#!/usr/bin/env bash
# Write unified diffs for ipc3.c, pcm.c, hda-dai.c (ChromeOS 5.15 vs Ubuntu HWE 6.17) to OUT dir.
set -euo pipefail
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_ROOT="$(cd "$SCRIPT_DIR/.." && pwd)"
CH="${CH:-$REPO_ROOT/chromiumos_kernel/v5.15}"
UB="${UB:-$REPO_ROOT/kernel-src/linux-hwe-6.17-6.17.0}"
OUT="${OUT:-$REPO_ROOT/patches/ubuntu-hwe-6.17/reference}"

FILES=(
  sound/soc/sof/ipc3.c
  sound/soc/sof/pcm.c
  sound/soc/sof/intel/hda-dai.c
)

mkdir -p "$OUT"
missing=0
for f in "${FILES[@]}"; do
  if [[ ! -f "$CH/$f" || ! -f "$UB/$f" ]]; then
    echo "WARN: skip (missing): $f" >&2
    missing=1
    continue
  fi
  safe="${f//\//_}"
  dest="$OUT/diff-u_${safe}.txt"
  ( diff -u "$CH/$f" "$UB/$f" || true ) > "$dest"
  echo "Wrote $dest ($(wc -l < "$dest") lines)"
done
if [[ "$missing" -eq 1 ]]; then
  echo "Ensure CH and UB trees exist. CH=$CH UB=$UB" >&2
  exit 1
fi
echo "Done. Directory $OUT is gitignored by default."