module GoogleDriveDownload

# File lib/google_drive_download.rb, line 12
def applicable?(url)
  GoogleDriveUrl.google_drive_url?(url)
end

# File lib/google_drive_download.rb, line 86
def confirmed_url_from_body(body, download_url:, original_url:)
  confirmed = GoogleDriveUrl.confirmed_url_from_warning_page(body)
  return confirmed if confirmed

  token = GoogleDriveUrl.extract_confirm_token(body)
  return nil unless token

  file_id = GoogleDriveUrl.extract_file_id(download_url) || GoogleDriveUrl.extract_file_id(original_url)
  if file_id
    GoogleDriveUrl.usercontent_download_url(file_id, confirm: token)
  else
    GoogleDriveUrl.confirmed_download_url(download_url, token)
  end
end

# File lib/google_drive_download.rb, line 16
def fetch(url, fetch:, api_key: nil)
  fetch_with_trace(url, fetch: fetch, api_key: api_key)[:body]
end

# File lib/google_drive_download.rb, line 101
def fetch_step(steps, url, fetch)
  body = fetch.call(url)
  steps << GoogleDriveBody.describe_fetch(url, body)
  body
rescue StandardError => e
  steps << GoogleDriveBody.describe_fetch(url, nil, error: e)
  nil
end

# File lib/google_drive_download.rb, line 20
def fetch_with_trace(url, fetch:, api_key: nil)
  steps = []
  body = try_api_download(url, fetch: fetch, api_key: api_key, steps: steps)
  return { body: body, steps: steps } if body && GoogleDriveBody.image_body?(body)

  scrape_result = scrape_with_trace(url, fetch: fetch)
  steps.concat(scrape_result[:steps])
  { body: scrape_result[:body], steps: steps }
end

# File lib/google_drive_download.rb, line 55
def follow_warning_pages(body, url:, download_url:, steps:, fetch:)
  current_body = body
  current_url = download_url
  attempts = 0

  while current_body && GoogleDriveUrl.html_warning_page?(current_body) && attempts < MAX_CONFIRM_FOLLOWS
    attempts += 1
    next_url = confirmed_url_from_body(current_body, download_url: current_url, original_url: url)
    break unless next_url
    break if steps.any? { |step| step[:url] == next_url }

    current_url = next_url
    current_body = fetch_step(steps, next_url, fetch)
  end

  current_body
end

# File lib/google_drive_download.rb, line 42
def scrape_with_trace(url, fetch:)
  steps = []
  download_url = GoogleDriveUrl.resolve_download_url(url)
  body = fetch_step(steps, download_url, fetch)

  if applicable?(url)
    body = follow_warning_pages(body, url: url, download_url: download_url, steps: steps, fetch: fetch)
    body = try_uc_fallback(body, url: url, steps: steps, fetch: fetch)
  end

  { body: body, steps: steps }
end

# File lib/google_drive_download.rb, line 30
def try_api_download(url, fetch:, api_key:, steps:)
  key = api_key.to_s.strip
  return nil unless GoogleDriveApi.configured?(api_key: key)

  file_id = GoogleDriveUrl.extract_file_id(url)
  return nil unless file_id

  api_result = GoogleDriveApi.fetch_with_trace(file_id, fetch: fetch, api_key: key)
  steps.concat(api_result[:steps])
  api_result[:body]
end

# File lib/google_drive_download.rb, line 73
def try_uc_fallback(body, url:, steps:, fetch:)
  return body if body.nil? || GoogleDriveBody.image_body?(body)
  return body unless applicable?(url)

  file_id = GoogleDriveUrl.extract_file_id(url)
  return body unless file_id

  uc_url = GoogleDriveUrl.uc_download_url(file_id)
  return body if steps.any? { |step| step[:url] == uc_url }

  fetch_step(steps, uc_url, fetch)
end