/**
 * Core interfaces for the Squongo SQL to MongoDB compiler
 */
/**
 * Represents an abstract command in the intermediate representation
 */
export interface Command {
    type: string;
    [key: string]: any;
}
/**
 * Base interface for all SQL statements
 */
export interface SqlStatement {
    type: string;
}
/**
 * Represents a SQL SELECT statement
 */
export interface SelectStatement extends SqlStatement {
    type: 'SELECT';
    fields: string[];
    from: string;
    where?: WhereClause;
    limit?: number;
    offset?: number;
    orderBy?: OrderByClause[];
}
/**
 * Represents a SQL INSERT statement
 */
export interface InsertStatement extends SqlStatement {
    type: 'INSERT';
    into: string;
    columns: string[];
    values: any[][];
}
/**
 * Represents a SQL UPDATE statement
 */
export interface UpdateStatement extends SqlStatement {
    type: 'UPDATE';
    table: string;
    set: {
        [key: string]: any;
    };
    where?: WhereClause;
}
/**
 * Represents a SQL DELETE statement
 */
export interface DeleteStatement extends SqlStatement {
    type: 'DELETE';
    from: string;
    where?: WhereClause;
}
/**
 * Represents an ORDER BY clause
 */
export interface OrderByClause {
    field: string;
    direction: 'ASC' | 'DESC';
}
/**
 * Represents a WHERE clause condition
 */
export interface WhereClause {
    operator: 'AND' | 'OR';
    conditions: Condition[];
}
/**
 * Represents a condition in a WHERE clause
 */
export interface Condition {
    type: 'COMPARISON' | 'LOGICAL' | 'IN' | 'BETWEEN' | 'LIKE' | 'NULL';
    field?: string;
    operator?: string;
    value?: any;
    left?: Condition;
    right?: Condition;
    values?: any[];
    not?: boolean;
}
/**
 * MongoDB command executor interface
 */
export interface CommandExecutor {
    execute(commands: Command[]): Promise<any>;
}
/**
 * SQL Parser interface
 */
export interface SqlParser {
    parse(sql: string): SqlStatement;
}
/**
 * SQL Compiler interface - converts SQL AST to MongoDB commands
 */
export interface SqlCompiler {
    compile(statement: SqlStatement): Command[];
}
/**
 * Main QueryLeaf interface
 */
export interface QueryLeaf {
    execute(sql: string): Promise<any>;
    parse(sql: string): SqlStatement;
    compile(statement: SqlStatement): Command[];
    getExecutor?(): any;
    close?(): Promise<void>;
}
/**
 * Alias for QueryLeaf (backwards compatibility)
 */
export interface Squongo extends QueryLeaf {
    execute(sql: string): Promise<any>;
    parse(sql: string): SqlStatement;
    compile(statement: SqlStatement): Command[];
}