# frozen_string_literal: true

# Requirements
# =======================================================================

# Stdlib
# -----------------------------------------------------------------------

# Deps
# -----------------------------------------------------------------------

# Project / Package
# -----------------------------------------------------------------------


# Refinements
# =======================================================================

require 'nrser/refinements/types'
using NRSER::Types


# Definitions
# =======================================================================

# 
class Locd::CLI::Table
  # Unicode superscript number to use as references for columns with
  # descriptions.
  # 
  # @return [Array<String>]
  # 
  SUPERSCRIPT_NUMBERS = [
    "\u2070",
    "\u00B9",
    "\u00B2",
    "\u00B3",
    "\u2070",
    "\u2074",
    "\u2075",
    "\u2076",
    "\u2077",
    "\u2078",
    "\u2079",
  ].freeze
  
  NULL = '␀'
  
  
  # Mixins
  # ============================================================================
  
  include Enumerable
  
  
  # Classes
  # ============================================================================
  
  # A column in a table.
  # 
  class Column
    attr_reader :name, :getter, :desc
    
    def initialize name, desc: nil, &getter
      @name = name
      @getter = getter
      @desc = desc
    end
  end # class Column
  
  
  # @todo Document build method.
  # 
  # @param [type] arg_name
  #   @todo Add name param description.
  # 
  # @return [return_type]
  #   @todo Document return value.
  # 
  def self.build &block
    new.tap &block
  end # .build
  
  def initialize
    @columns = []
    @rows = []
  end
  
  def each &block
    @rows.each &block
  end
  
  def each_index &block
    @rows.each_index &block
  end
  
  def column *args, &getter
    @columns << Column.new( *args, &getter )
  end
  
  alias_method :col, :column
  
  
  def rows entries = nil
    unless entries.nil?
      @rows = entries.to_a
    end
    
    @rows
  end
  
  
  def to_a header: true, col_desc_refs: true
    [].tap do |array|
    
      if header
        desc_ref_index = 0
        array << @columns.map { |column|
          if column.desc && col_desc_refs
            desc_ref_index += 1
            "#{ column.name }#{ SUPERSCRIPT_NUMBERS[desc_ref_index] }"
          else
            column.name
          end
        }
      end
        
      @rows.each do |row|
        values = if NRSER.array_like? row
          row.to_a
        else
          @columns.map do |column|
            column.getter.call( row )
          end
        end
        
        array << values.map { |value|
          if value.nil?
            NULL
          else
            value.to_s
          end
        }
      end
    
    end
  end # #to_a
  
  def footer
    NULL + " Null\n" +
    @columns.select { |col| col.desc }.each_with_index.map { |col, index|
      "#{ SUPERSCRIPT_NUMBERS[index + 1] } #{ col.desc }"
    }.join( "\n" )
  end
  
end # class Locd::CLI::Table