#![feature(phase, globs)]
extern crate regex;
#[phase(plugin)] extern crate regex_macros;
extern crate ansi_term;
extern crate unicode;

use std::os;
use std::io::fs;
use std::io::FileType::TypeDirectory;
use std::iter::AdditiveIterator;
use std::str::StrVector;

use file::File;
use dir::Dir;
use column::Column;
use column::Alignment::Left;
use options::{Options, View};
use unix::Unix;

use ansi_term::{Plain, strip_formatting};

pub mod column;
pub mod dir;
pub mod format;
pub mod file;
pub mod filetype;
pub mod unix;
pub mod options;
pub mod sort;
pub mod term;

fn main() {
    let args: Vec<String> = os::args();

    match Options::getopts(args) {
        Err(error_code) => os::set_exit_status(error_code),
        Ok(options) => exa(&options),
    };
}

fn exa(opts: &Options) {
    let mut dirs: Vec<String> = vec![];
    let mut files: Vec<File> = vec![];
    
    // Separate the user-supplied paths into directories and files.
    // Files are shown first, and then each directory is expanded
    // and listed second.
    for file in opts.path_strs.iter() {
        let path = Path::new(file);
        match fs::stat(&path) {
            Ok(stat) => {
                if !opts.list_dirs && stat.kind == TypeDirectory {
                    dirs.push(file.clone());
                }
                else {
                    // May as well reuse the stat result from earlier
                    // instead of just using File::from_path().
                    files.push(File::with_stat(stat, path, None));
                }
            }
            Err(e) => println!("{}: {}", file, e),
        }
    }

    // It's only worth printing out directory names if the user supplied
    // more than one of them.
    let print_dir_names = opts.path_strs.len() > 1;
    let mut first = files.is_empty();

    if !files.is_empty() {
        view(opts, files);
    }
    
    for dir_name in dirs.into_iter() {
        if first {
            first = false;
        }
        else {
            print!("\n");
        }

        match Dir::readdir(Path::new(dir_name.clone())) {
            Ok(dir) => {
                let unsorted_files = dir.files();
                let files: Vec<File> = opts.transform_files(unsorted_files);

                if print_dir_names {
                    println!("{}:", dir_name);
                }

                view(opts, files);
            }
            Err(e) => {
                println!("{}: {}", dir_name, e);
                return;
            }
        };
    }
}

fn view(options: &Options, files: Vec<File>) {
    match options.view {
        View::Details(ref cols) => details_view(options, cols, files),
        View::Lines => lines_view(files),
        View::Grid(across, width) => grid_view(across, width, files),
    }
}

fn lines_view(files: Vec<File>) {
    for file in files.iter() {
        println!("{}", file.file_name());
    }
}

fn grid_view(across: bool, console_width: uint, files: Vec<File>) {
    // Check if all the files can be displayed on one line, and do
    // that if possible. The width has to take into account the
    // two-space separator between file names for every file except
    // the last one (because it's a separator)
    let width = files.iter()
                     .map(|f| f.name.len() + 2)
                     .sum() - 2;
    
    if width <= console_width {
        let names: Vec<String> = files.iter()
                                      .map(|f| f.file_name().to_string())
                                      .collect();

        println!("{}", names.connect("  "));
        return;
    }

    // Otherwise, contort them into a grid.
    let max_column_length = files.iter().map(|f| f.file_name_width()).max().unwrap_or(0);
    let num_columns = (console_width + 1) / (max_column_length + 1);
    let count = files.len();

    let mut num_rows = count / num_columns;
    if count % num_columns != 0 {
        num_rows += 1;
    }
    
    for y in range(0, num_rows) {
        for x in range(0, num_columns) {
            let num = if across {
                y * num_columns + x
            }
            else {
                y + num_rows * x
            };
            
            if num >= count {
                continue;
            }
            
            let ref file = files[num];
            let file_name = file.name.clone();
            let styled_name = file.file_colour().paint(file_name.as_slice()).to_string();
            if x == num_columns - 1 {
                print!("{}", styled_name);
            }
            else {
                print!("{}", Left.pad_string(&styled_name, max_column_length - file_name.len() + 1));
            }
        }
        print!("\n");
    }
}

fn details_view(options: &Options, columns: &Vec<Column>, files: Vec<File>) {
    // The output gets formatted into columns, which looks nicer. To
    // do this, we have to write the results into a table, instead of
    // displaying each file immediately, then calculating the maximum
    // width of each column based on the length of the results and
    // padding the fields during output.

    let mut cache = Unix::empty_cache();

    let mut table: Vec<Vec<String>> = files.iter()
        .map(|f| columns.iter().map(|c| f.display(c, &mut cache)).collect())
        .collect();

    if options.header {
        table.insert(0, columns.iter().map(|c| Plain.underline().paint(c.header()).to_string()).collect());
    }

    // Each column needs to have its invisible colour-formatting
    // characters stripped before it has its width calculated, or the
    // width will be incorrect and the columns won't line up properly.
    // This is fairly expensive to do (it uses a regex), so the
    // results are cached.

    let lengths: Vec<Vec<uint>> = table.iter()
        .map(|row| row.iter().map(|col| strip_formatting(col.clone()).len()).collect())
        .collect();

    let column_widths: Vec<uint> = range(0, columns.len())
        .map(|n| lengths.iter().map(|row| row[n]).max().unwrap_or(0))
        .collect();

    for (field_widths, row) in lengths.iter().zip(table.iter()) {
        for (num, column) in columns.iter().enumerate() {
            if num != 0 {
                print!(" ");
            }

            if num == columns.len() - 1 {
                print!("{}", row[num]);
            }
            else {
                let padding = column_widths[num] - field_widths[num];
                print!("{}", column.alignment().pad_string(&row[num], padding));
            }
        }
        print!("\n");
    }
}