require 'daru'

df = Daru::DataFrame.from_csv '/home/sameer/github_repos/daru/spec/fixtures/music_data.tsv', col_sep: "\t"

df.timestamp.map! { |ts| ts += "+5:30"}

require 'date'
df = df.map_rows do |row|
  row[:timestamp] = DateTime.strptime(row[:timestamp], '%Y-%m-%dT%H:%M:%SZ%z').to_time
  row
end

artist_counts = {}

# Populate a hash which has artist names as keys with corresponding values set to the number of times the name of the artist
# has appeared.
artists = df.artname.uniq
artists.each do |artist|
  artist_counts[artist] = df.artname.count(artist)
end

# Since indexes are stored as symbols, convert each artist name to camel_case
a= artist_counts.to_a.each do |name_val_pair|
  name_val_pair[0] = name_val_pair[0].downcase.split(' ').join('_')
end
counts = Daru::Vector.new Hash[a], name: :counts

counts.max :vector

top_ten = counts.sort[-10..-1]

hsh = {}

top_ten.each do |count|
  hsh[counts.index_of(count)] = count
end

ten = Daru::Vector.new hsh

ten.plot type: :bar, width: 1120, height: 300