import {
    DSQL_IndexSchemaType,
    DSQL_MYSQL_SHOW_INDEXES_Type,
} from "../../types";
import grabDSQLSchemaIndexComment from "../utils/grab-dsql-schema-index-comment";
import dbHandler from "../../functions/backend/dbHandler";
import AppData from "../../data/app-data";

type Param = {
    tableName: string;
    dbFullName: string;
    indexes: DSQL_IndexSchemaType[];
};

/**
 * Handle DATASQUIREL Table Indexes
 * ===================================================
 * @description Iterate through each datasquirel schema
 * table index(if available), and perform operations
 */
export default async function handleIndexescreateDbFromSchema({
    dbFullName,
    tableName,
    indexes,
}: Param) {
    /**
     * Handle MYSQL Table Indexes
     * ===================================================
     * @description Iterate through each table index(if available)
     * and perform operations
     */
    const allExistingIndexes = (await dbHandler({
        query: `SHOW INDEXES FROM \`${dbFullName}\`.\`${tableName}\` WHERE Index_comment LIKE '%${AppData["IndexComment"]}%'`,
    })) as DSQL_MYSQL_SHOW_INDEXES_Type[] | null;

    if (allExistingIndexes) {
        for (let f = 0; f < allExistingIndexes.length; f++) {
            const { Key_name } = allExistingIndexes[f];

            try {
                const existingKeyInSchema = indexes?.find(
                    (indexObject) => indexObject.alias === Key_name
                );
                if (!existingKeyInSchema)
                    throw new Error(
                        `This Index(${Key_name}) Has been Deleted!`
                    );
            } catch (error) {
                /**
                 * @description Drop Index: This happens when the MYSQL index is not
                 * present in the datasquirel DB schema
                 */
                await dbHandler({
                    query: `ALTER TABLE \`${dbFullName}\`.\`${tableName}\` DROP INDEX \`${Key_name}\``,
                });
            }
        }
    }

    /**
     * # Re-Add New Indexes
     */
    for (let g = 0; g < indexes.length; g++) {
        const { indexType, indexName, indexTableFields, alias } = indexes[g];

        if (!alias?.match(/./)) continue;

        const queryString = `CREATE${
            indexType == "full_text"
                ? " FULLTEXT"
                : indexType == "vector"
                ? " VECTOR"
                : ""
        } INDEX \`${alias}\` ON \`${dbFullName}\`.\`${tableName}\`(${indexTableFields
            ?.map((nm) => nm.value)
            .map((nm) => `\`${nm}\``)
            .join(",")}) COMMENT '${AppData["IndexComment"]} ${indexName}'`;

        const addIndex = await dbHandler({ query: queryString });
    }
}