#!/usr/bin/env ruby

require 'github_api'
require 'date'
require 'optparse'
require 'optparse/date'

# Instructions:
#   Get a token from github's settings (https://github.com/settings/tokens)
#
# Example:
#   ruby change_log.rb -t abcdefghijklmnopqrstuvwxyz -s 2017-09-06
#

options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: change_log.rb [options]\n" +
  "Prints New, Open, Closed Issues, and number of accepted PRs"
  opts.separator ""

  # defaults, go back 90 days
  options[:start_date] = Date.today - 90
  options[:end_date] = Date.today

  opts.on('-s', '--start-date [DATE]', Date, 'Start of data (e.g. 2017-09-06)') do |v|
    options[:start_date] = v
  end
  opts.on('-e', '--end-date [DATE]', Date, 'End of data (e.g. 2017-09-13)') do |v|
    options[:end_date] = v
  end
  opts.on('-t', '--token [String]', String, 'Github API Token') do |v|
    options[:token] = v
  end
end.parse!

# Convert dates to time objects
options[:start_date] = Time.parse(options[:start_date].to_s)
options[:end_date] = Time.parse(options[:end_date].to_s)
puts options

### Repository options
repo_owner = 'NREL'
repo = 'openstudio-extension-gem'

github = Github.new
if options[:token]
  puts 'Using github token'
  github = Github.new oauth_token: options[:token]
end

total_open_issues = []
total_open_pull_requests = []
new_issues = []
closed_issues = []
accepted_pull_requests = []

def get_num(issue)
  issue.html_url.split('/')[-1].to_i
end

def get_issue_num(issue)
  "\##{get_num(issue)}"
end

def get_html_url(issue)
  issue.html_url
end

def get_title(issue)
  issue.title
end

def print_issue(issue)
  is_feature = false
  issue.labels.each { |label| is_feature = true if label.name == 'Feature Request' }

  if is_feature
    "- Improved [#{get_issue_num(issue)}]( #{get_html_url(issue)} ), #{get_title(issue)}"
  else
    "- Fixed [#{get_issue_num(issue)}]( #{get_html_url(issue)} ), #{get_title(issue)}"
  end
end

# Process Open Issues
results = -1
page = 1
while results != 0
  resp = github.issues.list user: repo_owner, repo: repo, sort: 'created', direction: 'asc',
                            state: 'open', per_page: 100, page: page
  results = resp.length
  resp.env[:body].each do |issue, _index|
    created = Time.parse(issue.created_at)
    if !issue.key?(:pull_request)
      total_open_issues << issue
      if created >= options[:start_date] && created <= options[:end_date]
        new_issues << issue
      end
    else
      total_open_pull_requests << issue
    end
  end

  page += 1
end

# Process Closed Issues
results = -1
page = 1
while results != 0
  resp = github.issues.list user: repo_owner, repo: repo, sort: 'created', direction: 'asc',
                            state: 'closed', per_page: 100, page: page
  results = resp.length
  resp.env[:body].each do |issue, _index|
    created = Time.parse(issue.created_at)
    closed = Time.parse(issue.closed_at)
    if !issue.key?(:pull_request)
      if created >= options[:start_date] && created <= options[:end_date]
        new_issues << issue
      end
      if closed >= options[:start_date] && closed <= options[:end_date]
        closed_issues << issue
      end
    elsif closed >= options[:start_date] && closed <= options[:end_date]
      accepted_pull_requests << issue
    end
  end

  page += 1
end

closed_issues.sort! { |x, y| get_num(x) <=> get_num(y) }
new_issues.sort! { |x, y| get_num(x) <=> get_num(y) }
accepted_pull_requests.sort! { |x, y| get_num(x) <=> get_num(y) }
total_open_pull_requests.sort! { |x, y| get_num(x) <=> get_num(y) }

puts "Total Open Issues: #{total_open_issues.length}"
puts "Total Open Pull Requests: #{total_open_pull_requests.length}"
puts "\nDate Range: #{options[:start_date].strftime('%m/%d/%y')} - #{options[:end_date].strftime('%m/%d/%y')}:"
puts "\nNew Issues: #{new_issues.length} (" + new_issues.map { |issue| get_issue_num(issue) }.join(', ') + ')'

puts "\nClosed Issues: #{closed_issues.length}"
closed_issues.each { |issue| puts print_issue(issue) }

puts "\nAccepted Pull Requests: #{accepted_pull_requests.length}"
accepted_pull_requests.each { |issue| puts print_issue(issue) }

puts "\nAll Open Issues: #{total_open_issues.length} (" + total_open_issues.map { |issue| get_issue_num(issue) }.join(', ') + ')'