(ns examples.list-selection
  "List selection example - demonstrates cursor navigation and multi-select.
   Mirrors bubbletea's list examples."
  (:require [tui.core :as tui]
            [tui.events :as ev]
            [clojure.string :as str]))

;; === Model ===
(def initial-model
  {:cursor 0
   :items ["Pizza" "Sushi" "Tacos" "Burger" "Pasta" "Salad" "Soup" "Steak"]
   :selected #{}
   :submitted false})

;; === Update ===
(defn update-fn [{:keys [model event]}]
  (let [{:keys [cursor items]} model]
    (cond
      ;; Quit
      (or (ev/key= event \q)
          (ev/key= event \c #{:ctrl}))
      {:model model :events [(ev/quit)]}

      ;; Move up
      (or (ev/key= event :up)
          (ev/key= event \k))
      {:model (update model :cursor #(max 0 (dec %)))}

      ;; Move down
      (or (ev/key= event :down)
          (ev/key= event \j))
      {:model (update model :cursor #(min (dec (count items)) (inc %)))}

      ;; Toggle selection
      (ev/key= event \space)
      {:model (update model :selected
                      #(if (contains? % cursor)
                         (disj % cursor)
                         (conj % cursor)))}

      ;; Submit
      (ev/key= event :enter)
      {:model (assoc model :submitted true)
       :events [(ev/quit)]}

      :else
      {:model model})))

;; === View ===
(defn view [{:keys [cursor items selected submitted]}]
  (if submitted
    [:col
     [:text {:bold true :fg :green} "You selected:"]
     [:text ""]
     (if (empty? selected)
       [:text {:fg :gray} "(nothing selected)"]
       [:col
        (for [idx (sort selected)]
          [:text (str "  - " (nth items idx))])])]

    [:col {:gap 1}
     [:box {:border :rounded :padding [0 1] :title "What's for lunch?"}
      [:col
       (for [[idx item] (map-indexed vector items)]
         (let [is-cursor (= idx cursor)
               is-selected (contains? selected idx)]
           [:row {:gap 1}
            [:text {:fg (when is-cursor :cyan)} (if is-cursor ">" " ")]
            [:text (if is-selected "[x]" "[ ]")]
            [:text {:bold is-cursor
                    :fg (cond
                          is-selected :green
                          is-cursor :cyan
                          :else :default)}
             item]]))]]
     [:row {:gap 2}
      [:text {:fg :gray} "j/k: move"]
      [:text {:fg :gray} "space: select"]
      [:text {:fg :gray} "enter: confirm"]
      [:text {:fg :gray} "q: quit"]]
     [:text {:fg :cyan}
      (str (count selected) " item" (when (not= 1 (count selected)) "s") " selected")]]))

;; === Main ===
(defn -main [& _args]
  (println "Starting list selection...")
  (let [{:keys [items selected submitted]} (tui/run {:init initial-model
                                                     :update update-fn
                                                     :view view})]
    (when submitted
      (println)
      (println "Your order:")
      (doseq [idx (sort selected)]
        (println "  -" (nth items idx))))))