#!/bin/bash
set -e

echo "== Fixing sequences across all databases =="

for db in $(psql -Atqc "SELECT datname FROM pg_database WHERE datallowconn AND datname NOT IN ('template1','postgres')"); do
  echo "---- DB: $db ----"

  # Generate fix statements
  SQL=$(psql -d "$db" -Atqc "
    SELECT
      'SELECT setval(' ||
      quote_literal(pg_get_serial_sequence(quote_ident(n.nspname)||'.'||quote_ident(c.relname), a.attname)) ||
      ', COALESCE(MAX(' || quote_ident(a.attname) || '), 0) + 1, false) FROM ' ||
      quote_ident(n.nspname)||'.'||quote_ident(c.relname) || ';'
    FROM pg_class c
    JOIN pg_namespace n ON n.oid = c.relnamespace
    JOIN pg_attribute a ON a.attrelid = c.oid
    WHERE c.relkind = 'r'
      AND a.attnum > 0
      AND NOT a.attisdropped
      AND pg_get_serial_sequence(quote_ident(n.nspname)||'.'||quote_ident(c.relname), a.attname) IS NOT NULL;
  ")

  if [ -z "$SQL" ]; then
    echo "No sequences found in $db"
    continue
  fi

  echo "Fixing sequences in $db..."

  # Execute generated statements
  echo "$SQL" | psql -d "$db"

done

echo "== Done fixing sequences =="