class Importmap::Packager

# File lib/importmap/packager.rb, line 18
def initialize(importmap_path = "config/importmap.rb", vendor_path: "vendor/javascript")
  @importmap_path = Pathname.new(importmap_path)
  @vendor_path    = Pathname.new(vendor_path)
end

# File lib/importmap/packager.rb, line 60
def download(package, url)
  ensure_vendor_directory_exists
  remove_existing_package_file(package)
  download_package_file(package, url)
end

# File lib/importmap/packager.rb, line 71
def extract_existing_pin_options(packages)
  return {} unless @importmap_path.exist?

  packages = Array(packages)

  all_package_options = build_package_options_lookup(importmap.lines)

  packages.to_h do |package|
    [package, all_package_options[package] || {}]
  end
end

# File lib/importmap/packager.rb, line 23
def import(*packages, env: "production", from: "jspm")
  response = post_json({
    "install"      => Array(packages),
    "flattenScope" => true,
    "env"          => [ "browser", "module", env ],
    "provider"     => normalize_provider(from),
  })

  case response.code
  when "200"
    extract_parsed_response(response)
  when "404", "401"
    nil
  else
    handle_failure_response(response)
  end
end

# File lib/importmap/packager.rb, line 56
def packaged?(package)
  importmap.match(Importmap::Map.pin_line_regexp_for(package))
end

# File lib/importmap/packager.rb, line 41
def pin_for(package, url = nil, preloads: nil)
  to = url ? %(, to: "#{url}") : ""
  preload_param = preload(preloads)

   %(pin "#{package}") + to + preload_param
end

# File lib/importmap/packager.rb, line 66
def remove(package)
  remove_existing_package_file(package)
  remove_package_from_importmap(package)
end

# File lib/importmap/packager.rb, line 48
def vendored_pin_for(package, url, preloads = nil)
  filename = package_filename(package)
  version  = extract_package_version_from(url)
  to = "#{package}.js" != filename ? filename : nil

  pin_for(package, to, preloads: preloads) + %( # #{version})
end

# File lib/importmap/packager.rb, line 84
def build_package_options_lookup(lines)
  lines.each_with_object({}) do |line, package_options|
    match = line.strip.match(PIN_REGEX)

    if match
      package_name = match[1]
      options_part = match[2]

      preload_match = options_part.match(PRELOAD_OPTION_REGEXP)

      if preload_match
        preload = preload_from_string(preload_match[1])
        package_options[package_name] = { preload: preload }
      end
    end
  end
end

# File lib/importmap/packager.rb, line 185
def download_package_file(package, url)
  response = Net::HTTP.get_response(URI(url))

  if response.code == "200"
    save_vendored_package(package, url, response.body)
  else
    handle_failure_response(response)
  end
end

# File lib/importmap/packager.rb, line 168
def ensure_vendor_directory_exists
  FileUtils.mkdir_p @vendor_path
end

# File lib/importmap/packager.rb, line 215
def extract_package_version_from(url)
  url.match(/@\d+\.\d+\.\d+/)&.to_a&.first
end

# File lib/importmap/packager.rb, line 140
def extract_parsed_response(response)
  parsed = JSON.parse(response.body)
  imports = parsed.dig("map", "imports")

  {
    imports: imports,
  }
end

# File lib/importmap/packager.rb, line 149
def handle_failure_response(response)
  if error_message = parse_service_error(response)
    raise ServiceError, error_message
  else
    raise HTTPError, "Unexpected response code (#{response.code})"
  end
end

# File lib/importmap/packager.rb, line 163
def importmap
  @importmap ||= File.read(@importmap_path)
end

# File lib/importmap/packager.rb, line 136
def normalize_provider(name)
  name.to_s == "jspm" ? "jspm.io" : name.to_s
end

# File lib/importmap/packager.rb, line 211
def package_filename(package)
  package.gsub("/", "--") + ".js"
end

# File lib/importmap/packager.rb, line 157
def parse_service_error(response)
  JSON.parse(response.body.to_s)["error"]
rescue JSON::ParserError
  nil
end

# File lib/importmap/packager.rb, line 130
def post_json(body)
  Net::HTTP.post(self.class.endpoint, body.to_json, "Content-Type" => "application/json")
rescue => error
  raise HTTPError, "Unexpected transport error (#{error.class}: #{error.message})"
end

# File lib/importmap/packager.rb, line 115
def preload(preloads)
  case Array(preloads)
  in []
    ""
  in ["true"] | [true]
    %(, preload: true)
  in ["false"] | [false]
    %(, preload: false)
  in [string]
    %(, preload: "#{string}")
  else
    %(, preload: #{preloads})
  end
end

# File lib/importmap/packager.rb, line 102
def preload_from_string(value)
  case value
  when "true"
    true
  when "false"
    false
  when /^\[.*\]$/
    JSON.parse(value)
  else
    value.gsub(/["']/, "")
  end
end

# File lib/importmap/packager.rb, line 172
def remove_existing_package_file(package)
  FileUtils.rm_rf vendored_package_path(package)
end

# File lib/importmap/packager.rb, line 176
def remove_package_from_importmap(package)
  all_lines = File.readlines(@importmap_path)
  with_lines_removed = all_lines.grep_v(Importmap::Map.pin_line_regexp_for(package))

  File.open(@importmap_path, "w") do |file|
    with_lines_removed.each { |line| file.write(line) }
  end
end

# File lib/importmap/packager.rb, line 203
def remove_sourcemap_comment_from(source)
  source.gsub(/^\/\/# sourceMappingURL=.*/, "")
end

# File lib/importmap/packager.rb, line 195
def save_vendored_package(package, url, source)
  File.open(vendored_package_path(package), "w+") do |vendored_package|
    vendored_package.write "// #{package}#{extract_package_version_from(url)} downloaded from #{url}\n\n"

    vendored_package.write remove_sourcemap_comment_from(source).force_encoding("UTF-8")
  end
end

# File lib/importmap/packager.rb, line 207
def vendored_package_path(package)
  @vendor_path.join(package_filename(package))
end