hammerwork_web/api/

system.rs

//! System information and administration API endpoints.
//!
//! This module provides comprehensive system administration and information endpoints
//! for monitoring the web dashboard service, runtime metrics, and maintenance operations.
//!
//! # API Endpoints
//!
//! - `GET /api/system/info` - Complete system information including build and runtime details
//! - `GET /api/system/config` - Current server configuration
//! - `GET /api/system/metrics` - Metrics and monitoring information
//! - `POST /api/system/maintenance` - Perform maintenance operations
//! - `GET /api/version` - Basic version information
//!
//! # Examples
//!
//! ## System Information
//!
//! ```rust
//! use hammerwork_web::api::system::{SystemInfo, BuildInfo, RuntimeInfo, DatabaseInfo};
//! use chrono::Utc;
//!
//! let build_info = BuildInfo {
//!     version: "1.3.0".to_string(),
//!     git_commit: Some("a1b2c3d".to_string()),
//!     build_date: Some("2024-01-15".to_string()),
//!     rust_version: "1.70.0".to_string(),
//!     target_triple: "x86_64-unknown-linux-gnu".to_string(),
//! };
//!
//! let runtime_info = RuntimeInfo {
//!     process_id: 12345,
//!     memory_usage_bytes: Some(134217728), // 128MB
//!     cpu_usage_percent: Some(5.2),
//!     thread_count: Some(8),
//!     gc_collections: None, // Not applicable for Rust
//! };
//!
//! let database_info = DatabaseInfo {
//!     database_type: "PostgreSQL".to_string(),
//!     connection_url: "***masked***".to_string(),
//!     pool_size: 10,
//!     active_connections: Some(3),
//!     connection_health: true,
//!     last_migration: Some("20240101_initial".to_string()),
//! };
//!
//! let system_info = SystemInfo {
//!     version: "1.3.0".to_string(),
//!     build_info,
//!     runtime_info,
//!     database_info,
//!     features: vec!["postgres".to_string(), "auth".to_string()],
//!     uptime_seconds: 86400,
//!     started_at: Utc::now(),
//! };
//!
//! assert_eq!(system_info.version, "1.3.0");
//! assert!(system_info.features.contains(&"postgres".to_string()));
//! assert_eq!(system_info.runtime_info.process_id, 12345);
//! ```
//!
//! ## Maintenance Operations
//!
//! ```rust
//! use hammerwork_web::api::system::MaintenanceRequest;
//! use serde_json::json;
//!
//! let cleanup_request = MaintenanceRequest {
//!     operation: "cleanup".to_string(),
//!     target: Some("old_jobs".to_string()),
//!     dry_run: Some(true),
//! };
//!
//! let vacuum_request = MaintenanceRequest {
//!     operation: "vacuum".to_string(),
//!     target: Some("hammerwork_jobs".to_string()),
//!     dry_run: Some(false),
//! };
//!
//! assert_eq!(cleanup_request.operation, "cleanup");
//! assert_eq!(cleanup_request.dry_run, Some(true));
//! assert_eq!(vacuum_request.operation, "vacuum");
//! ```
//!
//! ## Server Configuration
//!
//! ```rust
//! use hammerwork_web::api::system::ServerConfig;
//!
//! let config = ServerConfig {
//!     bind_address: "0.0.0.0".to_string(),
//!     port: 8080,
//!     authentication_enabled: true,
//!     cors_enabled: false,
//!     websocket_max_connections: 100,
//!     static_assets_path: "/var/www/dashboard".to_string(),
//! };
//!
//! assert_eq!(config.bind_address, "0.0.0.0");
//! assert_eq!(config.port, 8080);
//! assert!(config.authentication_enabled);
//! assert!(!config.cors_enabled);
//! ```
//!
//! ## Metrics Information
//!
//! ```rust
//! use hammerwork_web::api::system::MetricsInfo;
//! use chrono::Utc;
//!
//! let metrics_info = MetricsInfo {
//!     prometheus_enabled: true,
//!     metrics_endpoint: "/metrics".to_string(),
//!     custom_metrics_count: Some(15),
//!     last_scrape: Some(Utc::now()),
//! };
//!
//! assert!(metrics_info.prometheus_enabled);
//! assert_eq!(metrics_info.metrics_endpoint, "/metrics");
//! assert_eq!(metrics_info.custom_metrics_count, Some(15));
//! ```

use super::history::{FinishedKind, JobHistory, TableMaintenance, maintenance_tables};
use super::{ApiResponse, error_reply, json_reply, with_shared};
use hammerwork::queue::DatabaseQueue;
use serde::{Deserialize, Serialize};
use std::sync::Arc;
use tokio::sync::RwLock;
use warp::http::StatusCode;
use warp::{Filter, Reply};

/// Shared system state for tracking runtime information
#[derive(Clone)]
pub struct SystemState {
    /// Application start time
    pub started_at: chrono::DateTime<chrono::Utc>,
    /// Server configuration
    pub config: crate::DashboardConfig,
    /// Database type (detected at runtime)
    pub database_type: String,
    /// Pool size from actual connection pool
    pub pool_size: u32,
}

impl SystemState {
    pub fn new(config: crate::DashboardConfig, database_type: String, pool_size: u32) -> Self {
        Self {
            started_at: chrono::Utc::now(),
            config,
            database_type,
            pool_size,
        }
    }

    /// Seconds since the dashboard started; never negative, even if the clock went
    /// backwards since.
    pub fn uptime_seconds(&self) -> i64 {
        (chrono::Utc::now() - self.started_at).num_seconds().max(0)
    }
}

/// System information
#[derive(Debug, Serialize)]
pub struct SystemInfo {
    pub version: String,
    pub build_info: BuildInfo,
    pub runtime_info: RuntimeInfo,
    pub database_info: DatabaseInfo,
    pub features: Vec<String>,
    pub uptime_seconds: u64,
    pub started_at: chrono::DateTime<chrono::Utc>,
}

/// Build information
#[derive(Debug, Serialize)]
pub struct BuildInfo {
    pub version: String,
    pub git_commit: Option<String>,
    pub build_date: Option<String>,
    pub rust_version: String,
    pub target_triple: String,
}

/// Runtime information
#[derive(Debug, Serialize)]
pub struct RuntimeInfo {
    pub process_id: u32,
    pub memory_usage_bytes: Option<u64>,
    pub cpu_usage_percent: Option<f64>,
    pub thread_count: Option<usize>,
    pub gc_collections: Option<u64>,
}

/// Database information
#[derive(Debug, Serialize)]
pub struct DatabaseInfo {
    pub database_type: String,
    pub connection_url: String, // Masked for security
    pub pool_size: u32,
    pub active_connections: Option<u32>,
    pub connection_health: bool,
    pub last_migration: Option<String>,
}

/// Server configuration
#[derive(Debug, Serialize)]
pub struct ServerConfig {
    pub bind_address: String,
    pub port: u16,
    pub authentication_enabled: bool,
    pub cors_enabled: bool,
    pub websocket_max_connections: usize,
    pub static_assets_path: String,
}

/// Metrics endpoint information
#[derive(Debug, Serialize)]
pub struct MetricsInfo {
    pub prometheus_enabled: bool,
    pub metrics_endpoint: String,
    /// `null`: the dashboard keeps no metrics registry, so there is nothing to count.
    pub custom_metrics_count: Option<u32>,
    pub last_scrape: Option<chrono::DateTime<chrono::Utc>>,
}

/// Configuration update request
#[derive(Debug, Deserialize)]
pub struct ConfigUpdateRequest {
    pub setting: String,
    pub value: serde_json::Value,
}

/// Maintenance operation request.
///
/// - `cleanup`: deletes dead jobs older than 7 days.
/// - `vacuum`, `reindex`, `optimize`: table maintenance on the Hammerwork tables, see
///   [`TableMaintenance`] for the statements each runs per backend. `target` may name one
///   Hammerwork table (e.g. `hammerwork_jobs`); any other name is rejected. The response
///   lists the statements that ran, or with `dry_run` the ones that would run.
#[derive(Debug, Deserialize)]
pub struct MaintenanceRequest {
    /// `"cleanup"`, `"vacuum"`, `"reindex"` or `"optimize"`.
    pub operation: String,
    /// For table maintenance, a single Hammerwork table name; all of them when absent.
    pub target: Option<String>,
    pub dry_run: Option<bool>,
}

/// Create system routes
pub fn routes<T>(
    queue: Arc<T>,
    system_state: Arc<RwLock<SystemState>>,
) -> impl Filter<Extract = impl Reply, Error = warp::Rejection> + Clone
where
    T: JobHistory + 'static,
{
    let queue_filter = with_shared(queue);
    let state_filter = with_shared(system_state);

    let info = warp::path("system")
        .and(warp::path("info"))
        .and(warp::path::end())
        .and(warp::get())
        .and(queue_filter.clone())
        .and(state_filter.clone())
        .and_then(system_info_handler);

    let config = warp::path("system")
        .and(warp::path("config"))
        .and(warp::path::end())
        .and(warp::get())
        .and(state_filter.clone())
        .and_then(system_config_handler);

    let metrics_info = warp::path("system")
        .and(warp::path("metrics"))
        .and(warp::path::end())
        .and(warp::get())
        .and(state_filter.clone())
        .and_then(metrics_info_handler);

    let maintenance = warp::path("system")
        .and(warp::path("maintenance"))
        .and(warp::path::end())
        .and(warp::post())
        .and(queue_filter.clone())
        .and(crate::security::json_body())
        .and_then(maintenance_handler);

    let version = warp::path("version")
        .and(warp::path::end())
        .and(warp::get())
        .and_then(version_handler);

    info.or(config).or(metrics_info).or(maintenance).or(version)
}

/// Handler for system information
async fn system_info_handler<T>(
    queue: Arc<T>,
    system_state: Arc<RwLock<SystemState>>,
) -> Result<impl Reply, warp::Rejection>
where
    T: DatabaseQueue + Send + Sync,
{
    // Test database connection
    let database_healthy = queue.get_all_queue_stats().await.is_ok();

    let build_info = BuildInfo {
        version: env!("CARGO_PKG_VERSION").to_string(),
        git_commit: option_env!("GIT_COMMIT").map(|s| s.to_string()),
        build_date: option_env!("BUILD_DATE").map(|s| s.to_string()),
        rust_version: get_rust_version(),
        target_triple: get_target_triple(),
    };

    let runtime_info = RuntimeInfo {
        process_id: std::process::id(),
        memory_usage_bytes: get_memory_usage(),
        cpu_usage_percent: None, // unavailable
        thread_count: None,      // Would need thread monitoring
        gc_collections: None,    // Not applicable for Rust
    };

    let state = system_state.read().await;

    let database_info = DatabaseInfo {
        database_type: state.database_type.clone(),
        connection_url: "***masked***".to_string(),
        pool_size: state.pool_size,
        active_connections: None, // Would need pool access
        connection_health: database_healthy,
        last_migration: None, // Would need migration table query
    };

    let features = vec![
        #[cfg(feature = "postgres")]
        "postgres".to_string(),
        #[cfg(feature = "mysql")]
        "mysql".to_string(),
        #[cfg(feature = "auth")]
        "auth".to_string(),
    ];

    let system_info = SystemInfo {
        version: env!("CARGO_PKG_VERSION").to_string(),
        build_info,
        runtime_info,
        database_info,
        features,
        uptime_seconds: u64::try_from(state.uptime_seconds()).unwrap_or(0),
        started_at: state.started_at,
    };

    Ok(json_reply(&ApiResponse::success(system_info)))
}

/// Handler for system configuration
async fn system_config_handler(
    system_state: Arc<RwLock<SystemState>>,
) -> Result<impl Reply, warp::Rejection> {
    let state = system_state.read().await;
    let config = ServerConfig {
        bind_address: state.config.bind_address.clone(),
        port: state.config.port,
        authentication_enabled: state.config.auth.enabled,
        cors_enabled: state.config.enable_cors,
        websocket_max_connections: state.config.websocket.max_connections,
        static_assets_path: state.config.static_dir.to_string_lossy().to_string(),
    };

    Ok(json_reply(&ApiResponse::success(config)))
}

/// Handler for metrics information
async fn metrics_info_handler(
    _system_state: Arc<RwLock<SystemState>>,
) -> Result<impl Reply, warp::Rejection> {
    let metrics_info = MetricsInfo {
        // hammerwork-web does not serve a Prometheus endpoint itself (there is no
        // `metrics` feature on this crate), so this is always false.
        prometheus_enabled: false,
        metrics_endpoint: "/metrics".to_string(),
        custom_metrics_count: get_custom_metrics_count(),
        last_scrape: get_last_scrape_time().await,
    };

    Ok(json_reply(&ApiResponse::success(metrics_info)))
}

/// Handler for maintenance operations
async fn maintenance_handler<T>(
    queue: Arc<T>,
    request: MaintenanceRequest,
) -> Result<impl Reply, warp::Rejection>
where
    T: JobHistory,
{
    let dry_run = request.dry_run.unwrap_or(false);

    match request.operation.as_str() {
        "cleanup" => {
            let older_than = chrono::Utc::now() - chrono::Duration::days(7); // Remove jobs older than 7 days
            if dry_run {
                match queue
                    .count_jobs(None, FinishedKind::Dead, Some(older_than))
                    .await
                {
                    Ok(count) => {
                        let response = ApiResponse::success(serde_json::json!({
                            "operation": "cleanup",
                            "dry_run": true,
                            "message": format!("Dry run: would clean up {} dead jobs older than 7 days", count),
                            "estimated_deletions": count
                        }));
                        Ok(json_reply(&response))
                    }
                    Err(e) => Ok(error_reply(
                        StatusCode::INTERNAL_SERVER_ERROR,
                        format!("Cleanup dry run failed: {}", e),
                    )),
                }
            } else {
                match queue.purge_dead_jobs(older_than).await {
                    Ok(count) => {
                        let response = ApiResponse::success(serde_json::json!({
                            "operation": "cleanup",
                            "dry_run": false,
                            "message": format!("Cleaned up {} dead jobs", count),
                            "deletions": count
                        }));
                        Ok(json_reply(&response))
                    }
                    Err(e) => Ok(error_reply(
                        StatusCode::INTERNAL_SERVER_ERROR,
                        format!("Cleanup failed: {}", e),
                    )),
                }
            }
        }
        name => {
            let Some(operation) = TableMaintenance::parse(name) else {
                return Ok(error_reply(
                    StatusCode::BAD_REQUEST,
                    format!("Unknown maintenance operation: {}", request.operation),
                ));
            };
            // `target` only selects among the fixed Hammerwork table names; it is never
            // put into SQL.
            let tables = match maintenance_tables(request.target.as_deref()) {
                Ok(tables) => tables,
                Err(message) => return Ok(error_reply(StatusCode::BAD_REQUEST, message)),
            };
            match queue.table_maintenance(operation, &tables, dry_run).await {
                Ok(statements) => {
                    let message = if dry_run {
                        format!("Dry run: would run {} statements", statements.len())
                    } else {
                        format!("Ran {} on {} tables", name, statements.len())
                    };
                    Ok(json_reply(&ApiResponse::success(serde_json::json!({
                        "operation": operation,
                        "dry_run": dry_run,
                        "message": message,
                        "statements": statements,
                    }))))
                }
                Err(e) => Ok(error_reply(
                    StatusCode::INTERNAL_SERVER_ERROR,
                    format!("{} failed: {}", name, e),
                )),
            }
        }
    }
}

/// Handler for version information
async fn version_handler() -> Result<impl Reply, warp::Rejection> {
    let version_info = serde_json::json!({
        "version": env!("CARGO_PKG_VERSION"),
        "name": env!("CARGO_PKG_NAME"),
        "description": env!("CARGO_PKG_DESCRIPTION"),
        "authors": env!("CARGO_PKG_AUTHORS").split(':').collect::<Vec<_>>(),
        "repository": env!("CARGO_PKG_REPOSITORY"),
        "license": env!("CARGO_PKG_LICENSE"),
        "rust_version": get_rust_version(),
        "build_target": get_target_triple(),
    });

    Ok(json_reply(&ApiResponse::success(version_info)))
}

/// Get Rust compiler version
fn get_rust_version() -> String {
    option_env!("RUSTC_VERSION")
        .unwrap_or("unknown")
        .to_string()
}

/// Get target triple
fn get_target_triple() -> String {
    std::env::consts::ARCH.to_string() + "-" + std::env::consts::OS
}

/// Get memory usage (platform-specific)
fn get_memory_usage() -> Option<u64> {
    #[cfg(target_os = "linux")]
    {
        use std::fs;
        if let Ok(contents) = fs::read_to_string("/proc/self/status") {
            for line in contents.lines() {
                if let Some(rest) = line.strip_prefix("VmRSS:")
                    && let Some(kb) = rest
                        .split_whitespace()
                        .next()
                        .and_then(|s| s.parse::<u64>().ok())
                {
                    return Some(kb.saturating_mul(1024)); // Convert KB to bytes
                }
            }
        }
    }

    // Other platforms: current resident memory has no portable std API (macOS and Windows
    // need platform calls; `getrusage` only reports the peak), so report it as unavailable
    // rather than invent a number.
    None
}

/// Count of custom metrics: unavailable, hammerwork-web serves no metrics registry.
fn get_custom_metrics_count() -> Option<u32> {
    None
}

/// Last metrics scrape: unavailable, hammerwork-web serves no metrics endpoint.
async fn get_last_scrape_time() -> Option<chrono::DateTime<chrono::Utc>> {
    None
}

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

    /// #94: a clock that went backwards gives zero uptime, not a wrapped `u64`.
    #[test]
    fn uptime_is_never_negative() {
        let mut state = SystemState::new(crate::DashboardConfig::default(), "pg".into(), 1);
        state.started_at = chrono::Utc::now() + chrono::Duration::hours(1);
        assert_eq!(state.uptime_seconds(), 0);
        state.started_at = chrono::Utc::now() - chrono::Duration::seconds(90);
        assert!(state.uptime_seconds() >= 90);
    }

    #[test]
    fn test_maintenance_request_deserialization() {
        let json = r#"{
            "operation": "cleanup",
            "target": "completed_jobs",
            "dry_run": true
        }"#;

        let request: MaintenanceRequest = serde_json::from_str(json).unwrap();
        assert_eq!(request.operation, "cleanup");
        assert_eq!(request.target, Some("completed_jobs".to_string()));
        assert_eq!(request.dry_run, Some(true));
    }

    #[test]
    fn test_build_info_creation() {
        let build_info = BuildInfo {
            version: "1.0.0".to_string(),
            git_commit: Some("abc123".to_string()),
            build_date: Some("2024-01-01".to_string()),
            rust_version: "1.70.0".to_string(),
            target_triple: "x86_64-unknown-linux-gnu".to_string(),
        };

        let json = serde_json::to_string(&build_info).unwrap();
        assert!(json.contains("1.0.0"));
        assert!(json.contains("abc123"));
    }

    #[test]
    fn test_unavailable_metrics_are_none_not_zero() {
        assert_eq!(get_custom_metrics_count(), None);
    }

    #[tokio::test]
    async fn test_cleanup_dry_run_reports_database_failure() {
        let response = maintenance_handler(
            crate::api::test_support::unreachable_queue(),
            MaintenanceRequest {
                operation: "cleanup".to_string(),
                target: None,
                dry_run: Some(true),
            },
        )
        .await
        .unwrap()
        .into_response();
        let (status, _) = crate::api::test_support::body_json(response).await;
        assert_eq!(status, 500);
    }

    async fn maintenance_status(operation: &str, target: Option<&str>) -> u16 {
        let response = maintenance_handler(
            crate::api::test_support::unreachable_queue(),
            MaintenanceRequest {
                operation: operation.to_string(),
                target: target.map(str::to_string),
                dry_run: Some(false),
            },
        )
        .await
        .unwrap()
        .into_response();
        crate::api::test_support::body_json(response).await.0
    }

    #[tokio::test]
    async fn test_table_maintenance_rejects_foreign_tables_before_the_database() {
        for operation in ["vacuum", "reindex", "optimize"] {
            assert_eq!(maintenance_status(operation, Some("users")).await, 400);
            // A Hammerwork table passes validation and then fails on the dead database.
            assert_eq!(
                maintenance_status(operation, Some("hammerwork_jobs")).await,
                500
            );
        }
        assert_eq!(maintenance_status("defrag", None).await, 400);
    }

    #[test]
    fn test_get_rust_version() {
        let version = get_rust_version();
        assert!(!version.is_empty());
    }

    #[test]
    fn test_get_target_triple() {
        let target = get_target_triple();
        assert!(!target.is_empty());
        assert!(target.contains("-"));
    }
}