"use strict";

module.exports = CSSselect;

var DomUtils = require("domutils");
var falseFunc = require("boolbase").falseFunc;
var compileRaw = require("./lib/compile.js");

function wrapCompile(func) {
    return function addAdapter(selector, options, context) {
        options = options || {};
        options.adapter = options.adapter || DomUtils;

        return func(selector, options, context);
    };
}

var compile = wrapCompile(compileRaw);
var compileUnsafe = wrapCompile(compileRaw.compileUnsafe);

function getSelectorFunc(searchFunc) {
    return function select(query, elems, options) {
        options = options || {};
        options.adapter = options.adapter || DomUtils;

        if (typeof query !== "function") {
            query = compileUnsafe(query, options, elems);
        }
        if (query.shouldTestNextSiblings) {
            elems = appendNextSiblings((options && options.context) || elems, options.adapter);
        }
        if (!Array.isArray(elems)) elems = options.adapter.getChildren(elems);
        else elems = options.adapter.removeSubsets(elems);
        return searchFunc(query, elems, options);
    };
}

function getNextSiblings(elem, adapter) {
    var siblings = adapter.getSiblings(elem);
    if (!Array.isArray(siblings)) return [];
    siblings = siblings.slice(0);
    while (siblings.shift() !== elem);
    return siblings;
}

function appendNextSiblings(elems, adapter) {
    // Order matters because jQuery seems to check the children before the siblings
    if (!Array.isArray(elems)) elems = [elems];
    var newElems = elems.slice(0);

    for (var i = 0, len = elems.length; i < len; i++) {
        var nextSiblings = getNextSiblings(newElems[i], adapter);
        newElems.push.apply(newElems, nextSiblings);
    }
    return newElems;
}

var selectAll = getSelectorFunc(function selectAll(query, elems, options) {
    return query === falseFunc || !elems || elems.length === 0 ? [] : options.adapter.findAll(query, elems);
});

var selectOne = getSelectorFunc(function selectOne(query, elems, options) {
    return query === falseFunc || !elems || elems.length === 0 ? null : options.adapter.findOne(query, elems);
});

function is(elem, query, options) {
    options = options || {};
    options.adapter = options.adapter || DomUtils;
    return (typeof query === "function" ? query : compile(query, options))(elem);
}

/*
	the exported interface
*/
function CSSselect(query, elems, options) {
    return selectAll(query, elems, options);
}

CSSselect.compile = compile;
CSSselect.filters = compileRaw.Pseudos.filters;
CSSselect.pseudos = compileRaw.Pseudos.pseudos;

CSSselect.selectAll = selectAll;
CSSselect.selectOne = selectOne;

CSSselect.is = is;

//legacy methods (might be removed)
CSSselect.parse = compile;
CSSselect.iterate = selectAll;

//hooks
CSSselect._compileUnsafe = compileUnsafe;
CSSselect._compileToken = compileRaw.compileToken;