library(shiny)
library(ggplot2)
library(scales)

shinyServer(function(input, output) {

  # Panel 1
  output$nuage1 <- renderPlot({
    plot(mtcars$mpg ~ mtcars[,input$choix], 
         main = "Consommation",
         xlab = input$choix, ylab = "mpg")
  })
  tabXY <- reactive({
    tab = data.frame(
      y = mtcars$mpg,
      x = mtcars[,input$choix]
    )
  })
  output$nuage2 <- renderPlot({
    ggplot(tabXY(), aes(x, y)) + geom_point() +
      xlab(input$choix) + ylab("mpg")
  })
  output$nuage3 <- renderPlot({
    ggplot(mtcars, aes_string(input$choix, "mpg")) + 
      geom_point() 
  })
  
  output$resumeMpg <- renderText({
    res = round(mean(mtcars$mpg, na.rm = T), 2)
    paste("Moyenne mpg :", res)
  })
  output$resumeVar <- renderText({
    res = round(mean(mtcars[,input$choix], na.rm = T), 2)
    paste("Moyenne", input$choix, ":", res)
  })
  output$corMpgVar <- renderText({
    res = round(cor(mtcars$mpg, mtcars[, input$choix]), 2)
    paste0("Correlation mpg|", input$choix, " : ", res)
  })
  
  output$tableau <- renderTable({
    sub = subset(mtcars, select = c("mpg", input$choix))
    sapply(sub, summary)
  }, rownames = TRUE)
  
  # Panel 2
  output$ql.bar <- renderPlot({
    mtcars$nouv = factor(mtcars[,input$ql.choix])
    ggplot(mtcars, aes(nouv, fill = nouv)) +
      geom_bar() + 
      xlab("") + labs(fill = input$ql.choix)
  })
  output$ql.pie <- renderPlot({
    mtcars$nouv = factor(mtcars[,input$ql.choix])
    ggplot(mtcars, aes("", fill = nouv)) + 
      geom_bar(aes(y = (..count..)/sum(..count..)), width = 1) + 
      coord_polar(theta = "y") +
      scale_y_continuous(labels = percent) +
      xlab("") + ylab("") +
      theme(axis.ticks = element_blank()) +
      labs(fill = input$ql.choix)
  })
  output$ql.tab <- renderTable({
    t = unclass(table(mtcars[,input$ql.choix]))
    data.frame(
      Modalite = names(t),
      Effectif = t
    )
  })
  
  # Panel 3
  output$qlql.bar <- renderPlot({
    tab = data.frame(
      x = factor(mtcars[,input$qlql.choix1]),
      y = factor(mtcars[,input$qlql.choix2])
    )
    ggplot(tab, aes(x, fill = y)) + 
      geom_bar(position = "fill") +
      scale_y_continuous(labels = percent) + 
      xlab(input$qlql.choix1) + 
      ylab("") + 
      labs(fill = input$qlql.choix2)
  })
  output$qlql.tab <- renderTable({
    tab = table(
      mtcars[,input$qlql.choix1],
      mtcars[,input$qlql.choix2]
    )
    dimnames(tab)[[1]] = paste(
      input$qlql.choix1, dimnames(tab)[[1]], sep = "="
    )
    dimnames(tab)[[2]] = paste(
      input$qlql.choix2, dimnames(tab)[[2]], sep = "="
    )
    addmargins(unclass(tab))
  }, rownames = TRUE)
})