#!/bin/sh
# Kestrel sidecar installer.
#   curl -fsSL https://raw.githubusercontent.com/pingnestapp/kestrel/main/install.sh | sh
#
# Installs the kestrel-sidecar binary to /usr/local/bin and sets it up as a
# system service (systemd on Linux, launchd on macOS). The sidecar runs next
# to your Frigate server; the Kestrel app pairs with it over your LAN.
#
# Binaries + checksums are served from GitHub Releases (no bandwidth cost).
#
# Environment overrides:
#   KESTREL_FRIGATE_URL  Frigate base URL written into the service
#                        (default http://127.0.0.1:5000 — edit later if unsure)
#   KESTREL_DATA_DIR     sidecar data dir (default /var/lib/kestrel-sidecar)
#   KESTREL_REPO         GitHub owner/repo (default pingnestapp/kestrel)
#   VERSION              release tag to install, e.g. v0.1.0 (default: latest)
#   BASE_URL             override the release asset base URL directly
#   PREFIX               install root for testing, e.g. PREFIX=$HOME/kestrel-test.
#                        Binary goes to $PREFIX/bin; no root needed and NO
#                        system service is installed.
set -eu

REPO="${KESTREL_REPO:-pingnestapp/kestrel}"
VERSION="${VERSION:-latest}"
if [ "$VERSION" = "latest" ]; then
  REL_BASE="https://github.com/${REPO}/releases/latest/download"
else
  REL_BASE="https://github.com/${REPO}/releases/download/${VERSION}"
fi
BASE_URL="${BASE_URL:-$REL_BASE}"
INSTALL_URL="https://raw.githubusercontent.com/${REPO}/main/install.sh"
BIN="kestrel-sidecar"
FRIGATE_URL="${KESTREL_FRIGATE_URL:-http://127.0.0.1:5000}"
DATA_DIR="${KESTREL_DATA_DIR:-/var/lib/kestrel-sidecar}"
PREFIX="${PREFIX:-}"

log()  { printf '\033[36m==>\033[0m %s\n' "$1"; }
warn() { printf '\033[33mwarning:\033[0m %s\n' "$1" >&2; }
die()  { printf '\033[31merror:\033[0m %s\n' "$1" >&2; exit 1; }

install_systemd() {
  log "Installing systemd service (kestrel-sidecar.service)"
  mkdir -p "$DATA_DIR"
  cat > /etc/systemd/system/kestrel-sidecar.service <<EOF
[Unit]
Description=Kestrel sidecar (Frigate companion for the Kestrel app)
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
# Point KESTREL_FRIGATE_URL at your Frigate instance, then:
#   systemctl daemon-reload && systemctl restart kestrel-sidecar
Environment=KESTREL_FRIGATE_URL=${FRIGATE_URL}
Environment=KESTREL_DATA_DIR=${DATA_DIR}
ExecStart=${BIN_DIR}/${BIN}
Restart=always
RestartSec=3

[Install]
WantedBy=multi-user.target
EOF
  systemctl daemon-reload
  systemctl enable --now kestrel-sidecar.service
}

install_launchd() {
  log "Installing launchd daemon (dev.kestrel.sidecar)"
  mkdir -p "$DATA_DIR"
  cat > /Library/LaunchDaemons/dev.kestrel.sidecar.plist <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key><string>dev.kestrel.sidecar</string>
  <key>ProgramArguments</key>
  <array><string>${BIN_DIR}/${BIN}</string></array>
  <key>EnvironmentVariables</key>
  <dict>
    <key>KESTREL_FRIGATE_URL</key><string>${FRIGATE_URL}</string>
    <key>KESTREL_DATA_DIR</key><string>${DATA_DIR}</string>
  </dict>
  <key>StandardOutPath</key><string>/var/log/kestrel-sidecar.log</string>
  <key>StandardErrorPath</key><string>/var/log/kestrel-sidecar.log</string>
  <key>RunAtLoad</key><true/>
  <key>KeepAlive</key><true/>
</dict>
</plist>
EOF
  launchctl unload /Library/LaunchDaemons/dev.kestrel.sidecar.plist 2>/dev/null || true
  launchctl load /Library/LaunchDaemons/dev.kestrel.sidecar.plist
}

main() {
  if [ -n "$PREFIX" ]; then
    BIN_DIR="${PREFIX}/bin"
    log "PREFIX set — installing to ${BIN_DIR}; system service installation is SKIPPED"
  else
    BIN_DIR="/usr/local/bin"
    [ "$(id -u)" -eq 0 ] || die "please run as root: curl -fsSL ${INSTALL_URL} | sudo sh"
  fi

  OS="$(uname -s | tr '[:upper:]' '[:lower:]')"
  case "$OS" in
    linux|darwin) ;;
    *) die "unsupported OS: $OS (supported: linux, macOS; or use the Docker image)" ;;
  esac
  ARCH="$(uname -m)"
  case "$ARCH" in
    x86_64|amd64) ARCH="amd64" ;;
    aarch64|arm64) ARCH="arm64" ;;
    *) die "unsupported architecture: $ARCH (supported: amd64, arm64)" ;;
  esac
  log "Detected ${OS}/${ARCH}"

  TMP="$(mktemp -d)"
  trap 'rm -rf "$TMP"' EXIT
  ARCHIVE="${BIN}_${OS}_${ARCH}.tar.gz"
  log "Downloading ${BASE_URL}/${ARCHIVE}"
  curl -fsSL "${BASE_URL}/${ARCHIVE}" -o "${TMP}/${ARCHIVE}" || die "download failed"
  curl -fsSL "${BASE_URL}/checksums.txt" -o "${TMP}/checksums.txt" || die "checksum download failed"

  log "Verifying checksum"
  if command -v sha256sum >/dev/null 2>&1; then
    ( cd "$TMP" && grep " ${ARCHIVE}\$" checksums.txt | sha256sum -c - >/dev/null 2>&1 ) || die "checksum verification failed"
  elif command -v shasum >/dev/null 2>&1; then
    ( cd "$TMP" && grep " ${ARCHIVE}\$" checksums.txt | shasum -a 256 -c - >/dev/null 2>&1 ) || die "checksum verification failed"
  else
    die "neither sha256sum nor shasum found; cannot verify download"
  fi

  tar -xzf "${TMP}/${ARCHIVE}" -C "$TMP"
  mkdir -p "$BIN_DIR"
  install -m 0755 "${TMP}/${BIN}" "${BIN_DIR}/${BIN}"
  log "Installed ${BIN_DIR}/${BIN}"

  if [ -n "$PREFIX" ]; then
    log "Test install complete (no service). Run it manually:"
    printf '    KESTREL_FRIGATE_URL=%s KESTREL_DATA_DIR=<dir> %s/%s\n' "$FRIGATE_URL" "$BIN_DIR" "$BIN"
    return
  fi

  if [ "$OS" = "linux" ]; then
    if command -v systemctl >/dev/null 2>&1 && [ -d /run/systemd/system ]; then
      install_systemd
      LOG_HINT="journalctl -u kestrel-sidecar -f"
    else
      warn "systemd not detected; binary installed but no service was set up."
      warn "Run it under your init system with:"
      warn "  KESTREL_FRIGATE_URL=${FRIGATE_URL} KESTREL_DATA_DIR=${DATA_DIR} ${BIN_DIR}/${BIN}"
      return
    fi
  else
    install_launchd
    LOG_HINT="tail -f /var/log/kestrel-sidecar.log"
  fi

  log "Sidecar installed and running."
  echo
  echo "Next steps:"
  echo "  1. Frigate URL is currently '${FRIGATE_URL}'. If that's wrong, edit the"
  echo "     service config and restart (see comments inside the unit/plist)."
  echo "  2. Get the pairing QR / 6-digit code:"
  echo "       ${LOG_HINT}        # printed every 5 minutes while unpaired"
  echo "       ${BIN} pair                            # or fetch it on demand"
  echo "  3. In the Kestrel app: Add server -> scan the QR (or enter the code +"
  echo "     this machine's LAN IP, port 8790)."
  echo
  echo "Prefer Docker instead? Uninstall this service and run:"
  echo "  docker run -d --name kestrel-sidecar --restart unless-stopped \\"
  echo "    --network host -v kestrel-data:/data \\"
  echo "    -e KESTREL_FRIGATE_URL=${FRIGATE_URL} kestrel-sidecar"
  echo

  # The service may take a moment to come up; poll briefly so the pairing
  # code is shown reliably instead of racing a slow start.
  i=0
  while [ "$i" -lt 10 ]; do
    if "${BIN_DIR}/${BIN}" pair 2>/dev/null; then
      break
    fi
    i=$((i + 1))
    sleep 1
  done
  if [ "$i" -ge 10 ]; then
    warn "sidecar not ready yet; run '${BIN} pair' in a moment to display the pairing code"
  fi
}

main "$@"