//! Hardware Security Module (HSM) Integration
//!
//! Provides integration with Hardware Security Modules for high-security
//! key storage and cryptographic operations.

use async_trait::async_trait;

use crate::kms::traits::HsmProvider;
use crate::kms::types::{HsmConfig, HsmType};
use crate::kms::{HealthStatus, HsmInfo, HsmKeySpec, KmsError};

/// HSM provider factory
pub struct HsmProviderFactory;

impl HsmProviderFactory {
    /// Create HSM provider based on configuration
    pub async fn create(config: &HsmConfig) -> Result<Box<dyn HsmProvider>, KmsError> {
        if !config.enabled {
            return Err(KmsError::hsm("factory", "HSM support is disabled"));
        }

        match config.hsm_type {
            HsmType::Pkcs11 => Ok(Box::new(Pkcs11HsmProvider::new(config).await?)),
            HsmType::YubiHsm => Ok(Box::new(YubiHsmProvider::new(config).await?)),
            HsmType::CloudHsm => Ok(Box::new(CloudHsmProvider::new(config).await?)),
            HsmType::AzureHsm => Ok(Box::new(AzureHsmProvider::new(config).await?)),
        }
    }
}

/// PKCS#11 HSM provider implementation
#[allow(dead_code)]
struct Pkcs11HsmProvider {
    config: HsmConfig,
}

impl Pkcs11HsmProvider {
    async fn new(config: &HsmConfig) -> Result<Self, KmsError> {
        Ok(Self {
            config: config.clone(),
        })
    }
}

#[async_trait]
impl HsmProvider for Pkcs11HsmProvider {
    async fn initialize(&mut self) -> Result<(), KmsError> {
        // TODO: Initialize PKCS#11 library
        Ok(())
    }

    async fn generate_key(&self, _key_spec: &HsmKeySpec) -> Result<String, KmsError> {
        // TODO: Implement PKCS#11 key generation
        Err(KmsError::hsm(
            "pkcs11",
            "Key generation not yet implemented",
        ))
    }

    async fn import_key(
        &self,
        _key_data: &[u8],
        _key_spec: &HsmKeySpec,
    ) -> Result<String, KmsError> {
        // TODO: Implement PKCS#11 key import
        Err(KmsError::hsm("pkcs11", "Key import not yet implemented"))
    }

    async fn export_key(&self, _key_id: &str) -> Result<Vec<u8>, KmsError> {
        // TODO: Implement PKCS#11 key export
        Err(KmsError::hsm("pkcs11", "Key export not yet implemented"))
    }

    async fn delete_key(&self, _key_id: &str) -> Result<bool, KmsError> {
        // TODO: Implement PKCS#11 key deletion
        Ok(false)
    }

    async fn encrypt(&self, _key_id: &str, _plaintext: &[u8]) -> Result<Vec<u8>, KmsError> {
        // TODO: Implement PKCS#11 encryption
        Err(KmsError::hsm("pkcs11", "Encryption not yet implemented"))
    }

    async fn decrypt(&self, _key_id: &str, _ciphertext: &[u8]) -> Result<Vec<u8>, KmsError> {
        // TODO: Implement PKCS#11 decryption
        Err(KmsError::hsm("pkcs11", "Decryption not yet implemented"))
    }

    async fn sign(&self, _key_id: &str, _data: &[u8]) -> Result<Vec<u8>, KmsError> {
        // TODO: Implement PKCS#11 signing
        Err(KmsError::hsm("pkcs11", "Signing not yet implemented"))
    }

    async fn verify(
        &self,
        _key_id: &str,
        _data: &[u8],
        _signature: &[u8],
    ) -> Result<bool, KmsError> {
        // TODO: Implement PKCS#11 signature verification
        Err(KmsError::hsm(
            "pkcs11",
            "Signature verification not yet implemented",
        ))
    }

    async fn list_keys(&self) -> Result<Vec<String>, KmsError> {
        // TODO: Implement PKCS#11 key listing
        Ok(Vec::new())
    }

    async fn get_info(&self) -> Result<HsmInfo, KmsError> {
        // TODO: Implement PKCS#11 HSM info retrieval
        Ok(HsmInfo {
            manufacturer: "Unknown".to_string(),
            model: "PKCS#11 HSM".to_string(),
            serial_number: "Unknown".to_string(),
            firmware_version: "Unknown".to_string(),
            slot_count: 1,
            available_mechanisms: Vec::new(),
            max_session_count: 100,
            current_session_count: 0,
        })
    }

    async fn health_check(&self) -> Result<HealthStatus, KmsError> {
        Ok(HealthStatus::healthy("PKCS#11 HSM provider operational"))
    }

    async fn shutdown(&mut self) -> Result<(), KmsError> {
        // TODO: Cleanup PKCS#11 resources
        Ok(())
    }
}

/// YubiHSM 2 provider implementation
#[allow(dead_code)]
struct YubiHsmProvider {
    config: HsmConfig,
}

impl YubiHsmProvider {
    async fn new(config: &HsmConfig) -> Result<Self, KmsError> {
        Ok(Self {
            config: config.clone(),
        })
    }
}

#[async_trait]
impl HsmProvider for YubiHsmProvider {
    async fn initialize(&mut self) -> Result<(), KmsError> {
        // TODO: Initialize YubiHSM connection
        Ok(())
    }

    async fn generate_key(&self, _key_spec: &HsmKeySpec) -> Result<String, KmsError> {
        // TODO: Implement YubiHSM key generation
        Err(KmsError::hsm(
            "yubihsm",
            "Key generation not yet implemented",
        ))
    }

    async fn import_key(
        &self,
        _key_data: &[u8],
        _key_spec: &HsmKeySpec,
    ) -> Result<String, KmsError> {
        // TODO: Implement YubiHSM key import
        Err(KmsError::hsm("yubihsm", "Key import not yet implemented"))
    }

    async fn export_key(&self, _key_id: &str) -> Result<Vec<u8>, KmsError> {
        // TODO: Implement YubiHSM key export
        Err(KmsError::hsm("yubihsm", "Key export not yet implemented"))
    }

    async fn delete_key(&self, _key_id: &str) -> Result<bool, KmsError> {
        // TODO: Implement YubiHSM key deletion
        Ok(false)
    }

    async fn encrypt(&self, _key_id: &str, _plaintext: &[u8]) -> Result<Vec<u8>, KmsError> {
        // TODO: Implement YubiHSM encryption
        Err(KmsError::hsm("yubihsm", "Encryption not yet implemented"))
    }

    async fn decrypt(&self, _key_id: &str, _ciphertext: &[u8]) -> Result<Vec<u8>, KmsError> {
        // TODO: Implement YubiHSM decryption
        Err(KmsError::hsm("yubihsm", "Decryption not yet implemented"))
    }

    async fn sign(&self, _key_id: &str, _data: &[u8]) -> Result<Vec<u8>, KmsError> {
        // TODO: Implement YubiHSM signing
        Err(KmsError::hsm("yubihsm", "Signing not yet implemented"))
    }

    async fn verify(
        &self,
        _key_id: &str,
        _data: &[u8],
        _signature: &[u8],
    ) -> Result<bool, KmsError> {
        // TODO: Implement YubiHSM signature verification
        Err(KmsError::hsm(
            "yubihsm",
            "Signature verification not yet implemented",
        ))
    }

    async fn list_keys(&self) -> Result<Vec<String>, KmsError> {
        // TODO: Implement YubiHSM key listing
        Ok(Vec::new())
    }

    async fn get_info(&self) -> Result<HsmInfo, KmsError> {
        // TODO: Implement YubiHSM info retrieval
        Ok(HsmInfo {
            manufacturer: "Yubico".to_string(),
            model: "YubiHSM 2".to_string(),
            serial_number: "Unknown".to_string(),
            firmware_version: "Unknown".to_string(),
            slot_count: 1,
            available_mechanisms: Vec::new(),
            max_session_count: 16,
            current_session_count: 0,
        })
    }

    async fn health_check(&self) -> Result<HealthStatus, KmsError> {
        Ok(HealthStatus::healthy("YubiHSM 2 provider operational"))
    }

    async fn shutdown(&mut self) -> Result<(), KmsError> {
        // TODO: Cleanup YubiHSM resources
        Ok(())
    }
}

/// AWS CloudHSM provider implementation (stub)
#[allow(dead_code)]
struct CloudHsmProvider {
    config: HsmConfig,
}

impl CloudHsmProvider {
    async fn new(config: &HsmConfig) -> Result<Self, KmsError> {
        Ok(Self {
            config: config.clone(),
        })
    }
}

#[async_trait]
impl HsmProvider for CloudHsmProvider {
    async fn initialize(&mut self) -> Result<(), KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn generate_key(&self, _key_spec: &HsmKeySpec) -> Result<String, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn import_key(
        &self,
        _key_data: &[u8],
        _key_spec: &HsmKeySpec,
    ) -> Result<String, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn export_key(&self, _key_id: &str) -> Result<Vec<u8>, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn delete_key(&self, _key_id: &str) -> Result<bool, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn encrypt(&self, _key_id: &str, _plaintext: &[u8]) -> Result<Vec<u8>, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn decrypt(&self, _key_id: &str, _ciphertext: &[u8]) -> Result<Vec<u8>, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn sign(&self, _key_id: &str, _data: &[u8]) -> Result<Vec<u8>, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn verify(
        &self,
        _key_id: &str,
        _data: &[u8],
        _signature: &[u8],
    ) -> Result<bool, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn list_keys(&self) -> Result<Vec<String>, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn get_info(&self) -> Result<HsmInfo, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn health_check(&self) -> Result<HealthStatus, KmsError> {
        Err(KmsError::hsm("cloudhsm", "CloudHSM not yet implemented"))
    }

    async fn shutdown(&mut self) -> Result<(), KmsError> {
        Ok(())
    }
}

/// Azure Dedicated HSM provider implementation (stub)
#[allow(dead_code)]
struct AzureHsmProvider {
    config: HsmConfig,
}

impl AzureHsmProvider {
    async fn new(config: &HsmConfig) -> Result<Self, KmsError> {
        Ok(Self {
            config: config.clone(),
        })
    }
}

#[async_trait]
impl HsmProvider for AzureHsmProvider {
    async fn initialize(&mut self) -> Result<(), KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn generate_key(&self, _key_spec: &HsmKeySpec) -> Result<String, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn import_key(
        &self,
        _key_data: &[u8],
        _key_spec: &HsmKeySpec,
    ) -> Result<String, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn export_key(&self, _key_id: &str) -> Result<Vec<u8>, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn delete_key(&self, _key_id: &str) -> Result<bool, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn encrypt(&self, _key_id: &str, _plaintext: &[u8]) -> Result<Vec<u8>, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn decrypt(&self, _key_id: &str, _ciphertext: &[u8]) -> Result<Vec<u8>, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn sign(&self, _key_id: &str, _data: &[u8]) -> Result<Vec<u8>, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn verify(
        &self,
        _key_id: &str,
        _data: &[u8],
        _signature: &[u8],
    ) -> Result<bool, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn list_keys(&self) -> Result<Vec<String>, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn get_info(&self) -> Result<HsmInfo, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn health_check(&self) -> Result<HealthStatus, KmsError> {
        Err(KmsError::hsm("azurehsm", "Azure HSM not yet implemented"))
    }

    async fn shutdown(&mut self) -> Result<(), KmsError> {
        Ok(())
    }
}
