/* Pirate - A command-line arrrrguments parser, written in Rust.
 * Copyright (C) 2015 Zachary Dziura
 *
 * 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 <http://www.gnu.org/licenses/>.
 */

use std::collections::{HashMap, VecDeque};
use std::slice::Iter;

use errors::Error;
use token::{Token, token};

pub struct Vars {
    tokens: Vec<Token>,
    opts: HashMap<String, usize>,
    args: VecDeque<usize>,
    pub program_name: String
}

pub fn vars(program_name: &str, options: &[&str]) -> Result<Vars, Error> {
    let mut tokens: Vec<Token> = Vec::new();
    let mut opts: HashMap<String, usize> = HashMap::new();
    let mut args: VecDeque<usize> = VecDeque::new();
    let mut index: usize = 0;
    
    // The first option should be the help option, i.e. -h, --help
    let help_token = Token {
        short_name: String::from("h"),
        long_name: String::from("help"),
        description: String::from("Display usage information"),
        is_arg: false,
        has_arg: false,
        is_group: false,
        padding: 0
    };
    opts.insert(help_token.short_name.clone(), index);
    opts.insert(help_token.long_name.clone(), index);
    let mut longest_token_len: usize = help_token.len();    
    tokens.push(help_token);
    index += 1;

    // Second, add the other, user defined options
    for opt in options.iter() {
        let token = match token(opt) {
            Ok(t) => t,
            Err(why) => return Err(why)
        };

        if !token.is_group {
            if token.is_arg {
                args.push_back(index);
            } else {
                if !token.short_name.is_empty() {
                    opts.insert(token.short_name.clone(), index);
                }

                if !token.long_name.is_empty() {
                    opts.insert(token.long_name.clone(), index);
                }
            }

            if token.len() > longest_token_len {
                longest_token_len = token.len();
            }
        }
        tokens.push(token);
        index += 1;
    }
    
    // Finally, adjust the padding for each token so they display properly
    for t in tokens.iter_mut() {
        let token_len = t.len();
        if token_len < longest_token_len {
            let delta = longest_token_len - token_len;
            t.adjust_padding(delta);
        }
    }

    Ok(Vars {
        opts: opts,
        args: args,
        tokens: tokens,
        program_name: String::from(program_name)
    })
}

impl Vars {
    pub fn get_opt(&self, opt_name: &str) -> Option<&Token> {
        if let Some(&index) = self.opts.get(opt_name) { 
            self.tokens.get(index)
        } else {
            None
        }
    }

    pub fn contains_opt(&self, opt: &str) -> bool {
        self.opts.contains_key(opt)
    }

    pub fn get_arg(&mut self) -> Option<&Token> {
        if let Some(index) = self.args.pop_front() {
            self.tokens.get(index)
        } else {
            None
        }
    }

    pub fn arg_len(&self) -> usize {
        self.args.len()
    }
    
    pub fn tokens(&self) -> Iter<Token>{
        self.tokens.iter()
    }
}