module OpenApiHelper
  def indent(string, count)
    lines = string.lines
    first_line = lines.shift
    lines = lines.map { |line| ("  " * count).to_s + line }
    lines.unshift(first_line).join.html_safe
  end

  def components_for(model)
    for_model model do
      indent(render("api/#{@version}/open_api/#{model.name.underscore.pluralize}/components"), 2)
    end
  end

  def current_model
    @model_stack.last
  end

  def for_model(model)
    @model_stack ||= []
    @model_stack << model
    result = yield
    @model_stack.pop
    result
  end

  def automatic_paths_for(model, parent, except: [])
    output = render("api/#{@version}/open_api/shared/paths", except: except)
    output = Scaffolding::Transformer.new(model.name, [parent&.name]).transform_string(output).html_safe
    indent(output, 1)
  end

  def automatic_components_for(model, locals: {})
    path = "app/views/api/#{@version}"
    paths = ([path] + `bundle show --paths`.lines.map { |gem_path| "#{gem_path.chomp}/#{path}" })
    jbuilder = Jbuilder::Schema.renderer(paths, locals: {
      # If we ever get to the point where we need a real model here, we should implement an example team in seeds that we can source it from.
      model.name.underscore.split("/").last.to_sym => model.new,
      # Same here, if we ever need this to be a real object, this should be `test@example.com` with an `SecureRandom.hex` password.
      :current_user => User.new
    }.merge(locals))

    schema_json = jbuilder.json(
      model.new,
      title: I18n.t("#{model.name.underscore.pluralize}.label"),
      # TODO Improve this. We don't have a generic description for models we can use here.
      description: I18n.t("#{model.name.underscore.pluralize}.label"),
    )

    attributes_output = JSON.parse(schema_json)

    strong_params_module = "Api::#{@version.upcase}::#{model.name.pluralize}Controller::StrongParameters".constantize
    strong_parameter_keys = BulletTrain::Api::StrongParametersReporter.new(model, strong_params_module).report
    if strong_parameter_keys.last.is_a?(Hash)
      strong_parameter_keys += strong_parameter_keys.pop.keys
    end

    parameters_output = JSON.parse(schema_json)
    parameters_output["required"].select! { |key| strong_parameter_keys.include?(key.to_sym) }
    parameters_output["properties"].select! { |key, value| strong_parameter_keys.include?(key.to_sym) }

    (
      indent(attributes_output.to_yaml.gsub("---", "#{model.name.gsub("::", "")}Attributes:"), 3) +
      indent("    " + parameters_output.to_yaml.gsub("---", "#{model.name.gsub("::", "")}Parameters:"), 3)
    ).html_safe
  end

  def paths_for(model)
    for_model model do
      indent(render("api/#{@version}/open_api/#{model.name.underscore.pluralize}/paths"), 1)
    end
  end

  def attribute(attribute)
    heading = t("#{current_model.name.underscore.pluralize}.fields.#{attribute}.heading")
    # TODO A lot of logic to be done here.
    indent("#{attribute}:\n  description: \"#{heading}\"\n  type: string", 2)
  end

  def parameter(attribute)
    heading = t("#{current_model.name.underscore.pluralize}.fields.#{attribute}.heading")
    # TODO A lot of logic to be done here.
    indent("#{attribute}:\n  description: \"#{heading}\"\n  type: string", 2)
  end
end

class Api::OpenApiController < ApplicationController
  helper :open_api

  def set_default_response_format
    request.format = :yaml
  end

  before_action :set_default_response_format

  def index
    @version = params[:version]
    render "api/#{@version}/open_api/index", layout: nil, format: :text
  end
end