require 'json'
module FaaStRuby
  class Credentials # TODO: change it to YAML?
    def self.load_credentials_file(credentials_file = FaaStRuby.credentials_file)
      return {} unless File.file?(credentials_file)
      creds = Oj.load(File.read(credentials_file))
      if creds.is_a?(Hash)
        creds.delete_if{|workspace, credentials| credentials.nil?}
        return creds
      end
      return {}
    end

    def self.add(workspace_name, new_credentials, credentials_file)
      FaaStRuby::CLI.error("Error trying to save null credentials. You probably found a bug in the gem. Please report it at https://github.com/FaaStRuby/faastruby-cli/issues/new") unless new_credentials
      credentials = load_credentials_file(credentials_file)
      credentials.merge!({workspace_name => new_credentials})
      save_file(credentials, credentials_file)
    end

    def self.remove(workspace_name, credentials_file)
      credentials = load_credentials_file
      credentials.delete_if{|k,v| k == workspace_name}
      save_file(credentials, credentials_file)
    end

    def self.save_file(credentials, credentials_file)
      if File.file?(credentials_file)
        color = :yellow
        symbol = '~'
      else
        color = :green
        symbol = '+'
      end
      credentials.delete_if{|workspace, creds| creds.nil?}
      File.open(credentials_file, 'w') {|f| f.write JSON.pretty_generate(credentials)}
      puts "#{symbol} f #{credentials_file}".colorize(color)
    end

    def self.load_for(workspace_name, cred_file = FaaStRuby.credentials_file, exit_on_error: true)
      credentials = load_from_env(workspace_name) || load_credentials_file(cred_file)
      error_msg = "Could not find credentials for '#{workspace_name}' in '#{cred_file}'"
      if exit_on_error && !credentials[workspace_name]
        FaaStRuby::CLI.error(error_msg)
      elsif !credentials[workspace_name]
        puts error_msg
        return false
      end
      FaaStRuby.configure do |config|
        config.api_key = credentials[workspace_name]['api_key']
        config.api_secret = credentials[workspace_name]['api_secret']
      end
      return true
    end

    def self.load_from_env(workspace_name)
      return nil unless ENV['FAASTRUBY_API_KEY'] && ENV['FAASTRUBY_API_SECRET']
      puts "#{"WARNING:".red} Using credentials from env vars FAASTRUBY_API_KEY and FAASTRUBY_API_SECRET"
      {workspace_name => {'api_key' => ENV['FAASTRUBY_API_KEY'], 'api_secret' => ENV['FAASTRUBY_API_SECRET']}}
    end
  end
end