module RawSqlBuilder

# File lib/raw_sql_builder.rb, line 20
def execute(query)
  ActiveRecord::Base.connection.execute(query)
end

# File lib/raw_sql_builder.rb, line 8
def mass_create(objects)
  run([*objects], :create)
end

# File lib/raw_sql_builder.rb, line 16
def mass_create_or_update(objects)
  run([*objects], :both)
end

# File lib/raw_sql_builder.rb, line 12
def mass_update(objects)
  run([*objects], :update)
end

# File lib/raw_sql_builder.rb, line 45
def check_and_execute(type)
  if create?(type)
    results = execute(get_create_query) if @creates.size > 0
  end
  if update?(type)
    execute(get_update_query) if @updates_hash.size > 0
    get_update_exception_queries.each do |query|
      execute(query)
    end
  end
  results
end

# File lib/raw_sql_builder.rb, line 274
def convert_hash
  {
    datetime: 'timestamp',
    string: 'text',
    fixnum: 'integer',
    boolean: 'boolean'
  }
end

# File lib/raw_sql_builder.rb, line 263
def convert_type(attributes)
  if attributes.type == :text
    return 'text[]' if attributes.array
    'text'
  else
    convert_hash[attributes.type] || attributes.type.to_s
  end
end

# File lib/raw_sql_builder.rb, line 102
def create?(type)
  type == :create || type == :both
end

# File lib/raw_sql_builder.rb, line 155
def create_query(keys_string, values_string)
  "INSERT INTO #{@table_name} (\"#{keys_string}\") VALUES (#{values_string}) RETURNING id;"
end

# File lib/raw_sql_builder.rb, line 146
def create_values
  @creates.map do |o|
    o.attributes.except('id').map do |k, v|
      @type = convert_type(@columns_hash[k])
      format_value(v, 'DEFAULT')
    end
  end
end

# File lib/raw_sql_builder.rb, line 142
def create_values_string
  create_values.map { |v| v.join(', ') }.join('), (')
end

# File lib/raw_sql_builder.rb, line 220
def filter_changes(changes)
  return {} unless changes.size > 0
  filtered_changes = {}
  changes.each do |k, v|
    filtered_changes[k] = v[1] unless v[0].blank? && v[1].blank?
  end
  filtered_changes
end

# File lib/raw_sql_builder.rb, line 239
def format_value(value, default = 'NULL')
  if value.present? || value == false
    "'#{type_formatting(value)}'"
  else
    default
  end
end

# File lib/raw_sql_builder.rb, line 120
def get_create_query
  keys_string = (@columns_hash.keys - ['id']).join('", "')
  values_string = create_values_string
  create_query(keys_string, values_string)
end

# File lib/raw_sql_builder.rb, line 229
def get_table_name(name)
  name = name.deconstantize unless name.deconstantize.blank?
  name.tableize
end

# File lib/raw_sql_builder.rb, line 161
def get_update_arrays(columns_info)
  keys_array = []
  values_array = []
  columns_info.each do |k, v|
    @column = k
    @type = convert_type(v)
    values_array << update_values_string
    keys_array << update_keys_string unless @column == 'id'
  end
  [keys_array, values_array]
end

# File lib/raw_sql_builder.rb, line 134
def get_update_exception_queries
  @update_exceptions_hash.map do |exception|
    update_exception_query(exception)
  end
end

# File lib/raw_sql_builder.rb, line 126
def get_update_query
  changed_columns = @updates_hash.map { |c| c.values.map(&:keys) }.flatten.uniq
  columns_info = @columns_hash.slice(*(['id'] + changed_columns))
  return unless columns_info.size > 1

  update_query(*get_update_arrays(columns_info))
end

# File lib/raw_sql_builder.rb, line 234
def objects_count(type)
  return @creates.size if type == :create
  @updates_hash.size + @update_exceptions_hash.size
end

# File lib/raw_sql_builder.rb, line 75
def organize_objects(objects, type)
  objects.each do |o|
    next if o.blank?
    if o.new_record? && create?(type)
      @creates << o
    elsif o.changed? && update?(type)
      filtered_changes = filter_changes(o.changes)
      next if filtered_changes.blank?

      organize_updates(o, filtered_changes)
      @updates << o
    end
    set_created_at_and_updated_at(o)
    o.changes_applied
  end
end

# File lib/raw_sql_builder.rb, line 92
def organize_updates(object, filtered_changes)
  check_changes = filtered_changes.values.map { |v| true if v.blank? }.compact

  if check_changes.any?
    @update_exceptions_hash << { object.id => filtered_changes }
  else
    @updates_hash << { object.id => filtered_changes }
  end
end

# File lib/raw_sql_builder.rb, line 283
def response_hash
  {
    create: {
      skip: "No eligible objects to create for #{@object_class}... Skipping.",
      complete: "#{@object_class} creating complete."
    },
    update: {
      skip: "No changed columns for update for #{@object_class}... Skipping.",
      complete: "#{@object_class} updating complete."
    }
  }
end

# File lib/raw_sql_builder.rb, line 29
def run(objects, type)
  return puts 'No objects passed through.' if objects.blank?
  setup_and_loop_objects(objects, type)
  puts "Creates: #{@creates.size}, Updates: #{@updates.size}"
  results = check_and_execute(type)
  set_changes_applied(results)
  true
end

# File lib/raw_sql_builder.rb, line 58
def set_changes_applied(results = nil)
  return if @creates.none? && @updates.none?

  @creates.each_with_index do |c, i|
    c.id = results.values[i][0]
  end
end

# File lib/raw_sql_builder.rb, line 110
def set_created_at_and_updated_at(object)
  object.created_at = Time.zone.now if
    @columns_hash['created_at'].present? && object.created_at.blank?
  object.updated_at = Time.zone.now if
    @columns_hash['updated_at'].present? && object.updated_at.blank?
  object
end

# File lib/raw_sql_builder.rb, line 40
def setup_and_loop_objects(objects, type)
  setup_globals(objects)
  organize_objects(objects, type)
end

# File lib/raw_sql_builder.rb, line 68
def setup_globals(objects)
  @object_class = objects.first.class
  @table_name = get_table_name(@object_class.name)
  @columns_hash = @object_class.columns_hash
  @creates, @updates, @updates_hash, @update_exceptions_hash = [], [], [], []
end

# File lib/raw_sql_builder.rb, line 247
def type_formatting(value)
  @type = 'json' if @type == 'text' && (value.is_a?(Hash) || value.is_a?(Array))

  if @type == 'text[]'
    value = value.flatten.uniq.to_s if value.is_a?(Array)
    value = "{#{value.trim_ends(%w([ ]))}}"
  elsif @type == 'hstore' && value.is_a?(Hash)
    value = value.map do |k, v|
      "\"#{k}\"=>\"#{v.to_s.gsub('=>', ':').gsub('"', '\"')}\""
    end.join(', ')
  elsif @type == 'json'
    value = "#{value.to_s.gsub('=>', ':')}"
  end
  value.to_s.gsub("'nil'", "'null'").gsub("'", "''").gsub("''''", "''")
end

# File lib/raw_sql_builder.rb, line 106
def update?(type)
  type == :update || type == :both
end

# File lib/raw_sql_builder.rb, line 185
def update_array
  @updates_hash.map do |c|
    c.values.map do |v|
      format_value(v[@column])
    end
  end
end

# File lib/raw_sql_builder.rb, line 213
def update_exception_query(exception)
  "UPDATE #{@table_name} SET #{update_exception_values_array(exception).join(', ')}
WHERE #{@table_name}.id = #{exception.keys.first};"
end

# File lib/raw_sql_builder.rb, line 204
def update_exception_values_array(exception)
  exception.values.map do |hash|
    hash.map do |k, v|
      @type = convert_type(@columns_hash[k])
      "\"#{k}\" = #{format_value(v)}::#{@type}"
    end
  end
end

# File lib/raw_sql_builder.rb, line 193
def update_keys_string
  "\"#{@column}\" = COALESCE(source.#{@column}::#{@type}, #{@table_name}.#{@column}::#{@type})"
end

# File lib/raw_sql_builder.rb, line 197
def update_query(keys_array, values_array)
  "UPDATE #{@table_name} SET #{keys_array.join(', ')} FROM
( SELECT #{values_array.join(', ')}) as source WHERE #{@table_name}.id = source.id;"
end

# File lib/raw_sql_builder.rb, line 177
def update_values
  if @column == 'id'
    @updates_hash.map(&:keys)
  else
    update_array.join(', ')
  end
end

# File lib/raw_sql_builder.rb, line 173
def update_values_string
  "unnest(array[#{update_values}])#{"::#{@type}"} as #{@column}"
end