# frozen_string_literal: true

# Copyright (c) 2024 Yegor Bugayenko
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the 'Software'), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.

require 'json'
require 'time'
require 'others'
require_relative '../factbase'

# A single fact in a factbase.
#
# This is an internal class, it is not supposed to be instantiated directly,
# by the +Factbase+ class.
# However, it is possible to use it for testing directly, for example to make a
# fact with a single key/value pair inside:
#
#  require 'factbase/fact'
#  f = Factbase::Fact.new(Mutex.new, { 'foo' => [42, 256, 'Hello, world!'] })
#  assert_equal(42, f.foo)
#
# A fact is basically a key/value hash map, where values are non-empty
# sets of values.
#
# Author:: Yegor Bugayenko (yegor256@gmail.com)
# Copyright:: Copyright (c) 2024 Yegor Bugayenko
# License:: MIT
class Factbase::Fact
  # Ctor.
  # @param [Mutex] mutex A mutex to use for maps synchronization
  # @param [Hash] map A map of key/value pairs
  def initialize(mutex, map)
    @mutex = mutex
    @map = map
  end

  # Convert it to a string.
  # @return [String] String representation of it (in JSON)
  def to_s
    "[ #{@map.map { |k, v| "#{k}: #{v}" }.join(', ')} ]"
  end

  # Get a list of all props.
  # @return [Array<String>] List of all props in the fact
  def all_properties
    @map.keys
  end

  # When a method is missing, this method is called.
  others do |*args|
    k = args[0].to_s
    if k.end_with?('=')
      kk = k[0..-2]
      raise "Invalid prop name '#{kk}'" unless kk.match?(/^[a-z_][_a-zA-Z0-9]*$/)
      raise "Prohibited prop name '#{kk}'" if methods.include?(kk.to_sym)
      v = args[1]
      raise "The value of '#{kk}' can't be nil" if v.nil?
      raise "The value of '#{kk}' can't be empty" if v == ''
      raise "The type '#{v.class}' of '#{kk}' is not allowed" unless [String, Integer, Float, Time].include?(v.class)
      v = v.utc if v.is_a?(Time)
      @mutex.synchronize do
        @map[kk] = [] if @map[kk].nil?
        @map[kk] << v
        @map[kk].uniq!
      end
      nil
    elsif k == '[]'
      @map[args[1].to_s]
    else
      v = @map[k]
      if v.nil?
        raise "Can't get '#{k}', the fact is empty" if @map.empty?
        raise "Can't find '#{k}' attribute out of [#{@map.keys.join(', ')}]"
      end
      v[0]
    end
  end
end