require 'redis'
require 'biodiversity'
require_relative 'parsley-store/version'

if RUBY_VERSION < '1.9.1'
  raise 'IMPORTANT: Parsley-store gem  requires ruby >= 1.9.1'
end

class ParsleyStore
  #database numbers for Redis
  LOCAL = 1
  SLAVE = 2

  def initialize(local_db = LOCAL, slave_db = SLAVE, opts = {})
    redis_host = opts[:redis_host] || "0.0.0.0"
    @parser = ScientificNameParser.new
    @local = Redis.new(host: redis_host)
    @local.select(local_db)
  end

  def parse(scientific_name, opts = {})
    @canonical_only = !!opts[:canonical_only]
    @scientific_name = scientific_name

    parsed_data = get_redis_data
    return parsed_data if parsed_data

    cache_parsed_data(parse_scientific_name)
  end

  private

  def get_redis_data
    if @canonical_only
      begin
        stored = @local.hget(@scientific_name, 'canonical')
      rescue RuntimeError
        @local.flushdb
        stored = nil
      end
      return stored if stored
    else
      stored = @local.get(@scientific_name)
      return JSON.parse(stored, symbolize_names: true) if stored
    end
  end

  def parse_scientific_name
    begin
      @parser.parse(@scientific_name)
    rescue
      @parser = ScientificNameParser.new
      @parser.parse(@scientific_name) rescue {
        scientificName: {parsed: false,
                         parser_version: ScientificNameParser::VERSION,
                         anonical: nil,
                         verbatim: @scientific_name}}
    end
  end

  def cache_parsed_data(parsed_data)
    if @canonical_only
      @local.hset(@scientific_name,
                  'parsed',
                  parsed_data[:scientificName][:parsed])
      @local.hset(@scientific_name,
                  'parser_version',
                  parsed_data[:scientificName][:parser_version])
      @local.hset(@scientific_name,
                  'canonical', parsed_data[:scientificName][:canonical])
      parsed_data[:scientificName][:canonical]
    else
      serialized = parsed_data.to_json
      @local.set @scientific_name, serialized
      parsed_data
    end
  end

end