(ns example
  (:require
    [com.wsscode.pathom3.connect.indexes :as pci]
    [com.wsscode.pathom3.connect.operation :as pco]
    [com.wsscode.pathom3.interface.eql :as p.eql]))

(def companies
  {1 {:company/id 1
      :company/name "ACME Inc."}})

(def locations
  {1 {:location/id 1
      :location/name "Toon Town"
      :location/problems 2
      :location/deleted false
      :location/company 1}
   2 {:location/id 2
      :location/name "Snailville"
      :location/problems 0
      :location/deleted false
      :location/company 1}
   3 {:location/id 3
      :location/name "Laffy Forest"
      :location/problems 1
      :location/deleted true
      :location/company 1}})

(pco/defresolver company-attrs [env {:company/keys [id]}]
  {::pco/input [:company/id]
   ::pco/output [:company/name]}
  (select-keys (get companies id {}) [:company/name]))

(pco/defresolver location-attrs [env {:location/keys [id]}]
  {::pco/input [:location/id]
   ::pco/output [:location/name
                 :location/problems
                 :location/deleted]}
  (select-keys
    (get locations id {})
    [:location/name :location/problems :location/deleted]))

(pco/defresolver company-locations [env {:company/keys [id]}]
  {::pco/input [:company/id]
   ::pco/output [{:company/locations [:location/id]}]}
  (let [where-pred (get (pco/params env) :where (constantly true))]
    {:company/locations
     (->> (vals locations)
          (filter #(and (= (:location/company %) id)
                        (where-pred %)))
          (mapv #(select-keys % [:location/id])))}))

(pco/defresolver company-problems [env {:company/keys [locations]}]
  {::pco/input [{`(:company/locations
                    {:where ~(complement :location/deleted)})
                 [:location/problems]}]
   ::pco/output [:company/problems]}
  {:company/problems
   (reduce
     (fn [acc {:location/keys [problems]}]
       (+ acc problems))
     0 locations)})

(def indexes
  (pci/register
    [company-attrs
     location-attrs
     company-locations
     company-problems]))

(comment
  (p.eql/process
    indexes
    {:company/id 1}
    [:company/id
     :company/name
     :company/problems
     {:company/locations
      [:location/id
       :location/name
       :location/problems]}])

  ;; The above returns the following, filtering out the Laffy Forest
  ;; location because the :company/problems resolver ran and included
  ;; the attributes from it's input query of the :company/locations attribute.
  ;; I would expect the company-locations resolver to run twice, once
  ;; for each set of params. The node shouldn't be considered equivalent
  ;; with different params.
  {:company/id 1,
   :company/name "ACME Inc.",
   :company/problems 2, ;; correctly counted the problems without deleted location
   :company/locations
   ;; deleted location was dropped although it wasn't requested to be.
   ;; If :company/problems is removed from the query it will come back as
   ;; part of this result
   [{:location/id 1, :location/name "Toon Town", :location/problems 2}
    {:location/id 2, :location/name "Snailville", :location/problems 0}]}
  )