import {EscapedValue, isWhereClause, isWhereGroup, WhereStatement} from '../types.ts'
import {escape, SQLWhereOperator, WherePreOperator} from '../types.ts'
import {WhereBuilderFunction} from "./Select.ts";

export class WhereBuilder {
    protected _wheres: WhereStatement[] = []

    get where_items() {
        return this._wheres
    }

    wheres_to_sql(wheres?: WhereStatement[], level = 0): string {
        const indent = Array(level * 2).fill(' ').join('')
        let statements = []
        for ( const where of wheres || this._wheres ) {
            if ( isWhereClause(where) ) {
                statements.push(`${indent}${statements.length < 1 ? '' : where.preop + ' '}${where.field} ${where.operator} ${where.operand}`)
            } else if ( isWhereGroup(where) ) {
                statements.push(`${indent}${statements.length < 1 ? '' : where.preop + ' '}(\n${this.wheres_to_sql(where.items, level + 1)}\n${indent})`)
            }
        }

        return statements.filter(Boolean).join('\n')
    }

    private _createWhere(preop: WherePreOperator, field: string | WhereBuilderFunction, operator?: SQLWhereOperator, operand?: any) {
        if ( typeof field === 'function' ) {
            const where_builder = new WhereBuilder()
            field(where_builder)
            this._wheres.push({
                preop,
                items: where_builder.where_items,
            })
        } else if ( field && operator && typeof operand !== 'undefined' ) {
            this._wheres.push({
                field, operator, operand: escape(operand), preop
            })
        }
    }

    where(field: string | WhereBuilderFunction, operator?: SQLWhereOperator, operand?: any) {
        this._createWhere('AND', field, operator, operand)
        return this
    }

    whereIn(field: string, values: EscapedValue) {
        this._wheres.push({
            field,
            operator: 'IN',
            operand: escape(values),
            preop: 'AND',
        })
        return this
    }

    whereNot(field: string | WhereBuilderFunction, operator?: SQLWhereOperator, operand?: EscapedValue) {
        this._createWhere('AND NOT', field, operator, operand)
        return this
    }

    whereNotIn(field: string, values: EscapedValue) {
        this._wheres.push({
            field,
            operator: 'NOT IN',
            operand: escape(values),
            preop: 'AND'
        })
        return this
    }

    orWhere(field: string | WhereBuilderFunction, operator?: SQLWhereOperator, operand?: EscapedValue) {
        this._createWhere('OR', field, operator, operand)
        return this
    }

    orWhereNot(field: string | WhereBuilderFunction, operator?: SQLWhereOperator, operand?: EscapedValue) {
        this._createWhere('OR NOT', field, operator, operand)
        return this
    }

    orWhereIn(field: string, values: EscapedValue) {
        this._wheres.push({
            field,
            operator: 'IN',
            operand: escape(values),
            preop: 'OR',
        })
        return this
    }

    orWhereNotIn(field: string, values: EscapedValue) {
        this._wheres.push({
            field,
            operator: 'NOT IN',
            operand: escape(values),
            preop: 'OR',
        })
        return this
    }
}