#!/usr/bin/env bash

set -Eeuo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
readonly INVOCATION_DIR="$PWD"

usage() {
  printf 'Usage: %s [-v|--version <postgresql-version>] [-p|--prefix <path>] [-o|--options <configure-options>]\n' "$0"
  printf '       %s [-p|--prefix <path>] [-o|--options <configure-options>] <postgresql-version>\n' "$0"
  printf '       %s --help | -h\n' "$0"
}

for argument in "$@"; do
  if [[ "$argument" == "--help" || "$argument" == "-h" ]]; then
    usage
    exit 0
  fi
done

POSTGRES_VERSION=""
PREFIX_OVERRIDE=""
CONFIGURE_OPTIONS="--with-ssl=openssl,--with-lz4"
while (($#)); do
  case "$1" in
    -p|--prefix)
      (($# >= 2)) || { printf 'ERROR: %s requires a path\n' "$1" >&2; exit 2; }
      [[ -n "$2" ]] || { printf 'ERROR: prefix path must not be empty\n' >&2; exit 2; }
      PREFIX_OVERRIDE="$2"
      shift 2
      ;;
    -v|--version)
      (($# >= 2)) || { printf 'ERROR: %s requires a PostgreSQL version\n' "$1" >&2; exit 2; }
      [[ -n "$2" ]] || { printf 'ERROR: PostgreSQL version must not be empty\n' >&2; exit 2; }
      [[ -z "$POSTGRES_VERSION" ]] || { printf 'ERROR: PostgreSQL version was specified more than once\n' >&2; exit 2; }
      POSTGRES_VERSION="$2"
      shift 2
      ;;
    --prefix=*)
      PREFIX_OVERRIDE="${1#*=}"
      [[ -n "$PREFIX_OVERRIDE" ]] || { printf 'ERROR: prefix path must not be empty\n' >&2; exit 2; }
      shift
      ;;
    --version=*)
      [[ -n "${1#*=}" ]] || { printf 'ERROR: PostgreSQL version must not be empty\n' >&2; exit 2; }
      [[ -z "$POSTGRES_VERSION" ]] || { printf 'ERROR: PostgreSQL version was specified more than once\n' >&2; exit 2; }
      POSTGRES_VERSION="${1#*=}"
      shift
      ;;
    -o|--options)
      (($# >= 2)) || { printf 'ERROR: %s requires a comma-separated option list\n' "$1" >&2; exit 2; }
      CONFIGURE_OPTIONS="$2"
      shift 2
      ;;
    --options=*)
      CONFIGURE_OPTIONS="${1#*=}"
      shift
      ;;
    -*)
      printf 'ERROR: unknown option: %s\n' "$1" >&2
      usage >&2
      exit 2
      ;;
    *)
      [[ -z "$POSTGRES_VERSION" ]] || { printf 'ERROR: unexpected argument: %s\n' "$1" >&2; usage >&2; exit 2; }
      POSTGRES_VERSION="$1"
      shift
      ;;
  esac
done

[[ -n "$POSTGRES_VERSION" ]] || { usage >&2; exit 2; }
[[ "$POSTGRES_VERSION" =~ ^[0-9]+\.[0-9]+([.][0-9]+)?$ ]] || {
  printf 'ERROR: invalid PostgreSQL version: %s\n' "$POSTGRES_VERSION" >&2
  exit 1
}
SECONDS=0

readonly POSTGRES_ROOT="${POSTGRES_ROOT:-/app/postgres/rdbms}"
PREFIX="${PREFIX_OVERRIDE:-$POSTGRES_ROOT/$POSTGRES_VERSION}"
readonly POSTGRES_CONFIGURE_OPTIONS="$CONFIGURE_OPTIONS"
[[ "$PREFIX" == /* && "$PREFIX" != "/" && "$PREFIX" != "$POSTGRES_ROOT" ]] || {
  printf 'ERROR: prefix must be an absolute version-specific directory, not / or POSTGRES_ROOT itself: %s\n' "$PREFIX" >&2
  exit 1
}
readonly NORMALIZED_PREFIX="$(realpath -m -- "$PREFIX")"
readonly NORMALIZED_POSTGRES_ROOT="$(realpath -m -- "$POSTGRES_ROOT")"
[[ "$NORMALIZED_PREFIX" != "/" && "$NORMALIZED_PREFIX" != "$NORMALIZED_POSTGRES_ROOT" ]] || {
  printf 'ERROR: prefix must not resolve to / or POSTGRES_ROOT: %s\n' "$PREFIX" >&2
  exit 1
}
readonly PREFIX="$NORMALIZED_PREFIX"
if [[ -n "$POSTGRES_CONFIGURE_OPTIONS" ]]; then
  [[ "$POSTGRES_CONFIGURE_OPTIONS" != ,* &&
    "$POSTGRES_CONFIGURE_OPTIONS" != *, &&
    "$POSTGRES_CONFIGURE_OPTIONS" != *,,* ]] || {
    printf 'ERROR: configure options must be a non-empty comma-separated list\n' >&2
    exit 2
  }
  IFS=',' read -r -a parsed_configure_options <<< "$POSTGRES_CONFIGURE_OPTIONS"
  for option in "${parsed_configure_options[@]}"; do
    [[ "$option" == -* && "$option" != "-" ]] || {
      printf 'ERROR: invalid PostgreSQL configure option: %s\n' "$option" >&2
      exit 2
    }
  done
fi

readonly PREFIX_VERSION="$(basename -- "$PREFIX")"
readonly SOURCES_DIR="$SCRIPT_DIR/sources/$PREFIX_VERSION"
readonly SOURCE_MANIFEST="$SOURCES_DIR/.source-manifest.tsv"
readonly STAGING_DIR="$SCRIPT_DIR/tmp"
readonly PROCESS_LOG="$INVOCATION_DIR/postgresql-$POSTGRES_VERSION-process.log"
readonly ENGINE_ARCHIVE="$INVOCATION_DIR/postgresql-$PREFIX_VERSION-engine.tar.gz"

[[ "$STAGING_DIR" != "/" ]] || {
  printf 'ERROR: staging directory must not be the filesystem root\n' >&2
  exit 1
}
rm -rf -- "$STAGING_DIR"
mkdir -p "$STAGING_DIR"

export PREFIX POSTGRES_CONFIGURE_OPTIONS SOURCE_MANIFEST

if [[ -e "$PREFIX" || -L "$PREFIX" ]]; then
  printf 'WARNING: PostgreSQL installation directory already exists: %s\n' "$PREFIX" >&2
  if [[ ! -t 0 ]]; then
    printf 'Non-interactive input; defaulting to No and exiting without changes.\n' >&2
    exit 0
  fi

  read -r -p "Recreate this directory and continue? [y/N] " response || response=""
  case "$response" in
    Y|y) printf 'Confirmed: %s will be recreated.\n' "$PREFIX" ;;
    *) printf 'Installation cancelled; existing directory was left unchanged.\n'; exit 0 ;;
  esac
fi

exec > >(tee "$PROCESS_LOG") 2>&1

printf 'Installation started: %s\n' "$(date -Is)"
printf 'Invocation directory: %s\n' "$INVOCATION_DIR"
printf 'PostgreSQL version: %s\n' "$POSTGRES_VERSION"
printf 'Install prefix: %s\n' "$PREFIX"
printf 'PostgreSQL configure options: %s\n' "${POSTGRES_CONFIGURE_OPTIONS:-<none>}"
printf 'Recreating source archive directory: %s\n' "$SOURCES_DIR"
rm -rf -- "$SOURCES_DIR"
mkdir -p "$SOURCES_DIR"
: > "$SOURCE_MANIFEST"

"$SCRIPT_DIR/install_postgresql.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_pg_cron.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_timescaledb.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_pgaudit.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_set_user.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_pg_stat_statements.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_auto_explain.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_passwordcheck.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_pg_repack.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_pg_stat_monitor.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_pgvector.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_hypopg.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_pg_hint_plan.sh" --version "$POSTGRES_VERSION"
"$SCRIPT_DIR/install_wal2json.sh" --version "$POSTGRES_VERSION"

readonly CONFIG_FILE="${CONFIG_FILE:-}"
readonly SHARED_PRELOAD_LIBRARIES="pg_cron,timescaledb,pgaudit,pg_stat_statements,pg_stat_monitor,passwordcheck"

if [[ -n "$CONFIG_FILE" ]]; then
  [[ -f "$CONFIG_FILE" ]] || {
    printf 'ERROR: configuration file does not exist: %s\n' "$CONFIG_FILE" >&2
    exit 1
  }
  python3 - "$CONFIG_FILE" <<'PY'
import pathlib
import re
import sys

path = pathlib.Path(sys.argv[1])
text = path.read_text()
pattern = r"(?m)^[ \t]*(#?)[ \t]*shared_preload_libraries[ \t]*=[ \t]*'([^']*)'[^\n]*$"
match = re.search(pattern, text)
required = ("pg_cron", "timescaledb", "pgaudit", "pg_stat_statements", "pg_stat_monitor", "passwordcheck")
if match:
    libraries = [item.strip() for item in match.group(2).split(",") if item.strip()]
    for library in required:
        if library not in libraries:
            libraries.append(library)
    line = "shared_preload_libraries = '" + ",".join(libraries) + "'\\t# (change requires restart)"
    text = re.sub(pattern, line, text, count=1)
else:
    text = text.rstrip("\n") + "\n\nshared_preload_libraries = '" + ",".join(required) + "'\\t# (change requires restart)\n"
path.write_text(text)
PY
fi

printf 'Installed PostgreSQL and extensions in %s\n' "$PREFIX"
if [[ -n "$CONFIG_FILE" ]]; then
  grep -E '^[[:space:]]*shared_preload_libraries[[:space:]]*=' "$CONFIG_FILE"
fi

[[ -s "$SOURCE_MANIFEST" ]] || {
  printf 'ERROR: source download manifest is empty: %s\n' "$SOURCE_MANIFEST" >&2
  exit 1
}
printf '\nSource downloads:\n'
while IFS=$'\t' read -r product source_url git_tag; do
  [[ -n "$product" && -n "$source_url" ]] || {
    printf 'ERROR: invalid source download record in %s\n' "$SOURCE_MANIFEST" >&2
    exit 1
  }
  printf '  %s\n    Source URL: %s\n' "$product" "$source_url"
  if [[ -n "$git_tag" ]]; then
    printf '    Git tag: %s\n' "$git_tag"
  else
    printf '    Git tag: not applicable (PostgreSQL source archive)\n'
  fi
done < "$SOURCE_MANIFEST"

extension_version() {
  local extension="$1"
  awk -F"'" '/^[[:space:]]*default_version[[:space:]]*=/{print $2; exit}' \
    "$PREFIX/share/extension/$extension.control"
}

printf '\nInstalled products and extensions:\n'
printf '  PostgreSQL: %s\n' "$("$PREFIX/bin/pg_config" --version | sed 's/^PostgreSQL //')"
printf '  PostgreSQL configure options: %s\n' "${POSTGRES_CONFIGURE_OPTIONS//,/ }"
printf '  pg_cron: %s\n' "$(extension_version pg_cron)"
printf '  TimescaleDB: %s\n' "$(extension_version timescaledb)"
printf '  pgaudit: %s\n' "$(extension_version pgaudit)"
printf '  set_user: %s\n' "$(extension_version set_user)"
printf '  pg_stat_statements: %s\n' "$(extension_version pg_stat_statements)"
printf '  auto_explain: PostgreSQL %s contrib module\n' "$POSTGRES_VERSION"
printf '  passwordcheck: PostgreSQL %s contrib module\n' "$POSTGRES_VERSION"
printf '  pg_repack: %s\n' "$(extension_version pg_repack)"
printf '  pg_stat_monitor: %s\n' "$(extension_version pg_stat_monitor)"
printf '  pgvector: %s\n' "$(extension_version vector)"
printf '  hypopg: %s\n' "$(extension_version hypopg)"
printf '  pg_hint_plan: %s\n' "$(extension_version pg_hint_plan)"
printf '  wal2json: logical decoding output plugin\n'
printf "  shared_preload_libraries = '%s'\n" "$SHARED_PRELOAD_LIBRARIES"

rm -f -- "$ENGINE_ARCHIVE"
tar -czf "$ENGINE_ARCHIVE" -C "$(dirname -- "$PREFIX")" "$(basename -- "$PREFIX")"
printf '\nCreated engine archive: %s\n' "$ENGINE_ARCHIVE"
printf 'Archive size: %s\n' "$(du -h "$ENGINE_ARCHIVE" | awk '{print $1}')"
elapsed_seconds=$SECONDS
elapsed_hours=$((elapsed_seconds / 3600))
elapsed_minutes=$(((elapsed_seconds % 3600) / 60))
elapsed_remainder=$((elapsed_seconds % 60))
printf 'Total execution time: %dh %dm %ds\n' \
  "$elapsed_hours" "$elapsed_minutes" "$elapsed_remainder"
printf 'Installation completed: %s\n' "$(date -Is)"
exit 0