require 'yaml'
require 'openssl'

module AppRb
  class Cli
    def initialize(args)
      @args = args
      Thread.abort_on_exception = true
    end

    def run
      if @args.count < 2
        usage
        exit
      end
      if File.exists?(@args[0])
        config_path = @args.shift
      end

      if @args[0] == "--vault" && File.exists?(@args[1])
        @args.shift
        @vault_file = @args.shift
      elsif File.exists?(File.join(Dir.pwd, "vault.key"))
        @vault_file = File.join(Dir.pwd, "vault.key")
      else
        @vault_file = nil
      end

      command = @args.shift
      config = Config.new(read_yaml(config_path)) if config_path

      if config && AppRb::Util.compare_versions(config.tool_version, AppRb::VERSION) > 0
        puts "FATAL: need at least '#{config.tool_version}' tool version but current version is '#{AppRb::VERSION}'"
        exit -1
      end

      if %w[deploy d].index(command)
        Command.new(config).deploy(@args[2])
      elsif %w[status s].index(command)
        Command.new(config).status
      elsif command == "redeploy"
        Command.new(config).redeploy
      elsif command == "clean"
        Command.new(config).clean
      elsif command == "stop"
        Command.new(config).stop
      elsif %w[run r].index(command)
        Command.new(config).run(@args[2..-1].join(" "))
      elsif command == "cd"
        Command.new(config).cd
      elsif %w[encrypt en e].index(command)
        puts encrypt(@args.shift)
      elsif %w[decrypt de].index(command)
        puts decrypt(@args.shift)
      else
        puts "FATAL: unknown command '#{command}'"
        exit -1
      end
    end

  private
    MARKER = "__VAULT:"

    def read_yaml(file)
      unvault = proc { |o|
        if o.is_a?(Array)
          o.map { |i| unvault.call(i) }
        elsif o.is_a?(Hash)
          o.map { |k, v| [k, unvault.call(v)] }.to_h
        elsif o.is_a?(String) && o.index(MARKER) == 0
          decrypt(o)
        else
          o
        end
      }
      unvault.call(YAML.load(File.read(file)))
    end

    def die(msg = nil)
      if msg
        puts "FATAL: #{msg}"
      else
        puts "exit with status code -1"
      end
      exit -1
    end

    def bin_to_hex(s)
      s.unpack('H*').first
    end

    def hex_to_bin(s)
      s.scan(/../).map { |x| x.hex }.pack('c*')
    end

    def encrypt(string)
      die "missed vault file" unless @vault_file
      die "string encrypted yet" if string.index(MARKER) == 0
      cipher = OpenSSL::Cipher::AES256.new :CBC
      cipher.encrypt
      iv = cipher.random_iv
      cipher.key = Digest::SHA256.digest(File.read(@vault_file).strip)
      MARKER + bin_to_hex(cipher.update(string) + cipher.final) + ":" + bin_to_hex(iv)
    end

    def decrypt(string)
      die "missed vault file" unless @vault_file
      die "string not encrypted" unless string.index(MARKER) == 0
      cipher = OpenSSL::Cipher::AES256.new :CBC
      cipher.decrypt
      cipher.iv = hex_to_bin(string.sub(MARKER, "").split(":")[1])
      cipher.key = Digest::SHA256.digest(File.read(@vault_file).strip)
      cipher.update(hex_to_bin(string.sub(MARKER, "").split(":")[0])) + cipher.final
    end

    def usage
      puts "Just deploy your apps with docker and consul. Nothing else."
      puts "Version: #{AppRb::VERSION}"
      puts ""
      puts "  app-rb <yml> [options] <command>"
      puts ""
      puts "Options:"
      puts "  --vault <vault-file>    - vault file (<pwd>/vault.key by default)"
      puts ""
      puts "Commands:"
      puts "  deploy [hash]      - deploy new version of app"
      puts "  status             - status of app"
      puts "  stop               - stop app completely"
      puts "  run <cmd> [args]   - one time command"
      puts "  cd                 - go to run node"
      puts "  encrypt <string>   - encrypt script using vault-file"
      puts "  decrypt <string>   - decrypt script using vault-file"
      puts ""
      puts "Advanced commands:"
      puts "  redeploy           - redeploy app"
      puts "  clean              - stop and remove not current containers"
    end
  end
end