use once_cell::sync::Lazy;
use poise::serenity_prelude::{self as serenity, GatewayIntents};
mod command;

pub struct Data {} // User data, which is stored and accessible in all command invocations
type Context<'a> = poise::Context<'a, Data, anyhow::Error>;

static ENV: Lazy<BotEnv> = Lazy::new(|| {
    read_env()
});

#[tokio::main]
async fn main() {

    // Generate sick text like this: 
    // http://www.patorjk.com/software/taag/#p=testall&f=Graffiti&t=hello%20world
    println!(r#"
    Invite this bot with:
    "#);
    println!("https://discord.com/api/oauth2/authorize?client_id={}&permissions={}&scope=bot",
        ENV.id,
        ENV.intents.bits(),
    );
    print!("\n");

    // Setup framework
    let framework = poise::Framework::builder()
        .options(poise::FrameworkOptions {
            commands: vec![
                command::index_cmd(),
                command::scrape_all(),
            ],
            ..Default::default()
        })
        .setup(|ctx, _ready, framework| {
            Box::pin(async move {
                poise::builtins::register_globally(
                    ctx,
                    &framework.options().commands
                ).await?;
                Ok(Data {})
            })
        })
        .build();

    // Start the Bot.
    let client = serenity::ClientBuilder::new(&ENV.token, ENV.intents)
        .framework(framework)
        .await;
    
    client.unwrap().start().await.unwrap();
}

struct BotEnv {
    intents: GatewayIntents,
    token: String,
    id: String,
}

fn read_env() -> BotEnv {
    const DISCORD_INTENTS: &str = "DISCORD_INTENTS";
    const DISCORD_TOKEN: &str = "DISCORD_TOKEN";
    const DISCORD_ID: &str = "DISCORD_ID";
    dotenv::dotenv().ok();
    // ==================== ID ===========================
    let id: String = std::env::var(DISCORD_ID)
        .unwrap_or_else(|_| {
            println!(r#"
WARN: Missing {DISCORD_ID}
> This isn't really that problematic, just that the generated invite link won't work."#);
            String::from("")
        });
    // ==================== Token ========================
    let token: String = std::env::var(DISCORD_TOKEN)
        .unwrap_or_else(|_| panic!("ERROR: Missing {DISCORD_TOKEN}"));
    // ==================== Intents ======================
    let intents_env: String = std::env::var(DISCORD_INTENTS)
        .unwrap_or_else(|msg| {
            println!("DEBUG: what is: {msg}");
            println!("ERROR: Missing {DISCORD_INTENTS}");
            "0".to_string()
        });
    // ==================== Parse Intents =================
    // parse into u64, then into GatewayIntents
    let intents_u64 = intents_env.parse::<u64>().unwrap_or(0u64);
    let intents_truncated: GatewayIntents = GatewayIntents::from_bits_truncate(intents_u64);
    if intents_truncated.bits() != intents_u64 {
        println!("WARN: Intents integer got truncated from {} to {}!", intents_u64, intents_truncated.bits())
    };
    BotEnv {
        intents: intents_truncated,
        token,
        id,
    }
}