From bfc10e60341578c7a6fa209277c0259002d84847 Mon Sep 17 00:00:00 2001
From: Morten Olsen <morten+pgp@olsen.pro>
Date: Tue, 24 Aug 2021 21:45:59 +0200
Subject: [PATCH] feat: Add custom scripts and hook based setup

This commit introduces a hook system that allows the user to add custom
modules which can use these hooks to invoke function af specific NvChad
events to allow for extending og functionality
---
 lua/core/custom.lua   | 22 ++++++++++++++++++++++
 lua/core/hooks.lua    | 38 ++++++++++++++++++++++++++++++++++++++
 lua/core/init.lua     |  5 +++++
 lua/core/mappings.lua |  3 ++-
 lua/custom/init.lua   |  2 ++
 lua/plugins/init.lua  |  2 ++
 6 files changed, 71 insertions(+), 1 deletion(-)
 create mode 100644 lua/core/custom.lua
 create mode 100644 lua/core/hooks.lua
 create mode 100644 lua/custom/init.lua

diff --git a/lua/core/custom.lua b/lua/core/custom.lua
new file mode 100644
index 0000000..05a7329
--- /dev/null
+++ b/lua/core/custom.lua
@@ -0,0 +1,22 @@
+local function isModuleAvailable(name)
+  if package.loaded[name] then
+    return true
+  else
+    for _, searcher in ipairs(package.searchers or package.loaders) do
+      local loader = searcher(name)
+      if type(loader) == 'function' then
+        package.preload[name] = loader
+        return true
+      end
+    end
+    return false
+  end
+end
+
+local loadIfExists = function (module)
+  if isModuleAvailable(module) then
+    require(module)
+  end
+end
+
+loadIfExists('custom')
diff --git a/lua/core/hooks.lua b/lua/core/hooks.lua
new file mode 100644
index 0000000..3353d71
--- /dev/null
+++ b/lua/core/hooks.lua
@@ -0,0 +1,38 @@
+local hooks, M = {}, {};
+local allowed_hooks = {
+  "install_plugins",
+  "setup_mappings",
+  "ready",
+}
+
+local function has_value (tab, val)
+  for _, value in ipairs(tab) do
+    if value == val then
+      return true
+    end
+  end
+
+  return false
+end
+
+M.add = function(name, fn)
+  if not(has_value(allowed_hooks, name)) then
+    error("Custom lua uses unallowed hook " .. name)
+  end
+  if hooks[name] == nil then
+    hooks[name] = {}
+  end
+  table.insert(hooks[name], fn);
+end
+
+M.run = function(name, args)
+  if hooks[name] == nil then
+    return;
+  end
+
+  for _, hook in pairs(hooks[name]) do
+    hook(args)
+  end
+end
+
+return M;
diff --git a/lua/core/init.lua b/lua/core/init.lua
index 999576f..819bc51 100644
--- a/lua/core/init.lua
+++ b/lua/core/init.lua
@@ -1,9 +1,12 @@
 local core_modules = {
+   "core.custom",
    "core.options",
    "core.autocmds",
    "core.mappings",
 }
 
+local hooks = require('core.hooks');
+
 for _, module in ipairs(core_modules) do
    local ok, err = pcall(require, module)
    if not ok then
@@ -13,3 +16,5 @@ end
 
 -- set all the non plugin mappings
 require("core.mappings").misc()
+
+hooks.run("ready")
diff --git a/lua/core/mappings.lua b/lua/core/mappings.lua
index 2e86198..3a41a83 100644
--- a/lua/core/mappings.lua
+++ b/lua/core/mappings.lua
@@ -1,8 +1,8 @@
 local utils = require "core.utils"
+local hooks = require "core.hooks"
 
 local config = utils.load_config()
 local map = utils.map
-
 local maps = config.mappings
 local plugin_maps = maps.plugin
 
@@ -116,6 +116,7 @@ M.misc = function()
    optional_mappings()
    required_mappings()
    user_config_mappings()
+   hooks.run("setup_mappings", map)
 end
 
 -- below are all plugin related mappings
diff --git a/lua/custom/init.lua b/lua/custom/init.lua
new file mode 100644
index 0000000..56508a9
--- /dev/null
+++ b/lua/custom/init.lua
@@ -0,0 +1,2 @@
+-- This is where you custom modules and plugins goes.
+-- See the wiki for a guide on how to extend NvChad
diff --git a/lua/plugins/init.lua b/lua/plugins/init.lua
index e9e23a1..fbdb606 100644
--- a/lua/plugins/init.lua
+++ b/lua/plugins/init.lua
@@ -337,4 +337,6 @@ return packer.startup(function()
          require("core.mappings").vim_fugitive()
       end,
    }
+
+   require("core.hooks").run("install_plugins", use)
 end)