mod db;
mod filesystem;
mod lastfm;
mod metadata;

use std::env;
use std::path::Path;

fn main() {
    let args: Vec<String> = env::args().collect();
    let verbose = args.iter().any(|a| a == "-v");
    let rest: Vec<&String> = args.iter().skip(1).filter(|a| *a != "-v").collect();

    if rest.len() != 2 || rest[0] != "index" {
        eprintln!("Usage: {} index [-v] <directory>", args[0]);
        std::process::exit(1);
    }

    dotenvy::dotenv().ok();

    let api_key = env::var("LASTFM_API_KEY").unwrap_or_default();
    if api_key.is_empty() {
        eprintln!("Error: LASTFM_API_KEY not set");
        std::process::exit(1);
    }

    let conn = db::open("playlists.db").expect("failed to open database");
    let lastfm = lastfm::LastfmClient::new(api_key);
    let dir = Path::new(rest[1].as_str());

    for path in filesystem::walk_music_files(dir) {
        let artist_mbid = match metadata::read_artist_mbid(&path) {
            Ok(Some(mbid)) => mbid,
            Ok(None) => continue,
            Err(e) => {
                eprintln!("{}: could not read artist MBID: {e}", path.display());
                continue;
            }
        };

        let already_indexed = match db::artist_exists(&conn, &artist_mbid) {
            Ok(exists) => exists,
            Err(e) => {
                eprintln!("DB error checking artist {artist_mbid}: {e}");
                continue;
            }
        };

        let artist_name = metadata::read_artist_name(&path).ok().flatten();
        let display_name = artist_name.as_deref().unwrap_or(&artist_mbid);

        if already_indexed {
            if verbose {
                println!("Skipping {display_name} (already indexed)");
            }
            continue;
        }

        if verbose {
            println!("Indexing {display_name}...");
        }

        match lastfm.get_similar_artists(&artist_mbid) {
            Ok(similar) => {
                if let Err(e) = db::insert_artist_with_similar(
                    &conn,
                    &artist_mbid,
                    artist_name.as_deref(),
                    &similar,
                ) {
                    eprintln!("DB error inserting artist {artist_mbid}: {e}");
                }
            }
            Err(e) => eprintln!("Last.fm error for {artist_mbid}: {e}"),
        }
    }
}