extern crate regex;
#[macro_use] extern crate lazy_static;
extern crate structopt;
#[macro_use] extern crate structopt_derive;

pub mod qif;

use structopt::StructOpt;

use qif::*;
use std::io::prelude::*;
use std::io::*;

use std::ffi::{OsString, OsStr};
use std::path::PathBuf;
use std::result::Result;

use std::fs::File;
use std::error::Error;

fn parse_filepath(str: &OsStr) -> Result<PathBuf, OsString> {
    let path: PathBuf = ::std::convert::From::from(str);
    if path.is_file() {
        Ok(path)
    } else {
        Err(str.to_os_string())
    }
}

#[derive(StructOpt, Debug)]
#[structopt(name = "Qif Parser", about = "Qif file preprocessor to decrease duplication when importing to gnucash")]
struct CliArgs {
    #[structopt(help = "Files to preprocess", required, parse(try_from_os_str="parse_filepath"))]
    files: Vec<PathBuf>
}

fn main() -> Result<(), Box<Error>> {
    let args = CliArgs::from_args();
    
    for filepath in &args.files {
        let file = File::open(filepath)?;
        let file_reader = BufReader::new(file);
        let mut lines = file_reader.lines();

        if let Some(header_line) = lines.next() {
            let qif_result = {            
                let mut qif_file = QifFile::new(header_line?);
                let mut next_entry = Vec::new();

                for line_result in lines {
                    let line = line_result?;
                    if line == String::from("^") {
                        let new_qif_entry = QifEntry::new(&next_entry)?;
                        qif_file.push(new_qif_entry);
                        next_entry.clear();
                    } else {
                        next_entry.push(line);
                    }
                }
                qif_file
            };

            let mut file = File::create(filepath)?;
            writeln!(file, "{}", qif_result)?;
        } else {
            println!("{} was empty", filepath.display());
        }
    }
    println!("Processed {} files", args.files.len());
    Ok(())
}