#!/usr/bin/env ruby
# frozen_string_literal: true

# This script will promote post_migrate files
# which have existed for more than one Discourse
# stable version cycle.
#
# Renames will be staged in git, but not committed
#
# Usage:
#   script/promote_migrations [--dry-run] [--plugins]

require 'open3'
require 'fileutils'

VERSION_REGEX = %r{\/(\d+)_}
DRY_RUN = ARGV.include? '--dry-run'
PLUGINS = ARGV.include? '--plugins'

def run(*args, capture: true)
  out, s = Open3.capture2(*args)
  if s.exitstatus != 0
    STDERR.puts "Command failed: '#{args.join(' ')}'"
    exit 1
  end
  out.strip
end

current_version = run 'git describe --abbrev=0 --match "v*"'
puts "Current version is #{current_version}"

run 'git fetch'
current_stable_version =
  run 'git describe --abbrev=0 --match "v*" origin/stable'
puts "Current stable version is #{current_stable_version}"

minor = current_stable_version[/^(v\d+\.\d+)\./, 1]

previous_stable_version =
  run "git describe --abbrev=0 --match 'v*' --exclude '#{minor}*' origin/stable"
puts "Previous stable version is #{previous_stable_version}"

stable_post_migrate_filenames =
  run(
    'git',
    'ls-tree',
    '--name-only',
    '-r',
    previous_stable_version,
    'db/post_migrate'
  ).split("\n")

stable_post_migrate_filenames.sort!
latest_stable_post_migration = stable_post_migrate_filenames.last

puts "The latest core post_migrate file in #{previous_stable_version} is #{latest_stable_post_migration}"
puts 'Promoting this, and all earlier post_migrates, to regular migrations'

promote_threshold = latest_stable_post_migration[VERSION_REGEX, 1].to_i
current_post_migrations =
  if PLUGINS
    puts 'Looking in plugins...'
    Dir.glob('plugins/*/db/post_migrate/*')
  else
    Dir.glob('db/post_migrate/*')
  end

if current_post_migrations.length == 0
  puts 'No post_migrate files found. All done'
end

current_post_migrations.each do |path|
  version = path[VERSION_REGEX, 1].to_i
  file = File.basename(path)
  dir = File.dirname(path)

  if version <= promote_threshold
    print "Promoting #{path}..."
    if DRY_RUN
      puts ' (dry run)'
    else
      run 'mkdir', '-p', "#{dir}/../migrate"
      run 'git', '-C', dir, 'mv', file, "../migrate/#{file}"
      puts ' (done)'
    end
  end
end

puts 'Done! File moves are staged and ready for commit.'
puts 'Suggested commit message:'
puts '-' * 20
puts <<~MESSAGE
DEV: Promote historic post_deploy migrations

This commit promotes all post_deploy migrations which existed in Discourse #{previous_stable_version} (timestamp <= #{promote_threshold})
MESSAGE
puts '-' * 20