#!/bin/sh
# vmix: automated macOS install. Runs inside macOS Recovery's Terminal, started
# by vm-driver.py which types "sh /Volumes/VMIX/run.sh" for us.
#
#  1. erase the target disk (found by size) as APFS "Macintosh HD"
#  2. rebuild "Install macOS <name>.app": app skeleton from installer-app.tar
#     (host-extracted Payload) + SharedSupport.dmg = the WHOLE InstallAssistant.pkg
#     dd'd byte-exact from a raw disk (Apple's own postinstall hardlinks the pkg
#     there: it is a "pkgdmg" whose koly footer points at the dmg inside; the bare
#     xar member fails startosinstall with "pkgdmg is missing a footer")
#  3. startosinstall unattended, with the vmix agent pkg as --installpackage
#  4. startosinstall reboots itself into the install phase; the vmix agent pkg
#     installs during that phase and runs on the installed system's first boot
#
# On first boot of the installed system the agent runs /Volumes/VMIX/vmix-run.sh
# and powers off, which ends the QEMU session on the host.

# macOS Recovery invokes us as `sh` (bash in POSIX mode, no process substitution);
# re-exec once under bash so `>(tee ...)` and other bashisms work.
if [ -z "${VMIX_REEXEC:-}" ]; then VMIX_REEXEC=1 exec bash "$0" "$@"; fi

V="/Volumes/VMIX"
# tee to the Terminal (visible in host screenshots) and to a log on the volume
exec > >(tee "$V/install.log") 2>&1
set -x
. "$V/vmix.conf"
# keep the recovery display awake so the host driver can watch the screen
caffeinate -dimsu -t 86400 >/dev/null 2>&1 &
pmset -a displaysleep 0 sleep 0 >/dev/null 2>&1 || true

fail() {
  echo "vmix-install: FAIL: $*"
  cp /var/log/install.log "$V/system-install.log" 2>/dev/null || true
  echo 1 >"$V/install.status"
  sync
  sleep 2
  shutdown -h now 2>/dev/null || halt 2>/dev/null || true
  exit 1
}

# whole-disk identifier (diskN) whose size in bytes is exactly $1
disk_by_size() {
  for d in $(diskutil list | grep -oE '^/dev/disk[0-9]+'); do
    s=$(diskutil info "$d" | sed -n 's/.*Disk Size:.*(\([0-9][0-9]*\) Bytes).*/\1/p')
    [ "$s" = "$1" ] && { echo "${d#/dev/}"; return 0; }
  done
  return 1
}

echo "vmix-install: $(date) app=$APP_NAME volume=$VOLUME_NAME"
TARGET=$(disk_by_size "$TARGET_BYTES") || fail "target disk ($TARGET_BYTES bytes) not found"
SSDISK=$(disk_by_size "$PKG_DISK_BYTES") || fail "installer pkg disk ($PKG_DISK_BYTES bytes) not found"
echo "vmix-install: target=$TARGET sharedsupport=$SSDISK"

# --- 1. erase the target disk as an APFS volume
diskutil eraseDisk APFS "$VOLUME_NAME" GPT "$TARGET" || fail "eraseDisk $TARGET"
VOL="/Volumes/$VOLUME_NAME"
[ -d "$VOL" ] || fail "$VOL not mounted"

# --- 2. rebuild the installer app on the target volume
tar -xf "$V/installer-app.tar" -C "$VOL" || fail "untar installer-app.tar"
APP="$VOL/$APP_NAME"
SOI="$APP/Contents/Resources/startosinstall"
[ -x "$SOI" ] || fail "startosinstall missing in $APP"
SS="$APP/Contents/SharedSupport/SharedSupport.dmg"
mkdir -p "$APP/Contents/SharedSupport"
FULL=$((PKG_BYTES / 1048576))
REM=$((PKG_BYTES % 1048576))
dd if="/dev/r$SSDISK" of="$SS" bs=1048576 count=$FULL || fail "dd SharedSupport.dmg"
if [ "$REM" -gt 0 ]; then
  dd if="/dev/r$SSDISK" bs=1048576 skip=$FULL count=1 2>/dev/null | dd bs=1 count=$REM >>"$SS" || fail "dd SharedSupport.dmg tail"
fi
[ "$(stat -f %z "$SS")" = "$PKG_BYTES" ] || fail "SharedSupport.dmg size mismatch: $(stat -f %z "$SS") != $PKG_BYTES"
tail -c 512 "$SS" | grep -qa koly || fail "SharedSupport.dmg has no UDIF koly footer"
chflags -h norestricted "$SS" 2>/dev/null || true
echo "vmix-install: app=$APP SharedSupport.dmg=$(stat -f %z "$SS") bytes"

# macOS certificate validation needs a sane clock; a fresh VM RTC can be wrong.
echo "vmix-install: guest clock is $(date) (UTC $(date -u))"
if [ -n "${BUILD_DATE:-}" ]; then
  date -u "$BUILD_DATE" && echo "vmix-install: set clock to $(date)"
fi

# Blackhole Apple's install/verify endpoints so osinstallersetupd's network calls
# fail immediately instead of timing out (prepare otherwise crawls). Fully offline.
for d in swscan.apple.com swcdn.apple.com swdist.apple.com swquery.apple.com \
         gs.apple.com gsa.apple.com gdmf.apple.com mesu.apple.com xp.apple.com \
         albert.apple.com captive.apple.com deviceservices-external.apple.com \
         identity.apple.com ppq.apple.com crl.apple.com ocsp.apple.com \
         ocsp2.apple.com valid.apple.com; do
  echo "127.0.0.1 $d" >> /etc/hosts
done
echo "vmix-install: blackholed Apple install endpoints for a fast offline prepare"

# --- 3. unattended install. startosinstall prepares then reboots the machine
# itself into the install phase. Prepare intermittently stalls (~46% — an online
# verify/personalization step through the VM's NAT), so a watchdog kills and
# retries startosinstall if the target volume makes no write progress for a while.
# The vmix agent pkg installs during the install phase and runs on first boot.
# quote args properly — $VOL contains a space ("Macintosh HD")
run_soi() { "$SOI" --volume "$VOL" --agreetolicense --nointeraction --rebootdelay 5 "$@"; }
free_kb() { df -k "$VOL" 2>/dev/null | awk 'NR==2 {print $4}'; }

attempt=0
while [ "$attempt" -lt 10 ]; do
  attempt=$((attempt + 1))
  echo "vmix-install: startosinstall attempt $attempt"
  if [ "$attempt" -eq 1 ]; then
    run_soi --installpackage "$V/vmix-agent.pkg" 2>&1 &
  else
    # a stalled attempt leaves the volume dirty; re-erase and rebuild for a clean retry
    diskutil eraseDisk APFS "$VOLUME_NAME" GPT "$TARGET" || fail "eraseDisk on retry"
    tar -xf "$V/installer-app.tar" -C "$VOL" || fail "untar on retry"
    mkdir -p "$APP/Contents/SharedSupport"
    dd if="/dev/r$SSDISK" of="$SS" bs=1048576 count=$FULL 2>/dev/null
    [ "$REM" -gt 0 ] && dd if="/dev/r$SSDISK" bs=1048576 skip=$FULL count=1 2>/dev/null | dd bs=1 count=$REM >>"$SS" 2>/dev/null
    chflags -h norestricted "$SS" 2>/dev/null || true
    run_soi --installpackage "$V/vmix-agent.pkg" 2>&1 &
  fi
  SOI_PID=$!
  # watchdog: kill startosinstall if free space stalls for ~4 min OR the attempt
  # simply takes too long (prepare is intermittently slow; healthy = a few minutes)
  last=$(free_kb); stalled=0; elapsed=0
  while kill -0 "$SOI_PID" 2>/dev/null; do
    sleep 30; elapsed=$((elapsed + 30))
    now=$(free_kb)
    if [ "$now" = "$last" ]; then stalled=$((stalled + 30)); else stalled=0; last=$now; fi
    if [ "$stalled" -ge 240 ] || [ "$elapsed" -ge 540 ]; then
      echo "vmix-install: prepare too slow (stalled=${stalled}s elapsed=${elapsed}s), killing to retry"
      kill -9 "$SOI_PID" 2>/dev/null; pkill -9 -f startosinstall 2>/dev/null
      break
    fi
  done
  wait "$SOI_PID" 2>/dev/null
  # on success startosinstall reboots the machine and we never get here
  echo "vmix-install: startosinstall attempt $attempt ended without rebooting"
  sleep 3
done
fail "startosinstall did not complete after $attempt attempts"