#' Function for creating the main user interface.
#' @noRd
ui <- function() {
  navbarPage(
    theme = bslib::bs_theme(
      version = 5,
      bootswatch = "united",
      primary = "#7d19bf"
    ),
    title = "Ubigen",
    tabPanel(
      "Explore",
      sidebarLayout(
        sidebarPanel(
          width = 3,
          h3("Features"),
          sliderInput(
            "above_zero",
            verticalLayout(
              strong("Expressed"),
              paste0(
                "Percentage of samples in which the gene is ",
                "expressed."
              )
            ),
            min = -1.0,
            max = 1.0,
            step = 0.01,
            value = 0.33
          ),
          sliderInput(
            "above_median",
            verticalLayout(
              strong("Expressed above median"),
              paste0(
                "Percentage of samples that express the gene ",
                "more than the median of expression within ",
                "that sample."
              )
            ),
            min = -1.0,
            max = 1.0,
            step = 0.01,
            value = 0.33
          ),
          sliderInput(
            "above_95",
            verticalLayout(
              strong("Expressed above 95%"),
              paste0(
                "Percentage of samples that express the gene ",
                "more than the 95. percentile of expression ",
                "within that sample."
              )
            ),
            min = -1.0,
            max = 1.0,
            step = 0.01,
            value = 0.33
          ),
          sliderInput(
            "mean_expression",
            verticalLayout(
              strong("Mean expression"),
              div(paste0(
                "Average of the gene's expression across all ",
                "samples."
              ))
            ),
            min = -1.0,
            max = 1.0,
            step = 0.01,
            value = 1.0
          ),
          sliderInput(
            "sd_expression",
            verticalLayout(
              strong("Standard deviation"),
              paste0(
                "Standard deviation of the gene's expression ",
                "across all samples."
              )
            ),
            min = -1.0,
            max = 1.0,
            step = 0.01,
            value = -1.0
          )
        ),
        mainPanel(
          width = 9,
          h3("Distribution of scores"),
          h4("Overview"),
          plotly::plotlyOutput("overview_plot", height = "200px"),
          h4("Focus on top genes"),
          div(paste0(
            "Click or drag within the figure to select genes of ",
            "interest."
          )),
          plotly::plotlyOutput("scores_plot"),
          h3("Detailed ranking"),
          div(paste0(
            "Click on gene names to view them using the Ensembl ",
            "genome browser."
          )),
          div(class = "p-1"),
          DT::dataTableOutput("selected_genes")
        )
      )
    ),
    tabPanel(
      title = "Help"
    ),
    tabPanel(
      title = "Publication"
    )
  )
}