generate-config.ts

import { NotSupported, ObjectType } from '@hasura/ndc-sdk-typescript';
import { Configuration } from './src';
import * as duckdb from 'duckdb';
import * as fs from 'fs';
import { promisify } from "util";
const writeFile = promisify(fs.writeFile);
const readFile = promisify(fs.readFile);
let HASURA_CONFIGURATION_DIRECTORY = process.env["HASURA_CONFIGURATION_DIRECTORY"] as string | undefined;
if (HASURA_CONFIGURATION_DIRECTORY === undefined || HASURA_CONFIGURATION_DIRECTORY.length === 0){
    HASURA_CONFIGURATION_DIRECTORY = ".";
}
const DUCKDB_URL = process.env["DUCKDB_URL"] as string;
const db = new duckdb.Database(DUCKDB_URL);
const con = db.connect();

const determineType = (t: string): string => {
    switch (t) {
        case "BIGINT":
            return "BigInt";
        case "BIT":
            return "String";
        case "BOOLEAN":
            return "Boolean";
        case "BLOB":
            return "String";
        case "DATE":
            return "String";
        case "DOUBLE":
            return "Float";
        case "HUGEINT":
            return "HugeInt";
        case "INTEGER":
            return "Int";
        case "INTERVAL":
            return "String";
        case "REAL":
            return "Float";
        case "FLOAT":
            return "Float";
        case "SMALLINT":
            return "Int";
        case "TIME":
            return "String";
        case "TIMESTAMP":
            return "Timestamp";
        case "TIMESTAMP WITH TIME ZONE":
            return "TimestampTz";
        case "TINYINT":
            return "Int";
        case "UBIGINT":
            return "UBigInt";
        case "UHUGEINT":
            return "UHugeInt"
        case "UINTEGER":
            return "Int";
        case "USMALLINT":
            return "Int";
        case "UTINYINT":
            return "Int";
        case "UUID":
            return "String";
        case "VARCHAR":
            return "String";
        default:
            if (t.startsWith("DECIMAL") || t.startsWith("NUMERIC")){
                return "BigDecimal";
            }
            throw new NotSupported("Unsupported type", {});
    }
};

async function queryAll(con: any, query: any): Promise<any[]> {
    return new Promise((resolve, reject) => {
        con.all(query, function(err: any, res: any){
            if (err){
                reject(err);
            } else {
                resolve(res);
            }
        })
    })
};

async function main() {
    const tableNames: string[] = [];
    const tableAliases: {[k: string]: string} = {};
    const objectTypes: { [k: string]: ObjectType } = {};
    const tables = await queryAll(con, "SHOW ALL TABLES");

    // Get table comments
    const tableComments = await queryAll(con, `
    SELECT table_name, comment 
    FROM duckdb_tables() 
    WHERE schema_name = 'main'
    `);

    // Create a map of table comments for easier lookup
    const tableCommentMap = new Map(
    tableComments.map(row => [row.table_name, row.comment || "No description available"])
    );
    // Get all column comments upfront
    const columnComments = await queryAll(con, `
    SELECT table_name, column_name, comment 
    FROM duckdb_columns() 
    WHERE schema_name = 'main'
    `);
    // Create a nested map for column comments: table_name -> column_name -> comment
    const columnCommentMap = new Map();
    for (const row of columnComments) {
    if (!columnCommentMap.has(row.table_name)) {
        columnCommentMap.set(row.table_name, new Map());
    }
    columnCommentMap.get(row.table_name).set(row.column_name, row.comment || "No description available");
    }

    for (let table of tables){
        const tableName = table.name;
        const aliasName = `${table.database}.${table.schema}.${table.name}`;
        tableNames.push(tableName);
        tableAliases[tableName] = aliasName;
        if (!objectTypes[tableName]){
            objectTypes[tableName] = {
                fields: {},
                description: tableCommentMap.get(tableName) || "No Description Available"
            };
        }
        for (let i = 0; i < table.column_names.length; i++){
            const columnName = table.column_names[i];
            objectTypes[tableName]["fields"][columnName] = {
                type: {
                    type: "nullable",
                    underlying_type: {
                      type: "named",
                      name: determineType(table.column_types[i]),
                    },
                },
                description: columnCommentMap.get(tableName)?.get(columnName) || "No description available"
            }
        }
    }
    const res: Configuration = {
        config: {
            collection_names: tableNames,
            collection_aliases: tableAliases,
            object_types: objectTypes,
            functions: [],
            procedures: []
        }
    };
    const jsonString = JSON.stringify(res, null, 4);
    let filePath = `${HASURA_CONFIGURATION_DIRECTORY}/config.json`;
    try {
        const existingData = await readFile(filePath, 'utf8');
        if (existingData !== jsonString) {
            await writeFile(filePath, jsonString);
            console.log('File updated.');
        } else {
            console.log('No changes detected. File not updated.');
        }
    } catch (error) {
        await writeFile(filePath, jsonString);
        console.log('New file written.');
    }
};

main();