/*
Slick Finder
*/"use strict"

// Notable changes from Slick.Finder 1.0.x

// faster bottom -> up expression matching
// prefers mental sanity over *obsessive compulsive* milliseconds savings
// uses prototypes instead of objects
// tries to use matchesSelector smartly, whenever available
// can populate objects as well as arrays
// lots of stuff is broken or not implemented

var parse = require("./parser")

// utilities

var index = 0,
    counter = document.__counter = (parseInt(document.__counter || -1, 36) + 1).toString(36),
    key = "uid:" + counter

var uniqueID = function(n, xml){
    if (n === window) return "window"
    if (n === document) return "document"
    if (n === document.documentElement) return "html"

    if (xml) {
        var uid = n.getAttribute(key)
        if (!uid) {
            uid = (index++).toString(36)
            n.setAttribute(key, uid)
        }
        return uid
    } else {
        return n[key] || (n[key] = (index++).toString(36))
    }
}

var uniqueIDXML = function(n) {
    return uniqueID(n, true)
}

var isArray = Array.isArray || function(object){
    return Object.prototype.toString.call(object) === "[object Array]"
}

// tests

var uniqueIndex = 0;

var HAS = {

    GET_ELEMENT_BY_ID: function(test, id){
        id = "slick_" + (uniqueIndex++);
        // checks if the document has getElementById, and it works
        test.innerHTML = '<a id="' + id + '"></a>'
        return !!this.getElementById(id)
    },

    QUERY_SELECTOR: function(test){
        // this supposedly fixes a webkit bug with matchesSelector / querySelector & nth-child
        test.innerHTML = '_<style>:nth-child(2){}</style>'

        // checks if the document has querySelectorAll, and it works
        test.innerHTML = '<a class="MiX"></a>'

        return test.querySelectorAll('.MiX').length === 1
    },

    EXPANDOS: function(test, id){
        id = "slick_" + (uniqueIndex++);
        // checks if the document has elements that support expandos
        test._custom_property_ = id
        return test._custom_property_ === id
    },

    // TODO: use this ?

    // CHECKED_QUERY_SELECTOR: function(test){
    //
    //     // checks if the document supports the checked query selector
    //     test.innerHTML = '<select><option selected="selected">a</option></select>'
    //     return test.querySelectorAll(':checked').length === 1
    // },

    // TODO: use this ?

    // EMPTY_ATTRIBUTE_QUERY_SELECTOR: function(test){
    //
    //     // checks if the document supports the empty attribute query selector
    //     test.innerHTML = '<a class=""></a>'
    //     return test.querySelectorAll('[class*=""]').length === 1
    // },

    MATCHES_SELECTOR: function(test){

        test.className = "MiX"

        // checks if the document has matchesSelector, and we can use it.

        var matches = test.matchesSelector || test.mozMatchesSelector || test.webkitMatchesSelector

        // if matchesSelector trows errors on incorrect syntax we can use it
        if (matches) try {
            matches.call(test, ':slick')
        } catch(e){
            // just as a safety precaution, also test if it works on mixedcase (like querySelectorAll)
            return matches.call(test, ".MiX") ? matches : false
        }

        return false
    },

    GET_ELEMENTS_BY_CLASS_NAME: function(test){
        test.innerHTML = '<a class="f"></a><a class="b"></a>'
        if (test.getElementsByClassName('b').length !== 1) return false

        test.firstChild.className = 'b'
        if (test.getElementsByClassName('b').length !== 2) return false

        // Opera 9.6 getElementsByClassName doesnt detects the class if its not the first one
        test.innerHTML = '<a class="a"></a><a class="f b a"></a>'
        if (test.getElementsByClassName('a').length !== 2) return false

        // tests passed
        return true
    },

    // no need to know

    // GET_ELEMENT_BY_ID_NOT_NAME: function(test, id){
    //     test.innerHTML = '<a name="'+ id +'"></a><b id="'+ id +'"></b>'
    //     return this.getElementById(id) !== test.firstChild
    // },

    // this is always checked for and fixed

    // STAR_GET_ELEMENTS_BY_TAG_NAME: function(test){
    //
    //     // IE returns comment nodes for getElementsByTagName('*') for some documents
    //     test.appendChild(this.createComment(''))
    //     if (test.getElementsByTagName('*').length > 0) return false
    //
    //     // IE returns closed nodes (EG:"</foo>") for getElementsByTagName('*') for some documents
    //     test.innerHTML = 'foo</foo>'
    //     if (test.getElementsByTagName('*').length) return false
    //
    //     // tests passed
    //     return true
    // },

    // this is always checked for and fixed

    // STAR_QUERY_SELECTOR: function(test){
    //
    //     // returns closed nodes (EG:"</foo>") for querySelector('*') for some documents
    //     test.innerHTML = 'foo</foo>'
    //     return !!(test.querySelectorAll('*').length)
    // },

    GET_ATTRIBUTE: function(test){
        // tests for working getAttribute implementation
        var shout = "fus ro dah"
        test.innerHTML = '<a class="' + shout + '"></a>'
        return test.firstChild.getAttribute('class') === shout
    }

}

// Finder

var Finder = function Finder(document){

    this.document        = document
    var root = this.root = document.documentElement
    this.tested          = {}

    // uniqueID

    this.uniqueID = this.has("EXPANDOS") ? uniqueID : uniqueIDXML

    // getAttribute

    this.getAttribute = (this.has("GET_ATTRIBUTE")) ? function(node, name){

        return node.getAttribute(name)

    } : function(node, name){

        node = node.getAttributeNode(name)
        return (node && node.specified) ? node.value : null

    }

    // hasAttribute

    this.hasAttribute = (root.hasAttribute) ? function(node, attribute){

        return node.hasAttribute(attribute)

    } : function(node, attribute) {

        node = node.getAttributeNode(attribute)
        return !!(node && node.specified)

    }

    // contains

    this.contains = (document.contains && root.contains) ? function(context, node){

        return context.contains(node)

    } : (root.compareDocumentPosition) ? function(context, node){

        return context === node || !!(context.compareDocumentPosition(node) & 16)

    } : function(context, node){

        do {
            if (node === context) return true
        } while ((node = node.parentNode))

        return false
    }

    // sort
    // credits to Sizzle (http://sizzlejs.com/)

    this.sorter = (root.compareDocumentPosition) ? function(a, b){

        if (!a.compareDocumentPosition || !b.compareDocumentPosition) return 0
        return a.compareDocumentPosition(b) & 4 ? -1 : a === b ? 0 : 1

    } : ('sourceIndex' in root) ? function(a, b){

        if (!a.sourceIndex || !b.sourceIndex) return 0
        return a.sourceIndex - b.sourceIndex

    } : (document.createRange) ? function(a, b){

        if (!a.ownerDocument || !b.ownerDocument) return 0
        var aRange = a.ownerDocument.createRange(),
            bRange = b.ownerDocument.createRange()

        aRange.setStart(a, 0)
        aRange.setEnd(a, 0)
        bRange.setStart(b, 0)
        bRange.setEnd(b, 0)
        return aRange.compareBoundaryPoints(Range.START_TO_END, bRange)

    } : null

    this.failed = {}

    var nativeMatches = this.has("MATCHES_SELECTOR")

    if (nativeMatches) this.matchesSelector = function(node, expression){

        if (this.failed[expression]) return null

        try {
            return nativeMatches.call(node, expression)
        } catch(e){
            if (slick.debug) console.warn("matchesSelector failed on " + expression)
            this.failed[expression] = true
            return null
        }

    }

    if (this.has("QUERY_SELECTOR")){

        this.querySelectorAll = function(node, expression){

            if (this.failed[expression]) return true

            var result, _id, _expression, _combinator, _node


            // non-document rooted QSA
            // credits to Andrew Dupont

            if (node !== this.document){

                _combinator = expression[0].combinator

                _id         = node.getAttribute("id")
                _expression = expression

                if (!_id){
                    _node = node
                    _id = "__slick__"
                    _node.setAttribute("id", _id)
                }

                expression = "#" + _id + " " + _expression


                // these combinators need a parentNode due to how querySelectorAll works, which is:
                // finding all the elements that match the given selector
                // then filtering by the ones that have the specified element as an ancestor
                if (_combinator.indexOf("~") > -1 || _combinator.indexOf("+") > -1){

                    node = node.parentNode
                    if (!node) result = true
                    // if node has no parentNode, we return "true" as if it failed, without polluting the failed cache

                }

            }

            if (!result) try {
                result = node.querySelectorAll(expression.toString())
            } catch(e){
                if (slick.debug) console.warn("querySelectorAll failed on " + (_expression || expression))
                result = this.failed[_expression || expression] = true
            }

            if (_node) _node.removeAttribute("id")

            return result

        }

    }

}

Finder.prototype.has = function(FEATURE){

    var tested        = this.tested,
        testedFEATURE = tested[FEATURE]

    if (testedFEATURE != null) return testedFEATURE

    var root     = this.root,
        document = this.document,
        testNode = document.createElement("div")

    testNode.setAttribute("style", "display: none;")

    root.appendChild(testNode)

    var TEST = HAS[FEATURE], result = false

    if (TEST) try {
        result = TEST.call(document, testNode)
    } catch(e){}

    if (slick.debug && !result) console.warn("document has no " + FEATURE)

    root.removeChild(testNode)

    return tested[FEATURE] = result

}

var combinators = {

    " ": function(node, part, push){

        var item, items

        var noId = !part.id, noTag = !part.tag, noClass = !part.classes

        if (part.id && node.getElementById && this.has("GET_ELEMENT_BY_ID")){
            item = node.getElementById(part.id)

            // return only if id is found, else keep checking
            // might be a tad slower on non-existing ids, but less insane

            if (item && item.getAttribute('id') === part.id){
                items = [item]
                noId = true
                // if tag is star, no need to check it in match()
                if (part.tag === "*") noTag = true
            }
        }

        if (!items){

            if (part.classes && node.getElementsByClassName && this.has("GET_ELEMENTS_BY_CLASS_NAME")){
                items = node.getElementsByClassName(part.classList)
                noClass = true
                // if tag is star, no need to check it in match()
                if (part.tag === "*") noTag = true
            } else {
                items = node.getElementsByTagName(part.tag)
                // if tag is star, need to check it in match because it could select junk, boho
                if (part.tag !== "*") noTag = true
            }

            if (!items || !items.length) return false

        }

        for (var i = 0; item = items[i++];)
            if ((noTag && noId && noClass && !part.attributes && !part.pseudos) || this.match(item, part, noTag, noId, noClass))
                push(item)

        return true

    },

    ">": function(node, part, push){ // direct children
        if ((node = node.firstChild)) do {
            if (node.nodeType == 1 && this.match(node, part)) push(node)
        } while ((node = node.nextSibling))
    },

    "+": function(node, part, push){ // next sibling
        while ((node = node.nextSibling)) if (node.nodeType == 1){
            if (this.match(node, part)) push(node)
            break
        }
    },

    "^": function(node, part, push){ // first child
        node = node.firstChild
        if (node){
            if (node.nodeType === 1){
                if (this.match(node, part)) push(node)
            } else {
                combinators['+'].call(this, node, part, push)
            }
        }
    },

    "~": function(node, part, push){ // next siblings
        while ((node = node.nextSibling)){
            if (node.nodeType === 1 && this.match(node, part)) push(node)
        }
    },

    "++": function(node, part, push){ // next sibling and previous sibling
        combinators['+'].call(this, node, part, push)
        combinators['!+'].call(this, node, part, push)
    },

    "~~": function(node, part, push){ // next siblings and previous siblings
        combinators['~'].call(this, node, part, push)
        combinators['!~'].call(this, node, part, push)
    },

    "!": function(node, part, push){ // all parent nodes up to document
        while ((node = node.parentNode)) if (node !== this.document && this.match(node, part)) push(node)
    },

    "!>": function(node, part, push){ // direct parent (one level)
        node = node.parentNode
        if (node !== this.document && this.match(node, part)) push(node)
    },

    "!+": function(node, part, push){ // previous sibling
        while ((node = node.previousSibling)) if (node.nodeType == 1){
            if (this.match(node, part)) push(node)
            break
        }
    },

    "!^": function(node, part, push){ // last child
        node = node.lastChild
        if (node){
            if (node.nodeType == 1){
                if (this.match(node, part)) push(node)
            } else {
                combinators['!+'].call(this, node, part, push)
            }
        }
    },

    "!~": function(node, part, push){ // previous siblings
        while ((node = node.previousSibling)){
            if (node.nodeType === 1 && this.match(node, part)) push(node)
        }
    }

}

Finder.prototype.search = function(context, expression, found){

    if (!context) context = this.document
    else if (!context.nodeType && context.document) context = context.document

    var expressions = parse(expression)

    // no expressions were parsed. todo: is this really necessary?
    if (!expressions || !expressions.length) throw new Error("invalid expression")

    if (!found) found = []

    var uniques, push = isArray(found) ? function(node){
        found[found.length] = node
    } : function(node){
        found[found.length++] = node
    }

    // if there is more than one expression we need to check for duplicates when we push to found
    // this simply saves the old push and wraps it around an uid dupe check.
    if (expressions.length > 1){
        uniques = {}
        var plush = push
        push = function(node){
            var uid = uniqueID(node)
            if (!uniques[uid]){
                uniques[uid] = true
                plush(node)
            }
        }
    }

    // walker

    var node, nodes, part

    main: for (var i = 0; expression = expressions[i++];){

        // querySelector

        // TODO: more functional tests

        // if there is querySelectorAll (and the expression does not fail) use it.
        if (!slick.noQSA && this.querySelectorAll){

            nodes = this.querySelectorAll(context, expression)
            if (nodes !== true){
                if (nodes && nodes.length) for (var j = 0; node = nodes[j++];) if (node.nodeName > '@'){
                    push(node)
                }
                continue main
            }
        }

        // if there is only one part in the expression we don't need to check each part for duplicates.
        // todo: this might be too naive. while solid, there can be expression sequences that do not
        // produce duplicates. "body div" for instance, can never give you each div more than once.
        // "body div a" on the other hand might.
        if (expression.length === 1){

            part = expression[0]
            combinators[part.combinator].call(this, context, part, push)

        } else {

            var cs = [context], c, f, u, p = function(node){
                var uid = uniqueID(node)
                if (!u[uid]){
                    u[uid] = true
                    f[f.length] = node
                }
            }

            // loop the expression parts
            for (var j = 0; part = expression[j++];){
                f = []; u = {}
                // loop the contexts
                for (var k = 0; c = cs[k++];) combinators[part.combinator].call(this, c, part, p)
                // nothing was found, the expression failed, continue to the next expression.
                if (!f.length) continue main
                cs = f // set the contexts for future parts (if any)
            }

            if (i === 0) found = f // first expression. directly set found.
            else for (var l = 0; l < f.length; l++) push(f[l]) // any other expression needs to push to found.
        }

    }

    if (uniques && found && found.length > 1) this.sort(found)

    return found

}

Finder.prototype.sort = function(nodes){
    return this.sorter ? Array.prototype.sort.call(nodes, this.sorter) : nodes
}

// TODO: most of these pseudo selectors include <html> and qsa doesnt. fixme.

var pseudos = {


    // TODO: returns different results than qsa empty.

    'empty': function(){
        return !(this && this.nodeType === 1) && !(this.innerText || this.textContent || '').length
    },

    'not': function(expression){
        return !slick.matches(this, expression)
    },

    'contains': function(text){
        return (this.innerText || this.textContent || '').indexOf(text) > -1
    },

    'first-child': function(){
        var node = this
        while ((node = node.previousSibling)) if (node.nodeType == 1) return false
        return true
    },

    'last-child': function(){
        var node = this
        while ((node = node.nextSibling)) if (node.nodeType == 1) return false
        return true
    },

    'only-child': function(){
        var prev = this
        while ((prev = prev.previousSibling)) if (prev.nodeType == 1) return false

        var next = this
        while ((next = next.nextSibling)) if (next.nodeType == 1) return false

        return true
    },

    'first-of-type': function(){
        var node = this, nodeName = node.nodeName
        while ((node = node.previousSibling)) if (node.nodeName == nodeName) return false
        return true
    },

    'last-of-type': function(){
        var node = this, nodeName = node.nodeName
        while ((node = node.nextSibling)) if (node.nodeName == nodeName) return false
        return true
    },

    'only-of-type': function(){
        var prev = this, nodeName = this.nodeName
        while ((prev = prev.previousSibling)) if (prev.nodeName == nodeName) return false
        var next = this
        while ((next = next.nextSibling)) if (next.nodeName == nodeName) return false
        return true
    },

    'enabled': function(){
        return !this.disabled
    },

    'disabled': function(){
        return this.disabled
    },

    'checked': function(){
        return this.checked || this.selected
    },

    'selected': function(){
        return this.selected
    },

    'focus': function(){
        var doc = this.ownerDocument
        return doc.activeElement === this && (this.href || this.type || slick.hasAttribute(this, 'tabindex'))
    },

    'root': function(){
        return (this === this.ownerDocument.documentElement)
    }

}

Finder.prototype.match = function(node, bit, noTag, noId, noClass){

    // TODO: more functional tests ?

    if (!slick.noQSA && this.matchesSelector){
        var matches = this.matchesSelector(node, bit)
        if (matches !== null) return matches
    }

    // normal matching

    if (!noTag && bit.tag){

        var nodeName = node.nodeName.toLowerCase()
        if (bit.tag === "*"){
            if (nodeName < "@") return false
        } else if (nodeName != bit.tag){
            return false
        }

    }

    if (!noId && bit.id && node.getAttribute('id') !== bit.id) return false

    var i, part

    if (!noClass && bit.classes){

        var className = this.getAttribute(node, "class")
        if (!className) return false

        for (part in bit.classes) if (!RegExp('(^|\\s)' + bit.classes[part] + '(\\s|$)').test(className)) return false
    }

    var name, value

    if (bit.attributes) for (i = 0; part = bit.attributes[i++];){

        var operator  = part.operator,
            escaped   = part.escapedValue

        name  = part.name
        value = part.value

        if (!operator){

            if (!this.hasAttribute(node, name)) return false

        } else {

            var actual = this.getAttribute(node, name)
            if (actual == null) return false

            switch (operator){
                case '^=' : if (!RegExp(      '^' + escaped            ).test(actual)) return false; break
                case '$=' : if (!RegExp(            escaped + '$'      ).test(actual)) return false; break
                case '~=' : if (!RegExp('(^|\\s)' + escaped + '(\\s|$)').test(actual)) return false; break
                case '|=' : if (!RegExp(      '^' + escaped + '(-|$)'  ).test(actual)) return false; break

                case '='  : if (actual !== value) return false; break
                case '*=' : if (actual.indexOf(value) === -1) return false; break
                default   : return false
            }

        }
    }

    if (bit.pseudos) for (i = 0; part = bit.pseudos[i++];){

        name  = part.name
        value = part.value

        if (pseudos[name]) return pseudos[name].call(node, value)

        if (value != null){
            if (this.getAttribute(node, name) !== value) return false
        } else {
            if (!this.hasAttribute(node, name)) return false
        }

    }

    return true

}

Finder.prototype.matches = function(node, expression){

    var expressions = parse(expression)

    if (expressions.length === 1 && expressions[0].length === 1){ // simplest match
        return this.match(node, expressions[0][0])
    }

    // TODO: more functional tests ?

    if (!slick.noQSA && this.matchesSelector){
        var matches = this.matchesSelector(node, expressions)
        if (matches !== null) return matches
    }

    var nodes = this.search(this.document, expression, {length: 0})

    for (var i = 0, res; res = nodes[i++];) if (node === res) return true
    return false

}

var finders = {}

var finder = function(context){
    var doc = context || document
    if (doc.ownerDocument) doc = doc.ownerDocument
    else if (doc.document) doc = doc.document

    if (doc.nodeType !== 9) throw new TypeError("invalid document")

    var uid = uniqueID(doc)
    return finders[uid] || (finders[uid] = new Finder(doc))
}

// ... API ...

var slick = function(expression, context){
    return slick.search(expression, context)
}

slick.search = function(expression, context, found){
    return finder(context).search(context, expression, found)
}

slick.find = function(expression, context){
    return finder(context).search(context, expression)[0] || null
}

slick.getAttribute = function(node, name){
    return finder(node).getAttribute(node, name)
}

slick.hasAttribute = function(node, name){
    return finder(node).hasAttribute(node, name)
}

slick.contains = function(context, node){
    return finder(context).contains(context, node)
}

slick.matches = function(node, expression){
    return finder(node).matches(node, expression)
}

slick.sort = function(nodes){
    if (nodes && nodes.length > 1) finder(nodes[0]).sort(nodes)
    return nodes
}

slick.parse = parse;

// slick.debug = true
// slick.noQSA  = true

module.exports = slick