#!/bin/sh
DOCUMENTATION=$(cat <<END_OF_DOCUMENTATION
serve.sh 1.1

Serve the contents of this website using the python3 built-in
web server, while watching for changes.

When a file is detected as changed, and appropriate build.sh is run.
When format.sh or build.sh are detected as changed, a full rebuild is
triggered rather than an incremental one.

Note: serve.sh should be stopped by C-c (SIGINT).  Any other way of
exiting may not clean up correctly.

USAGE: serve.sh [OPTIONS]

Where the OPTIONS are:
  --directory DIR
    Builds the files into DIR instead of the default ./build folder.
    DIR should NOT contain a trailing '/'.

  --help
    Outputs this manual-style help message and immediately exits.

  --port PORT
    Serves the content on PORT instead of the default 8080.

  --version
    Outputs the script name along with its version number.

Requirements: This script depends on two external, non-POSIX,
programs, python3 and inotifywait.  Other than that this script is
POSIX compliant.

SPDX-FileCopyrightText: Copyright (c) 2022, Theodore Preduta.
SPDX-License-Identifier: BSD-2-Clause
END_OF_DOCUMENTATION
)

usage() {
  [ -n "$1" ] && echo "$1" && echo

  echo "Usage: serve.sh [OPTIONS]"
  echo "Try running with --help for more information."

  exit 1
}

build_dir="./build"
port="8080"

while [ ! "$*" = "" ]; do
  case "$1" in
    --directory)
      build_dir="$2"
      shift 2;;
    --help)
      echo "$DOCUMENTATION"
      exit 0;;
    --port)
      port="$2"
      shift 2;;
    --version)
      echo "$DOCUMENTATION" | head -n 1
      exit 0;;
    *)
      usage "Unkown argument: $1";;
  esac
done

clean_exit() {
  echo "Caught SIGINT, cleaning up and exiting..."

  kill "$server_port"

  exit 0
}
trap "clean_exit" SIGINT

echo "Starting serve.sh, press C-c or send SIGINT to stop."

python3 -m http.server --directory "$build_dir" "$port" &
server_port="$!"

echo "Running initial build..."
if ./build.sh --directory "$build_dir"; then
  echo "Initial build successful."
else
  echo "Initial build failed."
fi

while true
do
  file="$(inotifywait --recursive --quiet --event close_write --exclude "$build_dir/" ./ 2>&1;)"

  echo "Noticed change: $file"

  if [ "$file" = "./ CLOSE_WRITE,CLOSE format.sh" ] || [ "$file" = "./ CLOSE_WRITE,CLOSE build.sh" ]; then
    echo "Fully rebuilding..."
    ./build.sh --force --directory "$build_dir"
  else
    echo "Rebuilding..."
    ./build.sh --directory "$build_dir"
  fi

  if [ "$?" = "0" ]; then
    echo "Rebuild successful."
  else
    echo "Rebuild failed."
  fi
done