require "uri"

class MicroSql
end

require_relative "micro_sql/pg_adapter"
require_relative "micro_sql/sqlite_adapter"
require_relative "micro_sql/table"
require_relative "micro_sql/settings"

class MicroSql
  
  (class << self; self; end).class_eval do
    private :new

    def create(url)
      scheme = URI.parse(url).scheme
      klass_name = if !scheme
        "MicroSql::SqliteAdapter"
      else
        "MicroSql::#{scheme[0...1].upcase}#{scheme[1..-1]}Adapter"
      end

      eval(klass_name).send(:new, url)
    end
  end
  
  def ask(sql, *args)
    r = exec(sql, *args)
    return r unless r.is_a?(Array)

    r = r.first
    return r unless r.is_a?(Array)
    return r unless r.length == 1
    r.first
  end

  def exec!(sql, *args)
    execute :no_prepare, sql, *args
  end

  def exec(sql, *args)
    execute :prepare, sql, *args
  end

  def transaction(&block)
    @impl.transaction(&block)
  end
  
  def settings
    @settings ||= MicroSql::SettingsTable.new(self)
  end
  
  private
  
  def prepared_queries
    @prepared_queries ||= {}
  end

  def prepare(sql)
    key = sql.to_uid.to_s
    prepared_queries.fetch(key) 
  rescue KeyError
    prepared_queries[key] = prepare_query(key, sql) 
  end
end

# url = "pg://sqdb:sqdb@localhost:5433/sqdb"
# MicroSql.create(url)