library(shiny)
library(shinydashboard)
library(tidyverse)


random_data <- data.frame(replicate(2, sample(0:10, 1000, rep=TRUE)))
set.seed(1984)
random_data$date <- sample(seq(as.Date('2016-01-01'), as.Date(Sys.Date()), by = "day"), 1000)

sidebar <- dashboardSidebar(dateRangeInput(
  "dates", label = h4("Date range"), start = '2016-01-01', end = Sys.Date(),
  format = "dd-mm-yyyy", startview = "year", min = "2016-01-01", max = Sys.Date()
))

body <- dashboardBody(
  textOutput("selected_dates"),
  br(),
  fluidRow(
        infoBoxOutput("total", width = 12)
  ),
  fluidRow(
    box(width = 12, solidHeader = TRUE,
        title = "X1 over time",
        plotOutput(outputId = "x1_time")
    )
  ),
  fluidRow(
    box(width = 12, solidHeader = TRUE,
        title = "X2 over time",
        plotOutput(outputId = "x2_time")
    )
  )
)

ui <- dashboardPage(dashboardHeader(title = "Example"),
                    sidebar,
                    body
)

server <- function(input, output) {
  filtered <- reactive({
    filtered_data <- random_data %>%
        filter(date >= input$dates[1] & date <= input$dates[2])
    return(filtered_data)
  })

  output$selected_dates <- renderText({
    validate(
      need(input$dates[2] >= input$dates[1], "End date is earlier than start date"
      )
    )
  })


  output$total<- renderInfoBox({
    validate(
      need(input$dates[2] >= input$dates[1], "")
    )
    infoBox(title = "Sample size",
            value = nrow(filtered()),
            icon = icon("binoculars"), color = "light-blue")
  })

  output$x1_time <- renderPlot({
    validate(
      need(input$dates[2] >= input$dates[1], "")
    )
    x1_time_plot <- ggplot(filtered(), aes(x = date, y = X1)) +
      geom_bar(stat = "identity")
      theme_minimal()
    x1_time_plot
  })

  output$x2_time <- renderPlot({
    validate(
      need(input$dates[2] >= input$dates[1], "")
    )
    x2_time_plot <- ggplot(filtered(), aes(x = date, y = X2)) +
      geom_bar(stat = "identity")
    theme_minimal()
    x2_time_plot
  })

}

shinyApp(ui, server)