// Entry object
function entry(){
    this.id=ko.observable();
    this.pointed=ko.observable();
    this.operation_date=ko.observable();
    this.label=ko.observable();
    this.value=ko.observable();
    this.account_id=ko.observable();
    this.sold=ko.observable();
    this.pointedsold=ko.observable();
    this.category=ko.observable();
}

// Account object
function account() {
    this.id=ko.observable();
    this.name=ko.observable();
    this.authorized_overdraft=ko.observable();
    this.future=ko.observable();
    this.current=ko.observable();
    this.pointed=ko.observable();
}

// Month object
function month() {
    this.year=ko.observable();
    this.month=ko.observable();
}

// Util function to show a message in message placeholder.
function message(alertType, title, message) {
  $(".alert").alert('close');
  $("#message-placeholder").append('<div class="alert alert-' + alertType + '"><button type="button" class="close" data-dismiss="alert">&times;</button><h4>' + title + '</h4>' + message + '</div>');
}

// The ListViewModel used to instanciate viewmodel.
var ListViewModel = function() {
    var self = this;

    // Account store and selection
    self.account = ko.observable();
    self.accounts = ko.observableArray([]);

    self.savedAccount = null;
    self.editingAccount = ko.observable();
    self.removedAccount = null;

    // Month store and selection
    self.months = ko.observableArray();
    self.month = ko.observable();

    // Entry store and selection
    self.entries = ko.observableArray([]);
    self.selectedItem = ko.observable();
    self.newEntry = ko.observable(ko.mapping.fromJS({
        id: null,
        pointed: false,
        operation_date: null,
        label: null,
        value: null,
        sold: null,
        pointedsold: null,
        category: null,
        account_id: null
    }));

    // Placeholder for saved value to cancel entry edition
    self.savedItem = null;

    // Placeholder for entry to remove to be available in modal function "yes" click callback
    self.removedItem = null;

    self.addAccount = function() {
      self.editingAccount(ko.mapping.fromJS({
        id: null,
        name: null,
        authorized_overdraft: null
      }));

      $("#edit-account").modal();
    };

    self.editAccount = function(account) {
      self.editingAccount(account);
      self.savedAccount = ko.toJS(account);

      $("#edit-account").modal();
    };

    self.cancelEditAccount = function() {
      if(self.editingAccount() && self.savedAccount) {
        self.editingAccount().name(self.savedAccount.name);
        self.editingAccount().authorized_overdraft(self.savedAccount.authorized_overdraft);
      }

      self.editingAccount(null);
      self.savedAccount = null;

      $("#edit-account").modal('hide');
    };

    self.saveAccount = function() {
      var account = self.editingAccount();

      // Ajax call to save the entry.
      var type;
      var url = "api/accounts";

      if(account.id()) {
        url += "/" + account.id();
      }

      $.ajax({
        url: url,
        type: "PUT",
        data: ko.toJSON(account),
        dataType: "json",
        contentType: "application/json"
      }).success(function(data) {
        message("success", "Save", data);

        self.editingAccount(null);
        self.savedAccount = null;

        $("#edit-account").modal('hide');

        // Reload accounts to update solds.
        self.loadAccounts();
      });
    };

    self.removeAccount = function(account) {
      // Cancel current editing.
      self.removedAccount = account;
      $('#remove-account-confirm').modal();
    };

    // Function to confirm the removal of an entry.
    self.confirmAccountRemove = function() {
      var account = self.removedAccount;

      $.ajax("api/accounts/" + ko.utils.unwrapObservable(account.id), {type: "DELETE"}).success(function (data) {
        message("success", "Save", data);

        // Reload accounts to update solds.
        self.loadAccounts();
      }).complete(function (data) {
        // Reset removed item to null and hide the modal dialog.
        self.removedAccount = null;
        $('#remove-account-confirm').modal('hide');
      });
    };

    self.categories = ko.computed(function() {
      var unwrap = ko.utils.unwrapObservable;

      var entries=unwrap(self.entries);

      var categories = ko.observableArray([]);

      $.each(entries, function(index, entry) {
        if(entry.category() && entry.category() != '' && categories.indexOf(entry.category()) == -1) {
          categories.push(entry.category());
        }
      });

      return categories();
    });

    // Returns the data for the categories by summing values with same category
    self.expenseCategoriesChart = ko.computed(function() {
      var unwrap = ko.utils.unwrapObservable;

      var entries=unwrap(self.entries);

      // First pass: get sum values for each category.
      var chartValuesTmp = {};
      $.each(entries, function(index, entry) {
        var category = unwrap(entry.category);
        var value = unwrap(entry.value) ? Number(unwrap(entry.value)) : null;

        if(category && value && value < 0.0) {
          var oldValue = 0.0;

          if(chartValuesTmp[category]) {
            oldValue = chartValuesTmp[category];
          }

          chartValuesTmp[category] = oldValue - value
        }
      });
 
      // Second pass: transform to an array readable by jqplot.
      var chartValues = [];
      $.each(chartValuesTmp, function(key, value) {
        chartValues.push([key, value]);
      });

      return chartValues;
    });

    // Return the data for the sold chart.
    self.entriesChart = ko.computed(function() {
      var unwrap = ko.utils.unwrapObservable;

      // We assume that entries are sorted by value date descending.
      var entries = unwrap(self.entries).slice().reverse();

      // Transform to an array readable by jqplot Line renderer.
      var chartValues = [];
      $.each(entries, function(index, entry) {
        if(unwrap(entry.operation_date) && unwrap(entry.sold)) {
          chartValues.push([unwrap(entry.operation_date), Number(unwrap(entry.sold))]);
        }
      });

      return {account: self.account(), entries: chartValues};
    }, self);

    // Function to load entries from server for a specific account and month.
    self.loadEntries = function(account, month) {
      // An account may not have any month (new account)
      if(month) {
        $.get("api/entries/" + account.id() + "/" + month.year() + "/" + month.month()).success(function(data) {
          // Clean up selected entry.
          self.selectedItem(null);

          // Update entries
          self.clearNewEntry()
          var entries = [self.newEntry()].concat(ko.utils.arrayMap($.parseJSON(data), ko.mapping.fromJS));

          self.entries(entries);

          // Initialize date picker for operation date column.
          $("#new_operation_date").datepicker().on('changeDate', function(ev){
            self.newEntry().operation_date(ev.date.format(ev.currentTarget.dataset.dateFormat));
          });
        });
      } else {
        // If no month, just remove all entries.
        self.entries.removeAll();
      }
    };

    // Function to load accounts
    self.loadAccounts = function() {
      $.get("api/accounts").success(function (data) {
        // Update accounts
        self.accounts(ko.utils.arrayMap($.parseJSON(data), ko.mapping.fromJS));

        var accountToSelect = null

        // Reset selected account to the new instance corresponding to the old one.
        if(self.account()) {
          // Find the new instance of the previously selected account.
          $.each(self.accounts(), function(index, account) {
            if(account.id() == self.account().id()) {
              accountToSelect = account;
            }
          });
        }

        // Set selected account to first one if not yet selected
        if(!accountToSelect && self.accounts().length > 0){
          accountToSelect = self.accounts()[0];
        }

        // Reset to account to select
        self.account(accountToSelect);

        // Load months if there is any account, or remove months.
        if(self.account()) {
          self.loadMonths(self.account());
        } else {
          self.months.removeAll();
        }
      });
    };

    // Function to load months
    self.loadMonths = function(account){
      $.get("api/accounts/" + account.id() + "/months").success(function (data) {
        // Update months
        self.months(ko.utils.arrayMap($.parseJSON(data), ko.mapping.fromJS));
        
        var monthToSelect = null;

        var today = new Date();
        var currentYear = today.getFullYear().toString();
        var currentMonth = (today.getMonth() + 1 < 10 ? "0" : "") + (today.getMonth() + 1);

        // Find the new instance of the previously selected month.
        $.each(self.months(), function(index, month) {
          // Reset selected month to the new instance corresponding to the old one
          if(self.month()) {
            if(month.year() === self.month().year() && month.month() === self.month().month()) {
              monthToSelect = month;
            }
          } else {
            if(month.year() === currentYear && month.month() === currentMonth) {
              monthToSelect = month;
            }
          }
        });

        // Set selected month to the last one if not yet selected.
        if(!monthToSelect && self.months().length > 0) {
          monthToSelect = self.months()[self.months().length - 1];
        }

        // Reset to month to select
        self.month(monthToSelect);

        // Load entries if there is a month or remove entries.
        if(self.month) {
          self.loadEntries(self.account(), self.month());
        } else {
          self.entries.removeAll();
        }
      });
    };

    // Function to select template in function of selected item.
    self.templateToUse = function (item) {
      return  self.newEntry() === item ? 'newTmpl' : self.selectedItem() === item ? 'editTmpl' : 'itemsTmpl';
    };

    // Function to edit an item
    self.edit = function(item) {
      // Cancel previous editing.
      if(self.savedItem) {
        self.cancel();
      }

      // Save current item
      self.savedItem=ko.toJS(item);
      self.selectedItem(item);

      // Initialize date picker for operation date column.
      $("#operation_date").datepicker().on('changeDate', function(ev){
        self.selectedItem().operation_date(ev.date.format(ev.currentTarget.dataset.dateFormat));
      });
    };

    self.clearNewEntry = function() {
        self.newEntry().id(null); // id should not change, but just in case...
        self.newEntry().pointed(false)
        self.newEntry().operation_date(null);
        self.newEntry().label(null);
        self.newEntry().value(null);
        self.newEntry().account_id(self.account().id()); // account_id should not change, but just in case...
        self.newEntry().category(null);
    };

    // Function to cancel current editing.
    self.cancel = function(item) {
      // Reset selected item fields to saved item ones.
      if(item === self.selectedItem() && self.savedItem) {
        self.selectedItem().id(self.savedItem.id); // id should not change, but just in case...
        self.selectedItem().pointed(self.savedItem.pointed);
        self.selectedItem().operation_date(self.savedItem.operation_date);
        self.selectedItem().label(self.savedItem.label);
        self.selectedItem().value(self.savedItem.value);
        self.selectedItem().account_id(self.savedItem.account_id); // account_id should not change, but just in case...
        self.selectedItem().category(self.savedItem.category);
      }

      // We are cancelling the new entry, just reset it.
      if(item === self.newEntry()) {
        self.clearNewEntry();
      }

      // Reset saved and selected items to null.
      self.savedItem = null;
      self.selectedItem(null);
    };

    self.pointEntry = function(entry) {
      if(entry.pointed()) {
        entry.pointed(false);
      } else {
        entry.pointed(true);
      }

      if(entry != self.newEntry()) {
        self.save(entry);
      }
    };

    // Function to save the current selected entry.
    self.save = function(item) {
      //var item = self.selectedItem();
      if(item === self.newEntry()) {
        item.account_id(self.account().id());
      }

      // Ajax call to save the entry.
      var type;
      var url = "api/entries";

      if(item.id()) {
        url += "/" + item.id();
      }

      $.ajax({
        url: url,
        type: "PUT",
        contentType: "application/json",
        data:ko.toJSON(item),
        dataType: "json"
      }).success(function(data) {
        message("success", "Save", data);

        self.clearNewEntry();
        self.selectedItem(null);
        self.savedItem = null;

        // Reload accounts to update solds.
        self.loadAccounts();
      });
    };

    // Function to remove an entry.
    self.remove = function (item) {
      // Cancel current editing.
      self.cancel();

      if (item.id()) {
        // This entry is saved in database, we show a modal dialog to confirm the removal.
        self.removedItem = item;
        $('#remove-confirm').modal();
      } else {
        // This entry was not saved in database yet, we just remove it from the list.
        self.entries.remove(item);
      }
    };

    // Function to confirm the removal of an entry.
    self.confirmRemove = function() {
      var item = self.removedItem;

      $.ajax("api/entries/" + ko.utils.unwrapObservable(item.id), {type: "DELETE"}).success(function (result) {
        // Reload accounts to update solds.
        self.loadAccounts();
      }).success(function (data) {
        message("success", "Delete", data);
      }).complete(function (data) {
        // Reset removed item to null and hide the modal dialog.
        self.removedItem = null;
        $('#remove-confirm').modal('hide');
      });
    };

    // Callback function to select a new month.
    self.selectMonth = function(month) {
      if(month) {
        self.month(month);
        self.loadEntries(self.account(), month);
      }
    };

    // Callback function to select a new account.
    self.selectAccount = function(account) {
      if(account) {
        self.newEntry().account_id(account.id());
        self.account(account);
        self.loadMonths(account);
      }
    };
};

// Function to draw the sold evolution chart.
drawChart = function(data, element) {
  // Clear previous chart
  $(element).html("");

  var entries = data.entries;

  if(entries && entries.length > 0) {
    // Prepare for today vertical line.
    var today = new Date();
    today.setHours(0);
    today.setMinutes(0);

    // Find first and last days to set limits of the x axis.
    var day = 24 * 60 * 60 * 1000;
    var firstDate = new Date(Date.parse(entries[0][0]).valueOf() - day).format('yyyy-mm-dd');
    var lastDate = new Date(Date.parse(entries[entries.length -1][0]).valueOf() + day).format('yyyy-mm-dd');

    // Plot chart, and store it in a window parameter for resize callback (need to be done better than it...)
    window.chart = $.jqplot(element.id, [entries], {
        // Title of the chart
        title: "&Eacute;volution du solde",
        axes:{
          // Parameters for the date axis
          xaxis:{
            autoscale: true,

            // Date rendere for this axis
            renderer:$.jqplot.DateAxisRenderer,

            // Limits
            min: firstDate,
            max: lastDate,

            // Tick options
            tickOptions: {
              // Format date for x axis.
              formatString: "%F"
            }
          },
          // Parameters for the value axis
          yaxis: {
            autoscale: true,
          }
        },

        // Highlighter parameters
        highlighter: {
          show: true,
          //yvalues: 4,
          formatString: '<table class="jqplot-highlighter"><tr><td>date:</td><td>%s</td></tr><tr><td>sold:</td><td>%s</td></tr>'
        },

        // Series parameters
        series: [{
          // We use the OHLC (open, high, low, close) rendered.
          //renderer:$.jqplot.OHLCRenderer,
          color: "blue",
          rendererOptions: {
            smooth: true,
          }
        }],

        // To display horizontal (0) and vertical (today) lines
        canvasOverlay: {
          show: true,
          objects: [
            // Orange horizontal line for 0 limit
            {dashedHorizontalLine: {
              name: "zero",
              y: 0,
              lineWidth: 1,
              color: "orange",
              shadow: false
            }},
            // Red horizontal line for authorized overdraft limit
            {dashedHorizontalLine: {
              name: "overdraft",
              y: data.account.authorized_overdraft(),
              lineWidth: 1,
              color: "red",
              shadow: false
            }},
            // Gray vertical line for today
            { dashedVerticalLine: {
              name: "today",
              x: today,
              lineWidth: 1,
              color: "gray",
              shadow: false
            }}
          ]
        }
    });
  } else {
    // Reset chart to null to avoid redraw of a non existing chart in resize callback.
    window.chart = null;
  }
};

// Function to draw the expense category pie chart.
drawPieChart = function(entries, element) {
  // Clear previous chart
  $(element).html("");

  if(entries && entries.length > 0) {
    // Plot chart, and store it in a window parameter for resize callback (need to be done better than it...)
    window.pieChart = $.jqplot(element.id, [entries], {
        // Title of the chart
        title: "D&eacute;penses",

        // Series parameters.
        seriesDefaults: {
          // Pie chart renderer
          renderer: $.jqplot.PieRenderer,
          rendererOptions: {
            showDataLabels: true,
          }
        },

        // Legend parameters.
        legend: {
          show: true,
          location: 'e',
          rendererOptions: {
            numberRows: 9,
            numberColumns: 2
          }
        },

        // Highlighter parameters;
        highlighter: {
          show: true,
          formatString:'%s: %s', 
          tooltipLocation:'sw', 
          useAxesFormatters:false
        }
    });
  } else {
    // Reset chart to null to avoid redraw of a non existing chart in resize callback.
    window.pieChart = null;
  }
};

// Chart binding to redraw the chart on entries update.
ko.bindingHandlers.chart = {
    init: function (element, valueAccessor, allBindingsAccessor, viewModel) {
      // empty - left as placeholder if needed later
    },

    update: function (element, valueAccessor, allBindingsAccessor, viewModel) {
      var unwrap = ko.utils.unwrapObservable;
      var dataSource = valueAccessor();

      var data = dataSource ? unwrap(dataSource) : null;
      drawChart(data, element);
    }
};

// Pie chart binding to redraw expense chart on entries update.
ko.bindingHandlers.pieChart = {
    init: function (element, valueAccessor, allBindingsAccessor, viewModel) {
      // empty - left as placeholder if needed later
    },

    update: function (element, valueAccessor, allBindingsAccessor, viewModel) {
      var unwrap = ko.utils.unwrapObservable;
      var dataSource = valueAccessor();

      var entries = dataSource ? unwrap(dataSource) : null;
      drawPieChart(entries, element);
    }
};

// Default AJAX error handler.
$(document).ajaxError(function(event, xhr, settings) {
  message("error", xhr.statusText, xhr.responseText);
});

// Bootstrap.Typeahead binding.
// Use like so: data-bind="typeahead: { source: namespaces }"
ko.bindingHandlers.typeahead = {
  init: function(element, valueAccessor, allBindingsAccessor, viewModel) {
    $(element).typeahead({
      source: function() { return ko.utils.unwrapObservable(valueAccessor().source); },
      onselect: function(value) { allBindingsAccessor().value(value); }
    });
  },

  update: function(element, valueAccessor, allBindingsAccessor, viewModel) {
    $(element).typeahead({
      source: function() { ko.utils.unwrapObservable(valueAccessor().source); },
      onselect: function(value) { allBindingsAccessor().value(value); }
    });
  }
};

// Resize callback.
$(window).resize(function() {
  if(window.chart) {
    window.chart.replot({resetAxes: true});
  }

  if(window.pieChart) {
    window.pieChart.replot({resetAxes: true});
  }
});

// ViewModal instanciation.
var viewModel = new ListViewModel();
ko.applyBindings(viewModel);

// Load accounts after page initialization.
$(viewModel.loadAccounts);