import {
    DSQL_DatabaseSchemaType,
    DSQL_MARIADB_SHOW_INDEXES_TYPE,
    DSQL_MYSQL_FOREIGN_KEYS_Type,
    DSQL_TableSchemaType,
} from "../../types";
import createTableHandleTableRecord from "./create-table-handle-table-record";
import { DSQL_DATASQUIREL_USER_DATABASES } from "../../types/dsql";
import _ from "lodash";
import dbHandler from "../../functions/backend/dbHandler";

type Params = {
    dbFullName: string;
    tableName: string;
    tableSchema: DSQL_TableSchemaType;
    dbSchema: DSQL_DatabaseSchemaType;
    recordedDbEntry?: DSQL_DATASQUIREL_USER_DATABASES;
    isMain?: boolean;
};

/**
 * # Update table function
 */
export default async function updateTableInit({
    dbFullName,
    tableName,
    tableSchema,
    recordedDbEntry,
    isMain,
}: Params) {
    /**
     * @description Grab Table Record
     */
    if (!recordedDbEntry && !isMain) {
        throw new Error("Recorded Db entry not found!");
    }

    let tableID = await createTableHandleTableRecord({
        recordedDbEntry,
        tableSchema,
        update: true,
        isMain,
    });

    if (!tableID && !isMain) {
        throw new Error("Recorded Table entry not found!");
    }

    /**
     * Handle Table Default Collation
     *
     * @description Update Column Collation
     */
    if (tableSchema.collation) {
        try {
            const existingCollation = (await dbHandler({
                query: `SHOW TABLE STATUS LIKE '${tableName}'`,
                config: { database: dbFullName },
            })) as any[];

            const existingCollationStr = existingCollation?.[0].Collation;

            if (existingCollationStr !== tableSchema.collation) {
                await dbHandler({
                    query: `ALTER TABLE \`${dbFullName}\`.\`${tableName}\` CONVERT TO CHARACTER SET utf8mb4 COLLATE ${tableSchema.collation}`,
                });
            }
        } catch (error) {}
    }

    /**
     * Drop All Foreign Keys
     * ===================================================
     * @description Find all existing foreign keys and drop
     * them
     */
    const allForeignKeys = (await dbHandler({
        query: `SELECT CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_SCHEMA = '${dbFullName}' AND TABLE_NAME='${tableName}' AND CONSTRAINT_TYPE='FOREIGN KEY'`,
    })) as DSQL_MYSQL_FOREIGN_KEYS_Type[] | null;

    if (allForeignKeys?.[0]) {
        let dropFkSQL = `ALTER TABLE \`${dbFullName}\`.\`${tableName}\``;

        for (let c = 0; c < allForeignKeys.length; c++) {
            const { CONSTRAINT_NAME } = allForeignKeys[c];

            if (CONSTRAINT_NAME.match(/PRIMARY/)) continue;

            dropFkSQL += ` DROP FOREIGN KEY \`${CONSTRAINT_NAME}\`,`;
        }

        const finalSQL = dropFkSQL.endsWith(",")
            ? dropFkSQL.replace(/\,$/, "")
            : undefined;

        if (finalSQL) {
            await dbHandler({
                query: finalSQL,
            });
        }
    }

    /**
     * Drop All Unique Constraints
     * ===================================================
     * @description Find all existing unique field constraints
     * and remove them
     */
    const allUniqueConstraints = (await dbHandler({
        query: `SELECT CONSTRAINT_NAME FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE CONSTRAINT_SCHEMA = '${dbFullName}' AND TABLE_NAME='${tableName}' AND CONSTRAINT_TYPE='UNIQUE'`,
    })) as DSQL_MYSQL_FOREIGN_KEYS_Type[] | null;

    if (allUniqueConstraints?.[0]) {
        let dropIndxSQL = `ALTER TABLE \`${dbFullName}\`.\`${tableName}\``;

        for (let c = 0; c < allUniqueConstraints.length; c++) {
            const { CONSTRAINT_NAME } = allUniqueConstraints[c];

            dropIndxSQL += ` DROP INDEX ${CONSTRAINT_NAME},`;
        }

        const finalDropIndxSQL = dropIndxSQL.endsWith(",")
            ? dropIndxSQL.replace(/\,$/, "")
            : undefined;

        if (finalDropIndxSQL) {
            await dbHandler({
                query: finalDropIndxSQL,
            });
        }
    }

    /**
     * Drop All Indexes
     * ===================================================
     * @description Find all existing foreign keys and drop
     * them
     */
    const allMariadbIndexes = (await dbHandler({
        query: `SHOW INDEXES FROM \`${dbFullName}\`.\`${tableName}\``,
    })) as DSQL_MARIADB_SHOW_INDEXES_TYPE[] | null;

    if (allMariadbIndexes?.[0]) {
        let dropIndxs = `ALTER TABLE \`${dbFullName}\`.\`${tableName}\``;

        for (let c = 0; c < allMariadbIndexes.length; c++) {
            const { Key_name } = allMariadbIndexes[c];

            if (Key_name.match(/PRIMARY/)) continue;

            dropIndxs += ` DROP INDEX \`${Key_name}\`,`;
        }

        const finalDropIndxs = dropIndxs.endsWith(",")
            ? dropIndxs.replace(/\,$/, "")
            : undefined;

        if (finalDropIndxs) {
            const dropFkRes = await dbHandler({
                query: finalDropIndxs,
            });
        }
    }

    return { tableID };
}