use std::fs::{create_dir_all, File};
use std::path::Path;
use rand::Rng;
use crate::cli::cli::OutputFormat;
use crate::system::model::DLASystem;
use crate::system::{Position, Storage};
use crate::system::spawner::Spawner;
use crate::system::sticker::Sticker;
use crate::system::walker::Walker;

pub fn write<R: Rng, P: Position, S: Storage<P>, W: Walker<P>, Sp: Spawner<P>, St: Sticker<P, S>>(
    sys: &DLASystem<R, P, S, W, Sp, St>,
    format: OutputFormat,
    output: &Path,
) {
    // If the parent does not exist (and we are not in the root or operating a relative 1-component-length path))
    // create it. This greatly simplifies the harness code.
    if let Some(parent) = output.parent() &&
        parent.to_str().map(|x| x != "").unwrap_or(true) &&
        !parent.exists() {
        create_dir_all(parent).expect("Failed to create path to output");
    }

    match format {
        OutputFormat::FullDataJson => write_json_full_data(sys, output),
        OutputFormat::Positions => write_csv_positions(sys, output),
    }
}

fn write_csv_positions<R: Rng, P: Position, S: Storage<P>, W: Walker<P>, Sp: Spawner<P>, St: Sticker<P, S>>(sys: &DLASystem<R, P, S, W, Sp, St>, csv_path: &Path) {
    let mut wtr = csv::Writer::from_path(csv_path)
        .expect("Failed to open file");

    // CSVs can only store the raw positions
    let positions: Vec<&P> = sys.history
        .iter()
        .map(|line| &line.position)
        .collect();

    positions
        .iter()
        .for_each(|position|
            wtr.serialize(position).expect("Failed to write row")
        );

    wtr.flush()
        .unwrap();
}

fn write_json_full_data<R: Rng, P: Position, S: Storage<P>, W: Walker<P>, Sp: Spawner<P>, St: Sticker<P, S>>(sys: &DLASystem<R, P, S, W, Sp, St>, output_path: &Path) {
    let file = File::create(output_path).expect("Failed to open file");

    serde_json::to_writer_pretty(file, &sys.history)
        .expect("Failed to write json");
}