use fapra_osm_2::utils::load_graph;
use clap::Parser;
use std::process::exit;
use rand::seq::SliceRandom;
use fapra_osm_2::utils::RoutingQuery;
use serde_json;

#[derive(Parser, Debug)]
#[clap(author, version, about, long_about=None)]
struct Args {
    /// name of the FMI file to read
    #[clap(short, long)]
    graph: String,

    /// number of samples to generate
    #[clap(short, long, default_value_t = 1000)]
    samples: usize,
}

fn main() {
    let args = Args::parse();

    let graph = load_graph(&args.graph);

    let mut rng = rand::thread_rng();

    let mut targets = graph.nodes.choose_multiple(&mut rng, args.samples * 2);

    let mut queries: Vec<RoutingQuery> = Vec::new();

    for i in (0..targets.len()).step_by(2) {

        let source = match targets.next() {
            Some(t) => t.index as usize,
            None => {
                println!("Expected a source node with index {}, but there was None.", i);
                exit(2);
            },
        };

        let destination = match targets.next() {
            Some(t) => t.index as usize,
            None => {
                println!("Expected a destination node with index {}, but there was None.", i+1);
                exit(2);
            },
        };

        queries.push(RoutingQuery{ source, destination})
    }

    match serde_json::to_string(&queries) {
        Ok(s) => println!("{}", s),
        Err(e) => {
            println!("Error while serializeing: {}", e);
            exit(2);
        }
    };
}