//! Credential Management Module
//!
//! Handles automatic credential management and injection for cloud providers
//! like UpCloud and AWS with secure storage and automatic refresh.

use std::collections::HashMap;
use std::sync::Arc;

use chrono::{DateTime, Utc};
use tokio::sync::RwLock;

use crate::kms::config::CredentialConfig;
use crate::kms::error::KmsError;
use crate::kms::traits::CredentialStore;
use crate::kms::types::{HealthStatus, ProviderCredentials};

/// Credential Manager for cloud provider credentials
pub struct CredentialManager {
    store: Box<dyn CredentialStore>,
    /// Configuration for credential refresh intervals and policies
    #[allow(dead_code)]
    config: CredentialConfig,
    /// Scheduler for automatic credential refresh (planned feature)
    #[allow(dead_code)]
    refresh_scheduler: Arc<RwLock<RefreshScheduler>>,
    /// Credential injection system (planned feature)
    #[allow(dead_code)]
    injector: CredentialInjector,
}

/// Refresh scheduler for automatic credential renewal (planned feature)
#[allow(dead_code)]
struct RefreshScheduler {
    tasks: HashMap<String, RefreshTask>,
}

/// Individual refresh task for a provider (planned feature)
#[allow(dead_code)]
struct RefreshTask {
    provider: String,
    next_refresh: DateTime<Utc>,
    failure_count: u32,
    last_error: Option<String>,
}

/// Credential injector for automatic delivery to applications (planned feature)
#[allow(dead_code)]
struct CredentialInjector {
    targets: HashMap<String, InjectionTarget>,
}

/// Injection target configuration (planned feature)
#[allow(dead_code)]
struct InjectionTarget {
    method: InjectionMethod,
    config: HashMap<String, String>,
}

/// Injection methods (planned feature)
#[allow(dead_code)]
enum InjectionMethod {
    Environment,
    File,
    Api,
    Webhook,
}

impl CredentialManager {
    /// Create a new credential manager
    pub async fn new(config: CredentialConfig) -> Result<Self, KmsError> {
        let store = Self::create_store(&config).await?;
        let refresh_scheduler = Arc::new(RwLock::new(RefreshScheduler {
            tasks: HashMap::new(),
        }));
        let injector = CredentialInjector {
            targets: HashMap::new(), // TODO: Load from config
        };

        Ok(Self {
            store,
            config,
            refresh_scheduler,
            injector,
        })
    }

    /// Create credential store based on configuration
    async fn create_store(
        _config: &CredentialConfig,
    ) -> Result<Box<dyn CredentialStore>, KmsError> {
        // TODO: Implement different storage backends based on config
        // For now, return a placeholder error
        Err(KmsError::config("Credential storage not yet implemented"))
    }

    /// Initialize the credential manager
    pub async fn initialize(&mut self) -> Result<(), KmsError> {
        // TODO: Start refresh scheduler
        Ok(())
    }

    /// Get credentials for a provider
    pub async fn get_credentials(
        &self,
        provider: &str,
    ) -> Result<Option<ProviderCredentials>, KmsError> {
        self.store.get_credentials(provider).await
    }

    /// Store credentials for a provider
    pub async fn store_credentials(
        &self,
        provider: &str,
        credentials: ProviderCredentials,
    ) -> Result<(), KmsError> {
        self.store.store_credentials(provider, credentials).await
    }

    /// Health check
    pub async fn health_check(&self) -> Result<HealthStatus, KmsError> {
        self.store.health_check().await
    }
}

// TODO: Implement remaining credential management functionality
// This is a comprehensive stub for the credential management system
