delete_old_branches.rb

require 'date'
require 'graphlient'
require 'json'
require 'pry'
require 'octokit'

OWNER, REPO = ARGV
GITHUB_TOKEN = ENV['GITHUB_TOKEN']

def rest_client
  Octokit::Client.new(access_token: GITHUB_TOKEN)
end

def graphql_client
  Graphlient::Client.new('https://api.github.com/graphql',
    headers: {
      'Authorization' => "Bearer #{GITHUB_TOKEN}"
    },
    http_options: {
      read_timeout: 20,
      write_timeout: 30
    }
  )
end

def branches
  @branches ||= graphql_client.query <<~EOF
  {
    repository(owner: "#{OWNER}", name: "#{REPO}") {
      refs(refPrefix: "refs/heads/", first: 100, orderBy: {field: TAG_COMMIT_DATE, direction: ASC}) {
        edges {
          node {
            name
            branchProtectionRule {
              restrictsPushes
            }
            associatedPullRequests(first: 100, states: [OPEN, CLOSED, MERGED]) {
              edges {
                node {
                  url
                  closed
                  merged
                }
              }
            }
            target {
              ... on Commit {
                author {
                  user {
                    login
                  }
                  date
                }
              }
            }
          }
        }
      }
    }
  }
  EOF
end

branches.data.repository.refs.edges.map(&:node).each do |branch|
  name = branch.name
  author = branch.target.author.user&.login
  last_commit_date = Date.parse(branch.target.author.date)
  protected_branch = branch.branch_protection_rule
  associated_prs = branch.associated_pull_requests.edges
  one_year_ago = Date.today - 265

  next if name == "main" || name == "master" || protected_branch

  if associated_prs.any?
    open_prs = associated_prs.map(&:node).map { |pr| pr.merged == false || pr.closed == false }

    next if open_prs.any?

    pr_urls = associated_prs.map(&:node).map(&:url).join(', ')
    puts "Deleting branch #{name} because associated PRs #{pr_urls} are closed."
    # rest_client.delete_branch("#{OWNER}/#{REPO}", name)
  end

  if last_commit_date < one_year_ago
    puts "Deleting branch #{name} because it is more than a year old"
    # rest_client.delete_branch("#{OWNER}/#{REPO}", name)
  end
end