import { DefaultNamingStrategy, NamingStrategyInterface, Table } from 'typeorm';
import { snakeCase } from 'typeorm/util/StringUtils';

/**
 * Maps camelCase entity properties onto the snake_case columns used by the
 * SQL migrations. Explicit `name` options on @Column/@JoinColumn still win,
 * so existing decorators keep working unchanged.
 */
export class SnakeNamingStrategy
  extends DefaultNamingStrategy
  implements NamingStrategyInterface
{
  tableName(className: string, customName?: string): string {
    return customName || snakeCase(className);
  }

  columnName(
    propertyName: string,
    customName: string | undefined,
    embeddedPrefixes: string[],
  ): string {
    return (
      snakeCase(embeddedPrefixes.concat('').join('_')) +
      (customName || snakeCase(propertyName))
    );
  }

  relationName(propertyName: string): string {
    return snakeCase(propertyName);
  }

  joinColumnName(relationName: string, referencedColumnName: string): string {
    return snakeCase(`${relationName}_${referencedColumnName}`);
  }

  joinTableName(
    firstTableName: string,
    secondTableName: string,
    firstPropertyName: string,
  ): string {
    return snakeCase(
      `${firstTableName}_${firstPropertyName.replace(/\./gi, '_')}_${secondTableName}`,
    );
  }

  joinTableColumnName(
    tableName: string,
    propertyName: string,
    columnName?: string,
  ): string {
    return snakeCase(`${tableName}_${columnName || propertyName}`);
  }

  classTableInheritanceParentColumnName(
    parentTableName: any,
    parentTableIdPropertyName: any,
  ): string {
    return snakeCase(`${parentTableName}_${parentTableIdPropertyName}`);
  }

  eagerJoinRelationAlias(alias: string, propertyPath: string): string {
    return `${alias}__${propertyPath.replace('.', '_')}`;
  }

  indexName(tableOrName: Table | string, columns: string[]): string {
    const table =
      typeof tableOrName === 'string' ? tableOrName : tableOrName.name;
    return `idx_${table}_${columns.map((c) => snakeCase(c)).join('_')}`;
  }
}