auth-framework 0.5.0-rc18

// Monitoring integration for production deployment
// Comprehensive monitoring with Prometheus, Grafana, and custom metrics

use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::time::{Duration, SystemTime, UNIX_EPOCH};
use thiserror::Error;

#[derive(Debug, Error)]
pub enum MonitoringError {
    #[error("Metric collection error: {0}")]
    MetricCollection(String),
    #[error("Exporter error: {0}")]
    Exporter(String),
    #[error("Alert manager error: {0}")]
    AlertManager(String),
    #[error("Dashboard error: {0}")]
    Dashboard(String),
    #[error("Configuration error: {0}")]
    Configuration(String),
    #[error("Network error: {0}")]
    Network(String),
    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),
    #[error("Serialization error: {0}")]
    Serialization(#[from] serde_json::Error),
}

/// Metric types supported by the monitoring system
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum MetricType {
    Counter,
    Gauge,
    Histogram,
    Summary,
}

/// Metric value with timestamp
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MetricValue {
    pub value: f64,
    pub timestamp: u64,
    pub labels: HashMap<String, String>,
}

/// Metric definition
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Metric {
    pub name: String,
    pub metric_type: MetricType,
    pub description: String,
    pub unit: String,
    pub values: Vec<MetricValue>,
    pub retention: Duration,
}

/// Alert rule configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AlertRule {
    pub name: String,
    pub metric_name: String,
    pub condition: AlertCondition,
    pub threshold: f64,
    pub duration: Duration,
    pub severity: AlertSeverity,
    pub enabled: bool,
    pub labels: HashMap<String, String>,
    pub annotations: HashMap<String, String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum AlertCondition {
    GreaterThan,
    LessThan,
    Equal,
    NotEqual,
    GreaterThanOrEqual,
    LessThanOrEqual,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum AlertSeverity {
    Critical,
    Warning,
    Info,
}

/// Alert instance
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Alert {
    pub rule_name: String,
    pub metric_name: String,
    pub current_value: f64,
    pub threshold: f64,
    pub severity: AlertSeverity,
    pub message: String,
    pub started_at: u64,
    pub resolved_at: Option<u64>,
    pub labels: HashMap<String, String>,
}

/// Dashboard configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Dashboard {
    pub id: String,
    pub title: String,
    pub description: String,
    pub panels: Vec<DashboardPanel>,
    pub refresh_interval: Duration,
    pub time_range: TimeRange,
    pub variables: HashMap<String, String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DashboardPanel {
    pub id: String,
    pub title: String,
    pub panel_type: PanelType,
    pub metric_queries: Vec<String>,
    pub position: PanelPosition,
    pub options: HashMap<String, serde_json::Value>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum PanelType {
    LineGraph,
    BarChart,
    Gauge,
    SingleStat,
    Table,
    HeatMap,
    Alert,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PanelPosition {
    pub x: u32,
    pub y: u32,
    pub width: u32,
    pub height: u32,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TimeRange {
    pub from: String,
    pub to: String,
}

/// Monitoring configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct MonitoringConfig {
    pub enabled: bool,
    pub prometheus: PrometheusConfig,
    pub grafana: GrafanaConfig,
    pub alertmanager: AlertManagerConfig,
    pub custom_exporters: Vec<ExporterConfig>,
    pub dashboards: Vec<Dashboard>,
    pub retention_policy: RetentionPolicy,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct PrometheusConfig {
    pub endpoint: String,
    pub scrape_interval: Duration,
    pub evaluation_interval: Duration,
    pub external_labels: HashMap<String, String>,
    pub rule_files: Vec<String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct GrafanaConfig {
    pub endpoint: String,
    pub api_key: String,
    pub organization: String,
    pub datasource: String,
    pub auto_provision: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AlertManagerConfig {
    pub endpoint: String,
    pub receivers: Vec<AlertReceiver>,
    pub routing: AlertRouting,
    pub inhibit_rules: Vec<InhibitRule>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AlertReceiver {
    pub name: String,
    pub webhook_configs: Vec<WebhookConfig>,
    pub email_configs: Vec<EmailConfig>,
    pub slack_configs: Vec<SlackConfig>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct WebhookConfig {
    pub url: String,
    pub http_config: Option<HttpConfig>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct EmailConfig {
    pub to: Vec<String>,
    pub from: String,
    pub subject: String,
    pub body: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SlackConfig {
    pub api_url: String,
    pub channel: String,
    pub username: String,
    pub title: String,
    pub text: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct HttpConfig {
    pub basic_auth: Option<BasicAuth>,
    pub bearer_token: Option<String>,
    pub tls_config: Option<TlsConfig>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct BasicAuth {
    pub username: String,
    pub password: String,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TlsConfig {
    pub ca_file: Option<String>,
    pub cert_file: Option<String>,
    pub key_file: Option<String>,
    pub insecure_skip_verify: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AlertRouting {
    pub group_by: Vec<String>,
    pub group_wait: Duration,
    pub group_interval: Duration,
    pub repeat_interval: Duration,
    pub receiver: String,
    pub routes: Vec<Route>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Route {
    pub matchers: HashMap<String, String>,
    pub receiver: String,
    pub group_by: Vec<String>,
    pub continue_route: bool,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct InhibitRule {
    pub source_matchers: HashMap<String, String>,
    pub target_matchers: HashMap<String, String>,
    pub equal: Vec<String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ExporterConfig {
    pub name: String,
    pub endpoint: String,
    pub interval: Duration,
    pub timeout: Duration,
    pub labels: HashMap<String, String>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct RetentionPolicy {
    pub default_retention: Duration,
    pub metric_retentions: HashMap<String, Duration>,
    pub downsampling_rules: Vec<DownsamplingRule>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DownsamplingRule {
    pub resolution: Duration,
    pub retention: Duration,
    pub aggregation: AggregationType,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum AggregationType {
    Average,
    Sum,
    Min,
    Max,
    Count,
}

/// Monitoring system manager
pub struct MonitoringSystem {
    config: MonitoringConfig,
    metrics: HashMap<String, Metric>,
    alert_rules: Vec<AlertRule>,
    active_alerts: Vec<Alert>,
    dashboards: Vec<Dashboard>,
}

impl MonitoringSystem {
    /// Create new monitoring system
    pub fn new(config: MonitoringConfig) -> Self {
        Self {
            config,
            metrics: HashMap::new(),
            alert_rules: Vec::new(),
            active_alerts: Vec::new(),
            dashboards: Vec::new(),
        }
    }

    /// Initialize monitoring system
    pub async fn initialize(&mut self) -> Result<(), MonitoringError> {
        if !self.config.enabled {
            return Ok(());
        }

        // Initialize Prometheus
        self.initialize_prometheus().await?;

        // Initialize Grafana
        self.initialize_grafana().await?;

        // Initialize AlertManager
        self.initialize_alertmanager().await?;

        // Setup default metrics
        self.setup_default_metrics().await?;

        // Load dashboards
        self.load_dashboards().await?;

        Ok(())
    }

    /// Initialize Prometheus integration
    async fn initialize_prometheus(&self) -> Result<(), MonitoringError> {
        // Configure Prometheus scraping
        tracing::info!(
            endpoint = %self.config.prometheus.endpoint,
            "Initializing Prometheus"
        );
        Ok(())
    }

    /// Initialize Grafana integration
    async fn initialize_grafana(&self) -> Result<(), MonitoringError> {
        if self.config.grafana.auto_provision {
            // Auto-provision dashboards
            self.provision_grafana_dashboards().await?;
        }
        Ok(())
    }

    /// Initialize AlertManager integration
    async fn initialize_alertmanager(&self) -> Result<(), MonitoringError> {
        // Configure alert routing
        tracing::info!(
            endpoint = %self.config.alertmanager.endpoint,
            "Initializing AlertManager"
        );
        Ok(())
    }

    /// Setup default RBAC metrics
    async fn setup_default_metrics(&mut self) -> Result<(), MonitoringError> {
        // Authentication metrics
        self.register_metric(Metric {
            name: "auth_requests_total".to_string(),
            metric_type: MetricType::Counter,
            description: "Total number of authentication requests".to_string(),
            unit: "requests".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(30 * 24 * 3600), // 30 days
        });

        self.register_metric(Metric {
            name: "auth_success_total".to_string(),
            metric_type: MetricType::Counter,
            description: "Total number of successful authentications".to_string(),
            unit: "requests".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(30 * 24 * 3600),
        });

        self.register_metric(Metric {
            name: "auth_failures_total".to_string(),
            metric_type: MetricType::Counter,
            description: "Total number of failed authentications".to_string(),
            unit: "requests".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(30 * 24 * 3600),
        });

        // Authorization metrics
        self.register_metric(Metric {
            name: "authz_checks_total".to_string(),
            metric_type: MetricType::Counter,
            description: "Total number of authorization checks".to_string(),
            unit: "checks".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(30 * 24 * 3600),
        });

        self.register_metric(Metric {
            name: "authz_denied_total".to_string(),
            metric_type: MetricType::Counter,
            description: "Total number of denied authorization checks".to_string(),
            unit: "checks".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(30 * 24 * 3600),
        });

        // Performance metrics
        self.register_metric(Metric {
            name: "request_duration_seconds".to_string(),
            metric_type: MetricType::Histogram,
            description: "Request duration in seconds".to_string(),
            unit: "seconds".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(7 * 24 * 3600), // 7 days
        });

        self.register_metric(Metric {
            name: "active_sessions".to_string(),
            metric_type: MetricType::Gauge,
            description: "Number of active user sessions".to_string(),
            unit: "sessions".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(24 * 3600), // 1 day
        });

        Ok(())
    }

    /// Register a new metric
    pub fn register_metric(&mut self, metric: Metric) {
        self.metrics.insert(metric.name.clone(), metric);
    }

    /// Record metric value
    pub fn record_metric(
        &mut self,
        name: &str,
        value: f64,
        labels: HashMap<String, String>,
    ) -> Result<(), MonitoringError> {
        if let Some(metric) = self.metrics.get_mut(name) {
            let now = SystemTime::now()
                .duration_since(UNIX_EPOCH)
                .unwrap_or_default();

            let metric_value = MetricValue {
                value,
                timestamp: now.as_secs(),
                labels,
            };

            metric.values.push(metric_value);

            // Clean up old values based on retention policy
            let cutoff = now.as_secs() - metric.retention.as_secs();
            metric.values.retain(|v| v.timestamp > cutoff);

            Ok(())
        } else {
            Err(MonitoringError::MetricCollection(format!(
                "Metric not found: {}",
                name
            )))
        }
    }

    /// Add alert rule
    pub fn add_alert_rule(&mut self, rule: AlertRule) {
        self.alert_rules.push(rule);
    }

    /// Evaluate alert rules
    pub async fn evaluate_alerts(&mut self) -> Result<(), MonitoringError> {
        let now = SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .unwrap_or_default();

        for rule in &self.alert_rules {
            if !rule.enabled {
                continue;
            }

            if let Some(metric) = self.metrics.get(&rule.metric_name)
                && let Some(latest_value) = metric.values.last()
            {
                let should_alert = match rule.condition {
                    AlertCondition::GreaterThan => latest_value.value > rule.threshold,
                    AlertCondition::LessThan => latest_value.value < rule.threshold,
                    AlertCondition::Equal => {
                        (latest_value.value - rule.threshold).abs() < f64::EPSILON
                    }
                    AlertCondition::NotEqual => {
                        (latest_value.value - rule.threshold).abs() > f64::EPSILON
                    }
                    AlertCondition::GreaterThanOrEqual => latest_value.value >= rule.threshold,
                    AlertCondition::LessThanOrEqual => latest_value.value <= rule.threshold,
                };

                if should_alert {
                    // Check if alert already exists
                    let existing_alert = self
                        .active_alerts
                        .iter()
                        .find(|alert| alert.rule_name == rule.name && alert.resolved_at.is_none());

                    if existing_alert.is_none() {
                        let alert = Alert {
                            rule_name: rule.name.clone(),
                            metric_name: rule.metric_name.clone(),
                            current_value: latest_value.value,
                            threshold: rule.threshold,
                            severity: rule.severity.clone(),
                            message: format!(
                                "Alert: {} - Current value: {}, Threshold: {}",
                                rule.name, latest_value.value, rule.threshold
                            ),
                            started_at: now.as_secs(),
                            resolved_at: None,
                            labels: rule.labels.clone(),
                        };

                        self.active_alerts.push(alert.clone());
                        self.send_alert(&alert).await?;
                    }
                } else {
                    // Resolve existing alerts
                    let mut alerts_to_resolve = Vec::new();
                    for alert in &mut self.active_alerts {
                        if alert.rule_name == rule.name && alert.resolved_at.is_none() {
                            alert.resolved_at = Some(now.as_secs());
                            alerts_to_resolve.push(alert.clone());
                        }
                    }

                    // Send resolution notifications
                    for alert in &alerts_to_resolve {
                        self.send_alert_resolution(alert).await?;
                    }
                }
            }
        }
        Ok(())
    }

    /// Send alert notification
    async fn send_alert(&self, alert: &Alert) -> Result<(), MonitoringError> {
        // Send to AlertManager
        tracing::warn!(rule = %alert.rule_name, message = %alert.message, "ALERT triggered");

        // Send to configured receivers
        for receiver in &self.config.alertmanager.receivers {
            self.send_to_receiver(receiver, alert).await?;
        }

        Ok(())
    }

    /// Send alert resolution notification
    async fn send_alert_resolution(&self, alert: &Alert) -> Result<(), MonitoringError> {
        tracing::info!(rule = %alert.rule_name, message = %alert.message, "ALERT resolved");
        Ok(())
    }

    /// Send alert to specific receiver
    async fn send_to_receiver(
        &self,
        receiver: &AlertReceiver,
        alert: &Alert,
    ) -> Result<(), MonitoringError> {
        // Send to webhook endpoints
        for webhook in &receiver.webhook_configs {
            self.send_webhook_alert(webhook, alert).await?;
        }

        // Send to email endpoints
        for email in &receiver.email_configs {
            self.send_email_alert(email, alert).await?;
        }

        // Send to Slack endpoints
        for slack in &receiver.slack_configs {
            self.send_slack_alert(slack, alert).await?;
        }

        Ok(())
    }

    /// Send webhook alert
    async fn send_webhook_alert(
        &self,
        _webhook: &WebhookConfig,
        _alert: &Alert,
    ) -> Result<(), MonitoringError> {
        // Implement webhook sending
        Ok(())
    }

    /// Send email alert
    async fn send_email_alert(
        &self,
        _email: &EmailConfig,
        _alert: &Alert,
    ) -> Result<(), MonitoringError> {
        // Implement email sending
        Ok(())
    }

    /// Send Slack alert
    async fn send_slack_alert(
        &self,
        _slack: &SlackConfig,
        _alert: &Alert,
    ) -> Result<(), MonitoringError> {
        // Implement Slack sending
        Ok(())
    }

    /// Load dashboards configuration
    async fn load_dashboards(&mut self) -> Result<(), MonitoringError> {
        self.dashboards = self.config.dashboards.clone();
        Ok(())
    }

    /// Provision Grafana dashboards
    async fn provision_grafana_dashboards(&self) -> Result<(), MonitoringError> {
        for dashboard in &self.config.dashboards {
            tracing::info!(title = %dashboard.title, "Provisioning Grafana dashboard");
        }
        Ok(())
    }

    /// Export metrics in Prometheus format
    pub fn export_prometheus_metrics(&self) -> String {
        let mut output = String::new();

        for (name, metric) in &self.metrics {
            // Add metric metadata
            output.push_str(&format!("# HELP {} {}\n", name, metric.description));
            output.push_str(&format!(
                "# TYPE {} {}\n",
                name,
                match metric.metric_type {
                    MetricType::Counter => "counter",
                    MetricType::Gauge => "gauge",
                    MetricType::Histogram => "histogram",
                    MetricType::Summary => "summary",
                }
            ));

            // Add metric values
            for value in &metric.values {
                let labels = if value.labels.is_empty() {
                    String::new()
                } else {
                    let label_pairs: Vec<String> = value
                        .labels
                        .iter()
                        .map(|(k, v)| format!("{}=\"{}\"", k, v))
                        .collect();
                    format!("{{{}}}", label_pairs.join(","))
                };

                output.push_str(&format!(
                    "{}{} {} {}\n",
                    name,
                    labels,
                    value.value,
                    value.timestamp * 1000
                ));
            }
        }

        output
    }

    /// Get current metrics
    pub fn get_metrics(&self) -> &HashMap<String, Metric> {
        &self.metrics
    }

    /// Get active alerts
    pub fn get_active_alerts(&self) -> &Vec<Alert> {
        &self.active_alerts
    }

    /// Get dashboards
    pub fn get_dashboards(&self) -> &Vec<Dashboard> {
        &self.dashboards
    }
}

impl Default for MonitoringConfig {
    fn default() -> Self {
        Self {
            enabled: true,
            prometheus: PrometheusConfig {
                endpoint: "http://localhost:9090".to_string(),
                scrape_interval: Duration::from_secs(15),
                evaluation_interval: Duration::from_secs(15),
                external_labels: HashMap::new(),
                rule_files: vec!["alerts.yml".to_string()],
            },
            grafana: GrafanaConfig {
                endpoint: "http://localhost:3000".to_string(),
                api_key: "".to_string(),
                organization: "Main Org.".to_string(),
                datasource: "Prometheus".to_string(),
                auto_provision: true,
            },
            alertmanager: AlertManagerConfig {
                endpoint: "http://localhost:9093".to_string(),
                receivers: vec![AlertReceiver {
                    name: "default".to_string(),
                    webhook_configs: Vec::new(),
                    email_configs: Vec::new(),
                    slack_configs: Vec::new(),
                }],
                routing: AlertRouting {
                    group_by: vec!["alertname".to_string()],
                    group_wait: Duration::from_secs(10),
                    group_interval: Duration::from_secs(10),
                    repeat_interval: Duration::from_secs(3600),
                    receiver: "default".to_string(),
                    routes: Vec::new(),
                },
                inhibit_rules: Vec::new(),
            },
            custom_exporters: Vec::new(),
            dashboards: Vec::new(),
            retention_policy: RetentionPolicy {
                default_retention: Duration::from_secs(30 * 24 * 3600), // 30 days
                metric_retentions: HashMap::new(),
                downsampling_rules: Vec::new(),
            },
        }
    }
}

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

    #[test]
    fn test_monitoring_system_creation() {
        let config = MonitoringConfig::default();
        let system = MonitoringSystem::new(config);

        assert!(system.metrics.is_empty());
        assert!(system.alert_rules.is_empty());
        assert!(system.active_alerts.is_empty());
    }

    #[tokio::test]
    async fn test_metric_registration() {
        let config = MonitoringConfig::default();
        let mut system = MonitoringSystem::new(config);

        let metric = Metric {
            name: "test_metric".to_string(),
            metric_type: MetricType::Counter,
            description: "Test metric".to_string(),
            unit: "count".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(3600),
        };

        system.register_metric(metric);
        assert!(system.metrics.contains_key("test_metric"));
    }

    #[tokio::test]
    async fn test_metric_recording() {
        let config = MonitoringConfig::default();
        let mut system = MonitoringSystem::new(config);

        let metric = Metric {
            name: "test_counter".to_string(),
            metric_type: MetricType::Counter,
            description: "Test counter".to_string(),
            unit: "count".to_string(),
            values: Vec::new(),
            retention: Duration::from_secs(3600),
        };

        system.register_metric(metric);

        let mut labels = HashMap::new();
        labels.insert("service".to_string(), "auth".to_string());

        let result = system.record_metric("test_counter", 1.0, labels);
        assert!(result.is_ok());

        let metric = system.metrics.get("test_counter").unwrap();
        assert_eq!(metric.values.len(), 1);
        assert_eq!(metric.values[0].value, 1.0);
    }

    #[test]
    fn test_prometheus_export() {
        let config = MonitoringConfig::default();
        let mut system = MonitoringSystem::new(config);

        let metric = Metric {
            name: "test_gauge".to_string(),
            metric_type: MetricType::Gauge,
            description: "Test gauge".to_string(),
            unit: "value".to_string(),
            values: vec![MetricValue {
                value: 42.0,
                timestamp: 1640995200,
                labels: HashMap::new(),
            }],
            retention: Duration::from_secs(3600),
        };

        system.register_metric(metric);

        let export = system.export_prometheus_metrics();
        assert!(export.contains("# HELP test_gauge Test gauge"));
        assert!(export.contains("# TYPE test_gauge gauge"));
        assert!(export.contains("test_gauge 42"));
    }
}