(ns frontend.handler.block
  (:require
   [clojure.set :as set]
   [clojure.string :as string]
   [clojure.walk :as walk]
   [frontend.db :as db]
   [frontend.db.model :as db-model]
   [frontend.db.react :as react]
   [frontend.db.utils :as db-utils]
   [frontend.mobile.haptics :as haptics]
   [frontend.modules.outliner.core :as outliner-core]
   [frontend.modules.outliner.transaction :as outliner-tx]
   [frontend.state :as state]
   [frontend.util :as util]
   [goog.dom :as gdom]
   [logseq.graph-parser.block :as gp-block]))

;;  Fns

(defn long-page?
  [repo page-id]
  (>= (db/get-page-blocks-count repo page-id) db-model/initial-blocks-length))

;; TODO: reduced version
(defn- walk-block
  [block check? transform]
  (let [result (atom nil)]
    (walk/postwalk
     (fn [x]
       (if (check? x)
         (reset! result (transform x))
         x))
     (:block/body block))
    @result))

(defn get-timestamp
  [block typ]
  (walk-block block
              (fn [x]
                (and (gp-block/timestamp-block? x)
                     (= typ (first (second x)))))
              #(second (second %))))

(defn get-scheduled-ast
  [block]
  (get-timestamp block "Scheduled"))

(defn get-deadline-ast
  [block]
  (get-timestamp block "Deadline"))

(defn load-more!
  [db-id start-id]
  (let [repo (state/get-current-repo)
        db (db/get-db repo)
        block (db/entity repo db-id)
        block? (not (:block/name block))
        k (if block?
            :frontend.db.react/block-and-children
            :frontend.db.react/page-blocks)
        query-k [repo k db-id]
        option (cond-> {:limit db-model/step-loading-blocks}
                 block?
                 (assoc :scoped-block-id db-id))
        more-data (->> (db-model/get-paginated-blocks-no-cache db start-id option)
                       (map #(db/pull (:db/id %))))]
    (react/swap-new-result! query-k
                            (fn [result]
                              (->> (concat result more-data)
                                   (util/distinct-by :db/id))))))

(defn indentable?
  [{:block/keys [parent] :as block}]
  (when parent
    (let [parent-block (db-utils/pull (:db/id parent))
          first-child (first
                       (db-model/get-block-immediate-children
                        (state/get-current-repo)
                        (:block/uuid parent-block)))]
      (not= (:db/id block) (:db/id first-child)))))

(defn outdentable?
  [{:block/keys [level] :as _block}]
  (not= level 1))

(defn indent-outdent-block!
  [block direction]
  (outliner-tx/transact!
    {:outliner-op :move-blocks}
    (outliner-core/indent-outdent-blocks! [block] (= direction :right))))

(defn select-block!
  [block-uuid]
  (let [blocks (js/document.getElementsByClassName (str block-uuid))]
    (when (seq blocks)
      (state/exit-editing-and-set-selected-blocks! blocks))))

(def *swipe (atom nil))
(def *touch-start (atom nil))

(defn- target-disable-swipe?
  [target]
  (let [user-defined-tags (get-in (state/get-config)
                                  [:mobile :gestures/disabled-in-block-with-tags])]
    (or (.closest target ".dsl-query")
        (.closest target ".drawer")
        (.closest target ".draw-wrap")
        (some #(.closest target (util/format "[data-refs-self*=%s]" %))
              user-defined-tags))))

(defn on-touch-start
  [event uuid]
  (let [target (.-target event)
        input (state/get-input)
        input-id (state/get-edit-input-id)
        selection-type (.-type (.getSelection js/document))]
    (reset! *touch-start (js/Date.now))
    (when-not (and input
                   (string/ends-with? input-id (str uuid)))
      (state/clear-edit!))
    (when-not (target-disable-swipe? target)
      (when (not= selection-type "Range")
        (when-let [touches (.-targetTouches event)]
          (when (= (.-length touches) 1)
            (let [touch (aget touches 0)
                  x (.-clientX touch)
                  y (.-clientY touch)]
              (reset! *swipe {:x0 x :y0 y :xi x :yi y :tx x :ty y :direction nil}))))))))

(defn on-touch-move
  [event block uuid edit? *show-left-menu? *show-right-menu?]
  (when-let [touches (.-targetTouches event)]
    (let [selection-type (.-type (.getSelection js/document))]
      (when-not (= selection-type "Range")
        (when (or (not (state/sub :editor/editing?))
                  (< (- (js/Date.now) @*touch-start) 600))
          (when (and (= (.-length touches) 1) @*swipe)
            (let [{:keys [x0 xi direction]} @*swipe
                  touch (aget touches 0)
                  tx (.-clientX touch)
                  ty (.-clientY touch)
                  direction (if (nil? direction)
                              (if (> tx x0)
                                :right
                                :left)
                              direction)]
              (swap! *swipe #(-> %
                                 (assoc :tx tx)
                                 (assoc :ty ty)
                                 (assoc :xi tx)
                                 (assoc :yi ty)
                                 (assoc :direction direction)))
              (when (< (* (- xi x0) (- tx xi)) 0)
                (swap! *swipe #(-> %
                                   (assoc :x0 tx)
                                   (assoc :y0 ty))))
              (let [{:keys [x0 y0]} @*swipe
                    dx (- tx x0)
                    dy (- ty y0)]
                (when (and (< (. js/Math abs dy) 30)
                           (> (. js/Math abs dx) 30))
                  (let [left (gdom/getElement (str "block-left-menu-" uuid))
                        right (gdom/getElement (str "block-right-menu-" uuid))]

                    (cond
                      (= direction :right)
                      (do
                        (reset! *show-left-menu? true)
                        (when left
                          (when (>= dx 0)
                            (set! (.. left -style -width) (str dx "px")))
                          (when (< dx 0)
                            (set! (.. left -style -width) (str (max (+ 40 dx) 0) "px")))

                          (let [indent (gdom/getFirstElementChild left)]
                            (when (indentable? block)
                              (if (>= (.-clientWidth left) 40)
                                (set! (.. indent -style -opacity) "100%")
                                (set! (.. indent -style -opacity) "30%"))))))

                      (= direction :left)
                      (do
                        (reset! *show-right-menu? true)
                        (when right
                          (when (<= dx 0)
                            (set! (.. right -style -width) (str (- dx) "px")))
                          (when (> dx 0)
                            (set! (.. right -style -width) (str (max (- 80 dx) 0) "px")))

                          (let [outdent (gdom/getFirstElementChild right)
                                more (when-not edit?
                                       (gdom/getLastElementChild right))]
                            (when (and outdent (outdentable? block))
                              (if (and (>= (.-clientWidth right) 40)
                                       (< (.-clientWidth right) 80))
                                (set! (.. outdent -style -opacity) "100%")
                                (set! (.. outdent -style -opacity) "30%")))

                            (when more
                              (if (>= (.-clientWidth right) 80)
                                (set! (.. more -style -opacity) "100%")
                                (set! (.. more -style -opacity) "30%"))))))
                      :else
                      nil)))))))))))

(defn on-touch-end
  [_event block uuid *show-left-menu? *show-right-menu?]
  (when @*swipe
    (let [left-menu (gdom/getElement (str "block-left-menu-" uuid))
          right-menu (gdom/getElement (str "block-right-menu-" uuid))
          {:keys [x0 tx]} @*swipe
          dx (- tx x0)]
      (try
        (when (> (. js/Math abs dx) 10)
          (cond
            (and left-menu (>= (.-clientWidth left-menu) 40))
            (when (indentable? block)
              (haptics/with-haptics-impact
                (indent-outdent-block! block :right)
                :light))

            (and right-menu (<= 40 (.-clientWidth right-menu) 79))
            (when (outdentable? block)
              (haptics/with-haptics-impact
                (indent-outdent-block! block :left)
                :light))

            (and right-menu (>= (.-clientWidth right-menu) 80))
            (haptics/with-haptics-impact
              (do (state/set-state! :mobile/show-action-bar? true)
                  (state/set-state! :mobile/actioned-block block)
                  (select-block! uuid))
              :light)

            :else
            nil))
        (catch js/Error e
          (js/console.error e))
        (finally
          (reset! *show-left-menu? false)
          (reset! *show-right-menu? false)
          (reset! *swipe nil))))))

(defn on-touch-cancel
  [_event *show-left-menu? *show-right-menu?]
  (reset! *show-left-menu? false)
  (reset! *show-right-menu? false)
  (reset! *swipe nil))

(defn get-blocks-refed-pages
  [aliases [block & children]]
  (let [children-refs (mapcat :block/refs children)
        refs (->>
              (:block/path-refs block)
              (concat children-refs)
              (remove #(aliases (:db/id %))))]
    (keep (fn [ref]
            (when (:block/name ref)
              {:db/id (:db/id ref)
               :block/name (:block/name ref)
               :block/original-name (:block/original-name ref)})) refs)))

(defn filter-blocks
  [ref-blocks filters]
  (if (empty? filters)
    ref-blocks
    (let [exclude-ids (->> (keep (fn [page] (:db/id (db/entity [:block/name (util/page-name-sanity-lc page)]))) (get filters false))
                           (set))
          include-ids (->> (keep (fn [page] (:db/id (db/entity [:block/name (util/page-name-sanity-lc page)]))) (get filters true))
                           (set))]
      (cond->> ref-blocks
        (seq exclude-ids)
        (remove (fn [block]
                  (let [ids (set (map :db/id (:block/path-refs block)))]
                    (seq (set/intersection exclude-ids ids)))))

        (seq include-ids)
        (filter (fn [block]
                  (let [ids (set (map :db/id (:block/path-refs block)))]
                    (set/subset? include-ids ids))))))))

(defn get-filtered-ref-blocks-with-parents
  [all-ref-blocks filtered-ref-blocks]
  (when (seq filtered-ref-blocks)
    (let [id->block (zipmap (map :db/id all-ref-blocks) all-ref-blocks)
          get-parents (fn [block]
                        (loop [block block
                               result [block]]
                          (let [parent (id->block (:db/id (:block/parent block)))]
                            (if (and parent (not= (:db/id parent) (:db/id block)))
                              (recur parent (conj result parent))
                              result))))]
      (distinct (mapcat get-parents filtered-ref-blocks)))))
