#!/usr/bin/env bash

set -e

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
OUTPUT_TMP=$(mktemp)
OUTPUT="$SCRIPT_DIR/../../include/bindings/ruby_compiled.h"

if test "$1" = "clean"; then
  rm -f "$OUTPUT"
  exit 0
fi

trap 'rm -f "$OUTPUT_TMP"' EXIT

mapfile -t FILES < <(find "$SCRIPT_DIR" -name "*.rb" | sort)

LATEST_FILE_TIME=$(for file in "${FILES[@]}"; do
  echo $(stat -c "%Y" "$file")
done | sort -n | tail -1)

OUTPUT_TIME=$(stat -c "%Y" "$OUTPUT" 2>/dev/null || echo 0)

if test "$OUTPUT_TIME" -ge "$LATEST_FILE_TIME"; then
  echo "mgems is up to date."
  exit 0
fi

echo "Compiling mgems..."

"$SCRIPT_DIR/../mruby/bin/mrbc" -o "$OUTPUT_TMP" "${FILES[@]}"

{
  echo "#ifndef MGEMS_H"
  echo "#define MGEMS_H"
  xxd -i -n mgems $OUTPUT_TMP \
     | sed -e 's/^unsigned char /constexpr unsigned char /' \
           -e 's/^unsigned int /constexpr unsigned int /'
  echo "#endif"
} > "$OUTPUT"

echo "Compiled mgems!"