/*
    This class maps the tool form dom to an api compatible javascript dictionary.
*/
// dependencies
define(['utils/utils'], function(Utils) {

// tool form tree
return Backbone.Model.extend({
    // initialize
    initialize: function(app) {
        this.app = app;
    },

    /** Convert dictionary representation into tool api specific flat dictionary format.
    */
    finalize: function(patch) {
        // link this
        var self = this;

        // dictionary with api specific identifiers
        this.map_dict = {};

        // check if section is available
        if (!this.app.section) {
            return {};
        }

        // ensure that dictionary with patching functions exists
        patch = patch || {};

        // dictionary formatted for job submission or tool form update
        var result_dict = {};

        // prepare full dictionary
        var dict = {};

        // fill dictionary from dom
        this._iterate(this.app.section.$el, dict);

        // add identifier and value to job definition
        function add(job_input_id, input_id, input_value) {
            // add entry to result dictionary
            result_dict[job_input_id] = input_value;

            // backup id mapping
            self.map_dict[job_input_id] = input_id;
        };

        // converter between raw dictionary and job dictionary
        function convert(identifier, head) {
            for (var index in head) {
                var node = head[index];
                if (node.input) {
                    // get node
                    var input = node.input;

                    // create identifier
                    var job_input_id = identifier;
                    if (identifier != '') {
                        job_input_id += '|';
                    }
                    job_input_id += input.name;

                    // process input type
                    switch (input.type) {
                        // handle repeats
                        case 'repeat':
                            // section identifier
                            var section_label = 'section-';

                            // collect repeat block identifiers
                            var block_indices = [];
                            var block_prefix = null;
                            for (var block_label in node) {
                                var pos = block_label.indexOf(section_label);
                                if (pos != -1) {
                                    pos += section_label.length;
                                    block_indices.push(parseInt(block_label.substr(pos)));
                                    if (!block_prefix) {
                                        block_prefix = block_label.substr(0, pos);
                                    }
                                }
                            }

                            // sort repeat blocks
                            block_indices.sort(function(a,b) { return a - b; });

                            // add to response dictionary in created order
                            var index = 0;
                            for (var i in block_indices) {
                                convert(job_input_id + '_' + index++, node[block_prefix + block_indices[i]]);
                            }
                            break;
                        // handle conditionals
                        case 'conditional':
                            // get and patch conditional value
                            var value = self.app.field_list[input.id].value();
                            if (patch[input.test_param.type]) {
                                value = patch[input.test_param.type](value);
                            }

                            // add conditional value
                            add (job_input_id + '|' + input.test_param.name, input.id, value);

                            // identify selected case
                            var selectedCase = self.matchCase(input, value);
                            if (selectedCase != -1) {
                                convert(job_input_id, head[input.id + '-section-' + selectedCase]);
                            }
                            break;
                        // handle custom sub sections
                        case 'section':
                            convert('', node);
                            break;
                        default:
                            // get field
                            var field = self.app.field_list[input.id];
                            if (field && field.value) {
                                // validate field value
                                var value = field.value();

                                // get and patch field value
                                if (patch[input.type]) {
                                    value = patch[input.type](value);
                                }

                                // ignore certain values
                                if (input.ignore === undefined || input.ignore != value) {
                                    // add value to submission
                                    add (job_input_id, input.id, value);

                                    // add payload to submission
                                    if (input.payload) {
                                        for (var p_id in input.payload) {
                                            add (p_id, input.id, input.payload[p_id]);
                                        }
                                    }
                                }
                            }
                    }
                }
            }
        }

        // start conversion
        convert('', dict);

        // return result
        return result_dict;
    },

    /** Match job definition identifier to input element identifier
    */
    match: function (job_input_id) {
        return this.map_dict && this.map_dict[job_input_id];
    },

    /** Match conditional values to selected cases
    */
    matchCase: function(input, value) {
        // format value for boolean inputs
        if (input.test_param.type == 'boolean') {
            if (value == 'true') {
                value = input.test_param.truevalue || 'true';
            } else {
                value = input.test_param.falsevalue || 'false';
            }
        }

        // find selected case
        for (var i in input.cases) {
            if (input.cases[i].value == value) {
                return i;
            }
        }

        // selected case not found
        return -1;
    },

    /** Matches identifier from api model to input elements
    */
    matchModel: function(model, callback) {
        // final result dictionary
        var result = {};

        // link this
        var self = this;

        // search throughout response
        function search (id, head) {
            for (var i in head) {
                var node = head[i];
                var index = node.name;
                if (id != '') {
                    index = id + '|' + index;
                }
                switch (node.type) {
                    case 'repeat':
                        for (var j in node.cache) {
                            search (index + '_' + j, node.cache[j]);
                        }
                        break;
                    case 'conditional':
                        var value = node.test_param && node.test_param.value;
                        var selectedCase = self.matchCase(node, value);
                        if (selectedCase != -1) {
                            search (index, node.cases[selectedCase].inputs);
                        }
                        break;
                    default:
                        var input_id = self.map_dict[index];
                        if (input_id) {
                            callback(input_id, node);
                        }
                }
            }
        }

        // match all ids and return messages
        search('', model.inputs);

        // return matched results
        return result;
    },

    /** Matches identifier from api response to input elements
    */
    matchResponse: function(response) {
        // final result dictionary
        var result = {};

        // link this
        var self = this;

        // search throughout response
        function search (id, head) {
            if (typeof head === 'string') {
                var input_id = self.map_dict[id];
                if (input_id) {
                    result[input_id] = head;
                }
            } else {
                for (var i in head) {
                    var new_id = i;
                    if (id !== '') {
                        var separator = '|';
                        if (head instanceof Array) {
                            separator = '_';
                        }
                        new_id = id + separator + new_id;
                    }
                    search (new_id, head[i]);
                }
            }
        }

        // match all ids and return messages
        search('', response);

        // return matched results
        return result;
    },

    /** Iterate through the tool form dom and map it to the dictionary.
    */
    _iterate: function(parent, dict) {
        // get child nodes
        var self = this;
        var children = $(parent).children();
        children.each(function() {
            // get child element
            var child = this;

            // get id
            var id = $(child).attr('id');

            // create new branch
            if ($(child).hasClass('section-row')) {
                // create sub dictionary
                dict[id] = {};

                // add input element if it exists
                var input = self.app.input_list[id];
                if (input) {
                    dict[id] = {
                        input : input
                    }
                }

                // fill sub dictionary
                self._iterate(child, dict[id]);
            } else {
                self._iterate(child, dict);
            }
        });
    }
});

});