From 22a32e86a900389898aa4685641144daabeb5e2c Mon Sep 17 00:00:00 2001
From: Charlotte Meyer <dev@buffet.sh>
Date: Sat, 8 Feb 2020 15:08:37 +0000
Subject: [PATCH] Add kiwmi:schedule

---
 include/luak/kiwmi_lua_callback.h |  5 ++-
 include/luak/luak.h               |  2 ++
 kiwmi/luak/kiwmi_server.c         | 55 +++++++++++++++++++++++++++++++
 kiwmi/luak/luak.c                 | 10 ++++++
 lua_docs.md                       |  5 +++
 5 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/include/luak/kiwmi_lua_callback.h b/include/luak/kiwmi_lua_callback.h
index 2a10d19..7a1ac43 100644
--- a/include/luak/kiwmi_lua_callback.h
+++ b/include/luak/kiwmi_lua_callback.h
@@ -16,7 +16,10 @@ struct kiwmi_lua_callback {
     struct wl_list link;
     struct kiwmi_server *server;
     int callback_ref;
-    struct wl_listener listener;
+    union {
+        struct wl_event_source *event_source;
+        struct wl_listener listener;
+    };
 };
 
 int luaK_kiwmi_lua_callback_new(lua_State *L);
diff --git a/include/luak/luak.h b/include/luak/luak.h
index 8efcc59..9b326e6 100644
--- a/include/luak/luak.h
+++ b/include/luak/luak.h
@@ -11,12 +11,14 @@
 #include <stdbool.h>
 
 #include <lua.h>
+#include <wayland-server.h>
 
 #include "server.h"
 
 struct kiwmi_lua {
     lua_State *L;
     int objects;
+    struct wl_list scheduled_callbacks;
     struct wl_global *global;
 };
 
diff --git a/kiwmi/luak/kiwmi_server.c b/kiwmi/luak/kiwmi_server.c
index 0211a51..4e53b74 100644
--- a/kiwmi/luak/kiwmi_server.c
+++ b/kiwmi/luak/kiwmi_server.c
@@ -82,6 +82,60 @@ l_kiwmi_server_quit(lua_State *L)
     return 0;
 }
 
+static int
+kiwmi_server_schedule_handler(void *data)
+{
+    struct kiwmi_lua_callback *lc = data;
+    lua_State *L = lc->server->lua->L;
+
+    lua_rawgeti(L, LUA_REGISTRYINDEX, lc->callback_ref);
+    lua_pushvalue(L, -1);
+    if (lua_pcall(L, 1, 0, 0)) {
+        wlr_log(WLR_ERROR, "%s", lua_tostring(L, -1));
+    }
+
+    wl_event_source_remove(lc->event_source);
+
+    luaL_unref(L, LUA_REGISTRYINDEX, lc->callback_ref);
+
+    wl_list_remove(&lc->link);
+    free(lc);
+
+    return 0;
+}
+
+static int
+l_kiwmi_server_schedule(lua_State *L)
+{
+    struct kiwmi_object *obj =
+        *(struct kiwmi_object **)luaL_checkudata(L, 1, "kiwmi_server");
+    luaL_checktype(L, 2, LUA_TNUMBER);   // delay
+    luaL_checktype(L, 3, LUA_TFUNCTION); // callback
+
+    struct kiwmi_server *server = obj->object;
+
+    struct kiwmi_lua_callback *lc = malloc(sizeof(*lc));
+    if (!lc) {
+        return luaL_error(L, "failed to allocate kiwmi_lua_callback");
+    }
+
+    int delay = lua_tonumber(L, 2);
+
+    lc->event_source = wl_event_loop_add_timer(server->wl_event_loop, kiwmi_server_schedule_handler, lc);
+
+    if (wl_event_source_timer_update(lc->event_source, delay) < 0) {
+        free(lc);
+        return luaL_error(L, "failed to arm timer");
+    }
+
+    lc->server = server;
+    lc->callback_ref = luaL_ref(L, LUA_REGISTRYINDEX);
+
+    wl_list_insert(&server->lua->scheduled_callbacks, &lc->link);
+
+    return 0;
+}
+
 static int
 l_kiwmi_server_spawn(lua_State *L)
 {
@@ -159,6 +213,7 @@ static const luaL_Reg kiwmi_server_methods[] = {
     {"focused_view", l_kiwmi_server_focused_view},
     {"on", luaK_callback_register_dispatch},
     {"quit", l_kiwmi_server_quit},
+    {"schedule", l_kiwmi_server_schedule},
     {"spawn", l_kiwmi_server_spawn},
     {"stop_interactive", l_kiwmi_server_stop_interactive},
     {"view_at", l_kiwmi_server_view_at},
diff --git a/kiwmi/luak/luak.c b/kiwmi/luak/luak.c
index 4964c01..79677fd 100644
--- a/kiwmi/luak/luak.c
+++ b/kiwmi/luak/luak.c
@@ -179,6 +179,8 @@ luaK_create(struct kiwmi_server *server)
 
     luaL_openlibs(L);
 
+    wl_list_init(&lua->scheduled_callbacks);
+
     // init object registry
     lua_newtable(L);
     lua->objects = luaL_ref(L, LUA_REGISTRYINDEX);
@@ -248,5 +250,13 @@ luaK_destroy(struct kiwmi_lua *lua)
 {
     lua_close(lua->L);
 
+    struct kiwmi_lua_callback *lc;
+    struct kiwmi_lua_callback *tmp;
+    wl_list_for_each_safe (lc, tmp, &lua->scheduled_callbacks, link) {
+        wl_event_source_remove(lc->event_source);
+        wl_list_remove(&lc->link);
+        free(lc);
+    }
+
     free(lua);
 }
diff --git a/lua_docs.md b/lua_docs.md
index 9d72425..a587deb 100644
--- a/lua_docs.md
+++ b/lua_docs.md
@@ -29,6 +29,11 @@ Used to register event listeners.
 
 Quit kiwmi.
 
+#### kiwmi:schedule(delay, callback)
+
+Call `callback` after `delay` ms.
+Callback get passed itself, so that it can easily reregister itself.
+
 #### kiwmi:spawn(command)
 
 Spawn a new process.