import _ from "lodash";
import { AppData } from "../../data/app-data";
import handleDBSchemaTable from "./handle-db-schema-table";
import getExistingTablesFromTablesManagerTable from "./get-existing-tables-from-tables-manager-table";
import MariaDBQuoteGen from "./mariadb-quote-gen";
import runSchemaQuery, { querySchemaRows } from "./run-schema-query";
import schemaCondition from "./schema-condition";
import { removeDbManagerTable } from "./upsert-db-manager-table";
export default async function handleDBSchemaTables(params) {
    const { db_schema, config } = params;
    /**
     * Grab Tables that have been recorded in the Schema
     * Manager Table
     */
    const existing_schema_tables = await getExistingTablesFromTablesManagerTable(params);
    const schemaCond = schemaCondition(config);
    const existing_live_tables = await querySchemaRows({
        query: `SELECT TABLE_NAME FROM information_schema.TABLES WHERE ${schemaCond.where} AND TABLE_TYPE = 'BASE TABLE' AND TABLE_NAME != ?`,
        values: [...schemaCond.values, AppData["DbSchemaManagerTableName"]],
        config,
    });
    for (let i = 0; i < db_schema.tables.length; i++) {
        const table = db_schema.tables[i];
        if (!table)
            continue;
        const existing_table = existing_schema_tables.find((t) => t == table.tableName);
        const existing_live_table = existing_live_tables.find((t) => t.TABLE_NAME == table.tableName);
        await handleDBSchemaTable({
            ...params,
            table,
            db_manager_table_name: existing_table,
            existing_live_table,
        });
    }
    /**
     * Drop tables tracked by the manager but no longer in the schema.
     * Skip drops when remaining schema tables still reference the table via FK
     * (e.g. external tables like `users` that are referenced but not managed).
     */
    const schemaTableNames = db_schema.tables.map((t) => t.tableName);
    const tablesToDrop = _.uniq(existing_schema_tables.filter((tableName) => Boolean(tableName) && !schemaTableNames.includes(tableName)));
    if (tablesToDrop.length === 0) {
        return;
    }
    const fkRows = await querySchemaRows({
        query: `SELECT TABLE_NAME, REFERENCED_TABLE_NAME FROM information_schema.KEY_COLUMN_USAGE WHERE ${schemaCond.where} AND REFERENCED_TABLE_NAME IS NOT NULL`,
        values: schemaCond.values,
        config,
    });
    const referencedByRemaining = new Map();
    for (const row of fkRows) {
        if (!row.REFERENCED_TABLE_NAME ||
            !tablesToDrop.includes(row.REFERENCED_TABLE_NAME)) {
            continue;
        }
        // Referenced by a table we are keeping
        if (schemaTableNames.includes(row.TABLE_NAME) ||
            !tablesToDrop.includes(row.TABLE_NAME)) {
            const list = referencedByRemaining.get(row.REFERENCED_TABLE_NAME) || [];
            if (!list.includes(row.TABLE_NAME)) {
                list.push(row.TABLE_NAME);
            }
            referencedByRemaining.set(row.REFERENCED_TABLE_NAME, list);
        }
    }
    const safeToDrop = [];
    for (const tableName of tablesToDrop) {
        const dependents = referencedByRemaining.get(tableName);
        if (dependents && dependents.length > 0) {
            console.warn(`Skipping drop of table \`${tableName}\`: still referenced by ${dependents.join(", ")}. Removing from schema manager tracking only.`);
            await removeDbManagerTable({ tableName, config });
            continue;
        }
        safeToDrop.push(tableName);
    }
    if (safeToDrop.length === 0) {
        return;
    }
    await runSchemaQuery({ query: `SET FOREIGN_KEY_CHECKS = 0`, config });
    try {
        for (const tableName of safeToDrop) {
            console.log(`Dropping table: ${tableName}`);
            await runSchemaQuery({
                query: `DROP TABLE IF EXISTS ${MariaDBQuoteGen(tableName)}`,
                config,
            });
            await removeDbManagerTable({ tableName, config });
        }
    }
    finally {
        await runSchemaQuery({ query: `SET FOREIGN_KEY_CHECKS = 1`, config });
    }
}