module Farfugl

# File lib/farfugl.rb, line 24
def self.hashes(migrations)
  migrations.map { |file| Git.hash(file) }
end

# File lib/farfugl.rb, line 28
def self.migrate
  Git.stash
  original_branch = Git.current_branch
  hashes = self.hashes(self.pending_migrations(self.schema_versions))
  hashes.each do |commit_hash|
    Git.checkout(commit_hash)
    Rake::Task['db:migrate'].invoke
    Rake::Task['db:migrate'].reenable
  end
  Git.checkout(original_branch)
  Git.unstash
  Rake::Task['db:schema:dump'].invoke
end

# File lib/farfugl.rb, line 12
def self.pending_migrations(versions)
  migrations = []
  ActiveRecord::Migrator.migrations_paths.each do |path|
    Dir.foreach(path) do |file|
      if match_data = /^(\d{3,})_(.+)\.rb$/.match(file)
        migrations << "#{path}/#{file}" unless versions.delete(match_data[1])
      end
    end
  end
  migrations
end

# File lib/farfugl.rb, line 5
def self.schema_versions
  schema_table = ActiveRecord::Migrator.schema_migrations_table_name
  query = "SELECT version FROM #{schema_table}"
  ActiveRecord::Base.connection.select_values(query)
    .map { |version| "%.3d" % version }
end