//! Stacks (STX) Integration
//!
//! Stacks is a Bitcoin layer that enables smart contracts and dApps.
//! This module provides integration with the Stacks blockchain for:
//! - Smart contract deployment
//! - Token bridging (BTC <-> STX)
//! - Transaction monitoring

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

/// Stacks network type
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum StacksNetwork {
    /// Mainnet
    Mainnet,
    /// Testnet
    Testnet,
}

impl StacksNetwork {
    /// Get the API URL for this network
    pub fn api_url(&self) -> &str {
        match self {
            StacksNetwork::Mainnet => "https://api.mainnet.hiro.so",
            StacksNetwork::Testnet => "https://api.testnet.hiro.so",
        }
    }
}

/// Stacks address (STX address)
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct StacksAddress {
    /// Address string (e.g., SP2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKNRV9EJ7)
    pub address: String,
    /// Network this address belongs to
    pub network: StacksNetwork,
}

impl StacksAddress {
    /// Create a new Stacks address
    pub fn new(address: String, network: StacksNetwork) -> Result<Self, BitcoinError> {
        // Basic validation
        if address.is_empty() {
            return Err(BitcoinError::InvalidAddress("Address is empty".to_string()));
        }

        // Mainnet addresses start with SP, testnet with ST
        let expected_prefix = match network {
            StacksNetwork::Mainnet => "SP",
            StacksNetwork::Testnet => "ST",
        };

        if !address.starts_with(expected_prefix) {
            return Err(BitcoinError::InvalidAddress(format!(
                "Address {} does not match network {:?}",
                address, network
            )));
        }

        Ok(Self { address, network })
    }
}

/// Smart contract identifier
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
pub struct ContractId {
    /// Contract deployer address
    pub deployer: StacksAddress,
    /// Contract name
    pub name: String,
}

impl ContractId {
    /// Create a new contract ID
    pub fn new(deployer: StacksAddress, name: String) -> Self {
        Self { deployer, name }
    }

    /// Get the full contract identifier (address.contract-name)
    pub fn full_id(&self) -> String {
        format!("{}.{}", self.deployer.address, self.name)
    }
}

/// Clarity smart contract source code
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ClarityContract {
    /// Contract name
    pub name: String,
    /// Clarity source code
    pub source: String,
}

/// Contract deployment request
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DeploymentRequest {
    /// Request ID
    pub id: Uuid,
    /// Contract to deploy
    pub contract: ClarityContract,
    /// Deployer address
    pub deployer: StacksAddress,
    /// Gas fee (in microSTX)
    pub fee: u64,
}

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

/// Contract deployment result
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DeploymentResult {
    /// Request ID
    pub request_id: Uuid,
    /// Contract ID (if successful)
    pub contract_id: Option<ContractId>,
    /// Transaction ID on Stacks
    pub tx_id: Option<String>,
    /// Status
    pub status: DeploymentStatus,
    /// Error message (if failed)
    pub error: Option<String>,
}

/// Token bridge configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BridgeConfig {
    /// Minimum bridge amount (in satoshis)
    pub min_amount: u64,
    /// Maximum bridge amount (in satoshis)
    pub max_amount: u64,
    /// Bridge fee percentage (basis points, e.g., 100 = 1%)
    pub fee_bps: u16,
    /// Confirmation requirements for BTC deposits
    pub btc_confirmations: u32,
    /// Confirmation requirements for STX withdrawals
    pub stx_confirmations: u32,
}

impl Default for BridgeConfig {
    fn default() -> Self {
        Self {
            min_amount: 10_000,      // 0.0001 BTC
            max_amount: 100_000_000, // 1 BTC
            fee_bps: 50,             // 0.5%
            btc_confirmations: 6,
            stx_confirmations: 12,
        }
    }
}

/// Bridge operation type
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum BridgeOperation {
    /// Deposit BTC to get wrapped BTC on Stacks
    Deposit,
    /// Withdraw wrapped BTC from Stacks to get BTC
    Withdraw,
}

/// Bridge transaction
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BridgeTransaction {
    /// Transaction ID
    pub id: Uuid,
    /// Operation type
    pub operation: BridgeOperation,
    /// Amount in satoshis
    pub amount: u64,
    /// Source address
    pub source_address: String,
    /// Destination address
    pub destination_address: String,
    /// BTC transaction ID (for deposits)
    pub btc_tx_id: Option<String>,
    /// STX transaction ID (for withdrawals)
    pub stx_tx_id: Option<String>,
    /// Current status
    pub status: BridgeStatus,
    /// Confirmations received
    pub confirmations: u32,
}

/// Bridge transaction status
#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
pub enum BridgeStatus {
    /// Waiting for initial transaction
    Pending,
    /// Transaction confirmed, processing bridge
    Processing,
    /// Bridge completed successfully
    Completed,
    /// Failed or rejected
    Failed,
    /// Refunded to sender
    Refunded,
}

/// Stacks client for interacting with the Stacks blockchain
pub struct StacksClient {
    /// Network configuration
    network: StacksNetwork,
    /// API base URL
    #[allow(dead_code)]
    api_url: String,
    /// HTTP client
    #[allow(dead_code)]
    http_client: reqwest::Client,
}

impl StacksClient {
    /// Create a new Stacks client
    pub fn new(network: StacksNetwork) -> Self {
        Self {
            network,
            api_url: network.api_url().to_string(),
            http_client: reqwest::Client::new(),
        }
    }

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

    /// Validate a Stacks address
    pub fn validate_address(&self, address: &str) -> Result<StacksAddress, BitcoinError> {
        StacksAddress::new(address.to_string(), self.network)
    }

    /// Get account balance
    pub async fn get_balance(&self, address: &StacksAddress) -> Result<u64, BitcoinError> {
        // In a real implementation, this would call the Stacks API
        // GET /extended/v1/address/{address}/balances
        let _ = address;
        Ok(0)
    }

    /// Get account nonce (for transaction sequencing)
    pub async fn get_nonce(&self, address: &StacksAddress) -> Result<u64, BitcoinError> {
        // In a real implementation, this would call the Stacks API
        // GET /extended/v1/address/{address}/nonces
        let _ = address;
        Ok(0)
    }

    /// Get transaction status
    pub async fn get_transaction(&self, tx_id: &str) -> Result<StacksTransaction, BitcoinError> {
        // In a real implementation, this would call the Stacks API
        // GET /extended/v1/tx/{tx_id}
        let _ = tx_id;
        Err(BitcoinError::TransactionNotFound(
            "Not implemented".to_string(),
        ))
    }

    /// Broadcast a transaction
    pub async fn broadcast_transaction(&self, tx_hex: &str) -> Result<String, BitcoinError> {
        // In a real implementation, this would call the Stacks API
        // POST /v2/transactions
        let _ = tx_hex;
        Err(BitcoinError::BroadcastFailed("Not implemented".to_string()))
    }
}

/// Stacks transaction information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct StacksTransaction {
    /// Transaction ID
    pub tx_id: String,
    /// Transaction status
    pub status: String,
    /// Block height (if confirmed)
    pub block_height: Option<u64>,
    /// Fee paid (in microSTX)
    pub fee: u64,
    /// Sender address
    pub sender: String,
}

/// Smart contract deployment manager
pub struct ContractDeploymentManager {
    /// Stacks client
    client: StacksClient,
    /// Pending deployments
    deployments: HashMap<Uuid, DeploymentResult>,
}

impl ContractDeploymentManager {
    /// Create a new deployment manager
    pub fn new(client: StacksClient) -> Self {
        Self {
            client,
            deployments: HashMap::new(),
        }
    }

    /// Deploy a smart contract
    pub async fn deploy_contract(
        &mut self,
        request: DeploymentRequest,
    ) -> Result<DeploymentResult, BitcoinError> {
        // Validate the contract
        self.validate_contract(&request.contract)?;

        // In a real implementation:
        // 1. Compile Clarity code
        // 2. Create deployment transaction
        // 3. Sign with deployer's key
        // 4. Broadcast to Stacks network

        let result = DeploymentResult {
            request_id: request.id,
            contract_id: Some(ContractId::new(
                request.deployer.clone(),
                request.contract.name.clone(),
            )),
            tx_id: None,
            status: DeploymentStatus::Pending,
            error: None,
        };

        self.deployments.insert(request.id, result.clone());
        Ok(result)
    }

    /// Validate a Clarity contract
    fn validate_contract(&self, contract: &ClarityContract) -> Result<(), BitcoinError> {
        // Basic validation
        if contract.name.is_empty() {
            return Err(BitcoinError::Validation(
                "Contract name is empty".to_string(),
            ));
        }

        if contract.source.is_empty() {
            return Err(BitcoinError::Validation(
                "Contract source is empty".to_string(),
            ));
        }

        // In a real implementation, this would:
        // 1. Parse the Clarity code
        // 2. Check for syntax errors
        // 3. Validate against Clarity grammar

        Ok(())
    }

    /// Get deployment status
    pub fn get_deployment(&self, id: &Uuid) -> Option<&DeploymentResult> {
        self.deployments.get(id)
    }

    /// Get the Stacks client
    pub fn client(&self) -> &StacksClient {
        &self.client
    }
}

/// Token bridge manager
pub struct TokenBridge {
    /// Bridge configuration
    config: BridgeConfig,
    /// Stacks client
    stacks_client: StacksClient,
    /// Active bridge transactions
    transactions: HashMap<Uuid, BridgeTransaction>,
}

impl TokenBridge {
    /// Create a new token bridge
    pub fn new(config: BridgeConfig, stacks_client: StacksClient) -> Self {
        Self {
            config,
            stacks_client,
            transactions: HashMap::new(),
        }
    }

    /// Initiate a BTC deposit (BTC -> Stacks)
    pub fn initiate_deposit(
        &mut self,
        btc_address: String,
        stacks_address: String,
        amount: u64,
    ) -> Result<BridgeTransaction, 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 = BridgeTransaction {
            id: Uuid::new_v4(),
            operation: BridgeOperation::Deposit,
            amount,
            source_address: btc_address,
            destination_address: stacks_address,
            btc_tx_id: None,
            stx_tx_id: None,
            status: BridgeStatus::Pending,
            confirmations: 0,
        };

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

    /// Initiate a STX withdrawal (Stacks -> BTC)
    pub fn initiate_withdrawal(
        &mut self,
        stacks_address: String,
        btc_address: String,
        amount: u64,
    ) -> Result<BridgeTransaction, 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 = BridgeTransaction {
            id: Uuid::new_v4(),
            operation: BridgeOperation::Withdraw,
            amount,
            source_address: stacks_address,
            destination_address: btc_address,
            btc_tx_id: None,
            stx_tx_id: None,
            status: BridgeStatus::Pending,
            confirmations: 0,
        };

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

    /// Update bridge transaction status
    pub fn update_transaction(
        &mut self,
        id: Uuid,
        confirmations: u32,
        tx_id: Option<String>,
    ) -> Result<(), BitcoinError> {
        let tx = self
            .transactions
            .get_mut(&id)
            .ok_or_else(|| BitcoinError::TransactionNotFound(id.to_string()))?;

        tx.confirmations = confirmations;

        // Update transaction ID
        match tx.operation {
            BridgeOperation::Deposit => {
                if let Some(txid) = tx_id {
                    tx.btc_tx_id = Some(txid);
                }
                if confirmations >= self.config.btc_confirmations {
                    tx.status = BridgeStatus::Completed;
                } else {
                    tx.status = BridgeStatus::Processing;
                }
            }
            BridgeOperation::Withdraw => {
                if let Some(txid) = tx_id {
                    tx.stx_tx_id = Some(txid);
                }
                if confirmations >= self.config.stx_confirmations {
                    tx.status = BridgeStatus::Completed;
                } else {
                    tx.status = BridgeStatus::Processing;
                }
            }
        }

        Ok(())
    }

    /// Get bridge transaction
    pub fn get_transaction(&self, id: &Uuid) -> Option<&BridgeTransaction> {
        self.transactions.get(id)
    }

    /// Calculate bridge fee
    pub fn calculate_fee(&self, amount: u64) -> u64 {
        (amount * self.config.fee_bps as u64) / 10_000
    }

    /// Get the Stacks client
    pub fn stacks_client(&self) -> &StacksClient {
        &self.stacks_client
    }
}

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

    #[test]
    fn test_stacks_address_validation() {
        let addr = StacksAddress::new(
            "SP2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKNRV9EJ7".to_string(),
            StacksNetwork::Mainnet,
        );
        assert!(addr.is_ok());

        let testnet_addr = StacksAddress::new(
            "ST2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKPVKG2CE".to_string(),
            StacksNetwork::Testnet,
        );
        assert!(testnet_addr.is_ok());
    }

    #[test]
    fn test_stacks_address_network_mismatch() {
        let addr = StacksAddress::new(
            "SP2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKNRV9EJ7".to_string(),
            StacksNetwork::Testnet,
        );
        assert!(addr.is_err());
    }

    #[test]
    fn test_contract_id() {
        let deployer = StacksAddress::new(
            "SP2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKNRV9EJ7".to_string(),
            StacksNetwork::Mainnet,
        )
        .unwrap();

        let contract_id = ContractId::new(deployer, "my-token".to_string());
        assert_eq!(
            contract_id.full_id(),
            "SP2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKNRV9EJ7.my-token"
        );
    }

    #[test]
    fn test_bridge_config_defaults() {
        let config = BridgeConfig::default();
        assert_eq!(config.min_amount, 10_000);
        assert_eq!(config.max_amount, 100_000_000);
        assert_eq!(config.fee_bps, 50);
    }

    #[test]
    fn test_token_bridge_deposit() {
        let config = BridgeConfig::default();
        let client = StacksClient::new(StacksNetwork::Testnet);
        let mut bridge = TokenBridge::new(config, client);

        let result = bridge.initiate_deposit(
            "bc1qtest".to_string(),
            "ST2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKPVKG2CE".to_string(),
            50_000,
        );

        assert!(result.is_ok());
        let tx = result.unwrap();
        assert_eq!(tx.operation, BridgeOperation::Deposit);
        assert_eq!(tx.amount, 50_000);
    }

    #[test]
    fn test_token_bridge_amount_validation() {
        let config = BridgeConfig::default();
        let client = StacksClient::new(StacksNetwork::Testnet);
        let mut bridge = TokenBridge::new(config, client);

        // Too small
        let result = bridge.initiate_deposit(
            "bc1qtest".to_string(),
            "ST2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKPVKG2CE".to_string(),
            100,
        );
        assert!(result.is_err());

        // Too large
        let result = bridge.initiate_deposit(
            "bc1qtest".to_string(),
            "ST2J6ZY48GV1EZ5V2V5RB9MP66SW86PYKKPVKG2CE".to_string(),
            200_000_000,
        );
        assert!(result.is_err());
    }

    #[test]
    fn test_bridge_fee_calculation() {
        let config = BridgeConfig::default();
        let client = StacksClient::new(StacksNetwork::Testnet);
        let bridge = TokenBridge::new(config, client);

        let fee = bridge.calculate_fee(100_000);
        assert_eq!(fee, 500); // 0.5% of 100,000
    }

    #[test]
    fn test_contract_deployment_manager() {
        let client = StacksClient::new(StacksNetwork::Testnet);
        let manager = ContractDeploymentManager::new(client);

        assert_eq!(manager.client().network(), StacksNetwork::Testnet);
    }
}
