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

database="${POSTGRES_DB:-ludarium}"
database_user="${POSTGRES_USER:-ludarium}"
if [[ ! "$database" =~ ^[A-Za-z_][A-Za-z0-9_]*$ ]]; then
  echo "PostgreSQL collation repair requires a simple validated database identifier." >&2
  exit 1
fi
psql_base=(psql -v ON_ERROR_STOP=1 -U "$database_user" -d "$database")

versions="$("${psql_base[@]}" -At -F '|' -c \
  "select coalesce(datcollversion,''),coalesce(pg_database_collation_actual_version(oid),'') from pg_database where datname=current_database()")"
IFS='|' read -r stored_version actual_version <<< "$versions"

if [[ -z "$actual_version" || "$stored_version" == "$actual_version" ]]; then
  exit 0
fi

printf 'PostgreSQL collation drift detected for %s: stored=%s actual=%s\n' \
  "$database" "${stored_version:-<unversioned>}" "$actual_version"

has_platform_definitions="$("${psql_base[@]}" -At -c \
  "select to_regclass('public.platform_definitions') is not null")"
if [[ "$has_platform_definitions" == "t" ]]; then
  unsafe_duplicates="$("${psql_base[@]}" -At -c "
    with duplicate_ids as (
      select id from platform_definitions group by id having count(*) > 1
    ), variants as (
      select p.id,
        count(distinct jsonb_build_object(
          'custom',p.custom,'enabled',p.enabled,'version',p.version,
          'data',p.data - 'updatedAt')) as semantic_variants,
        bool_or(p.custom) as contains_custom
      from platform_definitions p join duplicate_ids d using(id)
      group by p.id
    )
    select count(*) from variants where contains_custom or semantic_variants <> 1")"
  if [[ "$unsafe_duplicates" != "0" ]]; then
    echo "Collation repair found ambiguous or custom platform duplicates; refusing automatic data changes." >&2
    exit 1
  fi

  removed_duplicates="$("${psql_base[@]}" -At -c "
    with ranked as (
      select ctid,row_number() over(partition by id order by updated_at desc,ctid desc) as ordinal
      from platform_definitions
    ), removed as (
      delete from platform_definitions p using ranked r
      where p.ctid=r.ctid and r.ordinal > 1 returning 1
    )
    select count(*) from removed")"
  if [[ "$removed_duplicates" != "0" ]]; then
    printf 'Removed %s semantically identical built-in platform duplicate(s) before reindex.\n' "$removed_duplicates"
  fi
fi

"${psql_base[@]}" -c "REINDEX DATABASE \"$database\"" >/dev/null
if [[ -z "$stored_version" ]]; then
  "${psql_base[@]}" -c "
    update pg_database
    set datcollversion=pg_database_collation_actual_version(oid)
    where datname=current_database() and datcollversion is null" >/dev/null
else
  "${psql_base[@]}" -c "ALTER DATABASE \"$database\" REFRESH COLLATION VERSION" >/dev/null
fi

refreshed_version="$("${psql_base[@]}" -At -c \
  "select coalesce(datcollversion,'') from pg_database where datname=current_database()")"
if [[ "$refreshed_version" != "$actual_version" ]]; then
  echo "PostgreSQL collation version did not refresh to the runtime version." >&2
  exit 1
fi
printf 'PostgreSQL collation indexes rebuilt and version refreshed to %s.\n' "$refreshed_version"