use std::sync::Arc;

use axum::Router;
use clap::Command;
use database::get_connection;
use sea_orm::ConnectOptions;
use tracing::{debug, info};
use tracing_subscriber::fmt::format::{DefaultFields, Format};

use crate::{
    cmd::CliCommand,
    configs::{ProgramSettings, get_program_settings, logging::LoggingSettings},
    log,
    routes::{self, AppService, AppState},
    services::settings::SettingsService,
    tasks,
};

pub fn get_cli_command() -> CliCommand {
    CliCommand {
        command: command(),
        action,
    }
}

fn command() -> Command {
    Command::new("start").about("Start the server")
}

fn action(
    _matches: &clap::ArgMatches,
) -> std::pin::Pin<Box<dyn std::future::Future<Output = ()> + Send>> {
    Box::pin(async move {})
}

pub async fn start_server() {
    let settings = tracing::subscriber::with_default(
        log::make_temporary_subscriber(),
        || -> ProgramSettings {
            debug!("Temporary subscriber installed.");
            info!("Reading configuration...");
            let settings = get_program_settings();
            info!("Configuration read successfully.");
            debug!("Resetting global subscriber...");

            let subscriber = get_global_tracing_subscriber_builder(&settings.logging).finish();
            tracing::subscriber::set_global_default(subscriber)
                .expect("Failed to set global default subscriber");

            debug!(
                "Global subscriber set with logging level: {:?}",
                settings.logging.level
            );

            settings
        },
    );

    tasks::startup::run_startup_tasks(&settings)
        .await
        .expect("Failed to run startup tasks");

    // setup database connection pool
    info!("Establishing database connection...");
    debug!("Database URL: {}", settings.database.url);

    let db_options = |options: &mut ConnectOptions| {
        options.max_connections(settings.database.max_connections);
    };

    let db_connection = Arc::new(
        get_connection(&settings.database.url, Some(db_options))
            .await
            .expect("Failed to establish database connection"),
    );

    info!("Database connection established.");

    // build the axum app and run the server...
    info!("Starting application...");
    let app: Router = routes::get_root_router(Arc::new(get_app_state(&db_connection)));

    let address = format!("{}:{}", settings.server.address, settings.server.port);
    info!("Starting server at http://{}", address);

    let listener = tokio::net::TcpListener::bind(address)
        .await
        .expect("Failed to bind to address");

    axum::serve(listener, app)
        .await
        .expect("Failed to run the server");
}

fn get_global_tracing_subscriber_builder(
    settings: &LoggingSettings,
) -> tracing_subscriber::fmt::SubscriberBuilder<
    DefaultFields,
    Format<tracing_subscriber::fmt::format::Full, BoxedTimer>,
> {
    // After configuration is read, install the global subscriber
    let builder = tracing_subscriber::fmt()
        .with_max_level(settings.level)
        .with_target(false)
        .with_level(true);

    if settings.utc {
        builder.with_timer(BoxedTimer(Box::new(
            tracing_subscriber::fmt::time::UtcTime::rfc_3339(),
        )))
    } else {
        builder.with_timer(BoxedTimer(Box::new(
            tracing_subscriber::fmt::time::ChronoLocal::rfc_3339(),
        )))
    }
}

fn get_app_state(db_connection: &Arc<sea_orm::DatabaseConnection>) -> AppState {
    AppState {
        database_connection: db_connection.clone(),
        service: Arc::new(AppService {
            settings: Arc::new(SettingsService::new(db_connection.clone())),
        }),
    }
}

// A small wrapper that holds a boxed `FormatTime` trait object and itself
// implements `FormatTime`, allowing us to use it as a concrete type with
// `builder.with_timer` while still picking the concrete timer implementation
// at runtime.
// wrapper type to hold boxed timers and implement the `FormatTime` trait for
// a concrete type so `with_timer` may be called once outside the conditional.
struct BoxedTimer(Box<dyn tracing_subscriber::fmt::time::FormatTime + Send + Sync + 'static>);

impl tracing_subscriber::fmt::time::FormatTime for BoxedTimer {
    fn format_time(
        &self,
        w: &mut tracing_subscriber::fmt::format::Writer<'_>,
    ) -> std::result::Result<(), std::fmt::Error> {
        self.0.format_time(w)
    }
}