// synops-health — Sjekk status for alle tjenester i Synops-stacken.
//
// Sjekker: PostgreSQL, Caddy, Maskinrommet, LiteLLM, Whisper, LiveKit, Authentik.
// Output: JSON med status per tjeneste + samlet status.
// Exit-kode: 0 = alle oppe, 1 = noe nede/degradert, 2 = kjørefeil.
//
// Brukes av admin-dashboard og overvåking.
//
// Miljøvariabler (alle valgfrie — har fornuftige defaults):
//   DATABASE_URL    — PostgreSQL-tilkobling
//   AI_GATEWAY_URL  — LiteLLM base-URL (default: http://localhost:4000)
//   WHISPER_URL     — faster-whisper base-URL (default: http://localhost:8000)
//   LIVEKIT_URL     — LiveKit base-URL (default: http://localhost:7880)
//
// Ref: docs/infra/observerbarhet.md, maskinrommet/src/health.rs

use clap::Parser;
use serde::Serialize;
use std::process;
use std::time::Instant;

/// Sjekk status for alle Synops-tjenester.
#[derive(Parser)]
#[command(name = "synops-health", about = "Sjekk tjenestestatus for Synops-stacken")]
struct Cli {
    /// Timeout per tjeneste i sekunder
    #[arg(long, default_value = "5")]
    timeout: u64,

    /// Kjør kun stille — bare exit-kode, ingen output
    #[arg(long)]
    quiet: bool,
}

#[derive(Serialize)]
struct HealthReport {
    timestamp: String,
    overall_status: String, // "healthy", "degraded", "critical"
    services: Vec<ServiceStatus>,
}

#[derive(Serialize, Clone)]
struct ServiceStatus {
    name: String,
    status: String, // "up", "down", "degraded"
    latency_ms: Option<u64>,
    #[serde(skip_serializing_if = "Option::is_none")]
    details: Option<String>,
}

#[tokio::main]
async fn main() {
    synops_common::logging::init("synops_health");

    let cli = Cli::parse();
    let timeout = std::time::Duration::from_secs(cli.timeout);

    let http = reqwest::Client::builder()
        .timeout(timeout)
        .danger_accept_invalid_certs(true) // Lokale tjenester kan ha self-signed
        .build()
        .expect("Kunne ikke opprette HTTP-klient");

    // Kjør alle sjekker parallelt
    let (pg, caddy, maskinrommet, litellm, whisper, livekit, authentik) = tokio::join!(
        check_pg(timeout),
        check_http(&http, "Caddy", "http://localhost:2019/config/"),
        check_http(&http, "Maskinrommet", "http://localhost:3100/health"),
        check_litellm(&http),
        check_whisper(&http),
        check_livekit(&http),
        check_http(&http, "Authentik", "https://auth.sidelinja.org/-/health/ready/"),
    );

    let services = vec![pg, caddy, maskinrommet, litellm, whisper, livekit, authentik];

    let overall_status = if services.iter().all(|s| s.status == "up") {
        "healthy"
    } else if services.iter().any(|s| s.status == "down") {
        "degraded"
    } else {
        "degraded"
    }
    .to_string();

    let report = HealthReport {
        timestamp: chrono::Utc::now().to_rfc3339(),
        overall_status: overall_status.clone(),
        services,
    };

    if !cli.quiet {
        println!(
            "{}",
            serde_json::to_string_pretty(&report).expect("JSON-serialisering feilet")
        );
    }

    let exit_code = if overall_status == "healthy" { 0 } else { 1 };
    process::exit(exit_code);
}

// =============================================================================
// Tjeneste-sjekker
// =============================================================================

/// Sjekk PostgreSQL med direkte SQL-spørring.
async fn check_pg(timeout: std::time::Duration) -> ServiceStatus {
    let name = "PostgreSQL".to_string();

    // Prøv å koble til med timeout
    let connect_result = tokio::time::timeout(timeout, synops_common::db::connect()).await;

    match connect_result {
        Ok(Ok(db)) => {
            let start = Instant::now();
            match sqlx::query_scalar::<_, i32>("SELECT 1").fetch_one(&db).await {
                Ok(_) => ServiceStatus {
                    name,
                    status: "up".to_string(),
                    latency_ms: Some(start.elapsed().as_millis() as u64),
                    details: None,
                },
                Err(e) => ServiceStatus {
                    name,
                    status: "down".to_string(),
                    latency_ms: None,
                    details: Some(format!("{e}")),
                },
            }
        }
        Ok(Err(e)) => ServiceStatus {
            name,
            status: "down".to_string(),
            latency_ms: None,
            details: Some(format!("Tilkobling feilet: {e}")),
        },
        Err(_) => ServiceStatus {
            name,
            status: "down".to_string(),
            latency_ms: None,
            details: Some("Timeout".to_string()),
        },
    }
}

/// Sjekk en HTTP-tjeneste. Aksepterer 401/403 som "up" (auth kreves men tjenesten kjører).
async fn check_http(client: &reqwest::Client, name: &str, url: &str) -> ServiceStatus {
    let start = Instant::now();
    match client.get(url).send().await {
        Ok(resp) => {
            let latency = start.elapsed().as_millis() as u64;
            let code = resp.status();
            if code.is_success() || code.as_u16() == 401 || code.as_u16() == 403 {
                ServiceStatus {
                    name: name.to_string(),
                    status: "up".to_string(),
                    latency_ms: Some(latency),
                    details: None,
                }
            } else {
                ServiceStatus {
                    name: name.to_string(),
                    status: "degraded".to_string(),
                    latency_ms: Some(latency),
                    details: Some(format!("HTTP {code}")),
                }
            }
        }
        Err(e) => ServiceStatus {
            name: name.to_string(),
            status: "down".to_string(),
            latency_ms: None,
            details: Some(format!("{e}")),
        },
    }
}

async fn check_litellm(client: &reqwest::Client) -> ServiceStatus {
    let url = std::env::var("AI_GATEWAY_URL")
        .unwrap_or_else(|_| "http://localhost:4000".to_string());
    check_http(client, "LiteLLM", &format!("{url}/health")).await
}

async fn check_whisper(client: &reqwest::Client) -> ServiceStatus {
    let url = std::env::var("WHISPER_URL")
        .unwrap_or_else(|_| "http://localhost:8000".to_string());
    check_http(client, "Whisper", &format!("{url}/health")).await
}

async fn check_livekit(client: &reqwest::Client) -> ServiceStatus {
    let url = std::env::var("LIVEKIT_URL")
        .unwrap_or_else(|_| "http://localhost:7880".to_string());
    check_http(client, "LiveKit", &url).await
}