modify nvim-jdtls settings by detecting processing-java core library

lua/plugins/nvim-jdtls.lua

@@ -49,6 +49,64 @@ return {
         dap_main = {},
         test = true,
         settings = {
+          java = {
+            project = (function()
+              -- START SEARCH FOR PROCESSING --
+              -- detect install path based on system
+              local is_windows = vim.fn.has("win32") == 1
+              local cmds = is_windows and {
+                "(gcm processing.exe).source",
+              } or {
+                "whereis",
+                "processing.exe",
+              }
+
+              -- run syscall and process output
+              local output = vim.system(cmds, { text = true }):wait()
+              local path = output.stdout or ""
+              if not is_windows then
+                -- on linux, get substr starting with path
+                local start_idx = string.find(path, "/")
+                path = (start_idx ~= nil) and string.sub(path, start_idx) or ""
+              end
+
+              -- for windows, remove backslashes
+              path = string.gsub(path, "\\", "/")
+              -- remove filename at end of path
+              local end_idx = string.find(path, "/[^/]*$")
+              path = string.sub(path, 1, end_idx)
+
+              -- in case of chocolatey install, navigate to binaries
+              local is_chocolatey = string.find(path, "chocolatey")
+              if is_chocolatey then
+                path = path .. "../lib/processing/tools/"
+                -- list directories for program version
+                cmds = is_windows
+                    and {
+                      "ls",
+                      path,
+                      "|select name",
+                      "|Out-String",
+                    }
+                  or {
+                    "ls",
+                    "-l",
+                    path,
+                  }
+
+                output = vim.system(cmds, { text = true }):wait()
+                local version = string.match(output.stdout, "processing[^%s]*")
+                path = path .. version
+              end
+              -- set path to processing-core library
+              path = path .. "/core/library/core.jar"
+
+              return {
+                referencedLibraries = {
+                  is_windows and string.gsub(path, "/", "\\") or path,
+                },
+              }
+            end)(),
             inlayHints = {
               parameterNames = {
                 enabled = "all",