use crate::lox_context;
use chrono::prelude::*;
use std::{
    env,
    error::Error,
    fs::{DirEntry, File},
    io::BufReader,
    path::Path,
};

pub fn read_context_from_file<P: AsRef<Path>>(
    path: P,
) -> Result<lox_context::LoxServerContext, Box<dyn Error>> {
    let file = File::open(path)?;
    let reader = BufReader::new(file);
    let context = serde_json::from_reader(reader)?;
    Ok(context)
}

pub fn write_context_to_file(context: lox_context::LoxServerContext) {
    let mut date = Local::now().format("%Y-%m-%d_%H:%M:%S").to_string();
    let path = "_lox.json";
    date.push_str(path);
    let file = File::create(&date).expect("Unable to write to file!");
    let _ = serde_json::to_writer(file, &context);
}

pub fn check_db_exists() -> Option<DirEntry> {
    let current_path = env::current_dir().expect("Unable to access current dir");
    std::fs::read_dir(current_path)
        .expect("Couldn't read local directory")
        .flatten() // Remove failed
        .filter(|f| {
            f.metadata().unwrap().is_file()
                && (f.file_name().into_string().unwrap().contains("_lox.json"))
        }) // Filter out directories (only consider files)
        .max_by_key(|x| x.metadata().unwrap().modified().unwrap())
}