gem 'jsonapi_responses'

class ApplicationController < ActionController::API
  include JsonapiResponses::Respondable
end

class ApplicationSerializer
  attr_reader :resource, :context

  def initialize(resource, context = {})
    @resource = resource
    @context = context
  end

  def current_user
    @context[:current_user]
  end
end

class DigitalProductSerializer < ApplicationSerializer
  def serializable_hash
    case context[:view]
    when :summary
      summary_hash
    when :minimal
      minimal_hash
    else
      full_hash
    end
  end

  private

  def full_hash
    {
      id: resource.id,
      name: resource.name,
      description: resource.description,
      # ... more attributes
    }
  end

  def summary_hash
    {
      id: resource.id,
      name: resource.name,
      price: resource.price,
      # ... fewer attributes
    }
  end

  def minimal_hash
    {
      id: resource.id,
      name: resource.name,
      # ... minimal attributes
    }
  end
end

class Api::V1::ProductsController < ApplicationController
  def index
    products = Product.includes(:categories, :attachments)
    render_with(products)
  end

  def create
    @product = Product.new(product_params)
    render_with(@product)
  end

  def show
    render_with(@product)
  end

  def update
    @product.update(product_params)
    render_with(@product)
  end

  def destroy
    render_with(@product)
  end

  # Optional: Override the view if needed
  def custom_action
    render_with(@product, context: { view: :custom_view })
  end
end

class Api::V1::AcademiesController < ApplicationController
  include JsonapiResponses::Respondable

  def index
    academies = Academy.page(params[:page]).per(15)
    
    # That's it! Pagination is automatic
    render_with(academies)
  end
end

def index
  academies = Academy
    .includes(:owner, :courses)
    .page(params[:page])
    .per(params[:per_page] || 15)
  
  # Supports view parameter and automatic pagination
  render_with(academies)
end

def index
  academies = Academy.page(params[:page]).per(15)
  
  render_with(
    academies,
    context: { view: view },
    meta: { 
      fetched_at: Time.current,
      filters_applied: params[:search].present?
    }
  )
end

class AcademyResponder < JsonapiResponses::Responder
  def respond_for_index
    if paginated?(record)
      render json: {
        data: serialize_collection(record, serializer_class, context),
        meta: pagination_meta(record, context)
      }
    else
      render json: {
        data: serialize_collection(record, serializer_class, context)
      }
    end
  end
end

class DigitalProductSerializer < ApplicationSerializer
  def serializable_hash
    # Validate the view against permissions
    authorized_view = authorize_view(context[:view] || :summary)

    case authorized_view
    when :full then full_hash
    when :summary then summary_hash
    else minimal_hash
    end
  end

  private

  def authorize_view(requested_view)
    return requested_view unless requested_view == :full
    
    # Check permission for the 'full' view
    if Pundit.policy!(context[:current_user], resource).show_full?
      :full
    else
      :summary # Fallback to a safe view
    end
  end
end

class Api::V1::CoursesController < ApplicationController
  include JsonapiResponses::Respondable

  # Map custom actions to existing response methods
  map_response_action :public_index, to: :index
  map_response_action :public_show, to: :show

  def public_index
    # Your logic here
    render_with(@courses)  # Will use respond_for_index
  end
end

class Api::V1::CoursesController < ApplicationController
  include JsonapiResponses::Respondable

  def dashboard_stats
    # Your logic here
    render_with(@stats)
  end

  private

  def respond_for_dashboard_stats(record, serializer_class, context)
    render json: {
      data: record,
      meta: { type: 'dashboard', generated_at: Time.current }
    }
  end
end

class Api::V1::CoursesController < ApplicationController
  include JsonapiResponses::Respondable

  # Generate methods automatically
  generate_rest_responses(
    namespace: 'public',
    actions: [:index, :show],
    context: { access_level: 'public' }
  )

  # Define similar responses in batch
  define_responses_for [:export_csv, :export_pdf] do |record, serializer_class, context|
    format = action_name.to_s.split('_').last
    render json: {
      data: serialize_collection(record, serializer_class, context),
      meta: { export_format: format, total: record.count }
    }
  end
end

# app/responders/product_responder.rb
class ProductResponder < ApplicationResponder
  # Custom action for bulk uploads
  def bulk_upload
    render_json({
      data: serialize_collection(record),
      meta: {
        processed_at: Time.current,
        total_records: record.count,
        status: 'completed'
      }
    })
  end
end

class Api::V1::ProductsController < ApplicationController
  def bulk_upload
    @products = Product.where(id: params[:ids])
    # The 'action' parameter tells the responder which method to execute
    render_with(@products, responder: ProductResponder, action: :bulk_upload)
  end
end

# app/responders/application_responder.rb
class ApplicationResponder < JsonapiResponses::Responder
  protected

  def render_collection_with_meta(type: nil, additional_meta: {})
    render_json({
      data: serialize_collection(record),
      meta: base_meta.merge({ type: type }.compact).merge(additional_meta)
    })
  end

  def base_meta
    {
      timestamp: Time.current.iso8601,
      count: record_count
    }.compact
  end

  def record_count
    return nil unless collection?
    record.respond_to?(:count) ? record.count : record.size
  end

  def filters_applied
    filter_keys = [:category_id, :level, :status]
    filters = {}
    filter_keys.each { |key| filters[key] = params[key] if params[key].present? }
    filters.empty? ? nil : filters
  end
end

# app/responders/academy_responder.rb
class AcademyResponder < ApplicationResponder

  # GET /api/v1/academies/featured
  def featured
    if params[:category_id].present?
      render_filtered_featured
    else
      render_all_featured
    end
  end

  # GET /api/v1/academies/popular
  def popular
    render_collection_with_meta(
      type: 'popular',
      additional_meta: {
        period: params[:period] || 'all_time',
        algorithm: 'view_count'
      }
    )
  end

  # GET /api/v1/academies/recommended
  def recommended
    render_collection_with_meta(
      type: 'recommended',
      additional_meta: {
        user_id: current_user&.id,
        based_on: 'user_preferences'
      }
    )
  end

  private

  def render_filtered_featured
    render_json({
      data: serialize_collection(record),
      meta: {
        type: 'featured',
        filtered_by: params[:category_id]
      }
    })
  end

  def render_all_featured
    render_collection_with_meta(type: 'featured')
  end
end

class Api::V1::AcademiesController < ApplicationController
  include JsonapiResponses::Respondable

  def featured
    @academies = load_featured_academies
    render_with(@academies, responder: AcademyResponder, action: :featured)
  end

  def popular
    @academies = Academy.popular.limit(20)
    render_with(@academies, responder: AcademyResponder, action: :popular)
  end

  def recommended
    @academies = Academy.recommended_for(current_user)
    render_with(@academies, responder: AcademyResponder, action: :recommended)
  end
end

class MyCustomResponder < JsonapiResponses::Responder
  def render
    # Access to controller instance
    controller.current_user

    # Access to params
    params[:filter]

    # Serialize data
    serialize_collection(record)  # For collections
    serialize_item(record)         # For single items

    # Serialize using a named method on the serializer (falls back to serializable_hash)
    serialize_for(:my_action)      # Calls serializer.my_action if defined

    # Check record type
    collection?    # true if record is a collection
    single_item?   # true if record is a single item

    # Render JSON
    render_json({ data: [], meta: {} })
  end
end

# app/serializers/user_serializer.rb
class UserSerializer < ApplicationSerializer
  def serializable_hash
    case view
    when :minimal then minimal_hash
    when :profile then profile_hash
    else summary_hash
    end
  end

  # Custom shape for the confirm action — reuses an existing private method
  def confirm = auth_hash

  private

  def summary_hash = { id: resource.id, email: resource.email }
  def auth_hash    = { id: resource.id, email: resource.email, confirmed: resource.confirmed? }
end

# app/responders/confirmation_responder.rb
class ConfirmationResponder < ApplicationResponder
  def confirm
    render_json({
      message: context[:message],
      user: serialize_for(:confirm)   # → UserSerializer#confirm
    })
  end
end

class Api::V1::ConfirmationsController < ApplicationController
  def confirm
    # ... validation logic ...
    render_with(
      user,
      responder: ConfirmationResponder,
      action: :confirm,
      serializer: UserSerializer,
      context: { message: I18n.t("auth.confirmation.success") }
    )
  end
end

serialize_for(:confirm)  # → UserSerializer#confirm   (if defined)
serialize_for(:confirm)  # → UserSerializer#serializable_hash  (fallback)

# app/responders/categorized_responder.rb
class CategorizedResponder < JsonapiResponses::Responder
  def render
    # Handle pre-structured data or group on the fly
    if structured_data?
      render_json(record)
    else
      render_json(group_by_category)
    end
  end

  private

  def structured_data?
    record.is_a?(Array) &&
    record.first.is_a?(Hash) &&
    record.first.key?(:category)
  end

  def group_by_category
    categories = {}

    serialize_collection(record).each do |item|
      category_id = item.dig(:category, :id) || 'uncategorized'
      categories[category_id] ||= {
        category: item[:category] || { name: 'Uncategorized' },
        items: []
      }
      categories[category_id][:items] << item
    end

    categories.values.map do |group|
      group.merge(count: group[:items].size)
    end
  end
end

class Api::V1::ProductsController < ApplicationController
  include JsonapiResponses::Respondable

  # Map simple actions
  map_response_action :public_index, to: :index

  # Use responder for complex actions
  def featured
    @products = Product.featured
    render_with(@products, responder: FeaturedResponder)
  end

  # Use custom method for one-off logic
  def statistics
    render_with(@stats)
  end

  private

  def respond_for_statistics(record, serializer_class, context)
    render json: { stats: record, generated_at: Time.current }
  end
end