#!/usr/bin/env ruby

require "bundler/inline"
gemfile do
  source "https://rubygems.org"
  gem "multi_repo", require: "multi_repo/cli", path: File.expand_path("..", __dir__)
end
require "active_support/core_ext/object/blank"
require "active_support/core_ext/string/inflections"

DISPLAY_FORMATS = %w[commit pr-title pr-label]

opts = Optimist.options do
  synopsis "Show the git commit log between two refs for all git repos."

  opt :from,    "The commit log 'from' ref", :type => :string,  :required => true
  opt :to,      "The commit log 'to' ref" ,  :type => :string,  :required => true
  opt :display, "How to display the history. Valid values are: #{DISPLAY_FORMATS.join(", ")}", :default => "commit"
  opt :summary, "Display a summary of the repos.", :default => false

  opt :skip,   "The repos to skip", :type => :strings, :default => []

  MultiRepo::CLI.common_options(self, :except => :dry_run)
end
Optimist.die :display, "must be one of: #{DISPLAY_FORMATS.join(", ")}" unless DISPLAY_FORMATS.include?(opts[:display])

range = "#{opts[:from]}..#{opts[:to]}"

puts "Git commit log between #{opts[:from]} and #{opts[:to]}\n\n"

repos_with_changes = []

MultiRepo::CLI.repos_for(**opts).each do |repo|
  next if opts[:skip].include?(repo.name)

  puts MultiRepo::CLI.header(repo.name)
  repo.git.fetch(output: false)

  case opts[:display]
  when "pr-label", "pr-title"
    github ||= MultiRepo::Service::Github.client
    pr_label_display = opts[:display] == "pr-label"

    results = {}
    if pr_label_display
      results["bug"] = []
      results["enhancement"] = []
    end
    results["other"] = []

    log =
      begin
        repo.git.client.capturing.log({:oneline => true}, range)
      rescue MiniGit::GitError
        puts "ERROR: commit range not found.".light_red
        puts
        next
      end

    log.lines.each do |line|
      next unless (match = line.match(/Merge pull request #(\d+)\b/))

      pr =
        begin
          github.pull_request(repo.name, match[1])
        rescue Octokit::NotFound
          next # PR not found could mean this was a cherry-pick from a different repo, so the PR doesn't exist.
        end
      label = pr.labels.detect { |l| results.key?(l.name) }&.name || "other"
      results[label] << pr
    end

    changes_found = false

    results.each do |label, prs|
      next if prs.blank?
      changes_found = true

      puts "\n## #{label.titleize}\n\n" if pr_label_display
      prs.each do |pr|
        puts "* #{pr.title} [[##{pr.number}]](#{pr.html_url})"
      end
    end

    repos_with_changes << repo if changes_found
  when "commit"
    output =
      begin
        repo.git.client.capturing.log({:oneline => true, :decorate => true, :graph => true}, range)
      rescue MiniGit::GitError
        puts "ERROR: commit range not found.".light_red
        puts
        next
      end

    puts output
    repos_with_changes << repo if output.present?
  end
  puts
end

if opts[:summary] && repos_with_changes.any?
  puts
  puts "Here are the changes per affected repository in GitHub:"
  repos_with_changes.each do |repo|
    puts "* [#{repo.name}](https://github.com/#{repo.name}/compare/#{opts[:from]}...#{opts[:to]})"
  end
  puts
end