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

# Incremental deployment for an existing Dockerized AlphaX server.
#
# Required:
#   DEPLOY_HOST="user@server"
#   REMOTE_DIR="/path/to/existing/alphax-docker"
#
# Optional:
#   DEPLOY_BRANCH="main"
#   DEPLOY_MESSAGE="deploy: update alphax"
#   DEPLOY_REMOTE="origin"
#   DEPLOY_SERVICES="alphax-web alphax-scheduler alphax-price-streamer"
#   DEPLOY_RUN_MIGRATIONS=1
#   DEPLOY_HEALTHCHECK_URL="http://127.0.0.1:8191/api/stats"
#   DEPLOY_SKIP_COMMIT=1
#   DEPLOY_SKIP_PUSH=1
#   DEPLOY_SKIP_BUILD=1

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
DEPLOY_HOST="${DEPLOY_HOST:-}"
REMOTE_DIR="${REMOTE_DIR:-}"
DEPLOY_BRANCH="${DEPLOY_BRANCH:-main}"
DEPLOY_REMOTE="${DEPLOY_REMOTE:-origin}"
DEPLOY_MESSAGE="${DEPLOY_MESSAGE:-}"
DEPLOY_SERVICES="${DEPLOY_SERVICES:-alphax-web alphax-scheduler alphax-price-streamer}"
DEPLOY_RUN_MIGRATIONS="${DEPLOY_RUN_MIGRATIONS:-1}"
DEPLOY_HEALTHCHECK_URL="${DEPLOY_HEALTHCHECK_URL:-http://127.0.0.1:8191/api/stats}"
DEPLOY_SKIP_COMMIT="${DEPLOY_SKIP_COMMIT:-0}"
DEPLOY_SKIP_PUSH="${DEPLOY_SKIP_PUSH:-0}"
DEPLOY_SKIP_BUILD="${DEPLOY_SKIP_BUILD:-0}"

die() {
  echo "[deploy] ERROR: $*" >&2
  exit 1
}

info() {
  echo "[deploy] $*"
}

require_cmd() {
  command -v "$1" >/dev/null 2>&1 || die "missing required command: $1"
}

quote_remote() {
  printf "%q" "$1"
}

if [[ -z "$DEPLOY_HOST" || -z "$REMOTE_DIR" ]]; then
  cat >&2 <<'USAGE'
Usage:
  DEPLOY_HOST="user@server" REMOTE_DIR="/path/to/alphax-docker" DEPLOY_MESSAGE="deploy: xxx" bash scripts/deploy_server.sh

What it does on the existing server directory:
  git fetch + git pull --ff-only
  docker compose build
  docker compose up -d postgres alphax-web alphax-scheduler alphax-price-streamer

Useful options:
  DEPLOY_BRANCH=main
  DEPLOY_SERVICES="alphax-web alphax-scheduler alphax-price-streamer"
  DEPLOY_RUN_MIGRATIONS=1
  DEPLOY_SKIP_COMMIT=1
  DEPLOY_SKIP_PUSH=1
USAGE
  exit 2
fi

require_cmd git
require_cmd ssh

cd "$ROOT_DIR"

current_branch="$(git branch --show-current)"
if [[ "$current_branch" != "$DEPLOY_BRANCH" ]]; then
  die "current branch is '$current_branch', expected '$DEPLOY_BRANCH'. Set DEPLOY_BRANCH or switch branch first."
fi

if [[ -n "$(git status --porcelain)" ]]; then
  if [[ "$DEPLOY_SKIP_COMMIT" == "1" ]]; then
    die "working tree has changes, but DEPLOY_SKIP_COMMIT=1. Commit or stash first."
  fi
  if [[ -z "$DEPLOY_MESSAGE" ]]; then
    die "working tree has changes. Provide DEPLOY_MESSAGE='deploy: ...' to commit them."
  fi
  info "staging local changes"
  git add -A
  info "creating local commit"
  git commit -m "$DEPLOY_MESSAGE"
else
  info "working tree clean; no local commit needed"
fi

if [[ "$DEPLOY_SKIP_PUSH" != "1" ]]; then
  info "pushing $DEPLOY_REMOTE/$DEPLOY_BRANCH"
  git push "$DEPLOY_REMOTE" "$DEPLOY_BRANCH"
else
  info "skip git push"
fi

remote_dir_q="$(quote_remote "$REMOTE_DIR")"
branch_q="$(quote_remote "$DEPLOY_BRANCH")"
remote_q="$(quote_remote "$DEPLOY_REMOTE")"
services_q="$DEPLOY_SERVICES"
health_q="$(quote_remote "$DEPLOY_HEALTHCHECK_URL")"

remote_cmd="
set -Eeuo pipefail
cd $remote_dir_q
test -d .git || { echo '[deploy:remote] ERROR: REMOTE_DIR is not an existing git checkout'; exit 1; }
test -f docker-compose.yml || { echo '[deploy:remote] ERROR: docker-compose.yml not found in REMOTE_DIR'; exit 1; }
echo '[deploy:remote] fetching code'
git fetch $remote_q $branch_q
echo '[deploy:remote] checking out and pulling branch'
git checkout $branch_q
git pull --ff-only $remote_q $branch_q
echo '[deploy:remote] docker compose config check'
docker compose config >/dev/null
if [[ '$DEPLOY_SKIP_BUILD' != '1' ]]; then
  echo '[deploy:remote] docker compose build'
  docker compose build $services_q
else
  echo '[deploy:remote] skip docker build'
fi
if [[ '$DEPLOY_RUN_MIGRATIONS' == '1' ]]; then
  echo '[deploy:remote] running PostgreSQL migrations'
  docker compose run --rm alphax-web python scripts/postgres/run_migrations.py
fi
echo '[deploy:remote] docker compose up'
docker compose up -d postgres $services_q
echo '[deploy:remote] service status'
docker compose ps
if [[ -n $health_q ]]; then
  echo '[deploy:remote] healthcheck'
  curl -fsS $health_q >/dev/null
fi
"

info "deploying on $DEPLOY_HOST:$REMOTE_DIR"
ssh "$DEPLOY_HOST" "$remote_cmd"
info "deployment complete"