lua: auto-generate configuration when none exists

Author: tesselslate

doc/00_setup.md

@@ -67,10 +67,10 @@ you compiled earlier.
 
 ## Configuration
 
-waywall will not start up without a configuration file. It will search for one
-in `$XDG_CONFIG_HOME/waywall` (typically `~/.config/waywall/`). You can create
-a file with the following contents at `~/.config/waywall/init.lua` as a starting
-point:
+waywall follows the [XDG Base Directory] specification and will search for a
+configuration file in `$XDG_CONFIG_HOME/waywall` (usually `~/.config/waywall`).
+If no configuration file exists, one will be automatically generated for you.
+You can use the following configuration as a starting point:
 
 ```lua
 local waywall = require("waywall")

waywall/lua/init.lua

@@ -5,6 +5,36 @@
     load their configuration.
 ]]
 
+local autogen_notice = [[
+Your configuration file is autogenerated!
+
+You can remove this notice by opening it in a text
+editor and following the instructions in the file.
+]]
+
+local default_config = [[
+-- This configuration file was auto-generated by waywall. Refer to the
+-- documentation for more information on how to configure waywall!
+--
+-- To remove the auto-generated notice, delete the 'config.autogen = true'
+-- line at the bottom of the file.
+
+local waywall = require("waywall")
+local helpers = require("waywall.helpers")
+
+local config = {
+    theme = {
+        background = "#303030ff",
+    },
+}
+
+config.actions = {}
+
+config.autogen = true -- Delete me to remove the auto-generated notice
+
+return config
+]]
+
 --[[
     Setup the environment for the user's configuration.
 ]]
@@ -102,13 +132,67 @@ for _, dir in ipairs(config_dirs) do
     package.path = package.path .. ";" .. dir .. "/waywall/?.lua"
 end
 
--- Run the user's configuration file.
-local user_config = require(priv.profile() or "init")
+-- Run the user's configuration file. If it doesn't exist, then create a default
+-- one for them.
+local profile = priv.profile() or "init"
+
+local function load_config(autogenerate)
+    local ok, result = pcall(require, profile)
+
+    if ok then
+        if type(result) == "table" then
+            print("loaded configuration from profile '" .. profile .. "'")
+            return result
+        end
+
+        error("expected table from user configuration, got " .. type(result))
+    else
+        if result:find("not found:") then
+            if not autogenerate then
+                error(result)
+            end
+
+            print(
+                "failed to find configuration file (profile = '"
+                    .. profile
+                    .. "', package.path = '"
+                    .. package.path
+                    .. "')"
+            )
+
+            local path = assert(config_dirs[1], "no config dirs")
+                .. "/waywall/"
+                .. profile
+                .. ".lua"
+            local file, err = io.open(path, "a+")
+            if err then
+                error("failed to auto-generate a configuration file: " .. err)
+            end
+            file:write(default_config)
+            file:close()
+
+            print("auto-generated configuration file at " .. path)
+
+            -- Try loading the new auto-generated configuration. Do not try to
+            -- generate a new one if somehow loading the configuration still
+            -- fails.
+            return load_config(false)
+        else
+            error(result)
+        end
+    end
+end
+
+local user_config = load_config(true)
+
+if user_config.autogen then
+    -- selene: allow(unused_variable)
+    local autogen_text = nil
 
--- If the user's configuration does not return a table, then `require` will
--- return a boolean to say whether or not the call was successful.
-if type(user_config) ~= "table" then
-    return {}
+    local waywall = require("waywall")
+    waywall.listen("load", function()
+        autogen_text = waywall.text(autogen_notice, { x = 10, y = 10, size = 1 })
+    end)
 end
 
 return user_config