require 'json'

# run from git repo. Make sure to pull first
# EXAMPLE
# cd MY_LIGHTNING_GLOBAL_GIT_FOLDER
# ~/cherrychecker.rb
# ~/cherrychecker.rb email=mmakarov@salesforce.com
# ~/cherrychecker.rb --slack
# ~/cherrychecker.rb compare=212-patch


# Getting a hash from params passed
args_hash = {}
ARGV.each { |a| key, value = a.split('='); args_hash[key] = value }

# Vars
SLACK_URL = ENV['SLACK_URL']
PR_REGEX = /#([0-9]+)/
LOG = 'git log --pretty=format:"%h||%an||%ae||%s"'
FIELDS = [:hash, :name, :email, :message]
AMOUNT = args_hash['amount'] ? args_hash['amount'].to_i : 20
USER_EMAIL = args_hash['email'] ? "| grep '#{args_hash['email']}'" : ''
PATCH_BRANCH_NAME = args_hash['compare'] || '212-patch'
prs = {}

def get_commits_array(branch)
    prs = []
    ref_prs = []
    history = `#{LOG} #{branch} #{USER_EMAIL}`.split("\n")
    records = history.map do |h|
        obj = {}
        records = h.split("||")
        parsed_prs = records.last.scan(PR_REGEX)
        if parsed_prs.length > 0
            obj[:pr] = parsed_prs.last
            prs << parsed_prs.last
        end
        if parsed_prs.length == 2
            obj[:ref_pr] = parsed_prs.first
            ref_prs << parsed_prs.first
        end
        FIELDS.each_with_index do |f, i|
            obj[f] = records[i]
        end
        obj
    end
    {
        records: records,
        prs: prs,
        ref_prs: ref_prs,
    }
end

master = get_commits_array('master')
patch = get_commits_array(PATCH_BRANCH_NAME)
missing_prs = patch[:prs] - master[:ref_prs]
missing_prs = missing_prs - master[:prs]
last_20_numbers = missing_prs.first(AMOUNT)
last_20 = last_20_numbers.map do |pr|
    patch[:records].select {|r| r[:pr] == pr}.first
end

# Posting to slack if slack param's present
if args_hash['--slack']
    last_20_json = last_20.map do |r|
        {
            "title": "#{r[:hash]} #{r[:pr]} #{r[:message]}",
            "value": "by #{r[:name]}",
            "short": false,
        }
    end
    message = [
            {
                "pretext": "Last 20 PRs that got merge to 212-patch and were not cherry picked to master",
                "fields": last_20_json,
            }
        ]

    puts message.to_json

    puts `curl -X POST --data-urlencode 'payload={"channel": "#cherry-picks", "username": "TEST: Mr. IO", "text": "TEST", "attachments": #{message.to_json}, "icon_emoji": ":philosoraptor:"}' #{SLACK_URL}`
else
    # if no slack param, outputting
    last_20.each_with_index do |r, i|
        puts "#{i + 1}) *** #{r[:hash]} *** #{r[:email]} #{r[:name]} #{r[:pr]}"
        puts "#{r[:message]}"
    end
end