#!/usr/bin/env bash
set -euo pipefail

# Reproducible custom WebRTC xcframework build for Rosetta iOS.
# Applies the same E2EE timestamp patch as the Android custom build.
#
# Requirements:
#   - macOS with Xcode (Command Line Tools)
#   - depot_tools in PATH (run bootstrap_depot_tools.sh first if needed)
#   - python3, git
#
# Usage:
#   cd /path/to/Rosetta/tools/webrtc-custom-ios
#   ./build_custom_webrtc_ios.sh

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROSETTA_DIR="$(cd "${SCRIPT_DIR}/../.." && pwd)"
PATCH_FILE="${SCRIPT_DIR}/patches/0001-audio-e2ee-pass-rtp-timestamp-as-additional-data.patch"

# Default: WebRTC M125 family — same as Android (branch-heads/6422).
WEBRTC_BRANCH="${WEBRTC_BRANCH:-branch-heads/6422}"
WEBRTC_TAG="${WEBRTC_TAG:-}"

# Source checkout root (contains src/).
WEBRTC_ROOT="${WEBRTC_ROOT:-$HOME/webrtc_ios}"
WEBRTC_SRC="${WEBRTC_SRC:-${WEBRTC_ROOT}/src}"

# Output framework consumed by Xcode project.
OUT_FRAMEWORK="${OUT_FRAMEWORK:-${ROSETTA_DIR}/Frameworks/WebRTC.xcframework}"

# Sync tuning (chromium.googlesource rate limits).
SYNC_JOBS="${SYNC_JOBS:-1}"
SYNC_RETRIES="${SYNC_RETRIES:-8}"
SYNC_RETRY_BASE_SEC="${SYNC_RETRY_BASE_SEC:-20}"

echo "[webrtc-ios] root: ${WEBRTC_ROOT}"
echo "[webrtc-ios] src:  ${WEBRTC_SRC}"
echo "[webrtc-ios] out:  ${OUT_FRAMEWORK}"
echo "[webrtc-ios] sync jobs: ${SYNC_JOBS}, retries: ${SYNC_RETRIES}"

export DEPOT_TOOLS_UPDATE=0

retry_cmd() {
  local max_attempts="$1"
  shift
  local attempt=1
  local backoff="${SYNC_RETRY_BASE_SEC}"

  while true; do
    if "$@"; then
      return 0
    fi
    if (( attempt >= max_attempts )); then
      return 1
    fi
    echo "[webrtc-ios] attempt ${attempt}/${max_attempts} failed, retrying in ${backoff}s: $*"
    sleep "${backoff}"
    backoff=$(( backoff * 2 ))
    if (( backoff > 300 )); then
      backoff=300
    fi
    attempt=$(( attempt + 1 ))
  done
}

sync_with_retry() {
  local attempt=1
  while true; do
    if gclient sync -D --jobs "${SYNC_JOBS}"; then
      return 0
    fi
    if (( attempt >= SYNC_RETRIES )); then
      echo "[webrtc-ios] ERROR: gclient sync failed after ${SYNC_RETRIES} attempts"
      return 1
    fi
    local wait_sec=$(( SYNC_RETRY_BASE_SEC * attempt ))
    if (( wait_sec > 300 )); then
      wait_sec=300
    fi
    echo "[webrtc-ios] gclient sync failed (attempt ${attempt}/${SYNC_RETRIES}), sleeping ${wait_sec}s..."
    sleep "${wait_sec}"
    attempt=$(( attempt + 1 ))
  done
}

if ! command -v fetch >/dev/null 2>&1; then
  echo "[webrtc-ios] ERROR: depot_tools 'fetch' not found in PATH"
  echo "[webrtc-ios] Run: git clone https://chromium.googlesource.com/chromium/tools/depot_tools.git"
  echo "[webrtc-ios] Then: export PATH=\$PATH:/path/to/depot_tools"
  exit 1
fi

# Step 1: Checkout WebRTC source for iOS
if [[ ! -d "${WEBRTC_SRC}/.git" ]]; then
  echo "[webrtc-ios] checkout not found, fetching webrtc_ios..."
  mkdir -p "${WEBRTC_ROOT}"
  pushd "${WEBRTC_ROOT}" >/dev/null
  retry_cmd "${SYNC_RETRIES}" fetch --nohooks --no-history webrtc_ios
  sync_with_retry
  popd >/dev/null
fi

pushd "${WEBRTC_SRC}" >/dev/null

# Step 2: Sync to target branch
echo "[webrtc-ios] syncing source..."
retry_cmd "${SYNC_RETRIES}" git fetch --all --tags

if [[ -n "${WEBRTC_TAG}" ]]; then
  retry_cmd "${SYNC_RETRIES}" git checkout "${WEBRTC_TAG}"
else
  if git show-ref --verify --quiet "refs/remotes/origin/${WEBRTC_BRANCH}"; then
    retry_cmd "${SYNC_RETRIES}" git checkout -B "${WEBRTC_BRANCH}" "origin/${WEBRTC_BRANCH}"
  else
    retry_cmd "${SYNC_RETRIES}" git checkout "${WEBRTC_BRANCH}"
  fi
  if git rev-parse --abbrev-ref --symbolic-full-name '@{u}' >/dev/null 2>&1; then
    retry_cmd "${SYNC_RETRIES}" git pull --ff-only
  fi
fi

sync_with_retry

# Step 3: Apply E2EE patch
echo "[webrtc-ios] applying Rosetta E2EE patch..."
git reset --hard
echo "[webrtc-ios] apply $(basename "${PATCH_FILE}")"
git apply --check "${PATCH_FILE}"
git apply "${PATCH_FILE}"
echo "[webrtc-ios] patch applied successfully"

# Step 4: Build iOS framework
echo "[webrtc-ios] building xcframework (this takes 30-60 minutes)..."
mkdir -p "$(dirname "${OUT_FRAMEWORK}")"

# Remove previous build if exists
rm -rf "${OUT_FRAMEWORK}"

python3 tools_webrtc/ios/build_ios_libs.py \
  --build-dir out_rosetta_ios \
  --output-dir "$(dirname "${OUT_FRAMEWORK}")" \
  --arch arm64 x86_64 \
  --extra-gn-args "is_debug=false is_component_build=false rtc_include_tests=false rtc_build_examples=false"

echo "[webrtc-ios] done"
echo "[webrtc-ios] framework: ${OUT_FRAMEWORK}"
echo ""
echo "Next steps:"
echo "  1. Remove stasel/WebRTC SPM dependency from Xcode"
echo "  2. Add ${OUT_FRAMEWORK} as Embedded Framework"
echo "  3. Build and verify: logs should show ad=8 (not ad=0)"

popd >/dev/null