/* ComputedStyleSubPanel.js */
var Montage   = require("montage").Montage,
    Component = require("montage/ui/component").Component,
    Editable  = require("js/components/editable.reel").Editable;


/*

EDITABLE - Methods
- startEdit
- stopEdit
- value
- 
- _suggest
- _suggestNext
- _suggestPrev
- _clearSuggest
- _accept
- _revert
- _setCaret

*/


exports.Hintable = Montage.create(Editable, {
    inheritsFrom : { value : Editable },
    _matchIndex  : { value : 0 },
    matches      : { value : [] },
    
    _hint : { value : null },
    hint : {
        get : function() {
            return this._hint;
        },
        set : function(hint) {
            hint = hint || '';
            
            ///// Set the hint element's text
            this._getFirstTextNode(this.hintElement).textContent = hint;
            ///// if hintElement was removed from the DOM, the object still
            ///// exists, so it needs to be re-appended
            if(this.hintElement.parentNode === null) {
                this._element.appendChild(this.hintElement);
            }

            this._hint = hint;
        }
    },
    
    _hintElement : { value : null },
    hintElement : {
        get : function() {
            if(!this._hintElement) {
                /// Remove the phantom "<BR>" element that is generated when 
                /// content editable element is empty
                this._children(this._element, function(item) { 
                    return item.nodeName === 'BR';
                }).forEach(function(item) {
                    this._element.removeChild(item);
                }, this);

                this._hintElement = document.createElement('span');
                this._hintElement.classList.add(this.hintClass);
                
                this._element.appendChild(this._hintElement);
            }
            
            return this._hintElement;
        },
        set : function(el) {
            this._hintElement = el;
        }
    },
    
    _getHintDifference : {
        value : function() {
            if(!this.matches[this._matchIndex]) {
                debugger;
            }
            return this.matches[this._matchIndex].substr(this.value.length);
        }
    },
    
    hintNext : {
        value : function(e) {
            if(e) { e.preventDefault(); }
                console.log('next1');
            
            if(this._matchIndex < this.matches.length - 1) {
                console.log('next');
                ++this._matchIndex;
                this.hint = this._getHintDifference();
            }
        }
    },
    hintPrev : {
        value : function(e) {
            if(e) { e.preventDefault(); }
                console.log('prev1');
            if(this._matchIndex !== 0) {
                console.log('prev');
                --this._matchIndex;
                this.hint = this._getHintDifference();
            }
        }
    },

    accept : {
        value: function(e, preserveCaretPosition) {
            if(e) {
                e.preventDefault();
            }
            var fullText = this._hint;
            this.hint = null;
            this.value += fullText;
            
            if(!preserveCaretPosition) {
                this.setCursor('end');
            }

            this._sendEvent('accept');
        }
    },
    revert : {
        value : function(e, forceRevert) {
            this.hint = null;
            
            if(this.isEditable || forceRevert) {
                /// revert to old value
                this.value = (this._preEditValue);
                this._sendEvent('revert');
                console.log('reverting');
                
            }
        }
    },
    value : {
        get: function() {
            return this._getFirstTextNode().textContent;
        },
        set: function(str) {
            var node = this._getFirstTextNode();
            node.textContent = str;
        }
    },

    handleKeydown : {
        value : function handleKeydown(e) {
            var k = e.keyCode,
                isCaretAtEnd, selection, text;
                
            this._super(arguments);
            
            if(k === 39) {
                selection = window.getSelection();
                text = selection.baseNode.textContent;
                isCaretAtEnd = (selection.anchorOffset === text.length);
            }
            
            if(this.hint && isCaretAtEnd) {
                ///// Advance the cursor
                this.hint = this.hint.substr(0, 1);
                this.accept(e);
                this.handleInput();
            }
            
            this._execKeyAction(e);
        }
    },
    ///// Text input has changed values
    handleInput : {
        value : function handleInput(e) {
            this._super(arguments);
            
            var val = this.value,
                 matches, hint;
            console.log('val = "' + val + '"');
            //// Handle auto-suggest if configured
            if(this.hints instanceof Array) {

                if(val.length > 0) { // content is not empty
                    
                    this._matchIndex = 0;                    
                    this.matches = this.hints.filter(function(h) {
                        return h.indexOf(val) === 0;
                    }).sort();
                    
                    ///// If there are no matches, or the new value doesn't match all the
                    ///// previous matches, then get new list of matches
                    if(!this.matches.length || !this._matchesAll(val)) {
                    }
                    
                    if(this.matches.length) { // match(es) found
                        if(this.matches[this._matchIndex] !== val) {
                            // Suggest the matched hint, subtracting the typed-in string
                            // Only if the hint is not was the user has typed already
                            this.hint = this._getHintDifference();
                        } else {
                            this.hint = null;                            
                        }
                    } else { // no matches found
                        this.hint = null;
                    }
                } else { // no suggestion for empty string
                    this.hint = null;
                }

            }
        }
    },
    handleBackspace : {
        value : function(e) {
            this.matches.length = 0;
        }
    },
    _matchesAll : {
        value : function(value) {
            return this.matches.every(function(match) {
                return match.indexOf(value) === 0;
            }, this);
        }
    },
    _execKeyAction : {
        value : function(e) {
            var key = e.keyCode,
                keys = this.keyActions;
            
            if(this.hint) {
                if( keys.hint.revert.indexOf(key) !== -1 ) { this.revert(e); }
                if( keys.hint.accept.indexOf(key) !== -1 ) { this.accept(e); }
                if( keys.hint.stop.indexOf(key) !== -1 )   { this.stop(e); }
                if( keys.hint.next.indexOf(key) !== -1 )   { this.hintNext(e); }
                if( keys.hint.prev.indexOf(key) !== -1 )   { this.hintPrev(e); }
                if( keys.hint.backsp.indexOf(key) !== -1 )   { this.handleBackspace(e); }
            } else {
                if(keys.noHint.revert.indexOf(key) !== -1) { this.revert(e); }
                if(keys.noHint.stop.indexOf(key) !== -1)   { this.stop(e); }
                //if( keys.hint.next.indexOf(key) !== -1 )   { this.handleDown(e); }
                //if( keys.hint.prev.indexOf(key) !== -1 )   { this.handleUp(e); }
                //if( keys.hint.backsp.indexOf(key) !== -1 )   { this.backspace(e); }
            }
        }
    },
    
    /* --------------- Utils --------------- */
    
    _children : {
        value : function(el, filter) {
            var f = filter || function(item) {
                return item.nodeType === 1;
            };
            return this._toArray(el.childNodes).filter(f);
        }
    },
    _toArray : {
        value : function(arrayLikeObj) {
            return Array.prototype.slice.call(arrayLikeObj);
        }
    },
    _getFirstTextNode : {
        value : function(el) {
            ///// optional el argument specified container element
            var e = el || this._element,
                nodes = e.childNodes, node;
            
            if(nodes.length) {
                for(var i=0; i<nodes.length; i++) {
                    if(nodes[i].nodeType === 3) {
                        ///// found the first text node
                        node = nodes[i];
                        break;
                    }
                }
            }
            
            ///// Text node not found
            if(!node) {
                node = document.createTextNode('');
                e.appendChild(node);
            }
        
        
            return node;
        }
    },
    _super : {
        value : function(args) {
            this.inheritsFrom[arguments.callee.caller.name].apply(this, args);
        }
    },

    /* --------- CONFIG ---------- */
    hints : {
        value : ['Testing a hint.', 'Testing another hint.', 'Testing the last hint.']
    },
    hintClass : {
        value : "hintable-hint"
    },
    keyActions : { 
        value : {
            hint : {
                accept : [9,13,186], // accept hint
                stop   : [27,186],   // stop editing
                next   : [40],       // cycle to next hint
                prev   : [38],       // cycle to prev hint
                revert : [27],       // revert value
                backsp : [8]         // backspace hit
            },
            noHint : {
                stop   : [27,9,13,186],
                next   : [40],
                prev   : [38],
                revert : [27],
                backsp : [8]
            }
        }
    }
    
});

// suggest : {
//     value : function(hint) {
//         ///// if no hint argument passed, clear suggestions
//         if(!hint) {
//             this.clearHint();
//             return false;            
//         }
//         
//         this._hint = hint;            
// 
//         ///// append span with suggested hint
//         if(this.hintElement) {
//             this.clearHint();
//             
//             ///// Set the hint element's text
//             this._getFirstTextNode(this.hintElement).textContent = hint;
// 
//             ///// if hintElement was removed from the DOM, the object still
//             ///// exists, so it needs to be re-appended
//             if(this.hintElement.parentNode === null) {
//                 this._element.appendChild(this.hintElement);
//             }
//         } else {
//             /// Remove the phantom "<BR>" element that is generated when 
//             /// content editable element is empty
//             this._children(this._element, function(item) { 
//                 return item.nodeName === 'BR';
//             }).forEach(function(item) {
//                 this._element.removeChild(item);
//             }, this);
// 
//             this.hintElement = document.createElement('span');
//             this.hintElement.classList.add(this.suggestClass);
//             this.hintElement.appendChild(document.createTextNode(hint));
//             this._element.appendChild(this.hintElement);
//         }
// 
//         this._hint = hint;
//     }
// },