degesch: Lua: add autocomplete hooks

degesch.c

@@ -1474,6 +1474,38 @@ struct irc_hook_vtable
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+struct completion_word
+{
+	size_t start;                       ///< Offset to start of word
+	size_t end;                         ///< Offset to end of word
+};
+
+struct completion
+{
+	char *line;                         ///< The line which is being completed
+
+	struct completion_word *words;      ///< Word locations
+	size_t words_len;                   ///< Number of words
+	size_t words_alloc;                 ///< Number of words allocated
+
+	size_t location;                    ///< Which word is being completed
+};
+
+struct completion_hook
+{
+	struct hook super;                  ///< Common hook fields
+	struct completion_hook_vtable *vtable;
+};
+
+struct completion_hook_vtable
+{
+	/// Tries to add possible completions of "word" to "output"
+	void (*complete) (struct completion_hook *self,
+		struct completion *data, const char *word, struct str_vector *output);
+};
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
 struct app_context
 {
 	bool no_colors;                     ///< Disable attribute printing
@@ -1543,6 +1575,7 @@ struct app_context
 	struct plugin *plugins;             ///< Loaded plugins
 	struct hook *input_hooks;           ///< Input hooks
 	struct hook *irc_hooks;             ///< IRC hooks
+	struct hook *completion_hooks;      ///< Autocomplete hooks
 }
 *g_ctx;
 
@@ -7644,6 +7677,7 @@ enum lua_hook_type
 	XLUA_HOOK_DEFUNCT,                  ///< No longer functional
 	XLUA_HOOK_INPUT,                    ///< Input hook
 	XLUA_HOOK_IRC,                      ///< IRC hook
+	XLUA_HOOK_COMPLETION,               ///< Autocomplete
 	XLUA_HOOK_TIMER,                    ///< One-shot timer
 };
 
@@ -7657,6 +7691,7 @@ struct lua_hook
 		struct hook hook;               ///< Hook base structure
 		struct input_hook input_hook;   ///< Input hook
 		struct irc_hook irc_hook;       ///< IRC hook
+		struct completion_hook c_hook;  ///< Autocomplete hook
 
 		struct poller_timer timer;      ///< Timer
 	}
@@ -7675,6 +7710,9 @@ lua_hook_unhook (lua_State *L)
 	case XLUA_HOOK_IRC:
 		LIST_UNLINK (hook->plugin->ctx->irc_hooks,        &hook->data.hook);
 		break;
+	case XLUA_HOOK_COMPLETION:
+		LIST_UNLINK (hook->plugin->ctx->completion_hooks, &hook->data.hook);
+		break;
 	case XLUA_HOOK_TIMER:
 		poller_timer_reset (&hook->data.timer);
 		break;
@@ -7766,6 +7804,95 @@ struct irc_hook_vtable lua_irc_hook_vtable =
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
+static void
+lua_plugin_push_completion (lua_State *L, struct completion *data)
+{
+	lua_createtable (L, 0, 3);
+
+	lua_pushstring (L, data->line);
+	lua_setfield (L, -2, "line");
+
+	lua_createtable (L, data->words_len, 0);
+	for (size_t i = 0; i < data->words_len; i++)
+	{
+		lua_pushlstring (L, data->line + data->words[i].start,
+			data->words[i].end - data->words[i].start);
+		lua_rawseti (L, -2, i + 1);
+	}
+	lua_setfield (L, -2, "words");
+
+	lua_pushinteger (L, data->location);
+	lua_setfield (L, -2, "location");
+}
+
+static bool
+lua_completion_hook_process_value (lua_State *L, struct str_vector *output,
+	struct error **e)
+{
+	if (lua_type (L, -1) != LUA_TSTRING)
+		FAIL ("%s: %s", "invalid type", lua_typename (L, lua_type (L, -1)));
+
+	size_t len;
+	const char *value = lua_tolstring (L, -1, &len);
+	if (!utf8_validate (value, len))
+		FAIL ("must be valid UTF-8");
+
+	str_vector_add (output, value);
+	return true;
+}
+
+static bool
+lua_completion_hook_process (lua_State *L, struct str_vector *output,
+	struct error **e)
+{
+	if (lua_isnil (L, -1))
+		return true;
+	if (!lua_istable (L, -1))
+		FAIL ("must return either a table or nil");
+
+	bool success = true;
+	for (lua_Integer i = 1; success && lua_rawgeti (L, -1, i); i++)
+		if ((success = lua_completion_hook_process_value (L, output, e)))
+			lua_pop (L, 1);
+	lua_pop (L, 1);
+	return success;
+}
+
+static void
+lua_completion_hook_complete (struct completion_hook *self,
+	struct completion *data, const char *word, struct str_vector *output)
+{
+	struct lua_hook *hook =
+		CONTAINER_OF (self, struct lua_hook, data.c_hook);
+	struct lua_plugin *plugin = hook->plugin;
+	lua_State *L = plugin->L;
+
+	lua_rawgeti (L, LUA_REGISTRYINDEX, hook->ref_callback);
+	lua_rawgetp (L, LUA_REGISTRYINDEX, hook);  // 1: hook
+	lua_plugin_push_completion (L, data);      // 2: data
+
+	lua_plugin_push_buffer (plugin, plugin->ctx->current_buffer);
+	lua_setfield (L, -2, "buffer");
+
+	lua_pushstring (L, word);                  // 3: word
+
+	struct error *e = NULL;
+	if (lua_plugin_call (plugin, 3, 1, &e))
+	{
+		lua_completion_hook_process (L, output, &e);
+		lua_pop (L, 1);
+	}
+	if (e)
+		lua_plugin_log_error (plugin, "autocomplete hook", e);
+}
+
+struct completion_hook_vtable lua_completion_hook_vtable =
+{
+	.complete = lua_completion_hook_complete,
+};
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
 static void
 lua_timer_hook_dispatch (void *user_data)
 {
@@ -7832,6 +7959,18 @@ lua_plugin_hook_irc (lua_State *L)
 	return 1;
 }
 
+static int
+lua_plugin_hook_completion (lua_State *L)
+{
+	struct lua_plugin *plugin = lua_touserdata (L, lua_upvalueindex (1));
+	struct lua_hook *hook = lua_plugin_push_hook
+		(plugin, 1, XLUA_HOOK_COMPLETION, luaL_optinteger (L, 2, 0));
+	hook->data.c_hook.vtable = &lua_completion_hook_vtable;
+	plugin->ctx->completion_hooks =
+		hook_insert (plugin->ctx->completion_hooks, &hook->data.hook);
+	return 1;
+}
+
 static int
 lua_plugin_hook_timer (lua_State *L)
 {
@@ -8115,7 +8254,8 @@ lua_plugin_setup_config (lua_State *L)
 		if (lua_type (L, -2) != LUA_TSTRING
 		 || lua_type (L, -1) != LUA_TTABLE)
 			return luaL_error (L, "%s: %s -> %s", "invalid types",
-				lua_typename (L, -2), lua_typename (L, -1));
+				lua_typename (L, lua_type (L, -2)),
+				lua_typename (L, lua_type (L, -1)));
 		lua_plugin_add_config_schema (plugin, subtree, lua_tostring (L, -2));
 	}
 
@@ -8521,6 +8661,7 @@ static luaL_Reg lua_plugin_library[] =
 {
 	{ "hook_input",      lua_plugin_hook_input      },
 	{ "hook_irc",        lua_plugin_hook_irc        },
+	{ "hook_completion", lua_plugin_hook_completion },
 	{ "hook_timer",      lua_plugin_hook_timer      },
 	{ "setup_config",    lua_plugin_setup_config    },
 	{ "connect",         lua_plugin_connect         },
@@ -10440,23 +10581,6 @@ process_input (struct app_context *ctx, char *user_input)
 // The amount of crap that goes into this is truly insane.
 // It's mostly because of Editline's total ignorance of this task.
 
-struct completion_word
-{
-	size_t start;                       ///< Offset to start of word
-	size_t end;                         ///< Offset to end of word
-};
-
-struct completion
-{
-	char *line;                         ///< The line which is being completed
-
-	struct completion_word *words;      ///< Word locations
-	size_t words_len;                   ///< Number of words
-	size_t words_alloc;                 ///< Number of words allocated
-
-	size_t location;                    ///< Which word is being completed
-};
-
 static void
 completion_init (struct completion *self)
 {
@@ -10698,6 +10822,12 @@ complete_word (struct app_context *ctx, struct completion *data,
 	if (try_topic)      complete_topic (ctx, data, word, &words);
 	if (try_nicknames)  complete_nicknames (ctx, data, word, &words);
 
+	LIST_FOR_EACH (struct hook, iter, ctx->completion_hooks)
+	{
+		struct completion_hook *hook = (struct completion_hook *) iter;
+		hook->vtable->complete (hook, data, word, &words);
+	}
+
 	if (words.len == 1)
 	{
 		// Nothing matched