module Dmenu

# File lib/dmenu.rb, line 86
def self.alignr(lhs, r, w)
    x = r
    str = lhs + x
    while str.width < w
        x = '.' + x
        str = lhs + x
    end
    str
end

# File lib/dmenu.rb, line 17
def self.dmenu (entries, prompt='select an item', height=false,
              width=1366,
              fg_color='#FFFFFF',
              bg_color='#000000',
              sel_fg_color='#555555',
              sel_bg_color='#eeeeee',
              font='Sazanami Mincho:pixelsize=14',
              line_height=nil)
    if !height
        height=entries.count
    end
    md = font.to_s.match('.*:pixelsize=(\d+).*')
    if md.nil?
        font_width = 14 #in pixels
    else
        font_width = md[1].to_i
    end

    findex = font.index(':')
    base_font = font[0..(findex > 0 ? findex - 1 : -1)]
    repl_chars = $DBL_CHARS[base_font]
    res = ""
    lr_separation = 4
    textwidth = 2 * width / font_width - lr_separation
    if !repl_chars.nil?
        expr = %r{[^#{repl_chars}]+}
    end
    entries.collect! do |line|
        transformed_line = line.each_char.reject{|char| char.ord < 32 or (char.ord >= 0x7f and char.ord < 0xa0)}.inject(:+)
        s = if !transformed_line.nil?
            l, r = transformed_line.split("|||")
            loff = 0
            roff = 0
            if !repl_chars.nil?
                loff = l.gsub(expr, "").length
                roff =  r.nil? ? 0 : r.gsub(expr, "").length
            end
            scrunched = scrunch(r, [textwidth - l.width - lr_separation, textwidth / 2].max)
            r ? alignr(l, scrunched, textwidth - loff - roff) : l
        else
            $stderr.puts "Couldn't list #{line.inspect}"
            nil
        end
        s
    end.reject! {|x| x.nil? or x.empty? or x.match(/^\s+$/) }

    cmdline = "dmenu -f -p \"#{prompt}\" -nf \"#{fg_color}\" \
    -nb \"#{bg_color}\" \
    -sb \"#{sel_bg_color}\" \
    -sf \"#{sel_fg_color}\" \
    -i -l #{height} \
    -w \"#{width}\" \
    -fn \"#{font}\" " + (if line_height.nil? then "" else "-lh " + line_height.to_s end)

    err_messages = nil
    Open3.popen3(cmdline) do |i, o, e, t|
        i.print(entries.join("\n"))
        i.close
        err_messages = e.read
        res = o.gets
    end
    stat = $?
    if stat != 0
        if err_messages.include?("Error")
            raise Exception.new("Couldn't print list: #{stat}\n#{err_messages}")
        end
    end
    res.to_s.chomp
end

# File lib/dmenu.rb, line 95
def self.scrunch(str, size, dots='...')
    if str.nil?
        nil
    elsif str.width < size
        str
    else
        middle = str.length / 2
        # Not centered; intentional
        lhs = str[0..middle]
        rhs = str[-middle..-1]
        lr = false
        while str.width > size
            if lr
                lhs = lhs[0..-2]
            else
                rhs = rhs[1..-1]
            end
            lr = !lr
            str = lhs + dots + rhs
        end
        str
    end
end