module S3Index

# File lib/s3_index.rb, line 85
def default_client
  @s3_client ||= new_client
end

# File lib/s3_index.rb, line 99
def default_client=(client)
  @s3_client = client
end

# File lib/s3_index.rb, line 58
def download!(s3: default_client, src: nil, s3_url: nil, index: nil, dst: nil)
  src || s3_url || index ||
    raise(ArgumentError, 'src:, s3_url:, or index: must be provided!')

  index ||=
    begin
      finder = src ? { origin_url: src } : { s3_url: s3_url }
      Index.find_by(finder) || raise(ActiveRecord::RecordNotFound, "S3Index::Index not found by #{finder}")
    end

  obj = s3.bucket(index.s3_bucket).object(index.origin_url)
  obj.get(response_target: dst || index.origin_url)
end

# File lib/s3_index.rb, line 13
def env
  @env ||= ActiveSupport::StringInquirer.new(ENV['S3_INDEX_ENV'])
end

# File lib/s3_index.rb, line 76
def index_attributes_for(path)
  {
    md5: Digest::MD5.file(path).to_s,
    file_name: File.basename(path),
    content_type: MIME::Types.type_for(path).first.try(:content_type),
    size: File.size(path)
  }
end

# File lib/s3_index.rb, line 72
def index_for_src(src)
  Index.where(origin_url: src).first_or_initialize
end

# File lib/s3_index.rb, line 23
def logger
  @logger ||= ActiveRecord::Base.logger
end

# File lib/s3_index.rb, line 27
def logger=(logger)
  @logger = logger
end

# File lib/s3_index.rb, line 104
def method_missing(meth, *args, &block)
  super unless Index.respond_to?(meth)
  Index.public_send(meth, *args, &block)
end

# File lib/s3_index.rb, line 89
def new_client
  credentials = Aws::SharedCredentials.new(profile_name: 'default')
  client = Aws::S3::Client.new(
    credentials: credentials,
    http_wire_trace: $DEBUG,
    logger: logger
  )
  Aws::S3::Resource.new(client: client)
end

# File lib/s3_index.rb, line 19
def root
  @root ||= Pathname(File.expand_path('../..', __FILE__))
end

# File lib/s3_index.rb, line 32
def upload!(s3: default_client, bucket:, src:, dst: src)
  obj = s3.bucket(bucket).object(dst)

  index = index_for_src(src)
  index_attrs = index_attributes_for(src)

  # nothing to do, file is registered and the same as before
  return index if index.md5 == index_attrs[:md5]

  # try to get the data to s3 first, then save in index.
  # order is important, we don't want to make the row until
  # S3 gets the file.
  obj.upload_file(
    src,
    content_type: index_attrs[:content_type],
    content_length: index_attrs[:size]
  )

  index.s3_url = obj.public_url
  index.s3_bucket = obj.bucket_name
  index.update!(index_attrs)
  index
end