class TrueTable

# File lib/true_table.rb, line 15
def from_csv(csv_string, options = {})
  default_options = { headers: true, converters: :numeric, header_converters: :symbol }
  csv = CSV.new csv_string, **default_options.merge(options)
  new.tap do |table|
    csv.each { |row| table << row.to_h }
  end
end

# File lib/true_table.rb, line 32
def load_csv(path, options = {})
  from_csv File.read(path), options
end

# File lib/true_table.rb, line 38
def +(other)
  result = self.class.new
  each_row { |row, i| result << row.merge(other[i]) }
  result
end

# File lib/true_table.rb, line 45
def -(cols)
  keep_keys = headers - cols
  result = self.class.new
  each_row { |row, i| result << row.slice(*keep_keys) }
  result
end

# File lib/true_table.rb, line 53
def [](key)
  key.is_a?(Symbol) ? col(key) : super
end

# File lib/true_table.rb, line 58
def []=(key, value)
  key.is_a?(Symbol) ? add_col(key.to_sym, value) : super
end

# File lib/true_table.rb, line 63
def clone
  self.class.new map(&:clone)
end

# File lib/true_table.rb, line 68
def col(key)
  map { |row| row[key] }
end

# File lib/true_table.rb, line 73
def cols
  result = {}
  each_col { |col, header| result[header] = col }
  result
end

# File lib/true_table.rb, line 80
def compact
  dup.compact!
end

# File lib/true_table.rb, line 85
def compact!
  delete_if { |row| row.values.include? nil }
end

# File lib/true_table.rb, line 90
def delete_at(index)
  if index.is_a?(Symbol) || index.is_a?(String)
    result = self[index]
    return nil unless result
    each_row { |row, i| row.delete index }
    result
  else
    super
  end
end

# File lib/true_table.rb, line 104
def difference(*others)
  self.class.new super
end

# File lib/true_table.rb, line 109
def dig(*indexes)
  key = indexes.shift
  if key.is_a?(Symbol)
    col(key.to_sym).dig *indexes
  else
    row(key).dig *indexes
  end
end

# File lib/true_table.rb, line 119
def drop(*args)
  self.class.new super
end

# File lib/true_table.rb, line 124
def drop_while(*args)
  self.class.new super
end

# File lib/true_table.rb, line 129
def each_col
  headers.each { |header| yield col(header), header }
end

# File lib/true_table.rb, line 136
def fetch(key, *default)
  if key.is_a?(Symbol)
    if headers.include? key
      col(key.to_sym)
    elsif default.any?
      default.first
    elsif block_given?
      yield key
    else
      raise IndexError, "row :#{key} does not exist"
    end
  else
    super
  end
end

# File lib/true_table.rb, line 153
def headers
  first.keys
end

# File lib/true_table.rb, line 158
def intersection(*others)
  self.class.new super
end

# File lib/true_table.rb, line 163
def join(row_separator = $,, col_separator = nil, with_headers: false)
  if col_separator
    result = map { |row| row.values.join col_separator }.join(row_separator)
    with_headers ? headers.join(col_separator) + row_separator + result : result
  else
    super row_separator
  end
end

# File lib/true_table.rb, line 173
def last(*args)
  args.empty? ? super : self.class.new(super)
end

# File lib/true_table.rb, line 178
def reject
  self.class.new super
end

# File lib/true_table.rb, line 183
def reverse
  self.class.new super
end

# File lib/true_table.rb, line 188
def rotate(count = 1)
  self.class.new super
end

# File lib/true_table.rb, line 196
def save_csv(path)
  File.write path, to_csv
end

# File lib/true_table.rb, line 201
def select
  self.class.new super
end

# File lib/true_table.rb, line 207
def shuffle(*args)
  self.class.new super
end

# File lib/true_table.rb, line 212
def slice(*args)
  if args.count == 1 and args.first.is_a? Integer
    super
  else
    self.class.new super
  end
end

# File lib/true_table.rb, line 221
def slice!(*args)
  if args.count == 1 and args.first.is_a? Integer
    super
  else
    self.class.new super
  end
end

# File lib/true_table.rb, line 230
def sort
  self.class.new super
end

# File lib/true_table.rb, line 235
def sort_by
  self.class.new super
end

# File lib/true_table.rb, line 240
def take(*args)
  self.class.new super
end

# File lib/true_table.rb, line 245
def take_while(*args)
  self.class.new super
end

# File lib/true_table.rb, line 250
def to_csv(row_separator = "\n", col_separator = ",")
  join(row_separator, col_separator, with_headers: true)
end

# File lib/true_table.rb, line 256
def to_h
  map { |row| [row.values.first, row] }.to_h
end

# File lib/true_table.rb, line 261
def values
  map { |row| row.values }
end

# File lib/true_table.rb, line 267
def add_col(key, values)
  values.each_with_index do |value, i|
    self[i] ||= {}
    self[i][key] = value
  end
end