//! Live diagnostic for the production artist-art resolver.
//!
//! Usage:
//!   cargo run -p metadata --example hero_source_probe -- [output-dir] [artist ...]
//!   cargo run -p metadata --example hero_source_probe -- [output-dir] --extended
//!   cargo run -p metadata --example hero_source_probe -- [output-dir] --bing-only [artist ...]
//!
//! With no artists, the five core sourcing fixtures are used. `--extended`
//! adds ten lesser-known stress fixtures. Passing `-` as the output directory
//! prints URLs without saving the image bytes.

use metadata::{CatalogArtist, MetadataClient};
use std::path::PathBuf;

const DEFAULT_ARTISTS: [&str; 5] = [
    "Camping in Alaska",
    "Partiboi69",
    "Hermeth",
    "Billy Cobb",
    "Fishmans",
];

const EXTENDED_ARTISTS: [&str; 10] = [
    "Wednesday",
    "Equipment",
    "Hana Vu",
    "Jane Remover",
    "DJ Sabrina The Teenage DJ",
    "Nikki Nair",
    "MSPAINT",
    "Horse Jumper of Love",
    "They Are Gutting a Body of Water",
    "Sword II",
];

#[tokio::main]
async fn main() {
    let mut args = std::env::args().skip(1);
    let output = args.next().filter(|value| value != "-").map(PathBuf::from);
    let mut requested: Vec<String> = args.collect();
    let bing_only = requested.iter().any(|value| value == "--bing-only");
    requested.retain(|value| value != "--bing-only");
    let artists: Vec<String> = if requested.is_empty() {
        DEFAULT_ARTISTS
            .iter()
            .map(|name| name.to_string())
            .collect()
    } else if requested.len() == 1 && requested[0] == "--extended" {
        DEFAULT_ARTISTS
            .iter()
            .chain(EXTENDED_ARTISTS.iter())
            .map(|name| name.to_string())
            .collect()
    } else {
        requested
    };

    if let Some(output) = output.as_ref() {
        if let Err(error) = std::fs::create_dir_all(output) {
            eprintln!("could not create {}: {error}", output.display());
            std::process::exit(2);
        }
    }

    let client = MetadataClient::new().with_hero_diagnostics();
    for requested in artists {
        // Bing-only diagnostics do not need a Deezer id. Keeping that path
        // independent means catalog rate limits cannot turn a scraper probe
        // into an immediate, misleading NOT_FOUND for every requested name.
        let (artist_id, artist_name, fans) = if bing_only {
            (None, requested, 0)
        } else {
            let search = client.catalog_search(&requested).await;
            let Some(artist) = best_exact_artist(&search.artists, &requested) else {
                println!("ARTIST\t{requested}\tNOT_FOUND");
                continue;
            };
            (
                Some(artist.id),
                artist.name.clone(),
                artist.fans.unwrap_or(0),
            )
        };
        println!(
            "ARTIST\t{}\t{}\t{}",
            artist_id
                .map(|id| id.to_string())
                .unwrap_or_else(|| "BING_ONLY".to_string()),
            artist_name,
            fans,
        );
        let banners = if let Some(artist_id) = artist_id {
            let Some(art) = client.catalog_artist_art(artist_id).await else {
                println!("ERROR\t{}\tartist art unavailable", artist_name);
                continue;
            };
            art.banners
        } else {
            client.debug_bing_hero_banners(&artist_name).await
        };
        if banners.is_empty() {
            println!("BANNER\t{}\tNONE", artist_name);
            continue;
        }
        for (index, url) in banners.iter().enumerate() {
            println!("BANNER\t{}\t{}\t{}", artist_name, index + 1, url);
            let Some(output) = output.as_ref() else {
                continue;
            };
            let Some(bytes) = client.fetch_image_bytes(url).await else {
                println!(
                    "SAVE_ERROR\t{}\t{}\tdownload failed",
                    artist_name,
                    index + 1
                );
                continue;
            };
            let extension = match image::guess_format(&bytes) {
                Ok(image::ImageFormat::Png) => "png",
                Ok(image::ImageFormat::WebP) => "webp",
                _ => "jpg",
            };
            let path = output.join(format!(
                "{}-{}.{}",
                file_stem(&artist_name),
                index + 1,
                extension
            ));
            match std::fs::write(&path, bytes) {
                Ok(()) => println!("SAVED\t{}", path.display()),
                Err(error) => println!("SAVE_ERROR\t{}\t{}", path.display(), error),
            }
        }
    }
}

fn best_exact_artist<'a>(
    artists: &'a [CatalogArtist],
    requested: &str,
) -> Option<&'a CatalogArtist> {
    artists
        .iter()
        .filter(|artist| artist.name.trim().eq_ignore_ascii_case(requested.trim()))
        .max_by_key(|artist| artist.fans.unwrap_or(0))
}

fn file_stem(name: &str) -> String {
    name.to_lowercase()
        .chars()
        .map(|character| {
            if character.is_ascii_alphanumeric() {
                character
            } else {
                '-'
            }
        })
        .collect::<String>()
        .split('-')
        .filter(|part| !part.is_empty())
        .collect::<Vec<_>>()
        .join("-")
}