A migrator for 37Signals' BCX.

migrator.rb

require 'httparty'
require 'active_support/all'

module PartyPooper
  def get(url, options = {})
    self.class.get("/#{account_id}/api/v1/#{url}", options.merge(extras))
  rescue => boom
    puts boom.message
    retry
  end

  def post(url, data, options = {})
    self.class.post("/#{account_id}/api/v1/#{url}", options.merge(extras(post_headers)).merge(body: data.to_json))
  rescue => boom
    puts boom.message
    retry
  end

  def put(url, data, options = {})
    self.class.put("/#{account_id}/api/v1/#{url}", options.merge(extras(post_headers)).merge(body: data.to_json))
  rescue => boom
    puts boom.message
    retry
  end

  def extras(h = headers)
    { basic_auth: basic_auth, headers: h }
  end

  def basic_auth
    { username: username, password: password }
  end

  def headers
    { 'User-Agent' => user_agent }
  end

  def post_headers
    headers.merge('Content-Type' => 'application/json')
  end
end

Client = Struct.new(:username, :password, :user_agent, :account_id, :project_id) do
  include HTTParty
  include PartyPooper

  base_uri 'https://basecamp.com'

  def todo_lists
    get("/projects/#{project_id}/todolists.json")
  end

  def completed_todo_lists
    get("/projects/#{project_id}/todolists/completed.json")
  end

  def todo_list(id)
    get("/projects/#{project_id}/todolists/#{id}.json")
  end

  def create_todo_list(data)
    post("/projects/#{project_id}/todolists.json", data)
  end

  def todos(list)
    get("/projects/#{project_id}/todolists/#{list}.json")
  end

  def todo(id)
    get("/projects/#{project_id}/todos/#{id}.json")
  end

  def create_todo(list, data)
    post("/projects/#{project_id}/todolists/#{list}/todos.json", data)
  end

  def complete_todo(id)
    put("/projects/#{project_id}/todos/#{id}.json", completed: true)
  end

  def create_todo_comment(id, data)
    post("/projects/#{project_id}/todos/#{id}/comments.json", data)
  end
end

Migrator = Struct.new(:from, :to, :log) do
  def migrate
    lists.each { |list| migrate_list(list) }
  end

  def migrate_list(list)
    log.info("Migrating #{list['name']}")
    destination = to.create_todo_list(list.slice('name'))
    todos_from_list(list).each { |todo| migrate_todo(todo, destination) }
  end

  def migrate_todo(todo, destination)
    log.info("\tMigrating todo #{todo['content']}")

    todo = from.todo(todo['id'])
    ctodo = to.create_todo(destination['id'], todo.slice('content'))

    comments = comments_from_todo(todo)
    if comments.present?
      log.info("\tMigrating #{comments.count} comments")
      comments.each { |comment| migrate_comment(comment, ctodo) }
    end

    complete_todo(ctodo) if todo['completed']
  end

  def complete_todo(todo)
    log.info("\tCompleting #{todo['content']}")
    to.complete_todo(todo['id'])
  end

  def comments_from_todo(todo)
    Array(todo['comments'])
  end

  def migrate_comment(comment, todo)
    to.create_todo_comment(todo['id'], comment.slice('content'))
  end

  def lists
    from.completed_todo_lists.reverse + from.todo_lists.reverse
  end

  def todos_from_list(list)
    todos = from.todo_list(list['id'])['todos']
    Array(todos['remaining']) + Array(todos['completed'])
  end
end

run.rb

require 'logger'
require_relative 'client'

username = 'username'
password = 'password'
user_agent = 'BCX Mover (email@example.com)'

from_account_id = 1234
from_project_id = 2345

to_account_id = 5678
to_project_id = 6789

from = Client.new(username, password, user_agent, from_account_id, from_project_id)
to = Client.new(username, password, user_agent, to_account_id, to_project_id)

log = Logger.new(STDOUT)
log.formatter = Logger::Formatter.new

Migrator.new(from, to, log).migrate