// api/summary.rs — Dashboard summary server function
//
// Returns the count of each main entity in a single server round-trip.
// The home page uses this to display a quick-glance dashboard without
// loading the full list of each entity.

use leptos::prelude::*;
use serde::{Deserialize, Serialize};

// Counts for every top-level entity shown on the dashboard.
// Add a field here when a new entity type is introduced.
#[derive(Clone, Debug, Serialize, Deserialize, Default)]
pub struct Summary {
    pub network_count: i64,
    pub host_count: i64,
    pub application_count: i64,
}

#[server]
pub async fn get_summary() -> Result<Summary, ServerFnError> {
    use sqlx::AnyPool;
    use leptos::prelude::use_context;

    let pool = use_context::<AnyPool>()
        .ok_or_else(|| ServerFnError::new("Database pool not found in context"))?;

    // Three lightweight COUNT queries — no full table scans on the payload side.
    // sqlx returns COUNT(*) as i64 for both SQLite and PostgreSQL.
    let network_count: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM networks")
        .fetch_one(&pool)
        .await
        .map_err(|e| ServerFnError::new(e.to_string()))?;

    let host_count: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM hosts")
        .fetch_one(&pool)
        .await
        .map_err(|e| ServerFnError::new(e.to_string()))?;

    let application_count: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM applications")
        .fetch_one(&pool)
        .await
        .map_err(|e| ServerFnError::new(e.to_string()))?;

    Ok(Summary { network_count, host_count, application_count })
}