require 'bearcat'

# Bearcat RSpec Helpers
# Can be included in your spec_helper.rb file by using:
# - `require 'bearcat/spec_helpers'`
# And
# - `config.include Bearcat::SpecHelpers`
module Bearcat::SpecHelpers
  SOURCE_REGEX = /(?<method>get|post|delete|put)\((?<quote>\\?('|"))(?<url>.*)\k<quote>/

  # Helper method to Stub Bearcat requests.
  # Automagically parses the Bearcat method source to determine the correct URL to stub.
  # Accepts optional keyword parameters to interpolate specific values into the URL.
  # Returns a mostly-normal Webmock stub (:to_return has been overridden to allow :body to be set to a Hash)
  def stub_bearcat(endpoint, prefix: nil, **kwargs)
    url = case endpoint
    when Symbol
      ruby_method = Bearcat::Client.instance_method(endpoint)
      match = SOURCE_REGEX.match(ruby_method.source)
      bits = []
      url = match[:url].gsub(/\/$/, '')
      lend = 0
      url.scan(/#\{(?<key>.*?)\}/) do |key|
        m = Regexp.last_match
        between = url[lend..m.begin(0)-1]
        bits << between if between.present? && (m.begin(0) > lend)
        lend = m.end(0)
        bits << (kwargs[m[:key].to_sym] || /\w+/)
      end
      between = url[lend..-1]
      bits << between if between.present?

      bits.map do |bit|
        case bit
        when Regexp
          bit.source
        when String
          Regexp.escape(bit)
        end
      end.join
    when String
      Regexp.escape(endpoint)
    when Regexp
      endpoint.source
    end

    url = Regexp.escape(resolve_prefix(prefix)) + url
    stub = stub_request(match[:method].to_sym, Regexp.new(url))

    # Override the to_return method to accept a Hash as body:
    stub.define_singleton_method(:to_return, ->(*resps) {
      resps.map do |resp|
        resp[:headers] ||= {}
        resp[:headers]["Content-Type"] ||= "application/json"
        resp[:body] = resp[:body].to_json
      end
      super(*resps)
    })

    stub
  end

  private

  def resolve_prefix(prefix)
    if prefix == true
      prefix = canvas_api_client if defined? canvas_api_client
      prefix = canvas_sync_client if defined? canvas_sync_client
    end
    prefix = case prefix
    when nil
      ''
    when false
      ''
    when true
      raise "stub_bearcat() prefix: set to true, but neither canvas_(sync|api)_client are defined"
    when Bearcat::Client
      prefix.prefix
    when String
      prefix
    end
  end
end