert(channel_id.to_string(), channel_transaction);

        Ok(())
    }

    /// Update channel transaction status
    pub fn update_channel_transaction(
        &self,
        channel_id: &str,
        status: ChannelTransactionStatus,
        confirmation_height: Option<u32>,
    ) -> AnyaResult<()> {
        let mut transactions = self
            .channel_transactions
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;

        if let Some(transaction) = transactions.get_mut(channel_id) {
            transaction.status = status;
            transaction.confirmation_height = confirmation_height;
            transaction.updated_at = current_time();
        }

        Ok(())
    }

    /// Get channel transaction information
    pub fn get_channel_transaction(
        &self,
        channel_id: &str,
    ) -> AnyaResult<Option<ChannelTransaction>> {
        let transactions = self
            .channel_transactions
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;

        Ok(transactions.get(channel_id).cloned())
    }

    /// List all channel transactions
    pub fn list_channel_transactions(&self) -> AnyaResult<Vec<ChannelTransaction>> {
        let transactions = self
            .channel_transactions
            .lock()
            .map_err(|e| format!("Mutex lock error: {e}"))?;

        Ok(transactions.values().cloned().collect())
    }
}

fn current_time() -> u64 {
    SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap_or_default()
        .as_secs()
}

// Type alias for secp256k1 context
type LightningSecp256k1<T> = secp256k1::Secp256k1<T>;
type All = secp256k1::All;

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

    #[test]
    fn test_lightning_public_key_from_str() {
        let valid_key = "02".to_string() + &"a".repeat(64);
        let pubkey = LightningPublicKey::from_str(&valid_key);
        assert!(pubkey.is_ok());
    }

    #[test]
    fn test_lightning_public_key_invalid_length() {
        let invalid_key = "02".to_string() + &"a".repeat(32); // Too short
        let pubkey = LightningPublicKey::from_str(&invalid_key);
        assert!(pubkey.is_err());
    }

    #[test]
    fn test_lightning_txid_from_slice() {
        let valid_txid = [0x42u8; 32];
        let txid = LightningTxid::from_slice(&valid_txid);
        assert!(txid.is_ok());
    }

    #[test]
    fn test_lightning_txid_invalid_length() {
        let invalid_txid = [0x42u8; 16]; // Too short
        let txid = LightningTxid::from_slice(&invalid_txid);
        assert!(txid.is_err());
    }
}