(ns glimmer-cosmic.ffi
  "Raw bindings for libjoltcosmic (`crates/jolt-cosmic/src/lib.rs`).

  The node half is libvidya's tree ABI under a `cosmic_` prefix. The loop half
  is not: libcosmic owns the main thread, so `run!` blocks there while the
  reconciler works from another thread, and its edits are published with
  `commit!`.

  **Any thread may call anything here except `raw-run`.** The arena sits behind
  a mutex; nothing is thread-local.

  **Strings returned are borrowed** until the next call of the same family —
  jolt copies a `:string` return as it crosses, so holding the value is safe."
  (:require [jolt.ffi :as ffi]))

;; --- the loop ----------------------------------------------------------------
;; :blocking releases the calling thread to Chez for the life of the call.
;; Without it, the worker would stall at its first collection waiting on a
;; thread parked inside libcosmic. A :blocking procedure may not take a string,
;; which is why the title is set by a call of its own.
(ffi/defcfn set-title! "cosmic_set_title" [:string] :void)
(ffi/defcfn raw-run "cosmic_run" [:int :int :int] :int {:blocking true})
(ffi/defcfn raw-wait "cosmic_wait" [:int] :int {:blocking true})
(ffi/defcfn wake! "cosmic_wake" [] :void)
(ffi/defcfn quit! "cosmic_quit" [] :void)
(ffi/defcfn raw-should-close "cosmic_should_close" [] :int)
(ffi/defcfn raw-commit "cosmic_tree_commit" [] :int)

;; --- the tree ----------------------------------------------------------------
(ffi/defcfn tree-root "cosmic_tree_root" [] :int)
(ffi/defcfn node-new "cosmic_node_new" [:string] :int)
(ffi/defcfn node-free! "cosmic_node_free" [:int] :void)
(ffi/defcfn raw-node-exists "cosmic_node_exists" [:int] :int)

(ffi/defcfn node-set-str! "cosmic_node_set_str" [:int :string :string] :void)
(ffi/defcfn node-set-num! "cosmic_node_set_num" [:int :string :double] :void)
(ffi/defcfn raw-node-set-bool "cosmic_node_set_bool" [:int :string :int] :void)
(ffi/defcfn node-clear-props! "cosmic_node_clear_props" [:int] :void)

(ffi/defcfn node-tag "cosmic_node_tag" [:int] :string)
(ffi/defcfn node-child-count "cosmic_node_child_count" [:int] :int)
(ffi/defcfn node-child-at "cosmic_node_child_at" [:int :int] :int)
(ffi/defcfn tree-dump "cosmic_tree_dump" [:int] :string)

(ffi/defcfn raw-node-append "cosmic_node_append" [:int :int] :int)
(ffi/defcfn node-remove! "cosmic_node_remove" [:int :int] :void)
(ffi/defcfn raw-node-insert-after "cosmic_node_insert_after" [:int :int :int] :int)
(ffi/defcfn raw-node-replace "cosmic_node_replace" [:int :int :int] :int)

;; --- events ------------------------------------------------------------------
(ffi/defcfn raw-poll-event "cosmic_tree_poll_event" [] :int)
(ffi/defcfn event-node "cosmic_tree_event_node" [] :int)
(ffi/defcfn event-name "cosmic_tree_event_name" [] :string)
(ffi/defcfn event-text "cosmic_tree_event_text" [] :string)
(ffi/defcfn event-num "cosmic_tree_event_num" [] :double)

;; --- the int/bool seam -------------------------------------------------------
(def system-mode 0)
(def dark-mode 1)
(def light-mode 2)

(defn run!
  "Open the window and block in libcosmic until it closes. Main thread only.
  Answers 0 on a clean exit, 1 on an error, 2 if a window already ran in this
  process."
  [width height title mode]
  (set-title! title)
  (raw-run width height mode))

(defn wait!
  "Block up to `ms` for an event, a `wake!`, or the window closing. True when
  an event is waiting."
  [ms]
  (not (zero? (raw-wait ms))))

(defn commit! [] (not (zero? (raw-commit))))
(defn should-close? [] (not (zero? (raw-should-close))))
(defn node-exists? [node] (not (zero? (raw-node-exists node))))
(defn node-set-bool! [node key value] (raw-node-set-bool node key (if value 1 0)))
(defn node-append! [parent child] (not (zero? (raw-node-append parent child))))
(defn node-insert-after! [parent child sibling]
  (not (zero? (raw-node-insert-after parent child sibling))))
(defn node-replace! [parent old new] (not (zero? (raw-node-replace parent old new))))
(defn poll-event! [] (not (zero? (raw-poll-event))))