emerge-snapshots

#!/usr/bin/env bash
#
# TODO: Potentially put this behind a CLI
#
#
# Benefits pulled from Emerge's internal iOS snapshot infrastructure:
#
# - Crash report collection: after any xcodebuild failure, captures .ips files from
#   ~/Library/Logs/DiagnosticReports scoped to the test run window
# - Retry on crash: distinguishes crash failures from legitimate test failures and
#   retries automatically (configurable via max_retries)
# - Zero-size image detection: scans extracted PNGs with sips after xcresulttool
#   export to catch renders that "succeed" but produce empty/corrupt images
# - Multi-device orchestration: runs against multiple simulators (iPhone, iPad, OS
#   versions) and collects results per-device before aggregating
# - Permission reset before run: calls xcrun simctl privacy reset all before each
#   run to prevent permission dialogs from blocking renders
# - Config file support: YAML config for scheme, test target, bundle ID, and
#   destinations — no bash knowledge required for customers
# - Simulator lifecycle management: boots simulators, waits for ready state, and
#   tears down cleanly between runs
# - Structured summary manifest: emits a JSON manifest with per-device image counts,
#   attempt numbers, and any captured crash report filenames
#
# Potential follow-ups (not yet implemented):
# - Regex-based exclusion filtering: filter extracted PNGs by filename pattern before
#   upload, driven by exclusion rules in the config file
# - Per-test timing: extract per-test duration from xcresult and include in the
#   manifest so Sentry can surface slow previews
# - Image metadata enrichment: emit a sidecar JSON per image with device name, OS
#   version, orientation, and color scheme for richer Sentry UI context
# - Sharding: split the test suite across multiple CI machines by enumerating test
#   method names (via xcodebuild build-for-testing + xctest list), accepting
#   shard/num_shards config params, and merging per-shard image directories
#   afterward; requires the customer's test target to expose one method per preview
set -euo pipefail

CONFIG_FILE=".github/emerge-snapshots.yml"
OUTPUT_DIR="snapshot-images"
XCRESULT_DIR=".."

while [[ $# -gt 0 ]]; do
  case "$1" in
    --config)       CONFIG_FILE="$2"; shift 2 ;;
    --output-dir)   OUTPUT_DIR="$2"; shift 2 ;;
    --xcresult-dir) XCRESULT_DIR="$2"; shift 2 ;;
    --help|-h) echo "Usage: emerge-snapshots [--config PATH] [--output-dir PATH] [--xcresult-dir PATH]"; exit 0 ;;
    *) echo "Unknown argument: $1"; exit 1 ;;
  esac
done
[[ -f "$CONFIG_FILE" ]] || { echo "Config not found: $CONFIG_FILE"; exit 1; }

parse_config() {
  ruby -ryaml -e "
    c = YAML.load_file(ARGV[0])
    %w[scheme test_target bundle_id].each { |k| abort(\"#{k} required\") unless c[k] }
    puts \"SCHEME=#{c['scheme']}\"
    puts \"TEST_TARGET=#{c['test_target']}\"
    puts \"BUNDLE_ID=#{c['bundle_id']}\"
    puts \"MAX_RETRIES=#{c.fetch('max_retries', 1)}\"
    puts '---'
    (c['destinations'] || []).select { |d| d['enabled'] }.each do |d|
      puts [d['name'], d['sdk'], d['xcode_flags']].join('|')
    end
  " "$1"
}

config_output=$(parse_config "$CONFIG_FILE")
eval "$(echo "$config_output" | awk '/^---$/{exit} {print}')"
DESTINATIONS=()
while IFS= read -r line; do
  DESTINATIONS+=("$line")
done < <(echo "$config_output" | awk '/^---$/{found=1; next} found{print}')

[[ ${#DESTINATIONS[@]} -gt 0 ]] || { echo "No enabled destinations in config"; exit 1; }

shopt -s nullglob

TOTAL_IMAGE_COUNT=0
declare -a DEVICE_SUMMARIES=()
declare -a CAPTURED_CRASH_REPORTS=()

boot_simulator() {
  local device_name="$1"
  xcrun simctl boot "$device_name" || true
  xcrun simctl bootstatus "$device_name" -b
  CURRENT_UDID=$(xcrun simctl list devices booted --json \
    | jq -r '.devices | to_entries[] | .value[] | select(.state == "Booted") | .udid' \
    | head -1)
}

reset_simulator_permissions() {
  local udid="$1"
  local bundle_id="$2"
  if [ -z "$udid" ]; then
    echo "Warning: UDID empty, skipping permission reset"
    return 0
  fi
  xcrun simctl privacy "$udid" reset all "$bundle_id"
}

run_tests() {
  local device_name="$1"
  local sdk="$2"
  local xcode_flags="$3"
  local result_path="$4"

  rm -rf "$result_path"
  touch /tmp/snapshot_test_start_marker
  TEST_START_EPOCH=$(date +%s)

  set +e
  set -o pipefail
  xcodebuild test \
    -scheme "$SCHEME" \
    -sdk "$sdk" \
    -destination "platform=iOS Simulator,name=${device_name}" \
    -only-testing:"$TEST_TARGET" \
    -resultBundlePath "$result_path" \
    $xcode_flags \
    ONLY_ACTIVE_ARCH=YES \
    SUPPORTS_MACCATALYST=NO \
    | xcpretty
  local exit_code=$?
  set -e
  return $exit_code
}

collect_crash_reports() {
  local dest_dir="$1"
  [ -d ~/Library/Logs/DiagnosticReports ] || return 0

  local count=0
  mkdir -p "$dest_dir"

  while IFS= read -r -d '' ips_file; do
    cp "$ips_file" "$dest_dir/"
    CAPTURED_CRASH_REPORTS+=("$(basename "$ips_file")")
    count=$((count + 1))
  done < <(find ~/Library/Logs/DiagnosticReports -name "*.ips" -newer /tmp/snapshot_test_start_marker -print0 2>/dev/null)

  echo "Crash reports collected: $count"
  return $count
}

extract_images() {
  local result_path="$1"
  local dest_dir="$2"
  xcrun xcresulttool export attachments \
    --path "$result_path" \
    --output-path "$dest_dir"
}

check_zero_size_images() {
  local dir="$1"
  command -v sips &>/dev/null || return 0

  for f in "$dir"/*.png; do
    local width
    width=$(sips -g pixelWidth "$f" | awk '/pixelWidth/{print $2}')
    if [ -z "$width" ] || [ "$width" -eq 0 ]; then
      echo "Error: Zero-size image detected: $f"
      exit 1
    fi
  done
}

run_device() {
  local device_name="$1"
  local sdk="$2"
  local xcode_flags="$3"
  local label="$4"

  boot_simulator "$device_name"
  reset_simulator_permissions "$CURRENT_UDID" "$BUNDLE_ID"

  local attempt=1
  local exit_code=0
  local xcresult=""

  while true; do
    xcresult="$XCRESULT_DIR/SnapshotResults-${label}-attempt${attempt}.xcresult"
    run_tests "$device_name" "$sdk" "$xcode_flags" "$xcresult" || exit_code=$?

    if [ "$exit_code" -eq 0 ]; then
      break
    fi

    local crash_count=0
    collect_crash_reports "$OUTPUT_DIR/crash-reports" || crash_count=$?

    if [ "$crash_count" -gt 0 ] && [ "$attempt" -le "$MAX_RETRIES" ]; then
      echo "Crash detected (attempt $attempt), retrying..."
      attempt=$((attempt + 1))
      exit_code=0
      continue
    else
      exit 1
    fi
  done

  extract_images "$xcresult" "$XCRESULT_DIR/snapshots-$label"
  check_zero_size_images "$XCRESULT_DIR/snapshots-$label"

  local copied=0
  for png in "$XCRESULT_DIR/snapshots-$label/"*.png; do
    cp "$png" "$OUTPUT_DIR/"
    copied=$((copied + 1))
  done

  TOTAL_IMAGE_COUNT=$((TOTAL_IMAGE_COUNT + copied))
  DEVICE_SUMMARIES+=("${label}|${device_name}|${copied}|${attempt}")
}

emit_summary() {
  echo ""
  echo "=== Snapshot Capture Summary ==="
  printf "%-35s %-8s %-9s\n" "Device" "Images" "Attempts"
  printf "%-35s %-8s %-9s\n" "------" "------" "--------"

  local devices_json="[]"
  for entry in ${DEVICE_SUMMARIES[@]+"${DEVICE_SUMMARIES[@]}"}; do
    IFS='|' read -r label name count attempts <<< "$entry"
    printf "%-35s %-8s %-9s\n" "$name" "$count" "$attempts"
    if command -v jq &>/dev/null; then
      devices_json=$(echo "$devices_json" | jq \
        --arg label "$label" \
        --arg name "$name" \
        --argjson count "$count" \
        --argjson attempts "$attempts" \
        '. + [{"label": $label, "name": $name, "image_count": $count, "attempts": $attempts}]')
    fi
  done

  echo "--------------------------------"
  echo "Total images: $TOTAL_IMAGE_COUNT"

  if ! command -v jq &>/dev/null; then
    echo "Warning: jq not available, skipping manifest write"
    return 0
  fi

  local crash_json="[]"
  for cr in ${CAPTURED_CRASH_REPORTS[@]+"${CAPTURED_CRASH_REPORTS[@]}"}; do
    crash_json=$(echo "$crash_json" | jq --arg cr "$cr" '. + [$cr]')
  done

  jq --null-input \
    --arg ts "$(date -u +"%Y-%m-%dT%H:%M:%SZ")" \
    --argjson devices "$devices_json" \
    --argjson total "$TOTAL_IMAGE_COUNT" \
    --argjson crashes "$crash_json" \
    '{
      generated_at: $ts,
      devices: $devices,
      total_image_count: $total,
      crash_reports_captured: $crashes
    }' > "$OUTPUT_DIR/snapshot-manifest.json"
}

mkdir -p "$OUTPUT_DIR"

for dest in "${DESTINATIONS[@]}"; do
  IFS='|' read -r device_name sdk xcode_flags <<< "$dest"
  label=$(echo "$device_name" | tr ' (),' '-' | tr '[:upper:]' '[:lower:]' | tr -s '-')
  run_device "$device_name" "$sdk" "$xcode_flags" "$label"
done

emit_summary
echo "Done. $TOTAL_IMAGE_COUNT images in $OUTPUT_DIR/"