import {JoinOperator, TableRef, WhereStatement} from '../../types.ts'
import {TableRefBuilder} from '../TableRefBuilder.ts'
import {applyMixins} from '../../../../../lib/src/support/mixins.ts'
import {WhereBuilder} from '../WhereBuilder.ts'
import {Scope} from '../../Scope.ts'

/**
 * Query builder class which builds JOIN clauses.
 */
export class Join {
    /**
     * The join operator to use in the SQL.
     * @type JoinOperator
     */
    public readonly operator: JoinOperator = 'JOIN'

    /**
     * The where statements applied to this join. (i.e. JOIN table ON ...)
     * @type Array<WhereStatement>
     */
    protected _wheres: WhereStatement[] = []

    /**
     * The scopes applied to this join.
     * @type Array<Scope>
     */
    protected _scopes: Scope[] = []

    constructor(
        /**
         * The table ref being joined.
         * @type TableRef
         */
        public readonly table_ref: TableRef
    ) {}

    /**
     * Serialize the join to raw SQL.
     * @param level
     */
    sql(level = 0): string {
        const indent = Array(level * 2).fill(' ').join('')
        return [
            `${this.operator} ${this.serialize_table_ref(this.table_ref)}`,
            ...[this._wheres.length > 0 ? ['ON'] : []],
            this.wheres_to_sql(this._wheres, level),
        ].filter(Boolean).join(`\n${indent}`)
    }
}

export interface Join extends TableRefBuilder, WhereBuilder {}
applyMixins(Join, [TableRefBuilder, WhereBuilder])