use std::fs::File;
use std::io::{BufRead, BufReader, Result};
use std::collections::HashMap;
use std::fs;

fn main() -> Result<()> {
    let file = File::open("beets_mv3u_renames")?;
    let mut renames = HashMap::new();
    for line in BufReader::new(file).lines() {
        let line = line?;
        let split: Vec<&str> = line.split("\t\t").collect();
        renames.insert(split[0].to_string(), split[1].to_string());
    }
    
    
    // get the number of lines in the file so we can pre-allocate the array
    let pf = fs::read_to_string("playlist.m3u").expect("unable to read");
    let num_lines = pf.split("\n").collect::<Vec<&str>>().len() - 1;
    let mut outputs: Vec<String> = vec![String::new(); num_lines];
    //println!("{}", num_lines);

    let pls_file = File::open("playlist.m3u")?;
    let mut i = 0;
    for entry in BufReader::new(pls_file).lines() {
        let entry = entry?;
        /*
        match renames.get(&entry.to_string()) {
            Some(line) => println!("found {}", line),
            None => print!("")
        }
        */
        let new = renames.get(&entry).unwrap_or(&entry).to_string();
        /*
        if new != &entry {
            println!("renamed “{}” to “{}”", entry, new);
        } else {
            println!("“{}” remains unchanged", entry);
        }
        */
        outputs[i] = new;
        i += 1;
    }
    /*for s in outputs {
        println!("{}", s);
    }*/
    let data = outputs.join("\n");
    fs::write("playlist2.m3u", data).expect("unable to write");
    //println!("{}", pf);
    //println!("{}", renames.get(&"a string".to_string()).unwrap());
    Ok(())
}