use chrono::Utc;
use clap::Parser;
use std::path::Path;

mod exporter;
mod generator;
mod schedule;

// 3 weeks by default
const DEFAULT: usize = 21 * 24 / 2;

// If no start time is specified, use the last even hour
pub fn default_timestamp() -> i64 {
    let now = Utc::now().timestamp();
    let block = 2 * 60 * 60;
    now - (now % block)
}

#[derive(Parser, Debug)]
#[command(name = "ikamaki")]
struct Args {
    // How many rotations to generate
    #[arg(short, long)]
    count: Option<usize>,

    // UNIX timestamp to start the schedule from
    #[arg(short, long)]
    start: Option<i64>,

    // Output file path
    #[arg(short, long, default_value = "VSSetting.byaml")]
    output: String,

    // Generate YAML in addition to the BYAML
    #[arg(long)]
    yml: bool,

    // Set DisconnectByMemoryHash to true
    #[arg(long)]
    hash_kick: bool,
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let args = Args::parse();
    let count = args.count.unwrap_or(DEFAULT);
    let start_time = args.start.unwrap_or_else(default_timestamp);
    let schedule = generator::generate(count, start_time);
    exporter::export(&schedule, &args.output, args.hash_kick)?;

    if args.yml {
        let yml_path = derive_yml_path(&args.output);
        exporter::export_text(&schedule, &yml_path, args.hash_kick)?;
        println!(
            "Successfully generated {} rotation(s) -> {} + {}",
            count, args.output, yml_path
        );
    } else {
        println!(
            "Successfully generated {} rotation(s) -> {}",
            count, args.output
        );
    }

    Ok(())
}

fn derive_yml_path(output: &str) -> String {
    let path = Path::new(output);
    if let Some(stem) = path.file_stem() {
        if let Some(parent) = path.parent() {
            return parent
                .join(format!("{}.yml", stem.to_string_lossy()))
                .to_string_lossy()
                .into_owned();
        }
        return format!("{}.yml", stem.to_string_lossy());
    }
    format!("{}.yml", output)
}