feat: preprocess before embedding as base64

lua/img-clip/clipboard.lua

@@ -1,4 +1,5 @@
 local util = require("img-clip.util")
+local config = require("img-clip.config")
 
 local M = {}
 
@@ -162,24 +163,29 @@ end
 
 M.get_base64_encoded_image = function()
   local cmd = M.get_clip_cmd()
+  local preprocess_cmd = config.get_opt("preprocess_cmd")
+  if preprocess_cmd ~= "" then
+    preprocess_cmd = "| " .. preprocess_cmd .. " "
+  end
 
   -- Linux (X11)
   if cmd == "xclip" then
-    local output, exit_code = util.execute("xclip -selection clipboard -o -t image/png | base64 | tr -d '\n'")
+    local output, exit_code =
+      util.execute("xclip -selection clipboard -o -t image/png " .. preprocess_cmd .. "| base64 | tr -d '\n'")
     if exit_code == 0 then
       return output
     end
 
   -- Linux (Wayland)
   elseif cmd == "wl-paste" then
-    local output, exit_code = util.execute("wl-paste --type image/png | base64 | tr -d '\n'")
+    local output, exit_code = util.execute("wl-paste --type image/png " .. preprocess_cmd .. "| base64 | tr -d '\n'")
     if exit_code == 0 then
       return output
     end
 
   -- MacOS (pngpaste)
   elseif cmd == "pngpaste" then
-    local output, exit_code = util.execute("pngpaste - | base64 | tr -d '\n'")
+    local output, exit_code = util.execute("pngpaste - " .. preprocess_cmd .. "| base64 | tr -d '\n'")
     if exit_code == 0 then
       return output
     end
@@ -189,7 +195,9 @@ M.get_base64_encoded_image = function()
     local output, exit_code = util.execute(
       [[osascript -e 'set theFile to (open for access POSIX file "/tmp/image.png" with write permission)' ]]
         .. [[-e 'try' -e 'write (the clipboard as «class PNGf») to theFile' -e 'end try' -e 'close access theFile'; ]]
-        .. [[cat /tmp/image.png | base64 | tr -d "\n" ]]
+        .. [[/tmp/image.png ]]
+        .. preprocess_cmd
+        .. [[ | base64 | tr -d "\n" ]]
     )
     if exit_code == 0 then
       return output

lua/img-clip/config.lua

@@ -10,6 +10,7 @@ local defaults = {
   default = {
     dir_path = "assets", -- directory path to save images to, can be relative (cwd or current file) or absolute
     file_name = "%Y-%m-%d-%H-%M-%S", -- file name format (see lua.org/pil/22.1.html)
+    preprocess_cmd = "", -- cli command to process image before saving/embedding (expects image from stdin, writes image to stdout)
     url_encode_path = false, -- encode spaces and special characters in file path
     use_absolute_path = false, -- expands dir_path to an absolute path
     relative_to_current_file = false, -- make dir_path relative to current file rather than the cwd

lua/img-clip/fs.lua

@@ -162,6 +162,10 @@ end
 ---@return string | nil
 M.get_base64_encoded_image = function(file_path)
   local cmd = clipoard.get_clip_cmd()
+  local preprocess_cmd = config.get_opt("preprocess_cmd")
+  if preprocess_cmd ~= "" then
+    preprocess_cmd = "| " .. preprocess_cmd .. " "
+  end
 
   -- Windows
   if cmd == "powershell.exe" then
@@ -173,7 +177,7 @@ M.get_base64_encoded_image = function(file_path)
 
   -- Linux/MacOS
   else
-    local command = string.format("base64 '%s' | tr -d '\n'", file_path)
+    local command = string.format("cat '%s' %s| base64 | tr -d '\n'", file_path, preprocess_cmd)
     local output, exit_code = util.execute(command)
     if exit_code == 0 then
       return output