/*  ******************************
  API
  Author: Jack Lukic
  Notes: First Commit May 08, 2012

  These are modules which bind API functionality to the DOM

  Requires: nada

  Initialization:
  $('.button')
    .apiButton({
      success: function() {}
    })
  ;

  in our example api is automapped to an object literal
  @ quirky.config.endpoint.api

  HTML:
  <div class="button" action="follow" data-id="5">

  URL        : quirky.config.endpoint.api.follow
  Given Value: /follow/{$id}/
  Sent Value : /follow/5/

  (4 ways to map api endpoint, each will be looked for in succession)
  url mapping order:
    first  : defined in plugin init as url (arbitrary url)
    second : defined in plugin init as action (action in obj literal grouping 'api')
    third  : defined in data-url
    fourth : defined in data-action

  beforeSend:
  this callback can be used to modify request settings before XHR
  it also can be used to look for for pre-conditions to prevent API
  call by returning "false"

******************************  */

;(function ( $, window, document, undefined ) {

  $.api = $.fn.api = function(parameters) {

    var
      settings       = $.extend(true, {}, $.api.settings, parameters),

      // if this keyword isn't a jQuery object, create one
      context        = (typeof this != 'function')
        ? this
        : $('<div/>'),
      // context defines the element used for loading/error state
      $context       = (settings.stateContext)
        ? $(settings.stateContext)
        : $(context),
      // module is the thing that initiates the api action, can be independent of context
      $module = typeof this == 'object'
        ? $(context)
        : $context,

      element         = this,
      time            = new Date().getTime(),
      performance     = [],

      moduleSelector  = $module.selector || '',
      moduleNamespace = settings.namespace + '-module',

      className       = settings.className,
      metadata        = settings.metadata,
      error           = settings.error,

      instance        = $module.data(moduleNamespace),

      query           = arguments[0],
      methodInvoked   = (instance !== undefined && typeof query == 'string'),
      queryArguments  = [].slice.call(arguments, 1),

      module,
      invokedResponse
    ;

    module = {
      initialize: function() {
        var
          runSettings,

          loadingTimer   = new Date().getTime(),
          loadingDelay,

          promise,
          url,

          formData       = {},
          data,

          ajaxSettings   = {},
          xhr
        ;

        // serialize parent form if requested!
        if(settings.serializeForm && $(this).toJSON() !== undefined) {
          formData = module.get.formData();
          module.debug('Adding form data to API Request', formData);
          $.extend(true, settings.data, formData);
        }

        // let beforeSend change settings object
        runSettings = $.proxy(settings.beforeSend, $module)(settings);

        // check for exit conditions
        if(runSettings !== undefined && !runSettings) {
          module.error(error.beforeSend);
          module.reset();
          return;
        }

        // get real url from template
        url = module.get.url( module.get.templateURL() );

        // exit conditions reached from missing url parameters
        if( !url ) {
          module.error(error.missingURL);
          module.reset();
          return;
        }

        // promise handles notification on api request, so loading min. delay can occur for all notifications
        promise =
          $.Deferred()
            .always(function() {
              if(settings.stateContext) {
                $context
                  .removeClass(className.loading)
                ;
              }
              $.proxy(settings.complete, $module)();
            })
            .done(function(response) {
              module.debug('API request successful');
              // take a stab at finding success state if json
              if(settings.dataType == 'json') {
                if (response.error !== undefined) {
                  $.proxy(settings.failure, $context)(response.error, settings, $module);
                }
                else if ($.isArray(response.errors)) {
                  $.proxy(settings.failure, $context)(response.errors[0], settings, $module);
                }
                else {
                  $.proxy(settings.success, $context)(response, settings, $module);
                }
              }
              // otherwise
              else {
                $.proxy(settings.success, $context)(response, settings, $module);
              }
            })
            .fail(function(xhr, status, httpMessage) {
              var
                errorMessage = (settings.error[status] !== undefined)
                  ? settings.error[status]
                  : httpMessage,
                response
              ;
              // let em know unless request aborted
              if(xhr !== undefined) {
                // readyState 4 = done, anything less is not really sent
                if(xhr.readyState !== undefined && xhr.readyState == 4) {

                  // if http status code returned and json returned error, look for it
                  if( xhr.status != 200 && httpMessage !== undefined && httpMessage !== '') {
                    module.error(error.statusMessage + httpMessage);
                  }
                  else {
                    if(status == 'error' && settings.dataType == 'json') {
                      try {
                        response = $.parseJSON(xhr.responseText);
                        if(response && response.error !== undefined) {
                          errorMessage = response.error;
                        }
                      }
                      catch(error) {
                        module.error(error.JSONParse);
                      }
                    }
                  }
                  $context
                    .removeClass(className.loading)
                    .addClass(className.error)
                  ;
                  // show error state only for duration specified in settings
                  if(settings.errorLength > 0) {
                    setTimeout(function(){
                      $context
                        .removeClass(className.error)
                      ;
                    }, settings.errorLength);
                  }
                  module.debug('API Request error:', errorMessage);
                  $.proxy(settings.failure, $context)(errorMessage, settings, this);
                }
                else {
                  module.debug('Request Aborted (Most likely caused by page change)');
                }
              }
            })
        ;

        // look for params in data
        $.extend(true, ajaxSettings, settings, {
          success    : function(){},
          failure    : function(){},
          complete   : function(){},
          type       : settings.method || settings.type,
          data       : data,
          url        : url,
          beforeSend : settings.beforeXHR
        });

        if(settings.stateContext) {
          $context
            .addClass(className.loading)
          ;
        }

        if(settings.progress) {
          module.verbose('Adding progress events');
          $.extend(true, ajaxSettings, {
            xhr: function() {
              var
                xhr = new window.XMLHttpRequest()
              ;
              xhr.upload.addEventListener('progress', function(event) {
                var
                  percentComplete
                ;
                if (event.lengthComputable) {
                  percentComplete = Math.round(event.loaded / event.total * 10000) / 100 + '%';
                  $.proxy(settings.progress, $context)(percentComplete, event);
                }
              }, false);
              xhr.addEventListener('progress', function(event) {
                var
                  percentComplete
                ;
                if (event.lengthComputable) {
                  percentComplete = Math.round(event.loaded / event.total * 10000) / 100 + '%';
                  $.proxy(settings.progress, $context)(percentComplete, event);
                }
              }, false);
              return xhr;
            }
          });
        }

        module.verbose('Creating AJAX request with settings: ', ajaxSettings);
        xhr =
          $.ajax(ajaxSettings)
            .always(function() {
              // calculate if loading time was below minimum threshold
              loadingDelay = ( settings.loadingLength - (new Date().getTime() - loadingTimer) );
              settings.loadingDelay = loadingDelay < 0
                ? 0
                : loadingDelay
              ;
            })
            .done(function(response) {
              var
                context = this
              ;
              setTimeout(function(){
                promise.resolveWith(context, [response]);
              }, settings.loadingDelay);
            })
            .fail(function(xhr, status, httpMessage) {
              var
                context = this
              ;
              // page triggers abort on navigation, dont show error
              if(status != 'abort') {
                setTimeout(function(){
                  promise.rejectWith(context, [xhr, status, httpMessage]);
                }, settings.loadingDelay);
              }
              else {
                $context
                  .removeClass(className.error)
                  .removeClass(className.loading)
                ;
              }
            })
        ;
        if(settings.stateContext) {
          $module
            .data(metadata.promise, promise)
            .data(metadata.xhr, xhr)
          ;
        }
      },

      get: {
        formData: function() {
          return $module
            .closest('form')
              .toJSON()
          ;
        },
        templateURL: function() {
          var
            action = $module.data(settings.metadata.action) || settings.action || false,
            url
          ;
          if(action) {
            module.debug('Creating url for: ', action);
            if(settings.api[action] !== undefined) {
              url = settings.api[action];
            }
            else {
              module.error(error.missingAction);
            }
          }
          // override with url if specified
          if(settings.url) {
            url = settings.url;
            module.debug('Getting url', url);
          }
          return url;
        },
        url: function(url, urlData) {
          var
            urlVariables
          ;
          if(url) {
            urlVariables = url.match(settings.regExpTemplate);
            urlData      = urlData || settings.urlData;

            if(urlVariables) {
              module.debug('Looking for URL variables', urlVariables);
              $.each(urlVariables, function(index, templateValue){
                var
                  term      = templateValue.substr( 2, templateValue.length - 3),
                  termValue = ($.isPlainObject(urlData) && urlData[term] !== undefined)
                    ? urlData[term]
                    : ($module.data(term) !== undefined)
                      ? $module.data(term)
                      : urlData[term]
                ;
                module.verbose('Looking for variable', term, $module, $module.data(term), urlData[term]);
                // remove optional value
                if(termValue === false) {
                  module.debug('Removing variable from URL', urlVariables);
                  url = url.replace('/' + templateValue, '');
                }
                // undefined condition
                else if(termValue === undefined || !termValue) {
                  module.error(error.missingParameter + term);
                  url = false;
                  return false;
                }
                else {
                  url = url.replace(templateValue, termValue);
                }
              });
            }
          }
          return url;
        }
      },

      // reset api request
      reset: function() {
        $module
          .data(metadata.promise, false)
          .data(metadata.xhr, false)
        ;
        $context
          .removeClass(className.error)
          .removeClass(className.loading)
        ;
      },

      setting: function(name, value) {
        if(value !== undefined) {
          if( $.isPlainObject(name) ) {
            $.extend(true, settings, name);
          }
          else {
            settings[name] = value;
          }
        }
        else {
          return settings[name];
        }
      },
      internal: function(name, value) {
        if(value !== undefined) {
          if( $.isPlainObject(name) ) {
            $.extend(true, module, name);
          }
          else {
            module[name] = value;
          }
        }
        else {
          return module[name];
        }
      },
      debug: function() {
        if(settings.debug) {
          if(settings.performance) {
            module.performance.log(arguments);
          }
          else {
            module.debug = Function.prototype.bind.call(console.info, console, settings.moduleName + ':');
            module.debug.apply(console, arguments);
          }
        }
      },
      verbose: function() {
        if(settings.verbose && settings.debug) {
          if(settings.performance) {
            module.performance.log(arguments);
          }
          else {
            module.verbose = Function.prototype.bind.call(console.info, console, settings.moduleName + ':');
            module.verbose.apply(console, arguments);
          }
        }
      },
      error: function() {
        module.error = Function.prototype.bind.call(console.error, console, settings.moduleName + ':');
        module.error.apply(console, arguments);
      },
      performance: {
        log: function(message) {
          var
            currentTime,
            executionTime,
            previousTime
          ;
          if(settings.performance) {
            currentTime   = new Date().getTime();
            previousTime  = time || currentTime;
            executionTime = currentTime - previousTime;
            time          = currentTime;
            performance.push({
              'Element'        : element,
              'Name'           : message[0],
              'Arguments'      : [].slice.call(message, 1) || '',
              'Execution Time' : executionTime
            });
          }
          clearTimeout(module.performance.timer);
          module.performance.timer = setTimeout(module.performance.display, 100);
        },
        display: function() {
          var
            title = settings.moduleName + ':',
            totalTime = 0
          ;
          clearTimeout(module.performance.timer);
          time = false;
          $.each(performance, function(index, data) {
            totalTime += data['Execution Time'];
          });
          title += ' ' + totalTime + 'ms';
          if(moduleSelector) {
            title += ' \'' + moduleSelector + '\'';
          }
          if( (console.group !== undefined || console.table !== undefined) && performance.length > 0) {
            console.groupCollapsed(title);
            if(console.table) {
              console.table(performance);
            }
            else {
              $.each(performance, function(index, data) {
                console.log(data['Name'] + ': ' + data['Execution Time']+'ms');
              });
            }
            console.groupEnd();
          }
          performance = [];
        }
      },
      invoke: function(query, passedArguments, context) {
        var
          maxDepth,
          found,
          response
        ;
        passedArguments = passedArguments || queryArguments;
        context         = element         || context;
        if(typeof query == 'string' && instance !== undefined) {
          query    = query.split(/[\. ]/);
          maxDepth = query.length - 1;
          $.each(query, function(depth, value) {
            var camelCaseValue = (depth != maxDepth)
              ? value + query[depth + 1].charAt(0).toUpperCase() + query[depth + 1].slice(1)
              : query
            ;
            if( $.isPlainObject( instance[value] ) && (depth != maxDepth) ) {
              instance = instance[value];
            }
            else if( $.isPlainObject( instance[camelCaseValue] ) && (depth != maxDepth) ) {
              instance = instance[camelCaseValue];
            }
            else if( instance[value] !== undefined ) {
              found = instance[value];
              return false;
            }
            else if( instance[camelCaseValue] !== undefined ) {
              found = instance[camelCaseValue];
              return false;
            }
            else {
              module.error(error.method);
              return false;
            }
          });
        }
        if ( $.isFunction( found ) ) {
          response = found.apply(context, passedArguments);
        }
        else if(found !== undefined) {
          response = found;
        }
        if($.isArray(invokedResponse)) {
          invokedResponse.push(response);
        }
        else if(typeof invokedResponse == 'string') {
          invokedResponse = [invokedResponse, response];
        }
        else if(response !== undefined) {
          invokedResponse = response;
        }
        return found;
      }
    };

    if(methodInvoked) {
      if(instance === undefined) {
        module.initialize();
      }
      module.invoke(query);
    }
    else {
      if(instance !== undefined) {
        module.destroy();
      }
      module.initialize();
    }

    return (invokedResponse !== undefined)
      ? invokedResponse
      : this
    ;
  };

  // handle DOM attachment to API functionality
  $.fn.apiButton = function(parameters) {
    $(this)
      .each(function(){
        var
          // if only function passed it is success callback
          $module  = $(this),
          selector = $(this).selector || '',

          settings = ( $.isFunction(parameters) )
            ? $.extend(true, {}, $.api.settings, $.fn.apiButton.settings, { stateContext: this, success: parameters })
            : $.extend(true, {}, $.api.settings, $.fn.apiButton.settings, { stateContext: this}, parameters),
          module
        ;
        module = {
          initialize: function() {
            if(settings.context && selector !== '') {
              $(settings.context)
                .on(selector, 'click.' + settings.namespace, module.click)
              ;
            }
            else {
              $module
                .on('click.' + settings.namespace, module.click)
              ;
            }
          },
          click: function() {
            if(!settings.filter || $(this).filter(settings.filter).size() === 0) {
              $.proxy( $.api, this )(settings);
            }
          }
        };
        module.initialize();
      })
    ;
    return this;
  };

  $.api.settings = {
    name  : 'API',
    namespace   : 'api',

    debug       : true,
    verbose     : true,
    performance : true,

    api         : {},

    beforeSend  : function(settings) {
      return settings;
    },
    beforeXHR   : function(xhr) {},
    success     : function(response) {},
    complete    : function(response) {},
    failure     : function(errorCode) {},
    progress    : false,

    error : {
      missingAction    : 'API action used but no url was defined',
      missingURL       : 'URL not specified for the API action',
      missingParameter : 'Missing an essential URL parameter: ',

      timeout          : 'Your request timed out',
      error            : 'There was an error with your request',
      parseError       : 'There was an error parsing your request',
      JSONParse        : 'JSON could not be parsed during error handling',
      statusMessage    : 'Server gave an error: ',
      beforeSend       : 'The before send function has aborted the request',
      exitConditions   : 'API Request Aborted. Exit conditions met'
    },

    className: {
      loading : 'loading',
      error   : 'error'
    },

    metadata: {
      action  : 'action',
      promise : 'promise',
      xhr     : 'xhr'
    },

    regExpTemplate: /\{\$([A-z]+)\}/g,

    action        : false,
    url           : false,
    urlData       : false,
    serializeForm : false,

    stateContext  : false,

    method        : 'get',
    data          : {},
    dataType      : 'json',
    cache         : true,

    loadingLength : 200,
    errorLength   : 2000

  };

  $.fn.apiButton.settings = {
    filter       : '.disabled, .loading',
    context      : false,
    stateContext : false
  };

})( jQuery, window , document );