mod configs;
mod error;
mod handlers;
mod models;
mod repo;

use std::{fs, sync::Arc};

use axum::{routing::get, Router};
use configs::Config;
use error::{AppError, AppResult};
use models::AppState;
use reqwest::Url;
use tokio::{net::TcpListener, sync::RwLock};

#[macro_use]
extern crate log;

/// Parse urls and return 2 lists: valid urls and errors
fn parse_urls(url_list: &[String]) -> (Vec<Url>, Vec<String>) {
    let (valid, invalid): (Vec<_>, Vec<_>) = url_list
        .into_iter()
        .map(|url| Url::parse(&url).map_err(|e| AppError::InvalidUrl(url.to_string(), e)))
        .partition(Result::is_ok);

    (
        valid.into_iter().map(Result::unwrap).collect(),
        invalid
            .into_iter()
            .map(|e| e.unwrap_err().to_string())
            .collect(),
    )
}

/// Extract raw urls from different sources:
/// - from args list
/// - from file
fn parse_urls_from_args(
    args: impl IntoIterator<Item = String>,
) -> AppResult<(Vec<Url>, Vec<String>)> {
    let mut args_iter = args.into_iter();

    match args_iter.nth(1) {
        Some(action) => match action.as_str() {
            "-f" => {
                let Some(source) = args_iter.next() else {
                    return Err(AppError::UsageError);
                };
                println!("Reading file '{source}'");
                let raw_urls = fs::read_to_string(source)?
                    .split('\n')
                    .map(|s| s.to_owned())
                    .collect::<Vec<_>>();

                Ok(parse_urls(&raw_urls))
            }
            "-u" => {
                let urls_list = args_iter.collect::<Vec<_>>();
                Ok(parse_urls(&urls_list))
            }
            _ => return Err(AppError::UsageError),
        },
        None => return Err(AppError::UsageError),
    }
}

async fn process_urls(config: &Config, urls: &[Url]) {}

async fn run() -> AppResult<()> {
    dotenv::dotenv().ok();

    let cfg = configs::get_configs()?;
    info!("{cfg:?}");

    // let (valid_urls, errors) = parse_urls_from_args(args)?;
    let state = Arc::new(RwLock::new(AppState::new(cfg.url_handlers_pool_size)));

    let app = Router::new()
        .route(
            "/urls",
            get(handlers::get_urls)
                .post(handlers::upload_urls)
                .delete(handlers::delete_urls),
        )
        .with_state(state);
    let listener = TcpListener::bind("0.0.0.0:8000").await?;

    axum::serve(listener, app).await.map_err(AppError::from)
}

#[tokio::main]
async fn main() {
    env_logger::init();

    if let Err(e) = run().await {
        println!("{e}");
    }
}