From f21fb241d66d477fa0d8eda48b1d73562a1722cf Mon Sep 17 00:00:00 2001
From: Chris <mononym@users.noreply.github.com>
Date: Wed, 9 Mar 2022 17:13:25 +0100
Subject: [PATCH] feat: add file to assist in formatting application

---
 scripts/format_app.py | 76 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)
 create mode 100755 scripts/format_app.py

diff --git a/scripts/format_app.py b/scripts/format_app.py
new file mode 100755
index 000000000..15bdefe3b
--- /dev/null
+++ b/scripts/format_app.py
@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+
+# format_app.py
+
+import argparse
+import os
+import re
+import subprocess
+import sys
+
+
+def handle_cli_args():
+  parser = argparse.ArgumentParser(description='A script for formatting a given app within emqx')
+  parser.add_argument("-a", "--application", required=True, help="The application which is to be formatted.")
+  parser.add_argument('-b', "--branch", help="The git branch to be switched to before formatting the code. Required unless the -f option is passed in which case the value will be ignored even if provided.")
+  parser.add_argument('-f', "--format_in_place", default=False, action="store_true", help="Pass the -f option to format on the current git branch, otherwise a branch name must be provided by passing the -b option.")
+  args = parser.parse_args()
+
+  if not args.format_in_place and not args.branch:
+    sys.exit("A new git branch name must be provided with the -b option unless the -f option is given to format the code in place.")
+
+  return args
+
+
+def get_app_path(application):
+  root_path = os.path.dirname(os.path.realpath(__file__))
+  full_path = f"{root_path}/../apps/{application}"
+  isdir = os.path.isdir(full_path) 
+
+  if isdir:
+    return full_path
+  
+  sys.exit(f"The application provided ({application}) does not appear at the expected location: {full_path}")
+
+
+def maybe_switch_git_branch(format_in_place, branch):
+  if not format_in_place:
+    PIPE = subprocess.PIPE
+    process = subprocess.Popen(["git", "status"], stdout=PIPE, text=True)
+    stdoutput, stderroutput = process.communicate()
+
+    if f"On branch {branch}" in stdoutput:
+      return
+    elif "working tree clean" in stdoutput:
+      subprocess.call(["git", "checkout", "-b", branch])
+    else:
+      sys.exit("Cannot switch git branches while there are changes waiting to be committed.")
+
+
+def maybe_add_rebar_plugin():
+  with open("rebar.config", "r+") as f:
+    text = f.read()
+    erlfmt_pattern = "\{project_plugins.+?erlfmt.+\}"
+    plugin_pattern = "\{project_plugins.+?\}"
+    
+    if not re.search(erlfmt_pattern, text) and not re.search(plugin_pattern, text):
+      f.write("\n{project_plugins, [erlfmt]}.\n")
+    elif not re.search(erlfmt_pattern, text) and re.search(plugin_pattern, text):
+      sys.exit("Could not find the erlfmt plugin but the 'project_plugins' declaration already exists. Please add 'erlfmt' to the plugins list manually and rerun the script.")
+
+
+def execute_formatting():
+  subprocess.call(["rebar3", "fmt", "-w"])
+
+
+def main():
+  args = handle_cli_args()
+  app_path = get_app_path(args.application)
+  os.chdir(app_path)
+  maybe_switch_git_branch(args.format_in_place, args.branch)
+  maybe_add_rebar_plugin()
+  execute_formatting()
+  
+
+if __name__ == "__main__":
+  main()