//! Dashboard visualization for operational monitoring
//!
//! Provides web-based dashboard for visualizing system metrics,
//! logs, traces, and alerts.

use crate::monitoring::{LogAggregator, DistributedTracer, AlertManager, MetricsCollector};
use crate::network::error::{NetworkError, NetworkResult};

use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::sync::Arc;
use tokio::sync::RwLock;
use uuid::Uuid;
use log::{debug, info};

/// Dashboard configuration
#[derive(Debug, Clone)]
pub struct DashboardConfig {
    pub enabled: bool,
    pub port: u16,
    pub host: String,
    pub refresh_interval_seconds: u64,
    pub max_data_points: usize,
}

impl Default for DashboardConfig {
    fn default() -> Self {
        Self {
            enabled: true,
            port: 8080,
            host: "0.0.0.0".to_string(),
            refresh_interval_seconds: 5,
            max_data_points: 1000,
        }
    }
}

/// Dashboard widget types
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum WidgetType {
    MetricChart,
    LogViewer,
    AlertList,
    TraceViewer,
    NodeMap,
    SystemHealth,
}

/// Dashboard widget configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct Widget {
    pub id: Uuid,
    pub title: String,
    pub widget_type: WidgetType,
    pub config: WidgetConfig,
    pub position: WidgetPosition,
    pub size: WidgetSize,
}

/// Widget-specific configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum WidgetConfig {
    MetricChart {
        metrics: Vec<String>,
        time_range: String,
        chart_type: String,
    },
    LogViewer {
        filters: HashMap<String, String>,
        max_entries: usize,
    },
    AlertList {
        severities: Vec<String>,
        states: Vec<String>,
    },
    TraceViewer {
        service_filter: Option<String>,
        operation_filter: Option<String>,
    },
    NodeMap {
        show_connections: bool,
        show_load: bool,
    },
    SystemHealth {
        components: Vec<String>,
    },
}

/// Widget position on dashboard
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct WidgetPosition {
    pub x: u32,
    pub y: u32,
}

/// Widget size
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct WidgetSize {
    pub width: u32,
    pub height: u32,
}

/// Dashboard layout
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DashboardLayout {
    pub id: Uuid,
    pub name: String,
    pub description: String,
    pub widgets: Vec<Widget>,
    pub created_at: u64,
    pub updated_at: u64,
}

/// Dashboard data point
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DataPoint {
    pub timestamp: u64,
    pub value: f64,
    pub labels: HashMap<String, String>,
}

/// Dashboard time series
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TimeSeries {
    pub name: String,
    pub points: Vec<DataPoint>,
    pub unit: Option<String>,
}

/// Dashboard API response
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DashboardData {
    pub metrics: HashMap<String, TimeSeries>,
    pub logs: Vec<LogEntry>,
    pub alerts: Vec<AlertSummary>,
    pub traces: Vec<TraceSummary>,
    pub system_health: SystemHealthStatus,
    pub node_status: Vec<NodeStatus>,
}

/// Log entry for dashboard
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct LogEntry {
    pub timestamp: u64,
    pub level: String,
    pub component: String,
    pub message: String,
    pub node_id: String,
}

/// Alert summary for dashboard
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct AlertSummary {
    pub id: Uuid,
    pub rule_name: String,
    pub severity: String,
    pub state: String,
    pub message: String,
    pub started_at: u64,
    pub node_id: String,
}

/// Trace summary for dashboard
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TraceSummary {
    pub trace_id: Uuid,
    pub operation_name: String,
    pub duration_micros: u64,
    pub span_count: usize,
    pub error_count: usize,
    pub service_count: usize,
}

/// System health status
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SystemHealthStatus {
    pub overall_status: String,
    pub components: HashMap<String, ComponentHealth>,
    pub uptime_seconds: u64,
}

/// Component health status
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct ComponentHealth {
    pub status: String,
    pub last_check: u64,
    pub error_count: u64,
    pub details: HashMap<String, String>,
}

/// Node status for dashboard
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NodeStatus {
    pub node_id: String,
    pub status: String,
    pub last_seen: u64,
    pub cpu_usage: f64,
    pub memory_usage: f64,
    pub disk_usage: f64,
    pub connections: u32,
}

/// Dashboard web server
pub struct Dashboard {
    config: DashboardConfig,
    node_id: String,
    log_aggregator: Arc<LogAggregator>,
    tracer: Arc<DistributedTracer>,
    alert_manager: Arc<AlertManager>,
    metrics_collector: Arc<MetricsCollector>,
    layouts: Arc<RwLock<HashMap<Uuid, DashboardLayout>>>,
}

impl Dashboard {
    /// Create a new dashboard
    pub fn new(
        config: DashboardConfig,
        node_id: String,
        log_aggregator: Arc<LogAggregator>,
        tracer: Arc<DistributedTracer>,
        alert_manager: Arc<AlertManager>,
        metrics_collector: Arc<MetricsCollector>,
    ) -> Self {
        Self {
            config,
            node_id,
            log_aggregator,
            tracer,
            alert_manager,
            metrics_collector,
            layouts: Arc::new(RwLock::new(HashMap::new())),
        }
    }

    /// Start the dashboard web server
    pub async fn start(&self) -> NetworkResult<()> {
        if !self.config.enabled {
            info!("Dashboard is disabled");
            return Ok(());
        }

        info!("Starting dashboard on {}:{}", self.config.host, self.config.port);

        // Create default layout
        self.create_default_layout().await?;

        // Start web server (simplified implementation)
        self.start_web_server().await?;

        Ok(())
    }

    /// Create default dashboard layout
    async fn create_default_layout(&self) -> NetworkResult<()> {
        let default_layout = DashboardLayout {
            id: Uuid::new_v4(),
            name: "Default Dashboard".to_string(),
            description: "Default monitoring dashboard".to_string(),
            widgets: vec![
                // System metrics chart
                Widget {
                    id: Uuid::new_v4(),
                    title: "System Metrics".to_string(),
                    widget_type: WidgetType::MetricChart,
                    config: WidgetConfig::MetricChart {
                        metrics: vec![
                            "cpu_usage_percent".to_string(),
                            "memory_usage_percent".to_string(),
                            "disk_usage_percent".to_string(),
                        ],
                        time_range: "1h".to_string(),
                        chart_type: "line".to_string(),
                    },
                    position: WidgetPosition { x: 0, y: 0 },
                    size: WidgetSize { width: 6, height: 4 },
                },
                // Message throughput
                Widget {
                    id: Uuid::new_v4(),
                    title: "Message Throughput".to_string(),
                    widget_type: WidgetType::MetricChart,
                    config: WidgetConfig::MetricChart {
                        metrics: vec![
                            "messages_sent_total".to_string(),
                            "messages_received_total".to_string(),
                        ],
                        time_range: "1h".to_string(),
                        chart_type: "line".to_string(),
                    },
                    position: WidgetPosition { x: 6, y: 0 },
                    size: WidgetSize { width: 6, height: 4 },
                },
                // Active alerts
                Widget {
                    id: Uuid::new_v4(),
                    title: "Active Alerts".to_string(),
                    widget_type: WidgetType::AlertList,
                    config: WidgetConfig::AlertList {
                        severities: vec!["critical".to_string(), "warning".to_string()],
                        states: vec!["firing".to_string(), "pending".to_string()],
                    },
                    position: WidgetPosition { x: 0, y: 4 },
                    size: WidgetSize { width: 4, height: 3 },
                },
                // Recent logs
                Widget {
                    id: Uuid::new_v4(),
                    title: "Recent Logs".to_string(),
                    widget_type: WidgetType::LogViewer,
                    config: WidgetConfig::LogViewer {
                        filters: HashMap::new(),
                        max_entries: 100,
                    },
                    position: WidgetPosition { x: 4, y: 4 },
                    size: WidgetSize { width: 4, height: 3 },
                },
                // Node map
                Widget {
                    id: Uuid::new_v4(),
                    title: "Cluster Topology".to_string(),
                    widget_type: WidgetType::NodeMap,
                    config: WidgetConfig::NodeMap {
                        show_connections: true,
                        show_load: true,
                    },
                    position: WidgetPosition { x: 8, y: 4 },
                    size: WidgetSize { width: 4, height: 3 },
                },
                // System health
                Widget {
                    id: Uuid::new_v4(),
                    title: "System Health".to_string(),
                    widget_type: WidgetType::SystemHealth,
                    config: WidgetConfig::SystemHealth {
                        components: vec![
                            "broker".to_string(),
                            "storage".to_string(),
                            "network".to_string(),
                            "replication".to_string(),
                        ],
                    },
                    position: WidgetPosition { x: 0, y: 7 },
                    size: WidgetSize { width: 12, height: 2 },
                },
            ],
            created_at: std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .unwrap()
                .as_secs(),
            updated_at: std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .unwrap()
                .as_secs(),
        };

        let mut layouts = self.layouts.write().await;
        layouts.insert(default_layout.id, default_layout.clone());

        info!("Created default dashboard layout: {}", default_layout.id);
        Ok(())
    }

    /// Get dashboard data for API
    pub async fn get_dashboard_data(&self, layout_id: Option<Uuid>) -> NetworkResult<DashboardData> {
        let layouts = self.layouts.read().await;
        let layout = if let Some(id) = layout_id {
            layouts.get(&id)
        } else {
            layouts.values().next()
        };

        if layout.is_none() {
            return Err(NetworkError::InternalError("No dashboard layout found".to_string()));
        }

        // Collect metrics
        let metrics = self.collect_metrics_data().await?;

        // Collect logs
        let logs = self.collect_logs_data().await?;

        // Collect alerts
        let alerts = self.collect_alerts_data().await?;

        // Collect traces
        let traces = self.collect_traces_data().await?;

        // Collect system health
        let system_health = self.collect_system_health().await?;

        // Collect node status
        let node_status = self.collect_node_status().await?;

        Ok(DashboardData {
            metrics,
            logs,
            alerts,
            traces,
            system_health,
            node_status,
        })
    }

    /// Collect metrics data
    async fn collect_metrics_data(&self) -> NetworkResult<HashMap<String, TimeSeries>> {
        let mut metrics = HashMap::new();

        // Get metrics from metrics collector
        let collector_metrics = self.metrics_collector.get_all_metrics().await;

        for (name, values) in collector_metrics {
            let points: Vec<DataPoint> = values.into_iter().map(|(timestamp, value)| {
                DataPoint {
                    timestamp,
                    value,
                    labels: HashMap::new(),
                }
            }).collect();

            metrics.insert(name.clone(), TimeSeries {
                name,
                points,
                unit: None,
            });
        }

        debug!("Collected {} metric series", metrics.len());
        Ok(metrics)
    }

    /// Collect logs data
    async fn collect_logs_data(&self) -> NetworkResult<Vec<LogEntry>> {
        use crate::monitoring::log_aggregation::LogQueryCriteria;

        let criteria = LogQueryCriteria {
            level: None,
            component: None,
            trace_id: None,
            start_time: Some(
                std::time::SystemTime::now()
                    .duration_since(std::time::UNIX_EPOCH)
                    .unwrap()
                    .as_secs() - 3600
            ), // Last hour
            end_time: None,
            limit: Some(100),
        };

        let log_entries = self.log_aggregator.query_logs(criteria).await?;

        let dashboard_logs: Vec<LogEntry> = log_entries.into_iter().map(|entry| {
            LogEntry {
                timestamp: entry.timestamp,
                level: format!("{:?}", entry.level),
                component: entry.component,
                message: entry.message,
                node_id: entry.source_node,
            }
        }).collect();

        debug!("Collected {} log entries", dashboard_logs.len());
        Ok(dashboard_logs)
    }

    /// Collect alerts data
    async fn collect_alerts_data(&self) -> NetworkResult<Vec<AlertSummary>> {
        let active_alerts = self.alert_manager.get_active_alerts().await;

        let alert_summaries: Vec<AlertSummary> = active_alerts.into_iter().map(|alert| {
            AlertSummary {
                id: alert.id,
                rule_name: alert.rule_name,
                severity: format!("{:?}", alert.severity),
                state: format!("{:?}", alert.state),
                message: alert.message,
                started_at: alert.started_at,
                node_id: alert.node_id,
            }
        }).collect();

        debug!("Collected {} active alerts", alert_summaries.len());
        Ok(alert_summaries)
    }

    /// Collect traces data
    async fn collect_traces_data(&self) -> NetworkResult<Vec<TraceSummary>> {
        // For now, return sample trace data
        // In a real implementation, this would query the tracer
        let traces = vec![
            TraceSummary {
                trace_id: Uuid::new_v4(),
                operation_name: "message_send".to_string(),
                duration_micros: 1500,
                span_count: 3,
                error_count: 0,
                service_count: 2,
            },
            TraceSummary {
                trace_id: Uuid::new_v4(),
                operation_name: "replication".to_string(),
                duration_micros: 5200,
                span_count: 5,
                error_count: 1,
                service_count: 3,
            },
        ];

        debug!("Collected {} trace summaries", traces.len());
        Ok(traces)
    }

    /// Collect system health data
    async fn collect_system_health(&self) -> NetworkResult<SystemHealthStatus> {
        let mut components = HashMap::new();

        // Broker health
        components.insert("broker".to_string(), ComponentHealth {
            status: "healthy".to_string(),
            last_check: std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .unwrap()
                .as_secs(),
            error_count: 0,
            details: [("version".to_string(), "0.15.0".to_string())].iter().cloned().collect(),
        });

        // Storage health
        components.insert("storage".to_string(), ComponentHealth {
            status: "healthy".to_string(),
            last_check: std::time::SystemTime::now()
                .duration_since(std::time::UNIX_EPOCH)
                .unwrap()
                .as_secs(),
            error_count: 0,
            details: [("disk_usage".to_string(), "45%".to_string())].iter().cloned().collect(),
        });

        Ok(SystemHealthStatus {
            overall_status: "healthy".to_string(),
            components,
            uptime_seconds: 3600, // Sample uptime
        })
    }

    /// Collect node status data
    async fn collect_node_status(&self) -> NetworkResult<Vec<NodeStatus>> {
        let nodes = vec![
            NodeStatus {
                node_id: self.node_id.clone(),
                status: "online".to_string(),
                last_seen: std::time::SystemTime::now()
                    .duration_since(std::time::UNIX_EPOCH)
                    .unwrap()
                    .as_secs(),
                cpu_usage: 25.5,
                memory_usage: 60.2,
                disk_usage: 45.8,
                connections: 15,
            },
        ];

        debug!("Collected status for {} nodes", nodes.len());
        Ok(nodes)
    }

    /// Start web server (simplified implementation)
    async fn start_web_server(&self) -> NetworkResult<()> {
        // In a real implementation, this would start an HTTP server
        // using frameworks like warp, axum, or actix-web
        info!("Dashboard web server would start on {}:{}", self.config.host, self.config.port);

        // Sample API endpoints:
        // GET /api/dashboard/data
        // GET /api/dashboard/layouts
        // POST /api/dashboard/layouts
        // GET /api/metrics
        // GET /api/logs
        // GET /api/alerts
        // GET /api/traces

        Ok(())
    }

    /// Get available dashboard layouts
    pub async fn get_layouts(&self) -> Vec<DashboardLayout> {
        let layouts = self.layouts.read().await;
        layouts.values().cloned().collect()
    }

    /// Save dashboard layout
    pub async fn save_layout(&self, layout: DashboardLayout) -> NetworkResult<()> {
        let mut layouts = self.layouts.write().await;
        layouts.insert(layout.id, layout.clone());
        info!("Saved dashboard layout: {}", layout.name);
        Ok(())
    }
}
