// bibiman - a TUI for managing BibLaTeX databases
// Copyright (C) 2024  lukeflo
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.
/////

use color_eyre::eyre::Result;
use color_eyre::owo_colors::OwoColorize;
use lexopt::prelude::*;
use std::env;
use std::ffi::OsString;
use std::path::PathBuf;
use walkdir::WalkDir;

// struct for CLIArgs
#[derive(Debug, Default)]
pub struct CLIArgs {
    pub helparg: bool,
    pub versionarg: bool,
    pub pos_args: Vec<PathBuf>,
}

impl CLIArgs {
    pub fn parse_args() -> Result<CLIArgs, lexopt::Error> {
        let mut args = CLIArgs::default();
        let mut parser = lexopt::Parser::from_env();

        while let Some(arg) = parser.next()? {
            match arg {
                Short('h') | Long("help") => args.helparg = true,
                Short('v') | Long("version") => args.versionarg = true,
                Value(pos_arg) => parse_files(&mut args, pos_arg),
                _ => return Err(arg.unexpected()),
            }
        }
        Ok(args)
    }
}

pub fn parse_files(args: &mut CLIArgs, pos_arg: OsString) {
    // convert to PathBuf to use methods for testing the path
    let path = PathBuf::from(pos_arg);
    // If pos arg is file, just push it to path vec
    if path.is_file() {
        args.pos_args.push(path);
    // If pos arg is dir, walk dir and collect bibfiles
    } else if path.is_dir() {
        for file in WalkDir::new(path) {
            let f = file.unwrap().into_path();
            if f.is_file() && f.extension().unwrap() == "bib" {
                args.pos_args.push(f)
            }
        }
    } else {
        println!(
            "{} {}",
            "The positional argument is neither a valid file, nor a path:"
                .red()
                .bold(),
            path.as_os_str().to_string_lossy().bright_red().italic()
        );
        println!();
        println!("{}", help_func());
        std::process::exit(1)
    }
}

pub fn help_func() -> String {
    let help = format!(
        "\
{} {}

USAGE:
    bibiman [FLAGS] [file]

POSITIONAL ARGS:
    <file>    Path to .bib file

FLAGS:
    -h, --help      Show this help and exit
    -v, --version   Show the version and exit",
        env!("CARGO_PKG_NAME"),
        env!("CARGO_PKG_VERSION"),
    );
    help
}

pub fn version_func() -> String {
    let version = format!(
        "\
{} {}
{}
{}

Target Triple: {}",
        env!("CARGO_PKG_NAME"),
        env!("CARGO_PKG_VERSION"),
        env!("CARGO_PKG_AUTHORS"),
        env!("CARGO_PKG_LICENSE"),
        env!("TARGET")
    );
    version
}