require 'digest/md5'

class Key < ActiveRecord::Base
  belongs_to :user
  belongs_to :project

  attr_accessible :key, :title

  before_validation :strip_white_space
  before_save :set_identifier

  validates :title, presence: true, length: { within: 0..255 }
  validates :key, presence: true, length: { within: 0..5000 }, format: { :with => /ssh-.{3} / }
  validate :unique_key, :fingerprintable_key

  delegate :name, :email, to: :user, prefix: true

  def strip_white_space
    self.key = self.key.strip unless self.key.blank?
  end

  def unique_key
    query = Key.where(key: key)
    query = query.where('(project_id IS NULL OR project_id = ?)', project_id) if project_id
    if (query.count > 0)
      errors.add :key, 'already exist.'
    end
  end

  def fingerprintable_key
    return true unless key # Don't test if there is no key.
    # `ssh-keygen -lf /dev/stdin <<< "#{key}"` errors with: redirection unexpected
    file = Tempfile.new('key_file')
    begin
      file.puts key
      file.rewind
      fingerprint_output = `ssh-keygen -lf #{file.path} 2>&1` # Catch stderr.
    ensure
      file.close
      file.unlink # deletes the temp file
    end
    errors.add(:key, "can't be fingerprinted") if fingerprint_output.match("failed")
  end

  def set_identifier
    if is_deploy_key
      self.identifier = "deploy_#{Digest::MD5.hexdigest(key)}"
    else
      self.identifier = "#{user.identifier}_#{Time.now.to_i}"
    end
  end

  def is_deploy_key
    true if project_id
  end

  # projects that has this key
  def projects
    if is_deploy_key
      [project]
    else
      user.projects
    end
  end

  def last_deploy?
    Key.where(identifier: identifier).count == 0
  end
end

# == Schema Information
#
# Table name: keys
#
#  id         :integer         not null, primary key
#  user_id    :integer
#  created_at :datetime        not null
#  updated_at :datetime        not null
#  key        :text
#  title      :string(255)
#  identifier :string(255)
#  project_id :integer
#