z.rb

# Since we can't change the current shell directory from a script, this only outputs the new
# directory. Please see README for instructions.

$LOAD_PATH << File.join(File.dirname(__FILE__))
require 'util'

Z_FILE = File.join(ENV['HOME'], '.compnav-z').freeze
Z_HEADER = 'compnav-z'.freeze
Z_VERSION = '0.0.1'.freeze

# compnav used to store its list in ~/.z, which clashes with the database of the original z
# utility (and used to silently overwrite it). Migrate a compnav-created ~/.z to the new
# location; a ~/.z belonging to another tool is left alone.
old_z_file = File.join(ENV['HOME'], '.z')
if !File.file?(Z_FILE) && File.file?(old_z_file)
  header = File.open(old_z_file, 'r') { |file| file.gets }
  if !header.nil? && header.start_with?(Z_HEADER)
    File.rename(old_z_file, Z_FILE)
  end
end

def read_z_dirs(dir_to_skip)
  z_dirs = []

  if File.file?(Z_FILE)
    File.open(Z_FILE, 'r') do |file|
      # Check the header. If the file wasn't created by compnav, ignore its contents
      # (it will be overwritten on the next --add).
      header = file.gets
      if !header.nil? && header.start_with?(Z_HEADER)
        # Read all lines from the file, removing our dir if it is present.
        # We add our dir to the end of the file later.
        z_dirs = file
          .map { |line| line.chomp }
          .filter { |line| !line.strip.empty? && line != dir_to_skip }
      end
    end
  end

  z_dirs
end

return if defined? REQUIRING_Z

if ARGV.length == 2 && ARGV[0] == '--add'
  # Add the passed-in dir to the recent-dirs list as the most recent one (last line of .z).

  # Remove any trailing slashes
  dir_to_add = ARGV[1].chomp('/')

  z_dirs = read_z_dirs dir_to_add

  # Write to a temp file and rename it into place. Every open shell writes this file on
  # every cd; the atomic rename ensures a concurrent reader or writer never sees a
  # partially-written list.
  tmp_file = "#{Z_FILE}.#{Process.pid}.tmp"
  File.open(tmp_file, 'w') do |file|
    file.write "#{Z_HEADER} #{Z_VERSION}\n"
    z_dirs.each { |z_dir| file.write "#{z_dir}\n" }
    file.write "#{dir_to_add}\n"
  end
  File.rename(tmp_file, Z_FILE)

  exit
end

z_dirs = read_z_dirs(PWD).map { |z_dir| path_with_tilde(z_dir) }.join("\n")

# Nothing to offer: exit nonzero (and print nothing) so the shell wrapper skips the cd.
exit 1 if z_dirs.empty?

if ARGV.length >= 1 && ARGV[0] == '--fzf'
  pipe_to_fzf_and_print(z_dirs, true, 'COMPNAV_FZF_Z_OPTS')
else
  puts z_dirs
end