# Copyright (C) 2013 Dmitry Yakimenko (detunized@gmail.com).
# Licensed under the terms of the MIT license. See LICENCE for details.

module LastPass
    class Vault
        attr_reader :accounts

        # Fetches a blob from the server and creates a vault
        def self.open_remote username, password, multifactor_password = nil, client_id = nil
            blob = Vault.fetch_blob username, password, multifactor_password, client_id
            open blob, username, password
        end

        # Creates a vault from a blob object
        def self.open blob, username, password
            new blob, blob.encryption_key(username, password)
        end

        # Just fetches the blob, could be used to store it locally
        def self.fetch_blob username, password, multifactor_password = nil, client_id = nil
            session = Fetcher.login username, password, multifactor_password, client_id
            blob = Fetcher.fetch session
            Fetcher.logout session

            blob
        end

        # This more of an internal method, use one of the static constructors instead
        def initialize blob, encryption_key
            chunks = Parser.extract_chunks blob
            if !complete? chunks
                raise InvalidResponseError, "Blob is truncated"
            end

            private_key = nil
            if blob.encrypted_private_key
                private_key = Parser.parse_private_key blob.encrypted_private_key, encryption_key
            end

            @accounts = parse_accounts chunks, encryption_key, private_key
        end

        def complete? chunks
            !chunks.empty? && chunks.last.id == "ENDM" && chunks.last.payload == "OK"
        end

        def parse_accounts chunks, encryption_key, private_key
            accounts = []
            key = encryption_key

            chunks.each do |i|
                case i.id
                when "ACCT"
                    # TODO: Put shared folder name as group in the account
                    account = Parser.parse_ACCT i, key
                    if account
                        accounts << account
                    end
                when "SHAR"
                    raise "private_key must be provided" if !private_key

                    # After SHAR chunk all the folliwing accounts are enrypted with a new key
                    key = Parser.parse_SHAR(i, encryption_key, private_key)[:encryption_key]
                end
            end

            accounts
        end
    end
end