anya-core 1.2.0

use std::collections::HashMap;
// [AIR-3][AIS-3][BPC-3][RES-3] Import necessary dependencies for HSM simulator
// This follows official Bitcoin Improvement Proposals (BIPs) standards for secure HSM implementation
use async_trait::async_trait;
use base64::Engine;
use bitcoin::secp256k1::{PublicKey, Secp256k1, SecretKey};
use bitcoin::{psbt::Psbt, Address, CompressedPublicKey, Network};
use chrono::Utc;
use rand::prelude::*;
use rand::rngs::OsRng;
use sha2::{Digest, Sha256};
use std::str::FromStr;
use std::time::Duration;
use tokio::sync::Mutex;
use tokio::time::sleep;
use uuid::Uuid;

use crate::security::hsm::config::SimulatorConfig;
use crate::security::hsm::error::HsmError;
use crate::security::hsm::provider::{
    HsmOperation, HsmProvider, HsmProviderStatus, HsmRequest, HsmResponse, KeyGenParams, KeyInfo,
    KeyPair, KeyType, KeyUsage, SigningAlgorithm,
};

/// Simulator HSM provider for testing and development
/// Simulates real hardware behavior with controlled conditions for Bitcoin testnet
#[derive(Debug)]
pub struct SimulatorHsmProvider {
    config: SimulatorConfig,
    keys: Mutex<HashMap<String, KeyInfo>>,
    key_data: Mutex<HashMap<String, Vec<u8>>>,
    rng: Mutex<OsRng>,
    network: Network,
    secp: Secp256k1<bitcoin::secp256k1::All>,
    // Simulated hardware state
    state: Mutex<HardwareState>,
}

/// Simulated hardware state
#[derive(Debug, Clone)]
struct HardwareState {
    battery_level: u8,
    firmware_version: String,
    is_locked: bool,
    pin_attempts: u8,
    max_pin_attempts: u8,
    session_timeout: Duration,
    last_operation: Option<chrono::DateTime<chrono::Utc>>,
}

impl SimulatorHsmProvider {
    /// Create a new simulator HSM provider
    pub fn new(config: &SimulatorConfig) -> Result<Self, HsmError> {
        // Ensure storage path exists
        std::fs::create_dir_all(&config.storage_path).map_err(|e| {
            HsmError::InitializationError(format!("Failed to create storage path: {}", e))
        })?;

        Ok(Self {
            config: config.clone(),
            keys: Mutex::new(HashMap::new()),
            key_data: Mutex::new(HashMap::new()),
            rng: Mutex::new(OsRng),
            network: Network::Testnet, // Always use testnet
            secp: Secp256k1::new(),
            state: Mutex::new(HardwareState {
                battery_level: 100,
                firmware_version: "1.0.0".to_string(),
                is_locked: true,
                pin_attempts: 0,
                max_pin_attempts: 3,
                session_timeout: Duration::from_secs(300), // 5 minutes
                last_operation: None,
            }),
        })
    }

    /// Generate a random key ID
    fn generate_key_id(&self) -> String {
        Uuid::new_v4().to_string()
    }

    /// Simulate hardware conditions like latency and random failures
    async fn simulate_conditions(&self) -> Result<(), HsmError> {
        // Get mutable state lock
        let mut state = self.state.lock().await;

        // Check for session timeout
        if let Some(last_op) = state.last_operation {
            let now = Utc::now();
            let elapsed = now.signed_duration_since(last_op);

            if elapsed.to_std().unwrap_or_default() > state.session_timeout {
                state.is_locked = true;
                return Err(HsmError::AuthenticationError(
                    "Session timed out".to_string(),
                ));
            }
        }

        // Update the last operation timestamp
        state.last_operation = Some(Utc::now());

        // Check if the device is locked
        if state.is_locked {
            return Err(HsmError::DeviceLocked("Device is locked".to_string()));
        }

        // Simulate battery drain
        if state.battery_level > 0 {
            state.battery_level = state.battery_level.saturating_sub(1);
        } else {
            return Err(HsmError::HardwareFailure("Battery depleted".to_string()));
        }

        // Release the mutex lock before simulating latency
        drop(state);

        // Simulate latency if enabled
        if self.config.simulate_latency {
            sleep(Duration::from_millis(self.config.latency_ms)).await;
        }

        // Simulate random failures if enabled
        if self.config.simulate_failures {
            let mut rng = self.rng.lock().await;
            let failure_roll: f64 = rng.gen();
            if failure_roll < self.config.failure_rate {
                return Err(HsmError::HardwareFailure(
                    "Random hardware failure".to_string(),
                ));
            }
        }

        Ok(())
    }

    /// Unlock the device with PIN
    pub async fn unlock(&self, pin: &str) -> Result<(), HsmError> {
        let mut state = self.state.lock().await;

        // Simulate fixed PIN for testnet simulation (1234)
        const CORRECT_PIN: &str = "1234";

        if state.pin_attempts >= state.max_pin_attempts {
            return Err(HsmError::PinLocked(
                "Too many incorrect attempts, device is locked".to_string(),
            ));
        }

        if pin != CORRECT_PIN {
            state.pin_attempts += 1;
            return Err(HsmError::AuthenticationError(format!(
                "Incorrect PIN, {} attempts remaining",
                state.max_pin_attempts - state.pin_attempts
            )));
        }

        // Correct PIN
        state.is_locked = false;
        state.pin_attempts = 0;
        state.last_operation = Some(chrono::Utc::now());

        Ok(())
    }

    /// Generate testnet Bitcoin key
    async fn generate_bitcoin_key(
        &self,
        _params: &KeyGenParams,
    ) -> Result<(Vec<u8>, Vec<u8>), HsmError> {
        self.simulate_conditions().await?;

        let mut rng = self.rng.lock().await;
        let secret_key = SecretKey::new(&mut *rng);
        let public_key = PublicKey::from_secret_key(&self.secp, &secret_key);

        // Generate testnet address
        let compressed_key = CompressedPublicKey::from_slice(&public_key.serialize()).unwrap();
        let address = Address::p2wpkh(&compressed_key, self.network);

        tracing::info!("Generated new testnet address: {}", address);

        Ok((
            public_key.serialize().to_vec(),
            secret_key.secret_bytes().to_vec(),
        ))
    }

    /// Sign Bitcoin transaction for testnet
    async fn sign_bitcoin_transaction(&self, key_id: &str, tx: &mut Psbt) -> Result<(), HsmError> {
        self.simulate_conditions().await?;

        let key_data = self.key_data.lock().await;
        let secret_data = key_data
            .get(key_id)
            .ok_or_else(|| HsmError::KeyNotFound(key_id.to_string()))?;

        let secret_key = SecretKey::from_slice(secret_data)
            .map_err(|e| HsmError::SigningError(format!("Invalid key data: {}", e)))?;

        // Generate public key from secret key
        let public_key = PublicKey::from_secret_key(&self.secp, &secret_key);

        // Sign the transaction for testnet
        let mut signing_keys = std::collections::BTreeMap::new();
        let bitcoin_public_key = bitcoin::PublicKey::new(public_key);
        signing_keys.insert(
            bitcoin_public_key,
            bitcoin::PrivateKey::new(secret_key, self.network),
        );

        let result = tx.sign(&signing_keys, &self.secp);
        match result {
            Ok(_) => {
                tracing::info!("Successfully signed testnet transaction");
                Ok(())
            }
            Err((_, errors)) => {
                tracing::error!("Failed to sign transaction: {:?}", errors);
                Err(HsmError::SigningError(
                    "Failed to sign transaction".to_string(),
                ))
            }
        }
    }

    /// Get device diagnostics
    pub async fn get_diagnostics(&self) -> Result<DeviceDiagnostics, HsmError> {
        let state = self.state.lock().await;

        let diagnostics = DeviceDiagnostics {
            battery_level: state.battery_level,
            firmware_version: state.firmware_version.clone(),
            is_locked: state.is_locked,
            last_operation: state.last_operation,
            active_keys: self.keys.lock().await.len(),
            network: "testnet".to_string(),
        };

        Ok(diagnostics)
    }
}

/// Device diagnostics information
#[derive(Debug, Clone, serde::Serialize)]
pub struct DeviceDiagnostics {
    battery_level: u8,
    firmware_version: String,
    is_locked: bool,
    last_operation: Option<chrono::DateTime<chrono::Utc>>,
    active_keys: usize,
    network: String,
}

#[async_trait]
impl HsmProvider for SimulatorHsmProvider {
    async fn initialize(&self) -> Result<(), HsmError> {
        // Ensure storage path exists
        std::fs::create_dir_all(&self.config.storage_path).map_err(|e| {
            HsmError::InitializationError(format!("Failed to create storage path: {}", e))
        })?;

        tracing::info!("Initialized simulator HSM for Bitcoin testnet operations");
        Ok(())
    }

    async fn generate_key(&self, params: KeyGenParams) -> Result<(KeyPair, KeyInfo), HsmError> {
        self.simulate_conditions().await?;

        let key_id = params.id.clone().unwrap_or_else(|| self.generate_key_id());

        // Generate key pair based on key type with real testnet support
        let (public_key, private_key) = match &params.key_type {
            KeyType::Ec { curve }
                if *curve == crate::security::hsm::provider::EcCurve::Secp256k1 =>
            {
                self.generate_bitcoin_key(&params).await?
            }
            _ => return Err(HsmError::UnsupportedKeyType),
        };

        // Store key information
        let key_info = KeyInfo {
            id: key_id.clone(),
            label: params.label.clone(),
            key_type: params.key_type.clone(),
            extractable: params.extractable,
            usages: params.usages.clone(),
            created_at: Utc::now(),
            expires_at: params.expires_at,
            attributes: params.attributes.clone(),
        };

        let mut keys = self.keys.lock().await;
        let mut key_data = self.key_data.lock().await;

        keys.insert(key_id.clone(), key_info.clone());
        key_data.insert(key_id.clone(), private_key);

        let key_pair = KeyPair {
            id: key_id.clone(),
            key_type: params.key_type,
            public_key,
            private_key_handle: key_id.clone(),
        };

        Ok((key_pair, key_info))
    }

    async fn sign(
        &self,
        key_id: &str,
        algorithm: SigningAlgorithm,
        data: &[u8],
    ) -> Result<Vec<u8>, HsmError> {
        self.simulate_conditions().await?;

        // Check if key exists and has signing capability
        let keys = self.keys.lock().await;
        let key_info = keys
            .get(key_id)
            .ok_or_else(|| HsmError::KeyNotFound(key_id.to_string()))?;

        if !key_info.usages.contains(&KeyUsage::Sign) {
            return Err(HsmError::PermissionDenied(
                "Key does not have signing permission".to_string(),
            ));
        }

        // Get the private key
        let key_data = self.key_data.lock().await;
        let private_key_data = key_data
            .get(key_id)
            .ok_or_else(|| HsmError::KeyNotFound(key_id.to_string()))?;

        // Perform real signing based on algorithm
        match algorithm {
            SigningAlgorithm::EcdsaSha256 => {
                let secret_key = SecretKey::from_slice(private_key_data)
                    .map_err(|e| HsmError::SigningError(format!("Invalid key data: {}", e)))?;

                // Create message hash
                let mut hasher = Sha256::new();
                hasher.update(data);
                let message_hash = hasher.finalize();

                // Sign the hash
                let message = bitcoin::secp256k1::Message::from_digest_slice(&message_hash)
                    .map_err(|e| HsmError::SigningError(format!("Invalid message hash: {}", e)))?;

                let signature = self.secp.sign_ecdsa(&message, &secret_key);
                Ok(signature.serialize_der().to_vec())
            }
            _ => Err(HsmError::UnsupportedOperation(format!(
                "Unsupported signing algorithm: {:?}",
                algorithm
            ))),
        }
    }

    async fn verify(
        &self,
        key_id: &str,
        algorithm: SigningAlgorithm,
        data: &[u8],
        signature: &[u8],
    ) -> Result<bool, HsmError> {
        self.simulate_conditions().await?;

        // Check if key exists and has verify capability
        let keys = self.keys.lock().await;
        let key_info = keys
            .get(key_id)
            .ok_or_else(|| HsmError::KeyNotFound(key_id.to_string()))?;

        if !key_info.usages.contains(&KeyUsage::Verify) {
            return Err(HsmError::PermissionDenied(
                "Key does not have verify permission".to_string(),
            ));
        }

        // Real verification for testnet
        match algorithm {
            SigningAlgorithm::EcdsaSha256 => {
                // Get the public key
                match key_info.key_type {
                    KeyType::Ec { curve }
                        if curve == crate::security::hsm::provider::EcCurve::Secp256k1 =>
                    {
                        // Create message hash
                        let mut hasher = Sha256::new();
                        hasher.update(data);
                        let message_hash = hasher.finalize();

                        // Get the serialized public key from key storage or regenerate
                        let pubkey_bytes = self.export_public_key(key_id).await?;
                        let public_key = PublicKey::from_slice(&pubkey_bytes).map_err(|e| {
                            HsmError::VerificationError(format!("Invalid public key data: {}", e))
                        })?;

                        // Parse the signature
                        let sig = bitcoin::secp256k1::ecdsa::Signature::from_der(signature)
                            .map_err(|e| {
                                HsmError::VerificationError(format!(
                                    "Invalid signature format: {}",
                                    e
                                ))
                            })?;

                        // Verify
                        let message = bitcoin::secp256k1::Message::from_digest_slice(&message_hash)
                            .map_err(|e| {
                                HsmError::VerificationError(format!("Invalid message hash: {}", e))
                            })?;

                        match self.secp.verify_ecdsa(&message, &sig, &public_key) {
                            Ok(_) => Ok(true),
                            Err(_) => Ok(false),
                        }
                    }
                    _ => Err(HsmError::UnsupportedKeyType),
                }
            }
            _ => Err(HsmError::UnsupportedOperation(format!(
                "Unsupported verification algorithm: {:?}",
                algorithm
            ))),
        }
    }

    async fn export_public_key(&self, key_id: &str) -> Result<Vec<u8>, HsmError> {
        self.simulate_conditions().await?;

        // Check if key exists
        let keys = self.keys.lock().await;
        let key_info = keys
            .get(key_id)
            .ok_or_else(|| HsmError::KeyNotFound(key_id.to_string()))?;

        // Get the private key and derive public key
        let key_data = self.key_data.lock().await;
        let private_key_data = key_data
            .get(key_id)
            .ok_or_else(|| HsmError::KeyNotFound(key_id.to_string()))?;

        match key_info.key_type {
            KeyType::Ec { curve }
                if curve == crate::security::hsm::provider::EcCurve::Secp256k1 =>
            {
                let secret_key = SecretKey::from_slice(private_key_data).map_err(|e| {
                    HsmError::KeyGenerationError(format!("Invalid key data: {}", e))
                })?;
                let public_key = PublicKey::from_secret_key(&self.secp, &secret_key);
                Ok(public_key.serialize().to_vec())
            }
            _ => Err(HsmError::UnsupportedKeyType),
        }
    }

    async fn list_keys(&self) -> Result<Vec<KeyInfo>, HsmError> {
        self.simulate_conditions().await?;

        let keys = self.keys.lock().await;
        Ok(keys.values().cloned().collect())
    }

    async fn delete_key(&self, key_id: &str) -> Result<(), HsmError> {
        self.simulate_conditions().await?;

        let mut keys = self.keys.lock().await;
        let mut key_data = self.key_data.lock().await;

        if keys.remove(key_id).is_none() {
            return Err(HsmError::KeyNotFound(key_id.to_string()));
        }

        key_data.remove(key_id);
        Ok(())
    }

    async fn get_status(&self) -> Result<HsmProviderStatus, HsmError> {
        let state = self.state.lock().await;

        if state.battery_level == 0 {
            return Ok(HsmProviderStatus::Error("Battery depleted".to_string()));
        }

        if state.is_locked {
            return Ok(HsmProviderStatus::Unavailable);
        }

        Ok(HsmProviderStatus::Ready)
    }

    async fn close(&self) -> Result<(), HsmError> {
        let mut state = self.state.lock().await;
        state.is_locked = true;
        Ok(())
    }

    async fn execute_operation(&self, request: HsmRequest) -> Result<HsmResponse, HsmError> {
        match request.operation {
            HsmOperation::GenerateKey => {
                let params: KeyGenParams = serde_json::from_value(request.parameters.clone())
                    .map_err(|e| {
                        HsmError::InvalidParameters(format!(
                            "Invalid key generation parameters: {}",
                            e
                        ))
                    })?;

                let key_pair = self.generate_key(params).await?;
                let response_data = serde_json::to_value(key_pair)
                    .map_err(|e| HsmError::SerializationError(e.to_string()))?;

                Ok(HsmResponse::success(request.id, Some(response_data)))
            }
            HsmOperation::Sign => {
                let params: SignParams = serde_json::from_value(request.parameters.clone())
                    .map_err(|e| {
                        HsmError::InvalidParameters(format!("Invalid signing parameters: {}", e))
                    })?;

                // [AIR-3][AIS-3][BPC-3][RES-3] Sign data using simulator HSM
                let signature = self
                    .sign(&params.key_id, params.algorithm, &params.data)
                    .await?;
                // [AIR-3][AIS-3][BPC-3][RES-3] Use base64 Engine for encoding
                // This follows official Bitcoin Improvement Proposals (BIPs) standards for secure data handling
                let response_data = serde_json::to_value(Base64SignatureResponse {
                    signature: base64::engine::general_purpose::STANDARD.encode(&signature),
                    algorithm: params.algorithm,
                })
                .map_err(|e| HsmError::SerializationError(e.to_string()))?;

                Ok(HsmResponse::success(request.id, Some(response_data)))
            }
            HsmOperation::Custom(op) if op == "sign_bitcoin_tx" => {
                let params: BitcoinTxSignParams =
                    serde_json::from_value(request.parameters.clone()).map_err(|e| {
                        HsmError::InvalidParameters(format!(
                            "Invalid Bitcoin TX signing parameters: {}",
                            e
                        ))
                    })?;

                // Decode PSBT
                let mut psbt = bitcoin::psbt::Psbt::from_str(&params.psbt)
                    .map_err(|e| HsmError::InvalidParameters(format!("Invalid PSBT: {}", e)))?;

                // Sign the transaction
                self.sign_bitcoin_transaction(&params.key_id, &mut psbt)
                    .await?;

                // Return the signed PSBT
                let response_data = serde_json::json!({
                    "signed_psbt": psbt.to_string(),
                    "network": "testnet",
                });

                Ok(HsmResponse::success(request.id, Some(response_data)))
            }
            HsmOperation::Custom(op) if op == "unlock" => {
                let params: UnlockParams = serde_json::from_value(request.parameters.clone())
                    .map_err(|e| {
                        HsmError::InvalidParameters(format!("Invalid unlock parameters: {}", e))
                    })?;

                // Unlock the device
                self.unlock(&params.pin).await?;

                Ok(HsmResponse::success(request.id, None))
            }
            HsmOperation::Custom(op) if op == "get_diagnostics" => {
                let diagnostics = self.get_diagnostics().await?;
                let response_data = serde_json::to_value(diagnostics)
                    .map_err(|e| HsmError::SerializationError(e.to_string()))?;

                Ok(HsmResponse::success(request.id, Some(response_data)))
            }
            _ => Err(HsmError::UnsupportedOperation(format!(
                "{:?}",
                request.operation
            ))),
        }
    }
}

/// Parameters for signing operation
#[derive(Debug, serde::Deserialize)]
struct SignParams {
    key_id: String,
    algorithm: SigningAlgorithm,
    data: Vec<u8>,
}

/// Parameters for Bitcoin transaction signing
#[derive(Debug, serde::Deserialize)]
struct BitcoinTxSignParams {
    key_id: String,
    psbt: String,
}

/// Parameters for unlocking the device
#[derive(Debug, serde::Deserialize)]
struct UnlockParams {
    pin: String,
}

/// Response for signature in base64 format
#[derive(Debug, serde::Serialize)]
struct Base64SignatureResponse {
    signature: String,
    algorithm: SigningAlgorithm,
}