/**
 * Copyright (c) 2017-2022 mol* contributors, licensed under MIT, See LICENSE file for more info.
 *
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 * @author Panagiotis Tourlas <panagiot_tourlov@hotmail.com>
 * @author Koya Sakuma <koya.sakuma.work@gmail.com>
 *
 * Adapted from MolQL project
 */

import * as P from '../../mol-util/monadic-parser';
import { MolScriptBuilder } from '../../mol-script/language/builder';
const B = MolScriptBuilder;
import { Expression } from '../language/expression';
import { KeywordDict, PropertyDict, FunctionDict, OperatorList } from './types';

export function escapeRegExp(s: String) {
    return String(s).replace(/[\\^$*+?.()|[\]{}]/g, '\\$&');
}

// Takes a parser for the prefix operator, and a parser for the base thing being
// parsed, and parses as many occurrences as possible of the prefix operator.
// Note that the parser is created using `P.lazy` because it's recursive. It's
// valid for there to be zero occurrences of the prefix operator.
export function prefix(opParser: P.MonadicParser<any>, nextParser: P.MonadicParser<any>, mapFn: any) {
    const parser: P.MonadicParser<any> = P.MonadicParser.lazy(() => {
        return P.MonadicParser.seq(opParser, parser)
            .map(x => mapFn(...x))
            .or(nextParser);
    });
    return parser;
}

export function prefixRemoveKet(opParser: P.MonadicParser<any>, nextParser: P.MonadicParser<any>, mapFn: any) {
    const parser: P.MonadicParser<any> = P.MonadicParser.lazy(() => {
        return P.MonadicParser.seq(opParser, parser.skip(P.MonadicParser.regexp(/\s*\)/)))
            .map(x => mapFn(...x))
            .or(nextParser);
    });
    return parser;
}


// Ideally this function would be just like `PREFIX` but reordered like
// `P.seq(parser, opParser).or(nextParser)`, but that doesn't work. The
// reason for that is that Parsimmon will get stuck in infinite recursion, since
// the very first rule. Inside `parser` is to match parser again. Alternatively,
// you might think to try `nextParser.or(P.seq(parser, opParser))`, but
// that won't work either because in a call to `.or` (aka `P.alt`), Parsimmon
// takes the first possible match, even if subsequent matches are longer, so the
// parser will never actually look far enough ahead to see the postfix
// operators.
export function postfix(opParser: P.MonadicParser<any>, nextParser: P.MonadicParser<any>, mapFn: any) {
    // Because we can't use recursion like stated above, we just match a flat list
    // of as many occurrences of the postfix operator as possible, then use
    // `.reduce` to manually nest the list.
    //
    // Example:
    //
    // INPUT  :: "4!!!"
    // PARSE  :: [4, "factorial", "factorial", "factorial"]
    // REDUCE :: ["factorial", ["factorial", ["factorial", 4]]]
    return P.MonadicParser.seqMap(
        nextParser,
        opParser.many(),
        (x: any, suffixes: any) =>
            suffixes.reduce((acc: any, x: any) => {
                return mapFn(x, acc);
            }, x)
    );
}

// Takes a parser for all the operators at this precedence level, and a parser
// that parsers everything at the next precedence level, and returns a parser
// that parses as many binary operations as possible, associating them to the
// right. (e.g. 1^2^3 is 1^(2^3) not (1^2)^3)
export function binaryRight(opParser: P.MonadicParser<any>, nextParser: P.MonadicParser<any>, mapFn: any) {
    const parser: P.MonadicParser<any> = P.MonadicParser.lazy(() =>
        nextParser.chain(next =>
            P.MonadicParser.seq(
                opParser,
                P.MonadicParser.of(next),
                parser
            ).map((x) => {
                return x;
            }).or(P.MonadicParser.of(next))
        )
    );
    return parser;
}

// Takes a parser for all the operators at this precedence level, and a parser
// that parsers everything at the next precedence level, and returns a parser
// that parses as many binary operations as possible, associating them to the
// left. (e.g. 1-2-3 is (1-2)-3 not 1-(2-3))
export function binaryLeft(opParser: P.MonadicParser<any>, nextParser: P.MonadicParser<any>, mapFn: any) {
    // We run into a similar problem as with the `POSTFIX` parser above where we
    // can't recurse in the direction we want, so we have to resort to parsing an
    // entire list of operator chunks and then using `.reduce` to manually nest
    // them again.
    //
    // Example:
    //
    // INPUT  :: "1+2+3"
    // PARSE  :: [1, ["+", 2], ["+", 3]]
    // REDUCE :: ["+", ["+", 1, 2], 3]
    return P.MonadicParser.seqMap(
        nextParser,
        P.MonadicParser.seq(opParser, nextParser).many(),
        (first: any, rest: any) => {
            return rest.reduce((acc: any, ch: any) => {
                const [op, another] = ch;
                return mapFn(op, acc, another);
            }, first);
        }
    );
}

/**
 * combine operators of decreasing binding strength
 */
export function combineOperators(opList: any[], rule: P.MonadicParser<any>) {
    const x = opList.reduce(
        (acc, level) => {
            const map = level.isUnsupported ? makeError(`operator '${level.name}' not supported`) : level.map;
            return level.type(level.rule, acc, map);
        },
        rule
    );
    return x;
}

export function infixOp(re: RegExp, group: number = 0) {
    return P.MonadicParser.optWhitespace.then(P.MonadicParser.regexp(re, group).skip(P.MonadicParser.optWhitespace));
}

export function prefixOp(re: RegExp, group: number = 0) {
    return P.MonadicParser.regexp(re, group).skip(P.MonadicParser.optWhitespace);
}

export function prefixOpNoWhiteSpace(re: RegExp, group: number = 0) {
    return P.MonadicParser.regexp(re, group).skip(P.MonadicParser.regexp(/\s*/));
}

export function postfixOp(re: RegExp, group: number = 0) {
    return P.MonadicParser.optWhitespace.then(P.MonadicParser.regexp(re, group));
}

export function ofOp(name: string, short?: string) {
    const op = short ? `${name}|${escapeRegExp(short)}` : name;
    const re = RegExp(`(${op})\\s+([-+]?[0-9]*\\.?[0-9]+)\\s+OF`, 'i');
    return infixOp(re, 2).map(parseFloat);
}

export function makeError(msg: string) {
    return function () {
        throw new Error(msg);
    };
}

export function andExpr(selections: any[]) {
    if (selections.length === 1) {
        return selections[0];
    } else if (selections.length > 1) {
        return B.core.logic.and(selections);
    } else {
        return undefined;
    }
}

export function orExpr(selections: any[]) {
    if (selections.length === 1) {
        return selections[0];
    } else if (selections.length > 1) {
        return B.core.logic.or(selections);
    } else {
        return undefined;
    }
}

export function testExpr(property: any, args: any) {
    if (args && args.op !== undefined && args.val !== undefined) {
        const opArgs = [property, args.val];
        switch (args.op) {
            case '=': return B.core.rel.eq(opArgs);
            case '!=': return B.core.rel.neq(opArgs);
            case '>': return B.core.rel.gr(opArgs);
            case '<': return B.core.rel.lt(opArgs);
            case '>=': return B.core.rel.gre(opArgs);
            case '<=': return B.core.rel.lte(opArgs);
            default: throw new Error(`operator '${args.op}' not supported`);
        }
    } else if (args && args.flags !== undefined) {
        return B.core.flags.hasAny([property, args.flags]);
    } else if (args && args.min !== undefined && args.max !== undefined) {
        return B.core.rel.inRange([property, args.min, args.max]);
    } else if (!Array.isArray(args)) {
        return B.core.rel.eq([property, args]);
    } else if (args.length > 1) {
        return B.core.set.has([B.core.type.set(args), property]);
    } else {
        return B.core.rel.eq([property, args[0]]);
    }
}

export function invertExpr(selection: Expression) {
    return B.struct.generator.queryInSelection({
        0: selection, query: B.struct.generator.all(), 'in-complement': true }
    );
}

export function strLenSortFn(a: string, b: string) {
    return a.length < b.length ? 1 : -1;
}

function getNamesRegex(name: string, abbr?: string[]) {
    const names = (abbr ? [name].concat(abbr) : [name])
        .sort(strLenSortFn).map(escapeRegExp).join('|');
    return RegExp(`${names}`, 'i');
}

export function getPropertyRules(properties: PropertyDict) {
    // in keyof typeof properties
    const propertiesDict: { [name: string]: P.MonadicParser<any> } = {};

    Object.keys(properties).sort(strLenSortFn).forEach(name => {
        const ps = properties[name];
        const errorFn = makeError(`property '${name}' not supported`);
        const rule = P.MonadicParser.regexp(ps.regex).map((x: any) => {
            if (ps.isUnsupported) errorFn();
            return testExpr(ps.property, ps.map(x));
        });

        if (!ps.isNumeric) {
            propertiesDict[name] = rule;
        }
    });

    return propertiesDict;
}

export function getNamedPropertyRules(properties: PropertyDict) {
    const namedPropertiesList: P.MonadicParser<any>[] = [];

    Object.keys(properties).sort(strLenSortFn).forEach(name => {
        const ps = properties[name];
        const errorFn = makeError(`property '${name}' not supported`);
        const rule = P.MonadicParser.regexp(ps.regex).map((x: any) => {
            if (ps.isUnsupported) errorFn();
            return testExpr(ps.property, ps.map(x));
        });
        const nameRule = P.MonadicParser.regexp(getNamesRegex(name, ps.abbr)).trim(P.MonadicParser.optWhitespace);
        const groupMap = (x: any) => B.struct.generator.atomGroups({ [ps.level]: x });

        if (ps.isNumeric) {
            namedPropertiesList.push(
                nameRule.then(P.MonadicParser.seq(
                    P.MonadicParser.regexp(/>=|<=|=|!=|>|</).trim(P.MonadicParser.optWhitespace),
                    P.MonadicParser.regexp(ps.regex).map(ps.map)
                )).map((x: any) => {
                    if (ps.isUnsupported) errorFn();
                    return testExpr(ps.property, { op: x[0], val: x[1] });
                }).map(groupMap)
            );
        } else {
            namedPropertiesList.push(nameRule.then(rule).map(groupMap));
        }
    });

    return namedPropertiesList;
}

export function getKeywordRules(keywords: KeywordDict) {
    const keywordsList: P.MonadicParser<any>[] = [];

    Object.keys(keywords).sort(strLenSortFn).forEach(name => {
        const ks = keywords[name];
        const mapFn = ks.map ? ks.map : makeError(`keyword '${name}' not supported`);
        const rule = P.MonadicParser.regexp(getNamesRegex(name, ks.abbr)).map(mapFn);
        keywordsList.push(rule);
    });

    return keywordsList;
}

export function getFunctionRules(functions: FunctionDict, argRule: P.MonadicParser<any>) {
    const functionsList: P.MonadicParser<any>[] = [];
    const begRule = P.MonadicParser.regexp(/\(\s*/);
    const endRule = P.MonadicParser.regexp(/\s*\)/);

    Object.keys(functions).sort(strLenSortFn).forEach(name => {
        const fs = functions[name];
        const mapFn = fs.map ? fs.map : makeError(`function '${name}' not supported`);
        const rule = P.MonadicParser.regexp(new RegExp(name, 'i')).skip(begRule).then(argRule).skip(endRule).map(mapFn);
        functionsList.push(rule);
    });

    return functionsList;
}

export function getPropertyNameRules(properties: PropertyDict, lookahead: RegExp) {
    const list: P.MonadicParser<any>[] = [];
    Object.keys(properties).sort(strLenSortFn).forEach(name => {
        const ps = properties[name];
        const errorFn = makeError(`property '${name}' not supported`);
        const rule = (P.MonadicParser as any).regexp(getNamesRegex(name, ps.abbr)).lookahead(lookahead).map(() => {
            if (ps.isUnsupported) errorFn();
            return ps.property;
        });
        list.push(rule);
    });

    return list;
}

export function getReservedWords(properties: PropertyDict, keywords: KeywordDict, operators: OperatorList, functions?: FunctionDict) {
    const w: string[] = [];
    for (const name in properties) {
        w.push(name);
        if (properties[name].abbr) w.push(...properties[name].abbr!);
    }
    for (const name in keywords) {
        w.push(name);
        if (keywords[name].abbr) w.push(...keywords[name].abbr!);
    }
    operators.forEach(o => {
        w.push(o.name);
        if (o.abbr) w.push(...o.abbr);
    });
    return w;
}

export function atomNameSet(ids: string[]) {
    return B.core.type.set(ids.map(B.atomName));
}

export function asAtoms(e: Expression) {
    return B.struct.generator.queryInSelection({
        0: e,
        query: B.struct.generator.all()
    });
}

export function wrapValue(property: any, value: any, sstrucDict?: any) {
    switch (property.head.name) {
        case 'structure-query.atom-property.macromolecular.label_atom_id':
            return B.atomName(value);
        case 'structure-query.atom-property.core.element-symbol':
            return B.es(value);
        case 'structure-query.atom-property.macromolecular.secondary-structure-flags':
            if (sstrucDict) {
                value = [sstrucDict[value.toUpperCase()] || 'none'];
            }
            return B.struct.type.secondaryStructureFlags([value]);
        default:
            return value;
    }
}

const propPrefix = 'structure-query.atom-property.macromolecular.';
const entityProps = ['entityKey', 'label_entity_id', 'entityType'];
const chainProps = ['chainKey', 'label_asym_id', 'label_entity_id', 'auth_asym_id', 'entityType'];
const residueProps = ['residueKey', 'label_comp_id', 'label_seq_id', 'auth_comp_id', 'auth_seq_id', 'pdbx_formal_charge', 'secondaryStructureKey', 'secondaryStructureFlags', 'isModified', 'modifiedParentName'];
export function testLevel(property: any) {
    if (property.head.name.startsWith(propPrefix)) {
        const name = property.head.name.substr(propPrefix.length);
        if (entityProps.indexOf(name) !== -1) return 'entity-test' as string;
        if (chainProps.indexOf(name) !== -1) return 'chain-test' as string;
        if (residueProps.indexOf(name) !== -1) return 'residue-test' as string;
    }
    return 'atom-test' as string;
}

const flagProps = [
    'structure-query.atom-property.macromolecular.secondary-structure-flags'
];
export function valuesTest(property: any, values: any[]) {
    if (flagProps.indexOf(property.head.name) !== -1) {
        const name = values[0].head;
        const flags: any[] = [];
        values.forEach(v => flags.push(...v.args[0]));
        return B.core.flags.hasAny([property, { head: name, args: flags }]);
    } else {
        if (values.length === 1) {
            return B.core.rel.eq([property, values[0]]);
        } else if (values.length > 1) {
            return B.core.set.has([B.core.type.set(values), property]);
        }
    }
}

export function resnameExpr(resnameList: string[]) {
    return B.struct.generator.atomGroups({
        'residue-test': B.core.set.has([
            B.core.type.set(resnameList),
            B.ammp('label_comp_id')
        ])
    });
}