#!/usr/bin/env bash
#
# StoreHealthAnalyzer Remote Agent — install / (re)start on a remote host.
#
# Run this after extracting the deploy ZIP:
#   unzip sha-remote-agent-<version>.zip
#   cd sha-remote-agent-<version>
#   ./install.sh
#
# On first run: verifies the image tarball, loads it into Docker, and drops
# a starter .env so you can fill in WS_URL / WS_TOKEN. Re-runs are safe —
# the script is idempotent.

set -euo pipefail

# Move to the script's own directory so relative paths work regardless of
# where the user invoked it from.
cd "$(dirname "$0")"

RED=$'\033[0;31m'
GRN=$'\033[0;32m'
YLW=$'\033[1;33m'
RST=$'\033[0m'

log()  { printf '%s[install]%s %s\n' "$GRN" "$RST" "$*"; }
warn() { printf '%s[install]%s %s\n' "$YLW" "$RST" "$*"; }
die()  { printf '%s[install]%s %s\n' "$RED" "$RST" "$*" >&2; exit 1; }

# --- 1. Preflight ----------------------------------------------------------

command -v docker >/dev/null 2>&1 || die "Docker not found on PATH."
docker info >/dev/null 2>&1 \
  || die "Cannot talk to the Docker daemon. Is it running / do you have permission?"

# Detect either `docker compose` (v2 plugin) or the legacy `docker-compose`.
if docker compose version >/dev/null 2>&1; then
  COMPOSE=(docker compose)
elif command -v docker-compose >/dev/null 2>&1; then
  COMPOSE=(docker-compose)
else
  die "Neither 'docker compose' nor 'docker-compose' is available. Install Docker Compose."
fi

[[ -f VERSION ]] || die "VERSION file missing from bundle — is this a valid deploy ZIP?"
VERSION="$(cat VERSION)"

IMAGE_TARBALL="sha-remote-agent-${VERSION}.tar.gz"
[[ -f "$IMAGE_TARBALL" ]] || die "Image tarball not found: $IMAGE_TARBALL"

# --- 2. Verify checksum (optional; skip gracefully if no shasum tool) -----

if [[ -f SHA256SUMS ]]; then
  if command -v sha256sum >/dev/null 2>&1; then
    log "Verifying SHA256 checksum..."
    sha256sum -c SHA256SUMS >/dev/null || die "Checksum verification FAILED."
  elif command -v shasum >/dev/null 2>&1; then
    log "Verifying SHA256 checksum (macOS shasum)..."
    shasum -a 256 -c SHA256SUMS >/dev/null || die "Checksum verification FAILED."
  else
    warn "No sha256sum/shasum tool found — skipping integrity check."
  fi
  log "Checksum OK."
else
  warn "No SHA256SUMS file in bundle — skipping integrity check."
fi

# --- 3. Load the image -----------------------------------------------------
# ALWAYS docker load, unconditionally. `docker load` reassigns the tag to
# whatever's in the tarball and is a fast no-op when the layers are already
# present, so this is safe to re-run. We intentionally do NOT "skip if the
# tag already exists" — a stale image left over from a previous wrong-arch
# attempt has this exact tag, and skipping the load would hide the correct
# image in the tarball we're actually holding.

IMAGE_TAG="sha-remote-agent:${VERSION}"

log "Loading Docker image from ${IMAGE_TARBALL}..."
docker load -i "$IMAGE_TARBALL"

# --- 3a. Platform sanity check --------------------------------------------
# Inspect the image we just (re)loaded — this is the ground truth for what
# was actually shipped in this ZIP, independent of anything that was on the
# host before. If the tarball was built for a different CPU architecture
# than this host, Docker will let it "run" but tini (and node) fail with
# cryptic errors like "exec format error". Catch that up front with a
# clear message.

IMAGE_ARCH="$(docker image inspect --format '{{.Architecture}}' "$IMAGE_TAG" 2>/dev/null || true)"
IMAGE_ID_SHORT="$(docker image inspect --format '{{.Id}}' "$IMAGE_TAG" 2>/dev/null | sed 's|^sha256:||' | cut -c1-12)"

HOST_ARCH_RAW="$(uname -m)"
case "$HOST_ARCH_RAW" in
  x86_64|amd64)  HOST_ARCH="amd64" ;;
  aarch64|arm64) HOST_ARCH="arm64" ;;
  armv7l)        HOST_ARCH="arm" ;;
  *)             HOST_ARCH="$HOST_ARCH_RAW" ;;
esac

log "Loaded ${IMAGE_TAG} (id: ${IMAGE_ID_SHORT:-unknown}, arch: ${IMAGE_ARCH:-unknown}); host arch: ${HOST_ARCH}."

if [[ -z "$IMAGE_ARCH" ]]; then
  die "Could not read image architecture from Docker — is the image really loaded?"
fi

if [[ "$IMAGE_ARCH" != "$HOST_ARCH" ]]; then
  warn "Image architecture (${IMAGE_ARCH}) does not match this host (${HOST_ARCH})."
  warn "The container would fail to start with 'exec /sbin/tini: exec format error'."
  warn ""
  warn "This means the ZIP was built for the wrong CPU. On the build host:"
  warn "  1. git pull    # make sure you have the fixed package.sh"
  warn "  2. ./docker/remote-agent/package.sh --platform linux/${HOST_ARCH}"
  warn "The updated package.sh verifies the architecture during build and"
  warn "refuses to produce a ZIP that would fail this check."
  die  "Aborting install. Ship a linux/${HOST_ARCH} bundle and re-run this script."
fi

# --- 4. Bootstrap .env -----------------------------------------------------

if [[ ! -f .env ]]; then
  if [[ -f .env.example ]]; then
    cp .env.example .env
    warn ".env did not exist — copied .env.example into place."
    warn "EDIT .env now to set WS_URL and WS_TOKEN, then re-run this script."
    exit 0
  else
    die ".env is missing and no .env.example is bundled. Cannot proceed."
  fi
fi

# --- 5. Start the container -----------------------------------------------

log "Starting sha-remote-agent (version ${VERSION})..."
"${COMPOSE[@]}" up -d

log "Done. Tail logs with:"
log "  ${COMPOSE[*]} logs -f"
log "Stop with:"
log "  ${COMPOSE[*]} down"