/**
 * Copyright (c) 2019 mol* contributors, licensed under MIT, See LICENSE file for more info.
 *
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 */

import { transpileMolScript } from './script/mol-script/symbols';
import { parseMolScript } from './language/parser';
import Expression from './language/expression';
import { StructureElement, QueryContext, StructureSelection, Structure, QueryFn } from '../mol-model/structure';
import { compile } from './runtime/query/compiler';

export { Script }

interface Script { expression: string, language: Script.Language }

function Script(expression: string, language: Script.Language): Script {
    return { expression, language }
}

namespace Script {
    export type Language = 'mol-script'

    export function areEqual(a: Script, b: Script) {
        return a.language === b.language && a.expression === b.expression
    }

    export function toExpression(script: Script): Expression {
        switch (script.language) {
            case 'mol-script':
                const parsed = parseMolScript(script.expression)
                if (parsed.length === 0) throw new Error('No query')
                return transpileMolScript(parsed[0])
        }
        throw new Error('unsupported script language')
    }

    export function toQuery(script: Script): QueryFn<StructureSelection> {
        const expression = toExpression(script)
        return compile<StructureSelection>(expression);
    }

    export function toLoci(script: Script, structure: Structure): StructureElement.Loci {
        const query = toQuery(script)
        const result = query(new QueryContext(structure))
        return StructureSelection.toLoci2(result)
    }
}