sql.ts

// Utilities
type TrimStart<String extends string> = String extends ` ${infer R}` ? TrimStart<R> : String;
type TrimEnd<String extends string> = String extends `${infer R} ` ? TrimEnd<R> : String;
type Trim<String extends string> = TrimEnd<TrimStart<String>>
type Head<Array extends any[]> = Array[0]
type Tail<Array extends any[]> =
    ((...a: Array) => void) extends (h: any, ...rest: infer Tail) => void ? Tail : never;
type MergeArrayOfObjects<T extends object[]> = T[1] extends undefined
    ? Head<T>
    : Head<T> & MergeArrayOfObjects<Tail<T>>;

type ParseCreateTableStatement<Text> = Text extends `CREATE ${| "TEMP "
    | "TEMPORARY "
    | ""}TABLE ${"IF NOT EXISTS" | ""} ${infer SchemaAndName} ${infer Rest}`
    ? Trim<SchemaAndName> extends `${infer Schema}.${infer Name} ${infer Rest}`
    ? { schema: Schema; name: Name; rest: Rest }
    : { schema: ""; name: SchemaAndName; rest: Rest }
    : never;

type ParseCreateTableColumnStatement<Text> =
    Text extends `${infer Column},${infer Rest}`
    ? [
        ParseColumnDefinition<Column>,
        ...ParseCreateTableColumnStatement<Trim<Rest>>
    ]
    : [ParseColumnDefinition<Text>];

type SQLTypes = {
    NULL: null;
    INTEGER: number;
    REAL: number;
    TEXT: string;
    BLOB: string;
};


type ParseColumnType<Type> = Type extends keyof SQLTypes
    ? SQLTypes[Type]
    : unknown;
type ParseColumnDefinition<Column> =
    Column extends `${infer Name} ${infer TypeName}`
    ? { [V in Name]: ParseColumnType<TypeName> }
    : never;

type ParseCreateStatement<
    Text extends string,
    CreateTableStatement = ParseCreateTableStatement<Text>
> = CreateTableStatement extends never
    ? never
    : {
        table: Omit<CreateTableStatement, "rest">;
        shape: "rest" extends keyof CreateTableStatement
        ? CreateTableStatement["rest"] extends `(${infer ColumnStatement})`
        ? MergeArrayOfObjects<ParseCreateTableColumnStatement<ColumnStatement>>
        : never
        : never;
    };

const QUERY = "CREATE TABLE IF NOT EXISTS BOZO (X NULL, Y INTEGER, Z INTEGER)";

type Bozo = ParseCreateStatement<typeof QUERY>;
type BozoResult = Bozo["shape"];


const a: BozoResult = {
    X: null,
    Y: 10,
    Z: 10
};

console.log(a);