feat(hooks): add hook system for post-file creation actions

- Implement hooks functionality in `lua/scratch/api.lua`
- Add `hooks` field to the configuration in `lua/scratch/config.lua`
- Update README.md with an example of using hooks

Author: LintaoAmons

Diff for: README.md

@@ -64,6 +64,13 @@ return {
           },
         },
       },
+      hooks = {
+        {
+          callback = function()
+            vim.api.nvim_buf_set_lines(0, 0, -1, false, { "hello", "world" })
+          end,
+        },
+      },
     })
   end,
   event = "VeryLazy",

Diff for: lua/scratch/api.lua

@@ -2,6 +2,7 @@ local config = require("scratch.config")
 local slash = require("scratch.utils").Slash()
 local utils = require("scratch.utils")
 local telescope_status, telescope_builtin = pcall(require, "telescope.builtin")
+local Hooks = require("scratch.hooks")
 local MANUAL_INPUT_OPTION = "MANUAL_INPUT"
 
 ---@class Scratch.ActionOpts
@@ -24,6 +25,11 @@ local function create_and_edit_file(abs_path, opts)
   else
     vim.api.nvim_command(cmd .. " " .. abs_path)
   end
+
+  local hooks = Hooks.get_hooks(vim.g.scratch_config.hooks, Hooks.trigger_points.AFTER)
+  for _, hook in ipairs(hooks) do
+    hook.callback()
+  end
 end
 
 local function write_lines_to_buffer(lines)

Diff for: lua/scratch/config.lua

@@ -43,13 +43,15 @@ local utils = require("scratch.utils")
 ---@field file_picker? "fzflua" | "telescope" | nil
 ---@field filetype_details Scratch.FiletypeDetails
 ---@field localKeys Scratch.LocalKeyConfig[]
+---@field hooks Scratch.Hook[]
 local default_config = {
   scratch_file_dir = vim.fn.stdpath("cache") .. slash .. "scratch.nvim", -- where your scratch files will be put
   filetypes = { "lua", "js", "py", "sh" }, -- you can simply put filetype here
   window_cmd = "edit", -- 'vsplit' | 'split' | 'edit' | 'tabedit' | 'rightbelow vsplit'
   file_picker = "fzflua",
   filetype_details = {},
   localKeys = {},
+  hooks = {},
 }
 
 ---@type Scratch.Config

Diff for: lua/scratch/hooks.lua

@@ -0,0 +1,32 @@
+local M = {}
+
+---@class Scratch.Hook
+---@field callback fun(param: table?)
+---@field name? string
+---@field trigger_point? string
+
+M.trigger_points = {
+  AFTER = "AFTER",
+}
+
+---@param hooks Scratch.Hook[]
+---@param target_trigger_point? string
+---@return Scratch.Hook[]
+M.get_hooks = function(hooks, target_trigger_point)
+  local matching_hooks = {}
+  for _, hook in ipairs(hooks) do
+    local matches = false
+    local trigger_point = hook.trigger_point or M.trigger_points.AFTER
+
+    if trigger_point == target_trigger_point then
+      matches = true
+    end
+
+    if matches then
+      table.insert(matching_hooks, hook)
+    end
+  end
+  return matching_hooks
+end
+
+return M