import {TableRef, QuerySource} from '../types.ts'

/**
 * Query builder mixin for queries that resolve table names.
 */
export class TableRefBuilder {
    /**
     * Resolve the raw table name to a table reference.
     * @param {string} from
     * @return TableRef
     */
    resolve_table_name(from: string): TableRef {
        const parts = from.split('.')
        const ref: any = {}
        if ( parts.length > 1 ) {
            ref.database = parts[0]
            ref.table = parts[1]
        } else {
            ref.table = parts[0]
        }

        const alias_parts = ref.table.split(/\s+/)
        if ( alias_parts.length > 1 ) {
            ref.table = alias_parts[0]
            ref.alias = alias_parts[1]
        }

        return ref as TableRef
    }

    /**
     * Serialize a table ref to its raw SQL form.
     * @param {TableRef} ref
     * @return string
     */
    serialize_table_ref(ref: TableRef): string {
        return `${ref.database ? ref.database+'.' : ''}${ref.table}${ref.alias ? ' '+ref.alias : ''}`
    }

    /**
     * Convert a query source and alias to a table ref.
     * @param {QuerySource} source
     * @param {string} [alias]
     * @return TableRef
     */
    source_alias_to_table_ref(source: QuerySource, alias?: string) {
        let string = ''
        if ( typeof source === 'string' ) {
            string = source
            if ( typeof alias === 'string' ) string += ` ${alias}`
        }
        else if ( typeof source === 'object' ) {
            string = `${source.ref}`
            if ( source.alias ) string += ` ${source.alias}`
            else if ( typeof alias === 'string' ) string += ` ${alias}`
        }

        return this.resolve_table_name(string)
    }
}