// ============================================================
// Column Data Types
// ============================================================
export type TClickhouseColumnType =
  | 'String'
  | 'UInt8' | 'UInt16' | 'UInt32' | 'UInt64'
  | 'Int8' | 'Int16' | 'Int32' | 'Int64'
  | 'Float32' | 'Float64'
  | 'Bool'
  | 'Date' | 'Date32'
  | 'DateTime' | 'DateTime64'
  | 'UUID'
  | 'IPv4' | 'IPv6'
  | (string & {}); // allow arbitrary ClickHouse types like "DateTime64(3, 'Europe/Berlin')"

// ============================================================
// Engine Configuration
// ============================================================
export type TClickhouseEngine =
  | 'MergeTree'
  | 'ReplacingMergeTree'
  | 'SummingMergeTree'
  | 'AggregatingMergeTree'
  | 'CollapsingMergeTree'
  | 'VersionedCollapsingMergeTree';

export interface IEngineConfig {
  engine: TClickhouseEngine;
  /** For ReplacingMergeTree: the version column name */
  versionColumn?: string;
  /** For CollapsingMergeTree: the sign column name */
  signColumn?: string;
}

// ============================================================
// Column Definition
// ============================================================
export interface IColumnDefinition {
  name: string;
  type: TClickhouseColumnType;
  defaultExpression?: string;
  codec?: string;
}

// ============================================================
// Table Options
// ============================================================
export interface IClickhouseTableOptions<T = any> {
  tableName: string;
  database?: string;
  engine?: IEngineConfig;
  orderBy: (keyof T & string) | (keyof T & string)[];
  partitionBy?: string;
  primaryKey?: (keyof T & string) | (keyof T & string)[];
  ttl?: {
    column: keyof T & string;
    interval: string; // e.g., '30 DAY', '1 MONTH'
  };
  columns?: IColumnDefinition[];
  /** Enable auto-schema evolution (add columns from data). Default: true */
  autoSchemaEvolution?: boolean;
  /** Data retention in days (shorthand for ttl). If ttl is set, this is ignored. */
  retainDataForDays?: number;
}

// ============================================================
// Column Info from system.columns
// ============================================================
export interface IColumnInfo {
  database: string;
  table: string;
  name: string;
  type: string;
  position: string;
  default_kind: string;
  default_expression: string;
  data_compressed_bytes: string;
  data_uncompressed_bytes: string;
  marks_bytes: string;
  comment: string;
  is_in_partition_key: 0 | 1;
  is_in_sorting_key: 0 | 1;
  is_in_primary_key: 0 | 1;
  is_in_sampling_key: 0 | 1;
  compression_codec: string;
}

// ============================================================
// Comparison Operators for Query Builder
// ============================================================
export type TComparisonOperator =
  | '='
  | '!='
  | '>'
  | '>='
  | '<'
  | '<='
  | 'LIKE'
  | 'NOT LIKE'
  | 'IN'
  | 'NOT IN'
  | 'BETWEEN';

// ============================================================
// Value Escaping (SQL Injection Prevention)
// ============================================================
export function escapeClickhouseValue(value: any): string {
  if (value === null || value === undefined) return 'NULL';
  if (typeof value === 'number') return String(value);
  if (typeof value === 'boolean') return value ? '1' : '0';
  if (value instanceof Date) return `'${value.toISOString().replace('T', ' ').replace('Z', '')}'`;
  if (Array.isArray(value)) {
    return `(${value.map(escapeClickhouseValue).join(', ')})`;
  }
  // String: escape single quotes and backslashes
  return `'${String(value).replace(/\\/g, '\\\\').replace(/'/g, "\\'")}'`;
}

// ============================================================
// ClickHouse Type Detection from JS Values
// ============================================================
export function detectClickhouseType(value: any): TClickhouseColumnType | null {
  if (value === null || value === undefined) return null;
  if (typeof value === 'string') return 'String';
  if (typeof value === 'number') return 'Float64';
  if (typeof value === 'boolean') return 'UInt8';
  if (value instanceof Array) {
    if (value.length === 0) return null;
    const elementType = detectClickhouseType(value[0]);
    if (!elementType) return null;
    return `Array(${elementType})` as TClickhouseColumnType;
  }
  return null;
}