github_issues.check

#!/usr/bin/env ruby
require "rubygems"
require "time"
require "json"
require "open-uri"
require "net/https"

class GithubIssue
  def initialize(hash)
    @hash = hash
  end

  def pull_request?
    @hash["pull_request"] && @hash["pull_request"]["html_url"]
  end

  def comments_count
    @hash["comments"]
  end

  def updated_at
    @updated_at ||=
      Time.parse(@hash["updated_at"])
  end

  def formatted_updated_at
    time_ago(updated_at)
  end

  def formatted_title
    "#{formatted_updated_at} [#{comments_count}] #{"[PR]" if pull_request?}"
  end

  def formatted_description
    @hash["title"].gsub(/[\r\n\t]/, " ")[0..100] + "..."
  end

  private

  # https://gist.github.com/3808180
  def time_ago(time)
    case delta = (Time.now.to_i - time.to_i)
      when 0..119 then "-1 min"
      when 120..3599 then "-#{delta / 60} mins"
      when 3600..86399 then "-#{(delta / 3600).round} hours"
      else "-#{(delta / 86400).round} days"
    end
  end
end

class GithubIssuesStatus
  def initialize(issues_url, json)
    @issues_url = issues_url
    @issues =
      Array(JSON.parse(json)) \
        .map { |e| GithubIssue.new(e) }

  rescue JSON::ParserError
    raise RuntimeError, "invalid json: '#{json}'"
  end

  def any_issues_with_0_comments?
    @issues.any? { |i| i.comments_count.zero? }
  end

  def as_json(*)
    {
      :result => @issues.empty?,
      :changing => any_issues_with_0_comments?,
      :url => @issues_url,
      :info => info
    }
  end

  def to_json(*)
    JSON.dump(as_json)
  end

  private

  def info
    @issues.inject([]) do |result, issue|
      result.concat(issue_details(issue))
      result
    end[0..-2]
  end

  def issue_details(issue)
    [ [issue.formatted_title, issue.formatted_description],
      ["-", ""] ]
  end
end

class GithubIssues
  def initialize(repo_owner, repo_name)
    raise ArgumentError "repo_owner must not be nil" \
      unless @repo_owner = repo_owner

    raise ArgumentError "repo_name must not be nil" \
      unless @repo_name = repo_name
  end

  def latest_status
    GithubIssuesStatus.new(issues_url, force_utf8(http_get))
  end

  private

  def http_get
    # Github rate limits unauthenticated requests to the api by ip.
    # To obtains client_id/client_secret just create new application on
    # `https://github.com/settings/applications`.
    if ENV.keys.grep(/GITHUB_ISSUES_CHECK/)
      auth  = "client_id=#{ENV["GITHUB_ISSUES_CHECK_CLIENT_ID"]}"
      auth += "&client_secret=#{ENV["GITHUB_ISSUES_CHECK_CLIENT_SECRET"]}"
    end

    http_opts = {
      "User-Agent" => "CheckmanGithubIssues (Hostname: #{`printf "%s" "$HOSTNAME"`})"
    }

    open("#{api_url}?#{auth}", http_opts).read
  end

  def api_url
    "https://api.github.com/repos/#{@repo_owner}/#{@repo_name}/issues"
  end

  def issues_url
    "https://github.com/#{@repo_owner}/#{@repo_name}/issues"
  end

  def force_utf8(string)
    if string.respond_to?(:encode)
      # Use 'binary' as source encoding since conversion
      # to the same encoding is a no-op even if there are
      # invalid bytes.
      string.encode(string.encoding, "binary", :invalid => :replace, :undef => :replace)
    else
      string
    end
  end
end

puts GithubIssues.new(*ARGV).latest_status.to_json if __FILE__ == $0