From 5c110716cfda6e616a795edd12f2012b132dca9f Mon Sep 17 00:00:00 2001
From: Joris
Date: Sun, 2 Apr 2017 17:51:12 +0200
Subject: Add a chart on payments by month by categories

---
 README.md                                |  12 +-
 elm-package.json                         |   3 +
 src/client/Chart/Api.elm                 |  41 +++++++
 src/client/Chart/Model.elm               |  73 +++++++++++++
 src/client/Chart/View.elm                | 182 +++++++++++++++++++++++++++++++
 src/client/Dialog/AddPayment/Model.elm   |   2 -
 src/client/LoggedData.elm                |  10 +-
 src/client/LoggedIn/Model.elm            |  28 ++---
 src/client/LoggedIn/Msg.elm              |   9 +-
 src/client/LoggedIn/Stat/Model.elm       |  34 ++++++
 src/client/LoggedIn/Stat/Msg.elm         |   7 ++
 src/client/LoggedIn/Stat/Update.elm      |  24 ++++
 src/client/LoggedIn/Stat/View.elm        | 101 +++++++++--------
 src/client/LoggedIn/Update.elm           |  73 +++++++------
 src/client/LoggedIn/View.elm             |   4 +-
 src/client/Main.elm                      |   2 +-
 src/client/Model.elm                     |   4 +-
 src/client/Model/Income.elm              |  11 +-
 src/client/Model/Payer.elm               |   1 -
 src/client/Model/Payment.elm             |   7 +-
 src/client/Model/PaymentCategory.elm     |  25 ++++-
 src/client/Update.elm                    |  64 +++++------
 src/client/Utils/List.elm                |  19 ++++
 src/client/Utils/Maybe.elm               |  34 ------
 src/client/View.elm                      |   2 -
 src/client/View/Date.elm                 |  11 +-
 src/client/View/Form.elm                 |  13 +--
 src/server/Model/Message/Key.hs          |   2 +
 src/server/Model/Message/Translations.hs | 110 ++++++++++---------
 29 files changed, 658 insertions(+), 250 deletions(-)
 create mode 100644 src/client/Chart/Api.elm
 create mode 100644 src/client/Chart/Model.elm
 create mode 100644 src/client/Chart/View.elm
 create mode 100644 src/client/LoggedIn/Stat/Model.elm
 create mode 100644 src/client/LoggedIn/Stat/Msg.elm
 create mode 100644 src/client/LoggedIn/Stat/Update.elm
 delete mode 100644 src/client/Utils/Maybe.elm

diff --git a/README.md b/README.md
index 9f9045c..4b220db 100644
--- a/README.md
+++ b/README.md
@@ -46,9 +46,17 @@ See [application.conf](application.conf).
 TODO
 ----
 
-- search by payment category
+### Chart
+
+- Tooltip with values
+- Show / Hide serie by clicking on caption
+- Adapt to screen width
+- Show only the last entries and allow to move in time ?
+
+### Other
+
+- search by payment category and payment date
 - Use `sqlite-simple` instead of `persistent`
-- show charts with payments and categories
 - Move up element ids security (editOwn is actually at db level)
 - Prevent a daemon to freeze when it got “SQLite3 returned ErrorBusy while
   attempting to perform step.”
diff --git a/elm-package.json b/elm-package.json
index 5f76d18..9f7fcbf 100644
--- a/elm-package.json
+++ b/elm-package.json
@@ -8,12 +8,15 @@
   "elm-version": "0.18.0 <= v < 0.19.0",
   "dependencies": {
     "elm-community/json-extra": "2.1.0 <= v < 3.0.0",
+    "elm-community/list-extra": "6.0.0 <= v < 7.0.0",
+    "elm-community/maybe-extra": "4.0.0 <= v < 5.0.0",
     "elm-lang/core": "5.1.1 <= v < 6.0.0",
     "elm-lang/dom": "1.1.1 <= v < 2.0.0",
     "elm-lang/html": "2.0.0 <= v < 3.0.0",
     "elm-lang/http": "1.0.0 <= v < 2.0.0",
     "elm-lang/mouse": "1.0.1 <= v < 2.0.0",
     "elm-lang/navigation": "2.0.1 <= v < 3.0.0",
+    "elm-lang/svg": "2.0.0 <= v < 3.0.0",
     "elm-lang/window": "1.0.1 <= v < 2.0.0",
     "etaque/elm-form": "2.0.0 <= v < 3.0.0",
     "evancz/url-parser": "2.0.1 <= v < 3.0.0",
diff --git a/src/client/Chart/Api.elm b/src/client/Chart/Api.elm
new file mode 100644
index 0000000..693f362
--- /dev/null
+++ b/src/client/Chart/Api.elm
@@ -0,0 +1,41 @@
+module Chart.Api exposing
+  ( from
+  , withSize
+  , withTitle
+  , withOrdinate
+  , toHtml
+  )
+
+import Html exposing (Html)
+import Svg exposing (..)
+import Svg.Attributes exposing (..)
+
+import Chart.Model as Chart exposing (Chart, Serie, Vec2, View)
+import Chart.View as Chart
+
+from : List String -> List Serie -> Chart
+from keys series =
+  { keys = keys
+  , series = series
+  , size = { x = 600, y = 400 }
+  , title = ""
+  , scaleColor = "#DDDDDD"
+  , formatOrdinate = toString
+  , ordinateLines = 5
+  }
+
+withSize : Vec2 -> Chart -> Chart
+withSize size chart = { chart | size = size }
+
+withTitle : String -> Chart -> Chart
+withTitle title chart = { chart | title = title }
+
+withOrdinate : Int -> (Float -> String) -> Chart -> Chart
+withOrdinate lines format chart =
+  { chart
+  | formatOrdinate = format
+  , ordinateLines = lines
+  }
+
+toHtml : Chart -> Html msg
+toHtml chart = Chart.view chart
diff --git a/src/client/Chart/Model.elm b/src/client/Chart/Model.elm
new file mode 100644
index 0000000..b5c176f
--- /dev/null
+++ b/src/client/Chart/Model.elm
@@ -0,0 +1,73 @@
+module Chart.Model exposing
+  ( Chart
+  , Serie
+  , maxScale
+  , Vec2
+  , View
+  , mkView
+  , bounds
+  )
+
+import List.Extra as List
+
+type alias Chart =
+  { keys : List String
+  , series : List Serie
+  , size : Vec2
+  , title : String
+  , scaleColor : String
+  , formatOrdinate : Float -> String
+  , ordinateLines : Int
+  }
+
+type alias Serie =
+  { values : List Float
+  , color : String
+  , label : String
+  }
+
+maxScale : Chart -> Float
+maxScale { keys, series } =
+  List.range 0 (List.length keys - 1)
+    |> List.map (\i ->
+         series
+           |> List.map (truncate << Maybe.withDefault 0 << List.getAt i << .values)
+           |> List.maximum
+           |> Maybe.withDefault 0
+       )
+    |> List.maximum
+    |> Maybe.withDefault 0
+    |> upperBound
+
+upperBound : Int -> Float
+upperBound n = toFloat (upperBoundInt 0 n)
+
+upperBoundInt : Int -> Int -> Int
+upperBoundInt count n =
+  if n < 10
+    then
+      (n + 1) * (10 ^ count)
+    else
+      upperBoundInt (count + 1) (n // 10)
+
+type alias Vec2 =
+  { x : Float
+  , y : Float
+  }
+
+type alias View =
+  { fx : Float -> Float
+  , fy : Float -> Float
+  }
+
+mkView : Vec2 -> Vec2 -> View
+mkView p1 p2 =
+  { fx = \x -> p1.x + x * (p2.x - p1.x)
+  , fy = \y -> p1.y + y * (p2.y - p1.y)
+  }
+
+bounds : View -> (Vec2, Vec2)
+bounds { fx, fy } =
+  ( { x = fx 0, y = fy 0 }
+  , { x = fx 1, y = fy 1 }
+  )
diff --git a/src/client/Chart/View.elm b/src/client/Chart/View.elm
new file mode 100644
index 0000000..af8b4b7
--- /dev/null
+++ b/src/client/Chart/View.elm
@@ -0,0 +1,182 @@
+module Chart.View exposing
+  ( view
+  )
+
+import Html exposing (Html)
+import List.Extra as List
+import Svg exposing (..)
+import Svg.Attributes exposing (..)
+
+import Chart.Model as Chart exposing (Chart, Serie, Vec2, View)
+import Utils.List as List
+
+view : Chart -> Html msg
+view chart =
+  let { size, title, series } = chart
+      titleHeight = 100
+      captionHeight = 50
+  in  svg
+        [ width << toString <| size.x
+        , height << toString <| size.y
+        , viewBox ("0 0 " ++ (toString size.x) ++ " " ++ (toString size.y))
+        ]
+        (  [ renderTitle (Chart.mkView { x = 0, y = 0 } { x = size.x, y = titleHeight }) title ]
+        ++ renderSeriesAndScales (Chart.mkView { x = 50, y = titleHeight } { x = size.x, y = size.y - captionHeight }) chart
+        ++ renderCaptions (Chart.mkView { x = 0, y = size.y - captionHeight } { x = size.x, y = size.y }) series
+        )
+
+renderTitle : View -> String -> Svg msg
+renderTitle view title =
+  text_
+    [ x << toString <| view.fx 0.5
+    , y << toString <| view.fy 0.5
+    , textAnchor "middle"
+    , dominantBaseline "middle"
+    , fontSize "20"
+    ]
+    [ text title ]
+
+renderSeriesAndScales : View -> Chart -> List (Svg msg)
+renderSeriesAndScales view chart =
+  let { keys, series, scaleColor, formatOrdinate } = chart
+      (p1, p2) = Chart.bounds view
+      ordinateWidth = 100
+      abscissaHeight = 60
+      maxScale = Chart.maxScale chart
+  in  (  renderOrdinates (Chart.mkView { x = p1.x, y = p1.y } { x = p1.x + ordinateWidth, y = p2.y - abscissaHeight }) formatOrdinate maxScale
+      ++ renderAbscissas (Chart.mkView { x = p1.x + ordinateWidth, y = p2.y - abscissaHeight } { x = p2.x, y = p2.y }) keys scaleColor
+      ++ renderSeries (Chart.mkView { x = p1.x + ordinateWidth, y = p1.y } { x = p2.x, y = p2.y - abscissaHeight }) series maxScale scaleColor
+      )
+
+renderOrdinates : View -> (Float -> String) -> Float -> List (Svg msg)
+renderOrdinates view formatOrdinate maxScale =
+  ordinates
+    |> List.map (\l ->
+         text_
+           [ x << toString <| view.fx 0.5
+           , y << toString <| view.fy l
+           , textAnchor "middle"
+           , dominantBaseline "middle"
+           ]
+           [ text << formatOrdinate <| (1 - l) * maxScale ]
+       )
+
+
+renderAbscissas : View -> List String -> String -> List (Svg msg)
+renderAbscissas view keys scaleColor =
+  let count = List.length keys
+  in  ( abscissasXPositions keys
+          |> List.map (\(xPos, key) ->
+               [ text_
+                   [ x << toString <| view.fx xPos
+                   , y << toString <| view.fy 0.5
+                   , textAnchor "middle"
+                   , dominantBaseline "middle"
+                   ]
+                   [ text key ]
+               , line
+                   [ x1 << toString <| view.fx xPos
+                   , y1 << toString <| view.fy 0
+                   , x2 << toString <| view.fx xPos
+                   , y2 << toString <| view.fy 0.2
+                   , stroke scaleColor
+                   ]
+                   []
+               ]
+             )
+          |> List.concat
+      )
+
+renderSeries : View -> List Serie -> Float -> String -> List (Svg msg)
+renderSeries view series maxScale scaleColor =
+  (  renderHorizontalLines view series scaleColor
+  ++ renderPoints view series maxScale
+  )
+
+renderHorizontalLines : View -> List Serie -> String -> List (Svg msg)
+renderHorizontalLines view series scaleColor =
+  ordinates
+    |> List.map (\l ->
+         line
+           [ x1 << toString <| view.fx 0
+           , y1 << toString <| view.fy l
+           , x2 << toString <| view.fx 1
+           , y2 << toString <| view.fy l
+           , stroke scaleColor
+           ]
+           []
+       )
+
+renderPoints : View -> List Serie -> Float -> List (Svg msg)
+renderPoints view series maxScale =
+  series
+    |> List.map (\serie ->
+         let points =
+               abscissasXPositions serie.values
+                 |> List.map (\(xPos, value) -> { x = xPos, y = 1 - value / maxScale })
+         in  [ renderLines view serie.color points
+             , List.map (renderPoint view serie.color) points
+             ]
+               |> List.concat
+       )
+    |> List.concat
+
+renderLines : View -> String -> List Vec2 -> List (Svg msg)
+renderLines view color points =
+  List.links points
+    |> List.map (\(p1, p2) ->
+         line
+           [ x1 << toString <| view.fx p1.x
+           , y1 << toString <| view.fy p1.y
+           , x2 << toString <| view.fx p2.x
+           , y2 << toString <| view.fy p2.y
+           , stroke color
+           ]
+           []
+       )
+
+renderPoint : View -> String -> Vec2 -> Svg msg
+renderPoint view color pos =
+  circle
+    [ cx << toString <| view.fx pos.x
+    , cy << toString <| view.fy pos.y
+    , r "4"
+    , fill color
+    ]
+    []
+
+abscissasXPositions : List a -> List (Float, a)
+abscissasXPositions xs =
+  let count = List.length xs
+  in  xs
+        |> List.zip (List.range 1 (count + 1))
+        |> List.map (\(i, x) -> (toFloat i / (toFloat count + 1), x))
+
+ordinates : List Float
+ordinates =
+  let count = 10
+  in  List.range 0 (count - 1)
+        |> List.map (\l -> toFloat l / (toFloat count - 1))
+
+renderCaptions : View -> List Serie -> List (Svg msg)
+renderCaptions view series =
+  let count = List.length series
+  in  series
+        |> List.zip (List.range 1 (List.length series))
+        |> List.map (\(i, serie) ->
+             renderCaption { x = view.fx (toFloat i / (toFloat count + 1)), y = view.fy 0.5 } serie
+           )
+        |> List.concat
+
+renderCaption : Vec2 -> Serie -> List (Svg msg)
+renderCaption point { label, color } =
+  [ text_
+      [ x << toString <| point.x
+      , y << toString <| point.y
+      , textAnchor "middle"
+      , dominantBaseline "middle"
+      , fill color
+      , fontSize "18"
+      ]
+      [ text label ]
+  ]
diff --git a/src/client/Dialog/AddPayment/Model.elm b/src/client/Dialog/AddPayment/Model.elm
index 8a94bc7..07e7cbb 100644
--- a/src/client/Dialog/AddPayment/Model.elm
+++ b/src/client/Dialog/AddPayment/Model.elm
@@ -21,8 +21,6 @@ import Model.Payment as Payment exposing (Payment, PaymentId)
 import Model.Frequency exposing (Frequency)
 import Model.Translations exposing (Translations)
 
-import Utils.Maybe as Maybe
-
 type alias Model =
   { id : Maybe PaymentId
   , name : String
diff --git a/src/client/LoggedData.elm b/src/client/LoggedData.elm
index 9bb0a7f..e048247 100644
--- a/src/client/LoggedData.elm
+++ b/src/client/LoggedData.elm
@@ -30,11 +30,11 @@ type alias LoggedData =
   , paymentCategories : PaymentCategories
   }
 
-build : Model -> LoggedInModel.Model -> LoggedData
-build model loggedIn =
-  { currentTime = model.currentTime
-  , translations = model.translations
-  , conf = model.conf
+build : Time -> Translations -> Conf -> LoggedInModel.Model -> LoggedData
+build currentTime translations conf loggedIn =
+  { currentTime = currentTime
+  , translations = translations
+  , conf = conf
   , users = loggedIn.users
   , me = loggedIn.me
   , payments = loggedIn.payments
diff --git a/src/client/LoggedIn/Model.elm b/src/client/LoggedIn/Model.elm
index 6c858a6..f4fad94 100644
--- a/src/client/LoggedIn/Model.elm
+++ b/src/client/LoggedIn/Model.elm
@@ -5,17 +5,18 @@ module LoggedIn.Model exposing
 
 import Time exposing (Time)
 
+import LoggedIn.Home.Model as Home
+import LoggedIn.Stat.Model as Stat
+import Model.Category exposing (Categories)
+import Model.Income exposing (Incomes)
 import Model.Init exposing (..)
 import Model.Payment exposing (Payments)
-import Model.User exposing (Users, UserId)
-import Model.Income exposing (Incomes)
-import Model.Category exposing (Categories)
 import Model.PaymentCategory exposing (PaymentCategories)
-
-import LoggedIn.Home.Model as Home
+import Model.User exposing (Users, UserId)
 
 type alias Model =
   { home : Home.Model
+  , stat : Stat.Model
   , users : Users
   , me : UserId
   , payments : Payments
@@ -24,13 +25,14 @@ type alias Model =
   , paymentCategories : PaymentCategories
   }
 
-init : Init -> Model
-init initData =
+init : Time -> Init -> Model
+init time { users, me, payments, incomes, categories, paymentCategories } =
   { home = Home.init
-  , users = initData.users
-  , me = initData.me
-  , payments = initData.payments
-  , incomes = initData.incomes
-  , categories = initData.categories
-  , paymentCategories = initData.paymentCategories
+  , stat = Stat.init time paymentCategories payments
+  , users = users
+  , me = me
+  , payments = payments
+  , incomes = incomes
+  , categories = categories
+  , paymentCategories = paymentCategories
   }
diff --git a/src/client/LoggedIn/Msg.elm b/src/client/LoggedIn/Msg.elm
index d00e2cb..d9b3bce 100644
--- a/src/client/LoggedIn/Msg.elm
+++ b/src/client/LoggedIn/Msg.elm
@@ -4,16 +4,17 @@ module LoggedIn.Msg exposing
 
 import Date exposing (Date)
 
-import Model.Payment exposing (PaymentId)
+import LoggedIn.Home.Msg as Home
+import LoggedIn.Stat.Msg as Stat
+import Model.Category exposing (CategoryId)
 import Model.Frequency exposing (Frequency)
 import Model.Income exposing (IncomeId)
-import Model.Category exposing (CategoryId)
-
-import LoggedIn.Home.Msg as Home
+import Model.Payment exposing (PaymentId)
 
 type Msg =
   NoOp
   | HomeMsg Home.Msg
+  | StatMsg Stat.Msg
   | ValidateCreatePayment PaymentId String Int Date CategoryId Frequency
   | ValidateEditPayment PaymentId String Int Date CategoryId Frequency
   | ValidateDeletePayment PaymentId
diff --git a/src/client/LoggedIn/Stat/Model.elm b/src/client/LoggedIn/Stat/Model.elm
new file mode 100644
index 0000000..bfc66f2
--- /dev/null
+++ b/src/client/LoggedIn/Stat/Model.elm
@@ -0,0 +1,34 @@
+module LoggedIn.Stat.Model exposing
+  ( Model
+  , init
+  , getPaymentsByMonthByCategory
+  )
+
+import Date exposing (Month)
+import List.Extra as List
+import Time exposing (Time)
+
+import Model.Category exposing (CategoryId)
+import Model.Conf exposing (Conf)
+import Model.Payment as Payment exposing (Payments)
+import Model.PaymentCategory as PaymentCategory exposing (PaymentCategories)
+
+type alias Model =
+  { paymentsByMonthByCategory : List ((Month, Int), List (CategoryId, Int))
+  }
+
+init : Time -> PaymentCategories -> Payments -> Model
+init currentTime paymentCategories payments =
+  { paymentsByMonthByCategory = getPaymentsByMonthByCategory currentTime paymentCategories payments
+  }
+
+getPaymentsByMonthByCategory : Time -> PaymentCategories -> Payments -> List ((Month, Int), List (CategoryId, Int))
+getPaymentsByMonthByCategory currentTime paymentCategories payments =
+  Payment.punctual payments
+    |> Payment.groupAndSortByMonth
+    |> List.map (\(m, payments) ->
+         ( m
+         , PaymentCategory.groupPaymentsByCategory paymentCategories payments
+             |> List.map (Tuple.mapSecond (List.sum << List.map .cost))
+         )
+       )
diff --git a/src/client/LoggedIn/Stat/Msg.elm b/src/client/LoggedIn/Stat/Msg.elm
new file mode 100644
index 0000000..d517544
--- /dev/null
+++ b/src/client/LoggedIn/Stat/Msg.elm
@@ -0,0 +1,7 @@
+module LoggedIn.Stat.Msg exposing
+  ( Msg(..)
+  )
+
+type Msg =
+  NoOp
+  | UpdateChart
diff --git a/src/client/LoggedIn/Stat/Update.elm b/src/client/LoggedIn/Stat/Update.elm
new file mode 100644
index 0000000..2415733
--- /dev/null
+++ b/src/client/LoggedIn/Stat/Update.elm
@@ -0,0 +1,24 @@
+module LoggedIn.Stat.Update exposing
+  ( update
+  )
+
+import LoggedData exposing (LoggedData)
+import LoggedIn.Stat.Model as Stat
+import LoggedIn.Stat.Msg as Stat
+
+update : LoggedData -> Stat.Msg -> Stat.Model -> (Stat.Model, Cmd Stat.Msg)
+update loggedData msg model =
+  case msg of
+
+    Stat.NoOp ->
+      ( model
+      , Cmd.none
+      )
+
+    Stat.UpdateChart ->
+      let { currentTime, paymentCategories, payments } = loggedData
+      in  ( { model
+            | paymentsByMonthByCategory = Stat.getPaymentsByMonthByCategory currentTime paymentCategories payments
+            }
+          , Cmd.none
+          )
diff --git a/src/client/LoggedIn/Stat/View.elm b/src/client/LoggedIn/Stat/View.elm
index f57316a..e389c67 100644
--- a/src/client/LoggedIn/Stat/View.elm
+++ b/src/client/LoggedIn/Stat/View.elm
@@ -3,60 +3,75 @@ module LoggedIn.Stat.View exposing
   )
 
 import Date exposing (Month)
-
+import Dict
 import Html exposing (..)
 import Html.Attributes exposing (..)
+import List.Extra as List
+import Time exposing (Time)
 
+import Chart.Api as Chart
 import LoggedData exposing (LoggedData)
-
-import Msg exposing (Msg)
-
-import Model.Payment as Payment exposing (Payments)
-import Model.Conf exposing (Conf)
-import Model.Translations exposing (getMessage, getParamMessage)
-
+import LoggedIn.Stat.Model as Stat
 import LoggedIn.View.Format as Format
+import Model.Category exposing (CategoryId, Categories)
+import Model.Conf exposing (Conf)
+import Model.Payment as Payment exposing (Payments)
+import Model.PaymentCategory as PaymentCategory exposing (PaymentCategories)
+import Model.Translations exposing (Translations, getMessage, getParamMessage)
+import Msg exposing (Msg)
+import Utils.List as List
 import View.Date as Date
 import View.Plural exposing (plural)
 
-import Utils.List as List
+view : LoggedData -> Stat.Model -> Html Msg
+view loggedData { paymentsByMonthByCategory } =
+  div
+    [ class "stat withMargin" ]
+    [ renderChart loggedData paymentsByMonthByCategory ]
 
-view : LoggedData -> Html Msg
-view loggedData =
-  let paymentsByMonth = Payment.groupAndSortByMonth (Payment.punctual loggedData.payments)
-      monthPaymentMean = getMonthPaymentMean loggedData paymentsByMonth
-  in  div
-        [ class "stat withMargin" ]
-        [ h1 [] [ text (getParamMessage [ Format.price loggedData.conf monthPaymentMean ] loggedData.translations "ByMonthsAndMean") ]
-        , ul
-            []
-            ( List.map (monthDetail loggedData) paymentsByMonth)
-        ]
+renderChart : LoggedData -> List ((Month, Int), List (CategoryId, Int)) -> Html msg
+renderChart { currentTime, paymentCategories, categories, conf, translations } paymentsByMonthByCategory =
+  let monthPaymentMean = getMonthPaymentMean currentTime paymentsByMonthByCategory
+      title = getParamMessage [ Format.price conf monthPaymentMean ] translations "ByMonthsAndMean"
+      keys =
+        paymentsByMonthByCategory
+          |> List.map (\((month, year), _) -> Date.shortMonthAndYear month year translations)
+      series =
+        categories
+          |> Dict.toList
+          |> List.map (\(categoryId, category) ->
+               { values =
+                   List.map
+                     (\(_, paymentsByCategory) ->
+                       paymentsByCategory
+                         |> List.find (\(c, _) -> c == categoryId)
+                         |> Maybe.map (toFloat << Tuple.second)
+                         |> Maybe.withDefault 0
+                     )
+                     paymentsByMonthByCategory
+               , color = category.color
+               , label = category.name
+               }
+             )
+      totalSerie =
+        { values =
+            List.transpose (List.map .values series)
+              |> List.map List.sum
+        , color = "black"
+        , label = getMessage translations "Total"
+        }
+  in  Chart.from keys (series ++ [totalSerie])
+        |> Chart.withSize { x = 2000, y = 900 }
+        |> Chart.withTitle title
+        |> Chart.withOrdinate 10 (Format.price conf << truncate)
+        |> Chart.toHtml
 
-getMonthPaymentMean : LoggedData -> List ((Month, Int), Payments) -> Int
-getMonthPaymentMean loggedData paymentsByMonth =
-  paymentsByMonth
+getMonthPaymentMean : Time -> List ((Month, Int), List (CategoryId, Int)) -> Int
+getMonthPaymentMean  currentTime paymentsByMonthByCategory =
+  paymentsByMonthByCategory
     |> List.filter (\((month, year), _) ->
-         let currentDate = Date.fromTime loggedData.currentTime
+         let currentDate = Date.fromTime currentTime
          in  not (Date.month currentDate == month && Date.year currentDate == year)
        )
-    |> List.map (List.sum << List.map .cost << Tuple.second)
+    |> List.map (List.sum << List.map Tuple.second << Tuple.second)
     |> List.mean
-
-monthDetail : LoggedData -> ((Month, Int), Payments) -> Html Msg
-monthDetail loggedData ((month, year), payments) =
-  li
-    []
-    [ text (Date.monthView loggedData.translations month)
-    , text " "
-    , text (toString year)
-    , text " − "
-    , text (paymentsSum loggedData.conf payments)
-    ]
-
-paymentsSum : Conf -> Payments -> String
-paymentsSum conf payments =
-  payments
-    |> List.map .cost
-    |> List.sum
-    |> Format.price conf
diff --git a/src/client/LoggedIn/Update.elm b/src/client/LoggedIn/Update.elm
index 753b1d3..a1d5f7d 100644
--- a/src/client/LoggedIn/Update.elm
+++ b/src/client/LoggedIn/Update.elm
@@ -2,55 +2,60 @@ module LoggedIn.Update exposing
   ( update
   )
 
+import Date exposing (Date)
 import Dict
-import String
-import Task
-
+import Form
 import Http exposing (Error(..))
-import Date exposing (Date)
 import Platform.Cmd exposing (Cmd)
+import String
+import Task
 
-import Form
-
+import LoggedData
+import LoggedIn.Home.Model as Home
+import LoggedIn.Home.Msg as Home
+import LoggedIn.Home.Update as Home
+import LoggedIn.Model as LoggedInModel
+import LoggedIn.Msg as LoggedIn
+import LoggedIn.Stat.Model as Stat
+import LoggedIn.Stat.Msg as Stat
+import LoggedIn.Stat.Update as Stat
 import Model exposing (Model)
-import Model.Payment as Payment exposing (Payment)
+import Model.Category exposing (Category)
 import Model.Frequency exposing (Frequency(..))
 import Model.Income as Income exposing (Income)
-import Model.Category exposing (Category)
+import Model.Payment as Payment exposing (Payment)
 import Model.PaymentCategory as PaymentCategory
-
 import Server
-import LoggedData
-
-import LoggedIn.Msg as LoggedInMsg
-import LoggedIn.Model as LoggedInModel
-
-import LoggedIn.Home.Msg as Home
-import LoggedIn.Home.Update as Home
-import LoggedIn.Home.Model as Home
 
 import Utils.Cmd exposing ((:>))
 
-update : Model -> LoggedInMsg.Msg -> LoggedInModel.Model -> (LoggedInModel.Model, Cmd LoggedInMsg.Msg)
+update : Model -> LoggedIn.Msg -> LoggedInModel.Model -> (LoggedInModel.Model, Cmd LoggedIn.Msg)
 update model msg loggedIn =
-  let loggedData = LoggedData.build model loggedIn
+  let loggedData = LoggedData.build model.currentTime model.translations model.conf loggedIn
   in  case msg of
 
-        LoggedInMsg.NoOp ->
+        LoggedIn.NoOp ->
           ( loggedIn
           , Cmd.none
           )
 
-        LoggedInMsg.HomeMsg homeMsg ->
+        LoggedIn.HomeMsg homeMsg ->
           case Home.update loggedData homeMsg loggedIn.home of
             (home, effects) ->
               ( { loggedIn | home = home }
-              , Cmd.map LoggedInMsg.HomeMsg effects
+              , Cmd.map LoggedIn.HomeMsg effects
+              )
+
+        LoggedIn.StatMsg statMsg ->
+          case Stat.update loggedData statMsg loggedIn.stat of
+            (stat, effects) ->
+              ( { loggedIn | stat = stat }
+              , Cmd.map LoggedIn.StatMsg effects
               )
 
-        LoggedInMsg.ValidateCreatePayment paymentId name cost date category frequency ->
-          update model (LoggedInMsg.HomeMsg <| Home.SearchMsg (Form.Reset (Home.searchInitial frequency))) loggedIn
-            :> update model (LoggedInMsg.HomeMsg <| Home.UpdatePage 1)
+        LoggedIn.ValidateCreatePayment paymentId name cost date category frequency ->
+          update model (LoggedIn.HomeMsg <| Home.SearchMsg (Form.Reset (Home.searchInitial frequency))) loggedIn
+            :> update model (LoggedIn.HomeMsg <| Home.UpdatePage 1)
             :> (\loggedIn ->
                  let newPayment = Payment paymentId name cost date loggedIn.me frequency
                  in  ( { loggedIn
@@ -61,7 +66,7 @@ update model msg loggedIn =
                      )
                )
 
-        LoggedInMsg.ValidateEditPayment paymentId name cost date category frequency ->
+        LoggedIn.ValidateEditPayment paymentId name cost date category frequency ->
           let updatedPayment = Payment paymentId name cost date loggedIn.me frequency
               mbOldPayment = Payment.find paymentId loggedIn.payments
           in  ( { loggedIn
@@ -76,7 +81,7 @@ update model msg loggedIn =
               , Cmd.none
               )
 
-        LoggedInMsg.ValidateDeletePayment paymentId ->
+        LoggedIn.ValidateDeletePayment paymentId ->
           let payments = Payment.delete paymentId loggedIn.payments
               frequency =
                 case Form.getOutput loggedIn.home.search of
@@ -88,7 +93,7 @@ update model msg loggedIn =
                 )
           in  if switchToPunctual
                 then
-                  update model (LoggedInMsg.HomeMsg <| Home.SearchMsg (Form.Reset (Home.searchInitial Punctual))) loggedIn
+                  update model (LoggedIn.HomeMsg <| Home.SearchMsg (Form.Reset (Home.searchInitial Punctual))) loggedIn
                     :> (\loggedIn ->
                          ( { loggedIn | payments = payments }
                          , Cmd.none
@@ -99,34 +104,34 @@ update model msg loggedIn =
                   , Cmd.none
                   )
 
-        LoggedInMsg.ValidateCreateIncome incomeId amount date ->
+        LoggedIn.ValidateCreateIncome incomeId amount date ->
           let newIncome = { userId = loggedIn.me, amount = amount, time = Date.toTime date }
           in  ( { loggedIn | incomes = Dict.insert incomeId newIncome loggedIn.incomes }
               , Cmd.none
               )
 
-        LoggedInMsg.ValidateEditIncome incomeId amount date ->
+        LoggedIn.ValidateEditIncome incomeId amount date ->
           let updateIncome _ = Just <| Income loggedIn.me (Date.toTime date) amount
           in  ( { loggedIn | incomes = Dict.update incomeId updateIncome loggedIn.incomes }
               , Cmd.none
               )
 
-        LoggedInMsg.ValidateDeleteIncome incomeId ->
+        LoggedIn.ValidateDeleteIncome incomeId ->
           ( { loggedIn | incomes = Dict.remove incomeId loggedIn.incomes }
           , Cmd.none
           )
 
-        LoggedInMsg.ValidateCreateCategory categoryId name color ->
+        LoggedIn.ValidateCreateCategory categoryId name color ->
           let newCategory = { name = name, color = color }
           in  ( { loggedIn | categories = Dict.insert categoryId newCategory loggedIn.categories }
               , Cmd.none
               )
 
-        LoggedInMsg.ValidateEditCategory categoryId name color ->
+        LoggedIn.ValidateEditCategory categoryId name color ->
           let updateCategory _ = Just <| Category name color
           in  ( { loggedIn | categories = Dict.update categoryId updateCategory loggedIn.categories } , Cmd.none)
 
-        LoggedInMsg.ValidateDeleteCategory categoryId ->
+        LoggedIn.ValidateDeleteCategory categoryId ->
           ( { loggedIn | categories = Dict.remove categoryId loggedIn.categories }
           , Cmd.none
           )
diff --git a/src/client/LoggedIn/View.elm b/src/client/LoggedIn/View.elm
index ddc85d5..4936c6e 100644
--- a/src/client/LoggedIn/View.elm
+++ b/src/client/LoggedIn/View.elm
@@ -23,11 +23,11 @@ view : Model -> LoggedInModel.Model -> Html Msg
 view model loggedIn =
   div
     [ class "loggedIn" ]
-    [ let loggedData = LoggedData.build model loggedIn
+    [ let loggedData = LoggedData.build model.currentTime model.translations model.conf loggedIn
       in  case model.page of
             Page.Home -> Home.view loggedData loggedIn.home
             Page.Income -> Income.view loggedData
             Page.Categories -> Categories.view loggedData
-            Page.Statistics -> Stat.view loggedData
+            Page.Statistics -> Stat.view loggedData loggedIn.stat
             Page.NotFound -> div [] [ text (getMessage model.translations "PageNotFound") ]
     ]
diff --git a/src/client/Main.elm b/src/client/Main.elm
index 9674b66..7981a1c 100644
--- a/src/client/Main.elm
+++ b/src/client/Main.elm
@@ -19,7 +19,7 @@ main =
     , update = update
     , subscriptions = (\model ->
         Sub.batch
-          [ Time.every 1000 Msg.UpdateTime
+          [ Time.every 60000 Msg.UpdateTime
           , Sub.map Msg.Tooltip Tooltip.subscription
           ]
       )
diff --git a/src/client/Model.elm b/src/client/Model.elm
index 5167e42..7f62416 100644
--- a/src/client/Model.elm
+++ b/src/client/Model.elm
@@ -27,8 +27,6 @@ import Dialog.Msg as DialogMsg
 
 import Tooltip
 
-import Utils.Maybe exposing (isJust)
-
 type alias Model =
   { view : View
   , currentTime : Time
@@ -50,7 +48,7 @@ init payload location =
                   InitEmpty ->
                     SignInView (SignInModel.init Nothing)
                   InitSuccess init ->
-                    LoggedInView (LoggedInModel.init init)
+                    LoggedInView (LoggedInModel.init time init)
                   InitError error ->
                     SignInView (SignInModel.init (Just error))
             , currentTime = time
diff --git a/src/client/Model/Income.elm b/src/client/Model/Income.elm
index 34578c6..aa5f05f 100644
--- a/src/client/Model/Income.elm
+++ b/src/client/Model/Income.elm
@@ -9,17 +9,16 @@ module Model.Income exposing
   , cumulativeIncomesSince
   )
 
+import Dict exposing (Dict)
 import Json.Decode as Decode exposing (Decoder)
-import Utils.Json as Json
-import Time exposing (Time, hour)
 import List exposing (..)
-import Dict exposing (Dict)
+import Maybe.Extra as Maybe
+import Time exposing (Time, hour)
+import Utils.Json as Json
 
 import Model.Date exposing (timeDecoder)
 import Model.User exposing (UserId, userIdDecoder)
 
-import Utils.Maybe as Maybe
-
 type alias Incomes = Dict IncomeId Income
 
 type alias IncomeId = Int
@@ -46,7 +45,7 @@ incomeDefinedForAll userIds incomes =
   let userIncomes = List.map (\userId -> List.filter ((==) userId << .userId) << Dict.values <| incomes) userIds
       firstIncomes = map (head << sortBy .time) userIncomes
   in  if all Maybe.isJust firstIncomes
-        then head << reverse << List.sort << map .time << Maybe.cat <| firstIncomes
+        then head << reverse << List.sort << map .time << Maybe.values <| firstIncomes
         else Nothing
 
 userCumulativeIncomeSince : Time -> Time -> Incomes -> UserId -> Int
diff --git a/src/client/Model/Payer.elm b/src/client/Model/Payer.elm
index 1663273..4d9190e 100644
--- a/src/client/Model/Payer.elm
+++ b/src/client/Model/Payer.elm
@@ -17,7 +17,6 @@ import Model.User exposing (Users, UserId, userIdDecoder)
 import Model.Income exposing (..)
 
 import Utils.Dict exposing (mapValues)
-import Utils.Maybe exposing (isJust)
 
 type alias Payers = Dict UserId Payer
 
diff --git a/src/client/Model/Payment.elm b/src/client/Model/Payment.elm
index 2412ab9..204f9f5 100644
--- a/src/client/Model/Payment.elm
+++ b/src/client/Model/Payment.elm
@@ -20,10 +20,11 @@ import Date.Extra.Core exposing (monthToInt, intToMonth)
 import Json.Decode as Decode exposing (Decoder)
 import Json.Decode.Extra as Decode
 import List
+import List.Extra as List
 
 import Form.Validate as Validate exposing (Validation)
-import Model.Frequency as Frequency exposing (Frequency(..))
 import Model.Date exposing (dateDecoder)
+import Model.Frequency as Frequency exposing (Frequency(..))
 import Model.User exposing (UserId, userIdDecoder)
 import Utils.List as List
 import Utils.Search as Search
@@ -63,8 +64,7 @@ paymentIdDecoder = Decode.int
 find : PaymentId -> Payments -> Maybe Payment
 find paymentId payments =
   payments
-    |> List.filter (\p -> p.id == paymentId)
-    |> List.head
+    |> List.find (\p -> p.id == paymentId)
 
 edit : Payment -> Payments -> Payments
 edit payment payments = payment :: delete payment.id payments
@@ -94,7 +94,6 @@ groupAndSortByMonth payments =
     |> List.groupBy (\payment -> (Date.year payment.date, monthToInt << Date.month <| payment.date))
     |> List.sortBy Tuple.first
     |> List.map (\((year, month), payments) -> ((intToMonth month, year), payments))
-    |> List.reverse
 
 search : String -> Frequency -> Payments -> Payments
 search name frequency payments =
diff --git a/src/client/Model/PaymentCategory.elm b/src/client/Model/PaymentCategory.elm
index bb6c152..a4fceb1 100644
--- a/src/client/Model/PaymentCategory.elm
+++ b/src/client/Model/PaymentCategory.elm
@@ -2,15 +2,20 @@ module Model.PaymentCategory exposing
   ( PaymentCategories
   , paymentCategoriesDecoder
   , search
+  , groupPaymentsByCategory
   , isCategoryUnused
   , save
   )
 
 import Dict exposing (Dict)
 import Json.Decode as Decode exposing (Decoder)
+import List.Extra as List
+import Maybe.Extra as Maybe
 
 import Model.Category exposing (CategoryId, categoryIdDecoder)
+import Model.Payment exposing (Payments)
 import Utils.Json as Json
+import Utils.List as List
 import Utils.Search as Search
 
 type alias PaymentCategories = List PaymentCategory
@@ -26,18 +31,30 @@ paymentCategoriesDecoder =
     (Decode.field "name" Decode.string)
     (Decode.field "category" categoryIdDecoder)
 
+groupPaymentsByCategory : PaymentCategories -> Payments -> List (CategoryId, Payments)
+groupPaymentsByCategory paymentCategories payments =
+  payments
+    |> List.groupBy (\payment ->
+         search payment.name paymentCategories
+           |> Maybe.withDefault -1
+       )
+    |> List.filterMap (\(category, payments) ->
+         case category of
+           -1 -> Nothing
+           _ -> Just (category, payments)
+       )
+
 search : String -> PaymentCategories -> Maybe CategoryId
 search paymentName paymentCategories =
   paymentCategories
-    |> List.filter (\pc -> Search.format pc.name == Search.format paymentName)
-    |> List.head
+    |> List.find (\pc -> Search.format pc.name == Search.format paymentName)
     |> Maybe.map .category
 
 isCategoryUnused : CategoryId -> PaymentCategories -> Bool
 isCategoryUnused category paymentCategories =
   paymentCategories
-    |> List.filter ((==) category << .category)
-    |> List.isEmpty
+    |> List.find ((==) category << .category)
+    |> Maybe.isNothing
 
 save : String -> CategoryId -> PaymentCategories -> PaymentCategories
 save name category paymentCategories =
diff --git a/src/client/Update.elm b/src/client/Update.elm
index 7006d5a..4284b65 100644
--- a/src/client/Update.elm
+++ b/src/client/Update.elm
@@ -2,35 +2,28 @@ module Update exposing
   ( update
   )
 
-import Task
-import Platform.Cmd exposing (Cmd)
 import Navigation exposing (Location)
+import Platform.Cmd exposing (Cmd)
+import Task
 
-import Page exposing (Page)
-
-import Server
-
-import Msg exposing (..)
-
+import Dialog
+import Dialog.Update as DialogUpdate
+import LoggedIn.Model as LoggedIn
+import LoggedIn.Msg as LoggedIn
+import LoggedIn.Stat.Msg as Stat
+import LoggedIn.Update as LoggedIn
 import Model exposing (Model)
 import Model.Translations exposing (getMessage)
 import Model.View as V
-
-import LoggedIn.Model as LoggedInModel
-import LoggedIn.Msg as LoggedInMsg
-import LoggedIn.Update as LoggedInUpdate
-
+import Msg exposing (..)
+import Page exposing (Page(..))
+import Server
 import SignIn.Model as SignInModel
 import SignIn.Msg as SignInMsg
 import SignIn.Update as SignInUpdate
-
-import Dialog
-import Dialog.Update as DialogUpdate
-
 import Tooltip
-
-import Utils.Http exposing (errorKey)
 import Utils.Cmd exposing ((:>))
+import Utils.Http exposing (errorKey)
 
 update : Msg -> Model -> (Model, Cmd Msg)
 update msg model =
@@ -40,7 +33,14 @@ update msg model =
       (model, Cmd.none)
 
     UpdatePage page ->
-      ({ model | page = page }, Cmd.none)
+      ( { model | page = page }
+      , if page == Statistics
+          then
+            let msg = UpdateLoggedIn <| LoggedIn.StatMsg <| Stat.UpdateChart
+            in  Task.perform (\_ -> msg) (Task.succeed ())
+          else
+            Cmd.none
+      )
 
     SignIn email ->
       ( applySignIn model (SignInMsg.WaitingServer)
@@ -51,7 +51,7 @@ update msg model =
       )
 
     GoLoggedInView init ->
-      ( { model | view = V.LoggedInView (LoggedInModel.init init) }
+      ( { model | view = V.LoggedInView (LoggedIn.init model.currentTime init) }
       , Cmd.none
       )
 
@@ -92,7 +92,7 @@ update msg model =
     CreatePayment name cost date category frequency ->
       ( model
       , Server.createPayment name cost date category frequency (\result -> case result of
-          Ok paymentId -> UpdateLoggedIn <| LoggedInMsg.ValidateCreatePayment paymentId name cost date category frequency
+          Ok paymentId -> UpdateLoggedIn <| LoggedIn.ValidateCreatePayment paymentId name cost date category frequency
           Err _ -> Error "CreatePaymentError"
         )
       )
@@ -100,7 +100,7 @@ update msg model =
     EditPayment paymentId name cost date category frequency ->
       ( model
       , Server.editPayment paymentId name cost date category frequency (\result -> case result of
-          Ok _ -> UpdateLoggedIn <| LoggedInMsg.ValidateEditPayment paymentId name cost date category frequency
+          Ok _ -> UpdateLoggedIn <| LoggedIn.ValidateEditPayment paymentId name cost date category frequency
           Err _ -> Error "EditPaymentError"
         )
       )
@@ -108,7 +108,7 @@ update msg model =
     DeletePayment paymentId ->
       ( model
       , Server.deletePayment paymentId (\result -> case result of
-          Ok _ -> UpdateLoggedIn <| LoggedInMsg.ValidateDeletePayment paymentId
+          Ok _ -> UpdateLoggedIn <| LoggedIn.ValidateDeletePayment paymentId
           Err _ -> Error "DeletePaymentError"
         )
       )
@@ -116,7 +116,7 @@ update msg model =
     CreateIncome amount date ->
       ( model
       , Server.createIncome amount date (\result -> case result of
-          Ok incomeId -> UpdateLoggedIn <| LoggedInMsg.ValidateCreateIncome incomeId amount date
+          Ok incomeId -> UpdateLoggedIn <| LoggedIn.ValidateCreateIncome incomeId amount date
           Err _ -> Error "CreateIncomeError"
         )
       )
@@ -124,7 +124,7 @@ update msg model =
     EditIncome incomeId amount date ->
       ( model
       , Server.editIncome incomeId amount date (\result -> case result of
-          Ok _ -> UpdateLoggedIn <| LoggedInMsg.ValidateEditIncome incomeId amount date
+          Ok _ -> UpdateLoggedIn <| LoggedIn.ValidateEditIncome incomeId amount date
           Err _ -> Error "EditIncomeError"
         )
       )
@@ -132,7 +132,7 @@ update msg model =
     DeleteIncome incomeId ->
       ( model
       , Server.deleteIncome incomeId (\result -> case result of
-          Ok _ -> UpdateLoggedIn <| LoggedInMsg.ValidateDeleteIncome incomeId
+          Ok _ -> UpdateLoggedIn <| LoggedIn.ValidateDeleteIncome incomeId
           Err _ -> Error "DeleteIncomeError"
         )
       )
@@ -140,7 +140,7 @@ update msg model =
     CreateCategory name color ->
       ( model
       , Server.createCategory name color (\result -> case result of
-          Ok categoryId -> UpdateLoggedIn <| LoggedInMsg.ValidateCreateCategory categoryId name color
+          Ok categoryId -> UpdateLoggedIn <| LoggedIn.ValidateCreateCategory categoryId name color
           Err _ -> Error "CreateCategoryError"
         )
       )
@@ -148,7 +148,7 @@ update msg model =
     EditCategory categoryId name color ->
       ( model
       , Server.editCategory categoryId name color (\result -> case result of
-          Ok _ -> UpdateLoggedIn <| LoggedInMsg.ValidateEditCategory categoryId name color
+          Ok _ -> UpdateLoggedIn <| LoggedIn.ValidateEditCategory categoryId name color
           Err _ -> Error "EditCategoryError"
         )
       )
@@ -156,7 +156,7 @@ update msg model =
     DeleteCategory categoryId ->
       ( model
       , Server.deleteCategory categoryId (\result -> case result of
-          Ok _ -> UpdateLoggedIn <| LoggedInMsg.ValidateDeleteCategory categoryId
+          Ok _ -> UpdateLoggedIn <| LoggedIn.ValidateDeleteCategory categoryId
           Err _ -> Error "DeleteCategoryError"
         )
       )
@@ -170,11 +170,11 @@ applySignIn model signInMsg =
     _ ->
       model
 
-applyLoggedIn : Model -> LoggedInMsg.Msg -> (Model, Cmd Msg)
+applyLoggedIn : Model -> LoggedIn.Msg -> (Model, Cmd Msg)
 applyLoggedIn model loggedInMsg =
   case model.view of
     V.LoggedInView loggedInView ->
-      let (view, cmd) = LoggedInUpdate.update model loggedInMsg loggedInView
+      let (view, cmd) = LoggedIn.update model loggedInMsg loggedInView
       in  ( { model | view = V.LoggedInView view }
           , Cmd.map UpdateLoggedIn cmd
           )
diff --git a/src/client/Utils/List.elm b/src/client/Utils/List.elm
index cc57d9f..8e26e85 100644
--- a/src/client/Utils/List.elm
+++ b/src/client/Utils/List.elm
@@ -1,9 +1,11 @@
 module Utils.List exposing
   ( groupBy
   , mean
+  , links
   )
 
 import Dict
+import Maybe.Extra as Maybe
 
 groupBy : (a -> comparable) -> List a -> List (comparable, List a)
 groupBy f xs =
@@ -15,3 +17,20 @@ groupBy f xs =
 
 mean : List Int -> Int
 mean xs = (List.sum xs) // (List.length xs)
+
+links : List a -> List (a, a)
+links xs =
+  let reversed = List.reverse xs
+  in  List.foldr
+        (\x acc ->
+          case Maybe.map Tuple.first (List.head acc) of
+            Just y ->
+              (x, y) :: acc
+            _ ->
+              acc
+        )
+        (case reversed of
+          x :: y :: _ -> [(y, x)]
+          _ -> []
+        )
+        (List.reverse << List.drop 2 <| reversed)
diff --git a/src/client/Utils/Maybe.elm b/src/client/Utils/Maybe.elm
deleted file mode 100644
index 46456e1..0000000
--- a/src/client/Utils/Maybe.elm
+++ /dev/null
@@ -1,34 +0,0 @@
-module Utils.Maybe exposing
-  ( isJust
-  , cat
-  , toList
-  , orElse
-  )
-
-isJust : Maybe a -> Bool
-isJust maybe =
-  case maybe of
-    Just _  -> True
-    Nothing -> False
-
-cat : List (Maybe a) -> List a
-cat =
-  List.foldr
-    (\mb xs ->
-      case mb of
-        Just x  -> x :: xs
-        Nothing -> xs
-    )
-    []
-
-toList : Maybe a -> List a
-toList mb =
-  case mb of
-    Just a  -> [a]
-    Nothing -> []
-
-orElse : Maybe a -> Maybe a -> Maybe a
-orElse mb1 mb2 =
-  case mb1 of
-    Just x -> Just x
-    Nothing -> mb2
diff --git a/src/client/View.elm b/src/client/View.elm
index 66c498a..deee272 100644
--- a/src/client/View.elm
+++ b/src/client/View.elm
@@ -18,8 +18,6 @@ import View.Errors as Errors
 import SignIn.View as SignInView
 import LoggedIn.View as LoggedInView
 
-import Utils.Maybe as Maybe
-
 view : Model -> Html Msg
 view model =
   div
diff --git a/src/client/View/Date.elm b/src/client/View/Date.elm
index 35806ba..6df971b 100644
--- a/src/client/View/Date.elm
+++ b/src/client/View/Date.elm
@@ -1,5 +1,6 @@
 module View.Date exposing
-  ( shortView
+  ( shortMonthAndYear
+  , shortView
   , longView
   , monthView
   )
@@ -10,6 +11,14 @@ import String
 
 import Model.Translations exposing (..)
 
+shortMonthAndYear : Month -> Int -> Translations -> String
+shortMonthAndYear month year translations =
+  let params =
+        [ String.pad 2 '0' (toString (Date.monthToInt month))
+        , toString year
+        ]
+  in  getParamMessage params translations "ShortMonthAndYear"
+
 shortView : Date -> Translations -> String
 shortView date translations =
   let params =
diff --git a/src/client/View/Form.elm b/src/client/View/Form.elm
index 7a4965d..977ca0a 100644
--- a/src/client/View/Form.elm
+++ b/src/client/View/Form.elm
@@ -9,6 +9,7 @@ module View.Form exposing
 import Html exposing (..)
 import Html.Attributes exposing (..)
 import Html.Events exposing (..)
+import Maybe.Extra as Maybe
 
 import FontAwesome
 import View.Color as Color
@@ -24,8 +25,6 @@ import LoggedData exposing (LoggedData)
 
 import Model.Translations as Translations exposing (Translations)
 
-import Utils.Maybe exposing (isJust)
-
 textInput : Translations -> Form String a -> String -> String -> Html Form.Msg
 textInput translations form formName fieldName =
   let field = Form.getFieldAsString fieldName form
@@ -33,13 +32,13 @@ textInput translations form formName fieldName =
   in  div
         [ classList
             [ ("textInput", True)
-            , ("error", isJust field.liveError)
+            , ("error", Maybe.isJust field.liveError)
             ]
         ]
         [ Input.textInput
             field
             [ id fieldId
-            , classList [ ("filled", isJust field.value) ]
+            , classList [ ("filled", Maybe.isJust field.value) ]
             , value (Maybe.withDefault "" field.value)
             ]
         , label
@@ -60,7 +59,7 @@ colorInput translations form formName fieldName =
   in  div
         [ classList
             [ ("colorInput", True)
-            , ("error", isJust field.liveError)
+            , ("error", Maybe.isJust field.liveError)
             ]
         ]
         [ label
@@ -79,7 +78,7 @@ radioInputs translations form formName radioName fieldNames =
   in  div
         [ classList
             [ ("radioGroup", True)
-            , ("error", isJust field.liveError)
+            , ("error", Maybe.isJust field.liveError)
             ]
         ]
         [ div
@@ -115,7 +114,7 @@ selectInput translations form formName selectName options =
   in  div
         [ classList
             [ ("selectInput", True)
-            , ("error", isJust field.liveError)
+            , ("error", Maybe.isJust field.liveError)
             ]
         ]
         [ label
diff --git a/src/server/Model/Message/Key.hs b/src/server/Model/Message/Key.hs
index efe8aaa..18f16f0 100644
--- a/src/server/Model/Message/Key.hs
+++ b/src/server/Model/Message/Key.hs
@@ -45,6 +45,7 @@ data Key =
   | December
 
   | ShortDate
+  | ShortMonthAndYear
   | LongDate
 
   -- Search
@@ -106,6 +107,7 @@ data Key =
   | Statistics
   | ByMonthsAndMean
   | By
+  | Total
 
   -- Income
 
diff --git a/src/server/Model/Message/Translations.hs b/src/server/Model/Message/Translations.hs
index 90f509a..7d26c3f 100644
--- a/src/server/Model/Message/Translations.hs
+++ b/src/server/Model/Message/Translations.hs
@@ -181,6 +181,11 @@ m l ShortDate =
     English -> "{3}-{2}-{1}"
     French  -> "{1}/{2}/{3}"
 
+m l ShortMonthAndYear =
+  case l of
+    English -> "{2}-{1}"
+    French  -> "{1}/{2}"
+
 m l LongDate =
   case l of
     English -> "{2} {1}, {3}"
@@ -295,6 +300,56 @@ m l NoPayment =
     English -> "No payment found from your search criteria."
     French  -> "Aucun paiement ne correspond à vos critères de recherches."
 
+m l PaymentName =
+  case l of
+    English -> "Name"
+    French  -> "Nom"
+
+m l PaymentCost =
+  case l of
+    English -> "Cost"
+    French  -> "Coût"
+
+m l PaymentDate =
+  case l of
+    English -> "Date"
+    French  -> "Date"
+
+m l PaymentCategory =
+  case l of
+    English -> "Category"
+    French  -> "Catégorie"
+
+m l PaymentPunctual =
+  case l of
+    English -> "Punctual"
+    French  -> "Ponctuel"
+
+m l PaymentMonthly =
+  case l of
+    English -> "Monthly"
+    French  -> "Mensuel"
+
+m l ConfirmPaymentDelete =
+  case l of
+    English -> "Are you sure to delete this payment ?"
+    French  -> "Voulez-vous vraiment supprimer ce paiement ?"
+
+m l Edit =
+  case l of
+    English -> "Edit"
+    French  -> "Modifier"
+
+m l Clone =
+  case l of
+    English -> "Clone"
+    French  -> "Cloner"
+
+m l Delete =
+  case l of
+    English -> "Delete"
+    French  -> "Supprimer"
+
 -- Categories
 
 m l Categories =
@@ -361,63 +416,18 @@ m l Statistics =
 
 m l ByMonthsAndMean =
   case l of
-    English -> "By months ({1} on average)"
-    French  -> "Par mois (en moyenne {1})"
+    English -> "Payments by category by month months ({1} on average)"
+    French  -> "Paiements par catégorie par mois (en moyenne {1})"
 
 m l By =
   case l of
     English -> "{1}: {2}"
     French  -> "{1} : {2}"
 
-m l PaymentName =
-  case l of
-    English -> "Name"
-    French  -> "Nom"
-
-m l PaymentCost =
-  case l of
-    English -> "Cost"
-    French  -> "Coût"
-
-m l PaymentDate =
-  case l of
-    English -> "Date"
-    French  -> "Date"
-
-m l PaymentCategory =
-  case l of
-    English -> "Category"
-    French  -> "Catégorie"
-
-m l PaymentPunctual =
-  case l of
-    English -> "Punctual"
-    French  -> "Ponctuel"
-
-m l PaymentMonthly =
-  case l of
-    English -> "Monthly"
-    French  -> "Mensuel"
-
-m l ConfirmPaymentDelete =
-  case l of
-    English -> "Are you sure to delete this payment ?"
-    French  -> "Voulez-vous vraiment supprimer ce paiement ?"
-
-m l Edit =
+m l Total =
   case l of
-    English -> "Edit"
-    French  -> "Modifier"
-
-m l Clone =
-  case l of
-    English -> "Clone"
-    French  -> "Cloner"
-
-m l Delete =
-  case l of
-    English -> "Delete"
-    French  -> "Supprimer"
+    English -> "Total"
+    French  -> "Total"
 
 -- Income
 
-- 
cgit v1.2.3