# Functions
getMatchesList <- function(first_team, second_team, football_data) {
  matches <- football_data %>%
    filter(home_team %in% c(first_team, second_team)
           & away_team %in% c(first_team, second_team))
  return(matches)
}

getBalance <- function(football_data) {
  balance <- football_data %>%
    count(winner, sort = TRUE)
  return(balance)
}

# Results with pagination
resultsWithPagination <- function(input, output) {
  output$results_pagination <- DT::renderDataTable(
    getMatchesList(input$first_team, input$second_team, football_data),
    extensions = 'Buttons',
    options = list(
      lengthMenu = list(c(5, 10, -1), c('5', '10', 'All')),
      pageLength = 10,
      searching = FALSE
    )
  )
}

# Balance
balanceBetweenTeams <- function(input, output) {
  output$balance <- renderPlot({
    barplot(
      bal <- getBalance(getMatchesList(input$first_team, input$second_team, football_data_ext))$n,
      main = "Balance between teams",
      col = rainbow(3),
      names.arg = getBalance(getMatchesList(input$first_team, input$second_team, football_data_ext))$winner
    )
  })
}