use anyhow::Result;
use std::fs;
use std::path::{Path, PathBuf};
use structopt::StructOpt;
use thiserror::Error;

#[derive(Debug, StructOpt)]
#[structopt(about = "maintain a journal")]
enum JT {
    Init {
        #[structopt(help = "Directory where journal should be stored")]
        dirname: PathBuf,
        #[structopt(help = "Short name for journal")]
        journalname: String,
        #[structopt(help = "Short description of journal, its title")]
        description: String,
    },
    IsJournal {
        #[structopt(help = "Directory that may or may not be a journal")]
        dirname: PathBuf,
    },
}

#[derive(Debug, Error)]
enum JournalError {
    #[error("directory {0} is not a journal")]
    NotAJournal(String),
}

fn main() -> Result<()> {
    let opt = JT::from_args();
    match opt {
        JT::Init {
            dirname,
            journalname,
            description,
        } => init(&dirname, &journalname, &description)?,
        JT::IsJournal { dirname } => is_journal(&dirname)?,
    }
    Ok(())
}

fn init(dirname: &Path, _journalname: &str, _description: &str) -> anyhow::Result<()> {
    std::fs::create_dir(dirname)?;
    Ok(())
}

fn is_journal(dirname: &Path) -> anyhow::Result<()> {
    let meta = fs::symlink_metadata(dirname)?;
    if !meta.is_dir() {
        return Err(JournalError::NotAJournal(dirname.display().to_string()).into());
    }
    Ok(())
}