#!/usr/bin/env ruby

## fcl: Fantastic CLoner
#
# Clones git repos into a predictable directory structure, according to local
# customs (HTTPS instead of SSH for Buildkite repos, for example)
#
# Makes educated guesses about incomplete repo identifiers.
#
# Also with some CLI pretty thanks to `gum`.
#

# TODO LIST
#
# [ ] Make a way to turn off the pretty, in case it's getting in the way
#


ConfigPath = File.join(File.expand_path(File.dirname(__FILE__)), 'config.bash')
ConfigValues = `env -i bash --noprofile --norc -c 'source #{ConfigPath}; env'`.lines.map(&:chomp)
ConfigPairs = ConfigValues.map {|v| v.split('=',2) }.to_h
Config = ConfigPairs.reject {|k,v| ['_','SHLVL','PWD'].include?(k) }

def clone(repo_url, destination)
  spinner_command = %Q[gum spin --show-output --spinner dot]
  git_command = ['git', 'clone', repo_url, destination].join(' ')
  system("#{spinner_command} -- #{git_command}")
end

def log_error(message)
  system(%Q[gum style --bold --border=double --padding='0 1' --foreground 212 "#{message}"])
end

# Transform SSH URLs for GitHub into HTTPS, so we can do the recommended auth
# things.
#
# Also, make some assumptions when info is missing, so I can provide stuff like
# `buildkite-plugins/ecr-buildkite-plugin` and have this puppy still work.
#
def repo_url(repo_str)
  case repo_str
  # GitHub HTTPS. We like these, use it as-is.
  when /^(git|https)\:\/\/github\.com\//
    repo_str
  # Some other HTTPS. This is probably fine too, as long as it ends with '.git'
  when /^(git|https)\:\/\/.+\.git$/
    repo_str
  # GitHub SSH. Let's convert this to HTTPS.
  when /^git@github\.com\:.+\.git$/
    repo_str.sub(/^git@github\.com:/, 'https://github.com/')
  # Host, user/org and repo. Assume it's HTTPS.
  when /^[^\/\s]+\/[^\/\s]+\/[^\/\s]+/
    "https://#{repo_str}#{repo_str.end_with?('.git') ? '' : '.git'}"
  # Just a user/org name and repo name. Assume it's on GitHub and make an HTTPS URL.
  when /^[\w\-_]+\/[\w\-_\.]+$/
    "https://github.com/#{repo_str}.git"
  # Just a repo name. Assume it's a FCL_DEFAULT_ORG repo on GitHub and make an HTTPS URL.
  when /^[\w\-_\.]+$/
    "https://github.com/#{Config['FCL_DEFAULT_ORG']}/#{repo_str}.git"
  else
    raise "I can't make a repo URL out of '#{repo_str}'."
  end
end

def destination_path(repo_str)
  repo_elms = repo_str.split('/')

  repo  = repo_elms.pop.sub(/\.git$/, '')
  org   = repo_elms.pop || Config.fetch('FCL_DEFAULT_ORG')
  forge = repo_elms.pop || 'github.com'

  File.join(forge, org, repo)
end

repo_str = ARGV.empty? ? `gum input --header="Enter a repo name" --placeholder=""`.chomp : ARGV[0]

destination = ARGV[1] || destination_path(repo_str)
full_dest = File.join(Config['REPOSITORY_BASE'], destination)

clone_url = repo_url(repo_str)

if Dir.exist?(full_dest)
  log_error "#{destination} already exists. Doing nothing."
else
  clone(clone_url, full_dest)
end