#!/usr/bin/env bash
# ANOUMA — server-side deployment script.
#
# This is NOT a manual update tool. It is invoked exclusively by Gitea
# Actions over SSH as the restricted `anouma-deploy` user (see setup.sh,
# which installs a forced-command SSH key that can only ever run this
# script). The production server never builds an image — it only ever
# pulls an already-built, already-tested tag from the registry.
#
#   deploy.sh deploy vX.Y.Z
#
# Runs from /opt/anouma (installed there by setup.sh). Safe by design:
# never deletes volumes, never force-deploys an untagged commit, always
# backs up the database first, and rolls the *code* back automatically if
# the post-deploy healthcheck fails.
set -euo pipefail
cd "$(dirname "${BASH_SOURCE[0]}")"

COLOR_INFO="\033[36m"; COLOR_WARN="\033[33m"; COLOR_ERROR="\033[31m"; COLOR_OK="\033[32m"; COLOR_RESET="\033[0m"
log_info()    { printf "${COLOR_INFO}[INFO]${COLOR_RESET} %s\n" "$1"; }
log_warn()    { printf "${COLOR_WARN}[WARN]${COLOR_RESET} %s\n" "$1"; }
log_error()   { printf "${COLOR_ERROR}[ERROR]${COLOR_RESET} %s\n" "$1" >&2; }
log_success() { printf "${COLOR_OK}[SUCCESS]${COLOR_RESET} %s\n" "$1"; }
fail() { log_error "$1"; exit 1; }

# ---------------------------------------------------------------------------
# When invoked through the restricted SSH key (see setup.sh), OpenSSH's
# forced "command=" ignores whatever the SSH client asked for and runs this
# script with NO arguments — the client's actual request arrives in
# $SSH_ORIGINAL_COMMAND instead. Re-split it into "$@" so the rest of this
# script doesn't need to care which path it came from. This is intentionally
# unquoted (word-splitting, not `eval`) — no shell metacharacter in
# SSH_ORIGINAL_COMMAND is ever interpreted as code, it just becomes literal
# argument text, which the strict version regex below then validates.
# ---------------------------------------------------------------------------
if [ $# -eq 0 ] && [ -n "${SSH_ORIGINAL_COMMAND:-}" ]; then
  # shellcheck disable=SC2086
  set -- $SSH_ORIGINAL_COMMAND
fi

ACTION="${1:-}"
VERSION="${2:-}"

[ -f .env ] || fail ".env not found — run setup.sh on this server first."

COMPOSE="docker compose"
docker compose version >/dev/null 2>&1 || COMPOSE="docker-compose"

# ---------------------------------------------------------------------------
# Deployment lock — never run two deployments concurrently.
# ---------------------------------------------------------------------------
LOCK_FILE="$(pwd)/.deploy.lock"
if [ -f "$LOCK_FILE" ] && kill -0 "$(cat "$LOCK_FILE")" 2>/dev/null; then
  log_warn "Deployment already running."
  exit 0
fi
echo $$ > "$LOCK_FILE"
trap 'rm -f "$LOCK_FILE"' EXIT

# ---------------------------------------------------------------------------
# .env helpers — same idempotent read/write approach as setup.sh.
# ---------------------------------------------------------------------------
env_get() { grep -E "^$1=" .env 2>/dev/null | tail -n1 | cut -d'=' -f2- || true; }
env_set() {
  local key="$1" value="$2"
  if grep -qE "^$key=" .env; then
    local tmp; tmp="$(mktemp)"
    awk -v k="$key" -v v="$value" 'BEGIN{FS=OFS="="} $1==k{$0=k "=" v} {print}' .env > "$tmp" && mv "$tmp" .env
  else
    printf '%s=%s\n' "$key" "$value" >> .env
  fi
}

wait_healthy() {
  local service="$1" timeout_iterations="$2" id status
  for _ in $(seq 1 "$timeout_iterations"); do
    id="$($COMPOSE ps -q "$service" 2>/dev/null || true)"
    if [ -n "$id" ]; then
      status="$(docker inspect --format '{{.State.Health.Status}}' "$id" 2>/dev/null || true)"
      [ "$status" = "healthy" ] && return 0
    fi
    sleep 2
  done
  return 1
}

backup_database() {
  mkdir -p backups
  local file="backups/database-$(date +%Y-%m-%d-%H%M).sql.gz"
  if $COMPOSE ps -q postgres >/dev/null 2>&1 && [ -n "$($COMPOSE ps -q postgres)" ]; then
    log_info "Backing up database → $file"
    $COMPOSE exec -T postgres pg_dump -U "${POSTGRES_USER:-postgres}" "${POSTGRES_DB:-anouma}" | gzip > "$file"
    log_success "Backup created ($(du -h "$file" | cut -f1))."
  else
    log_warn "Postgres is not running yet — skipping backup (first-ever deploy?)."
  fi
  local retention="${BACKUP_RETENTION_DAYS:-14}"
  find backups -name 'database-*.sql.gz' -mtime "+${retention}" -not -name "$(basename "$file")" -delete 2>/dev/null || true
}

registry_login() {
  if [ -n "${REGISTRY_USERNAME:-}" ] && [ -n "${REGISTRY_PASSWORD:-}" ]; then
    echo "$REGISTRY_PASSWORD" | docker login "${REGISTRY:-git.maro.run}" -u "$REGISTRY_USERNAME" --password-stdin >/dev/null 2>&1 \
      && log_success "Registry login OK." \
      || fail "Registry login failed — check REGISTRY_USERNAME/REGISTRY_PASSWORD in .env."
  fi
}

# Sets ANOUMA_IMAGE in .env to the given release tag, then re-sources .env so
# the rest of this script (and `docker compose`, via env_file) picks it up.
set_image_version() {
  local version="$1"
  env_set ANOUMA_IMAGE "${REGISTRY:-git.maro.run}/${REGISTRY_REPO:-maro/anouma}:${version}"
  set -a; source .env; set +a
}

# One full deploy attempt for a given version tag: pull → migrate → start →
# healthcheck. Returns non-zero on any failure without partially cleaning up
# — the caller decides whether to retry with the previous version.
deploy_version() {
  local version="$1"
  set_image_version "$version"
  registry_login
  log_info "Pulling ${ANOUMA_IMAGE} …"
  $COMPOSE pull app || return 1
  log_info "Running database migrations …"
  $COMPOSE run --rm app npm run migrate || return 1
  log_info "Starting containers …"
  $COMPOSE up -d || return 1
  log_info "Waiting for healthcheck …"
  wait_healthy app 60
}

do_deploy() {
  local version="$1"
  [[ "$version" =~ ^v[0-9]+\.[0-9]+\.[0-9]+$ ]] || fail "Invalid version '${version}' (expected vX.Y.Z)."

  set -a; source .env; set +a
  local previous_version=""
  local previous_image; previous_image="$(env_get ANOUMA_IMAGE)"
  if [[ "$previous_image" =~ :(v[0-9]+\.[0-9]+\.[0-9]+)$ ]]; then
    previous_version="${BASH_REMATCH[1]}"
  fi

  log_info "Deploying ${version} (current: ${previous_version:-none}) …"
  backup_database

  if deploy_version "$version"; then
    log_success "${version} is live."
    echo "$version" > .current-version
    exit 0
  fi

  log_error "${version} FAILED post-deploy healthcheck."
  if [ -z "$previous_version" ]; then
    fail "No previous version on record — nothing to roll back to. Check: $COMPOSE logs app"
  fi

  log_warn "Rolling back to ${previous_version} …"
  if deploy_version "$previous_version"; then
    log_warn "Rollback to ${previous_version} succeeded — production is back on the previous version."
    log_warn "Database migrations from the failed deploy were NOT reverted (see DEPLOYMENT.md) — restore the backup above manually if ${version} shipped an incompatible migration."
    echo "$previous_version" > .current-version
    exit 1
  fi

  fail "Rollback to ${previous_version} ALSO failed — manual intervention required: $COMPOSE logs app"
}

case "$ACTION" in
  deploy)
    [ -n "$VERSION" ] || fail "Usage: deploy.sh deploy vX.Y.Z"
    do_deploy "$VERSION"
    ;;
  *)
    echo "Usage: deploy.sh deploy vX.Y.Z" >&2
    exit 1
    ;;
esac