set-current-project

#!/usr/bin/env ruby
#
# Set the current project, so you can auto cd to that folder when you
# open a new terminal. Also sets up some handy aliases to jump into
# the current project's databases: if the project folder has a
# config/database.yml file in it, then for each environment defined
# inside, a db* alias (e.g. db_development, db_test) will be created.
# (Currently only supports mysql and psql.)
#
# set-current-project [<path>]
#
# If path is omitted, uses current folder.
#
# This will set a ./current-project file in your home folder and
# export CURRENT_PROJECT into your environment. With the appropriate
# code in your profile, this will automatically cd you into the
# project folder as soon as you login.
#
# Add this to the end of your .profile or
# .bashrc:
#
# if [[ -s ~/.current-project ]] ; then
#     source ~/.current-project
# fi
#
# Notes:
#
# * You can clear the current project by deleting the file, or running
#   unset-current-project (which just deletes the file)
#
# * I think aliases like db_development are cleaner and easier to read
#   than aliases like dbdevelopment, but dbd<TAB> is a LOT easier to
#   type, so that's why.
require 'yaml'

$known_databases = {
  "psql" => {
    "adapter" => /postgresql/,
    "command" => "psql",
    # psql does not accept password at command line. Sorry.
    "short_switches" => { "username" => "U", "host" => "h", "port" => "p" },
    "long_switches" => { },
    "args" => ["database"]
  },
  "postgresql" => {
    "adapter" => /postgresql/,
    "command" => "psql",
    # psql does not accept password at command line. Sorry.
    "short_switches" => { "username" => "U", "host" => "h", "port" => "p" },
    "long_switches" => { },
    "args" => ["database"]
  },
  "postgis" => {
    "adapter" => /postgis/,
    "command" => "psql",
    # psql does not accept password at command line. Sorry.
    "short_switches" => { "username" => "U", "host" => "h", "port" => "p" },
    "long_switches" => { },
    "args" => ["database"]
  },
  "mysql" => {
    "adapter" => /mysql(2)?/,
    "command" => "mysql",
    "short_switches" => { "username" => "u", "host" => "h", "port" => "P" },
    "long_switches" => { "password" => "password" },
    "args" => ["database"]
  },
  "sqlite3" => {
    "adapter" => /sqlite3/,
    "command" => "sqlite3",
    "short_switches" => {},
    "long_switches" => {},
    "args" => ["database"]
  }

}

args = ARGV.dup
include_aliases = true
if args.include?("--quick") || args.include?("-q")
  args.delete("--quick")
  args.delete("-q")
  include_aliases = false
end

target = if args.empty?
           Dir.pwd
         else
           args.first
         end

def fetch_adapter(adapter)
  adapter = $known_databases.detect {|name, data| adapter =~ data["adapter"]}
  adapter = adapter.last if adapter
end

def recognized_adapter?(env)
  fetch_adapter env["adapter"]
end

def build_config_aliases(config, prefix='')
  aliases = []
  Array(config).each do |name, env|
    next unless env.key?("database") && env.key?("adapter")
    next if name == 'default'

    if !recognized_adapter?(env)
      puts "Skipping environment #{env} because adapter #{fetch_adapter env['adapter']} was unrecognized"
      next
    end
    adapter = fetch_adapter env["adapter"]
    command = "%s %s %s %s" % [adapter["command"],
                               adapter["short_switches"].map {|env_key, switch| '-%s "%s"' % [switch, env[env_key]] if env[env_key]}.compact.join(' '),
                               adapter["long_switches"].map {|env_key, switch| '--%s="%s"' % [switch, env[env_key]] if env[env_key]}.compact.join(' '),
                               adapter["args"].map {|env_key| env[env_key]}.compact.join(' ')]
    command = command.gsub(/\s+/, ' ').strip
    aliases << "alias 'db%s%s'='%s'" % [prefix, name, command]
  end
  aliases
end

def cdp_alias
  %q(alias 'cdp'="cd \\"$CURRENT_PROJECT\\"")
end

def build_command_aliases
  aliases = []
  aliases << cdp_alias
  aliases
end

# some projects have multiple databases, configured with files like
# database_history.yml; capture these with a prefix so e.g. dbh<TAB>t<TAB> will
# expand to alias dbhistorytest, etc.
def config_filename_prefix(config_filename)
  regex = %r|database_?([^/]*).yml|
  prefix = config_filename.match(regex)[1]
  puts "#{config_filename.inspect} => #{prefix.inspect}"
  prefix
end

aliases = []
if include_aliases
  Dir.glob(File.join(target, 'config/database*.yml')).each do |config_file|
    if File.exist? config_file
      # Don't use YAML.load_file, Syck barfs when the yaml file lacks \n at EOF
      output = File.read(config_file)
      config = YAML.load(output, aliases: true)
      prefix = config_filename_prefix(config_file)
      aliases += build_config_aliases config, prefix
    end
  end

  aliases += build_command_aliases

  puts '-' * 80
  puts "Command aliases:"
  puts aliases
  puts '-' * 80
else
  aliases = Array(cdp_alias)
end

File.open(File.expand_path("~/.current-project"), "w") do |file|
  file.puts <<EOF
CURRENT_PROJECT="#{target}"
cd "$CURRENT_PROJECT"

# Path
if [[ -e "$CURRENT_PROJECT/script" ]] ; then
  export PATH=$PATH:"$CURRENT_PROJECT/script"
fi

# Aliases:
#{aliases * "\n"}
EOF
end

puts "Current project has been set to #{target}. You will automatically cd to this folder on login."
puts "If plan to keep working this terminal session, you should run:"
puts "\e[1;37;40msource ~/.current-project\e[0m"