Export HTML from Kobito.db with tags and dates (like Evernote)

kobito2html.rb

#!/usr/bin/env ruby
# Usage: ./kobito2html.rb Kobito.db ./export
gem "activerecord", "~> 5.1.4"
gem "nokogiri", "~> 1.8.1"
gem "sqlite3", "~> 1.3.13"

require "active_record"
require "nokogiri"
require "sqlite3"

db, dest = ARGV

ActiveRecord::Base.establish_connection(
  adapter: "sqlite3",
  database: db
)

TIMESTAMP_OFFSET = Time.parse("2001-01-01T00:00:00Z").to_i

class Item < ActiveRecord::Base
  self.table_name = "ZITEM"
  self.primary_key = "Z_PK"

  has_many :taggings, foreign_key: :Z_2ITEMS
  has_many :tags, through: :taggings

  def title
    self.ZTITLE
  end

  def body
    self.ZBODY
  end

  def body_with_metadata
    doc = Nokogiri.parse(body)
    head = doc.css("head")[0]
    head << doc.create_element("meta", name: "keywords", content: tags.map(&:name).join(", "))
    head << doc.create_element("meta", name: "created", content: created_at.utc.strftime("%Y-%m-%d %H:%M:%S %z"))
    head << doc.create_element("meta", name: "updated", content: updated_at.utc.strftime("%Y-%m-%d %H:%M:%S %z"))
    doc.css("title")[0].content = title
    doc.to_html
  end

  def created_at
    Time.at(TIMESTAMP_OFFSET + self.ZCREATED_AT)
  end

  def updated_at
    Time.at(TIMESTAMP_OFFSET + self.ZUPDATED_AT)
  end
end

class Tag < ActiveRecord::Base
  self.table_name = "ZTAG"
  self.primary_key = "Z_PK"

  def name
    self.ZNAME
  end
end

class Tagging < ActiveRecord::Base
  self.table_name = "Z_2TAGS"
  belongs_to :item, foreign_key: :Z_2ITEMS
  belongs_to :tag, foreign_key: :Z_3TAGS
end


Item.all.each do |item|
  filename = File.join(dest, "#{item.id}.html")
  $stderr.puts "Export to #{filename}"
  File.write(filename, item.body_with_metadata)
end