class CSVParser

# File lib/csv_parser.rb, line 25
def initialize(csv)
  @csv = csv
end

# File lib/csv_parser.rb, line 3
def parsers
  @parsers ||= []
end

# File lib/csv_parser.rb, line 10
def parse(criteria, params={}, &block)
  parsers << {
    criteria: criteria,
    block: block,
  }.merge(params)
end

# File lib/csv_parser.rb, line 18
def parse_once(criteria, params={}, &block)
  parse criteria, {
    once: true,
  }.merge(params), &block
end

# File lib/csv_parser.rb, line 31
def each
  # Get header values used later in prasing
  @headers = @csv.shift.map(&:to_s).map(&:strip)

  # Parse each row
  @csv.each do |row|
    yield parse_row row
  end
end

# File lib/csv_parser.rb, line 95
def [](name)
  @attributes[name]
end

# File lib/csv_parser.rb, line 99
def []=(name, val)
  @attributes[name] = val
end

# File lib/csv_parser.rb, line 89
def defaults
  Hash.new
end

# File lib/csv_parser.rb, line 79
def match?(parser, val, key)
  case criteria = parser[:criteria]
  when Symbol
    send criteria, key
  else
    criteria === key
  end
end

# File lib/csv_parser.rb, line 74
def onced?(parser)
  parser[:once] && @executed.include?(parser)
end

# File lib/csv_parser.rb, line 47
def parse_row(row)
  # Create a new attributes hash for this row, this will be our result
  @attributes = defaults
  # Keep track of which parsers have already been executed for this row
  @executed = []

  # Parse each column of the row
  row.each_with_index do |val, i|
    parse_val val.to_s.strip, @headers[i].to_s
  end

  # Return the attributes that were built using #[]=
  @attributes
end

# File lib/csv_parser.rb, line 63
def parse_val(val, key)
  parsers.each do |parser|
    # Execute any parsers that match this column
    if ! onced?(parser) && match?(parser, val, key)
      instance_exec val, key, &parser[:block]
      @executed << parser
    end
  end
end

# File lib/csv_parser.rb, line 43
def parsers
  self.class.parsers
end