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

GITEA_BASE_URL="https://git.awaioi.com"
REPOSITORY="awaioi/ERP"
VERSION="0.3.8"
TAG="v${VERSION}"
INSTALL_SHA256="716f6a9ea75659be3c7162d031f1b1fe5e8aa0e82e0101296153842dff9b35d6"
UNINSTALL_SHA256="98c56fed2fd4d01874e4ab5a1a4f3ec42ec3e29b315ffd87385a95488d587546"
PG_ROOT="${ERP_RECOVERY_PG_ROOT:-/www/server/pgsql}"
PG_DATA="${ERP_RECOVERY_PG_DATA:-/www/server/pgsql/data}"
PG_INIT_SCRIPT="${ERP_RECOVERY_PG_INIT_SCRIPT:-/etc/init.d/pgsql}"
TMP_DIR=""

say() { printf '[ERP Recovery] %s\n' "$*"; }
fail() { printf '[ERP Recovery] ERROR: %s\n' "$*" >&2; exit 1; }

cleanup() {
  [[ -z "$TMP_DIR" || ! -d "$TMP_DIR" ]] || rm -rf -- "$TMP_DIR"
}
trap cleanup EXIT

postgres_port_open() {
  timeout 2 bash -c 'exec 3<>/dev/tcp/127.0.0.1/5432' >/dev/null 2>&1
}

wait_for_postgres() {
  local _
  for _ in {1..60}; do
    postgres_port_open && return 0
    sleep 1
  done
  return 1
}

start_erp_postgres() {
  if postgres_port_open; then
    say 'PostgreSQL is already listening on 127.0.0.1:5432'
    return 0
  fi

  [[ -f "$PG_DATA/PG_VERSION" ]] \
    || fail "PostgreSQL data directory is missing: $PG_DATA"

  if [[ -x "$PG_INIT_SCRIPT" ]]; then
    say "Starting PostgreSQL with $PG_INIT_SCRIPT"
    if ! "$PG_INIT_SCRIPT" start; then
      say 'The init script returned an error; checking whether PostgreSQL still started'
    fi
  else
    local pg_ctl pg_user
    pg_ctl="$(find "$PG_ROOT" -type f -name pg_ctl -print -quit 2>/dev/null || true)"
    [[ -n "$pg_ctl" && -x "$pg_ctl" ]] || fail "pg_ctl was not found below $PG_ROOT"
    pg_user="$(stat -c '%U' "$PG_DATA")" || fail 'Unable to determine the PostgreSQL owner'
    id "$pg_user" >/dev/null 2>&1 || fail "PostgreSQL owner does not exist: $pg_user"
    say "Starting PostgreSQL as $pg_user"
    runuser -u "$pg_user" -- "$pg_ctl" \
      -D "$PG_DATA" \
      -l "$PG_DATA/startup.log" \
      -w -t 60 start
  fi

  if ! wait_for_postgres; then
    [[ ! -r "$PG_DATA/startup.log" ]] || tail -n 100 "$PG_DATA/startup.log" >&2
    fail 'PostgreSQL did not listen on 127.0.0.1:5432 within 60 seconds'
  fi
  say 'PostgreSQL is ready on 127.0.0.1:5432'
}

download_verified_script() {
  local name="$1" expected="$2" destination
  destination="$TMP_DIR/$name"
  curl -fsSL --connect-timeout 15 --max-time 300 \
    "$GITEA_BASE_URL/$REPOSITORY/raw/tag/$TAG/$name" \
    -o "$destination"
  printf '%s  %s\n' "$expected" "$destination" | sha256sum -c - >&2
  printf '%s' "$destination"
}

main() {
  [[ "$(id -u)" == "0" ]] || fail 'Run this recovery command as root'
  for command in bash curl find runuser sha256sum stat timeout; do
    command -v "$command" >/dev/null 2>&1 || fail "Missing command: $command"
  done

  start_erp_postgres
  TMP_DIR="$(mktemp -d "${TMPDIR:-/tmp}/kaidi-erp-recovery.XXXXXX")"

  local uninstaller installer
  uninstaller="$(download_verified_script uninstall.sh "$UNINSTALL_SHA256")"
  say 'Removing the pending installation and its PostgreSQL schema safely'
  bash "$uninstaller" --purge-database --yes

  installer="$(download_verified_script install.sh "$INSTALL_SHA256")"
  say "Installing Kaidi ERP $VERSION"
  bash "$installer" \
    --gitea-url "$GITEA_BASE_URL" \
    --repository "$REPOSITORY" \
    --version "$VERSION"
}

if [[ "${BASH_SOURCE[0]:-$0}" == "$0" ]]; then
  main "$@"
fi