# Syntaxes

# favorite_foods.csv
id,name
1,chocolate
2,bacon
3,apple
4,banana

# ========== #

csv_format = "id,name\n1,chocolate\n2,bacon\n3,apple\n4,banana\n"

# Read
require 'csv'

csv_read = CSV.read("favorite_foods.csv")
p csv_read

# Parse
require 'csv'

csv_parse = CSV.parse("id,name\n1,chocolate\n2,bacon\n3,apple\n4,banana\n5,almonds")
p csv_parse

# Result

[
  ["id", "name"],
  ["1", "chocolate"],
  ["2", "bacon"],
  ["3", "apple"],
  ["4", "banana"],
  ["5", "almonds"]
]

# CSV read

require 'csv'

table = CSV.read("favorite_foods.csv", headers: true)
# table = CSV.parse(File.read("favorite_foods.csv"), headers: true)

# CSV read

require 'csv'

table = CSV.read('favorite_foods.csv', headers: true)

# table['file']['column']

table[0]["id"]
# "1"

table[0]["name"]
# "chocolate"

# by_col

table.by_col[0]
# ["1", "2", "3", "4", "5"]

table.by_col[1]
# ["chocolate", "bacon", "apple", "banana", "almonds"]

# by_row

table.by_row[0]
#<CSV::Row "id":"1" "name":"chocolate">

table.by_row[1]
#<CSV::Row "id":"2" "name":"bacon">

# Exercise

table.each do |row_object|
  p "[#{row_object['id']}, #{row_object['name']}]"
  p "-"*10
end

# Create a CSV string

cats = [
  [:blue, 1],
  [:white, 2],
  [:black_and_white, 3]
]

csv_cats = cats.map { |c| c.join(",") }.join("\n")
p csv_cats

# With 'generate'
require 'csv'

csv_cats = CSV.generate do |csv|
  csv << [:blue, 1]
  csv << [:white, 2]
  csv << [:black_and_white, 3]
end

p csv_cats

# Create CSV File

CSV.open("cats.csv", "w") do |csv|
  csv << [:blue, 1]
  csv << [:white, 2]
  csv << [:black_and_white, 3]
end

# Append

CSV.open("cats.csv", "a") do |csv|
  csv << [:brown, 4]
end

# Syntaxes

json = {
  "key": "value"
}

require 'json'

pokemon = {
  name: "Bulbasaur", 
  type: ["grass", "poison"], 
  weaknesses: ["Fire","Psychic","Flying","Ice"] 
}

pokemon.methods

# From Hash to JSON
puts json_string = pokemon.to_json # built-in method
puts json_string = JSON.generate(pokemon) # generates a json string
p json_string = JSON.dump(pokemon) # generate with presets and a limit

# From JSON to Hash
p json_hash = JSON.parse json_string # a string
puts json_hash = JSON.load json_string # a IO stream => File

# Read
require 'json'

file = File.read('books.json')
data_hash = JSON.parse(file)

data_hash['books']['1'] = 'I, Robot'
data_hash['books']['2'] = 'The Caves of Steel'

# Write

File.open("saved_hash.json","w") do |file|
  file.write data_hash.to_json
end

# Syntaxes

---
:name: Bulbasaur
:type:
  - grass
  - poison
:weaknesses:
  - Fire
  - Psychic
  - Flying
  - Ice


# Other form.

---
:name: Bulbasaur
:type: ['grass', 'poison']
:weaknesses: ['Fire', 'Psychic', 'Flying', 'Ice']

require 'yaml'

pokemon = {
  name: "Bulbasaur", 
  type: ["grass", "poison"], 
  weaknesses: ["Fire","Psychic","Flying","Ice"] 
}

# Hash to YAML
yaml_string = pokemon.to_yaml # built-in method
yaml_string_dump = YAML.dump(pokemon)

# YAML to Hash
yaml_object = YAML.load(yaml_string)

# Write
require 'yaml'

pokemon = {
  name: "Bulbasaur", 
  type: ["grass", "poison"], 
  weaknesses: ["Fire","Psychic","Flying","Ice"] 
}


# Write (or overwrite) our character to `saved_hash.txt`
File.open("saved_hash.yaml","w") do |file|
  file.write pokemon.to_yaml
end

# Read

# Read file & parsed to hash
parsed = YAML.load(File.read("saved_hash.yaml"))
p parsed