#' The ermoji emoji gadget
#'
#' Opens a miniUI based Shiny gadget in the RStudio Viewer pane with a
#' searchable table of emoji. Select a row and click the copy button.
#'
#' @return nothing
#' @export
ermoji_gadget <- function() {
  require(shiny)
  require(miniUI)

  ui <- miniPage(
    gadgetTitleBar("ermoji"),
    miniContentPanel(
      padding = 10,
      DT::dataTableOutput('emojis', height = "100%", width = "98%")
    ),
    miniButtonBlock(
      actionButton("copy_name", "Copy :emoji_name:", class = "btn-success"),
      actionButton("copy_utf", "Copy Unicode", class = "btn-warning"),
      actionButton("copy_gliph", "Copy Emoji", class = "btn-primary")
    )
  )

  server <- function(input, output, session) {
    output$emojis <- DT::renderDataTable({
      emojis <- emo::jis
      emojis <- emojis[, c('emoji', 'name', "group", "keywords", "aliases")]
      emojis$keywords <- purrr::map_chr(emojis$keywords, ~ paste(., collapse = ", "))
      emojis$aliases <- purrr::map_chr(emojis$aliases, ~ paste(., collapse = ", "))
      DT::datatable(
        emojis,
        rownames = FALSE,
        colnames = c("Emoji", "Name", "Group", "Keywords", "Aliases"),
        filter = "top",
        selection = "single",
        fillContainer = TRUE,
        # style = 'bootstrap',
        class = 'compact stripe nowrap hover',
        options = list(
          searchHighlight = TRUE,
          search = list(regex = TRUE, caseInsensitive = FALSE),
          columnDefs = list(list(
            className = "dt-center", targets = 0
          )),
          pageLength = 10,
          lengthMenu = c(4, 5, 10)
        )
      )
    })

    this_emoji <- reactive({
      req(input$emojis_rows_selected)
      as.list(emo::jis[input$emojis_rows_selected, ])
    })

    this_emoji_name <- reactive({
      # name <- this_emoji()$name
      name <- this_emoji()$aliases[[1]][1]
      paste0(":", gsub(" ", "_", name), ":")
    })

    this_emoji_uni <- reactive({
      uni <- paste0("\\U", this_emoji()$runes)
      gsub(" ", "\\\\U", uni)
    })

    this_emoji_uni_trunc <- reactive({
      uni <- this_emoji()$runes
      uni <- sub(" .+", "...", uni)
      paste0("\\U", uni)
    })

    observeEvent(input$emojis_rows_selected, {
      if (!isTruthy(input$emojis_rows_selected)) {
        updateActionButton(session, "copy_name", "Copy :emoji_name:")
        updateActionButton(session, "copy_utf", "Copy Unicode")
        updateActionButton(session, "copy_gliph", "Copy Emoji")
      } else {
        updateActionButton(session, "copy_name", paste0("Copy <code>", this_emoji_name(), "</code>"))
        updateActionButton(session, "copy_utf", paste("Copy <code>", this_emoji_uni_trunc(), "</code>"))
        updateActionButton(session, "copy_gliph", paste("Copy", this_emoji()$emoji))
      }
    })
    observeEvent(input$copy_name, {
      clipr::write_clip(this_emoji_name())
    })
    observeEvent(input$copy_utf, {
      clipr::write_clip(this_emoji_uni())
    })
    observeEvent(input$copy_gliph, {
      clipr::write_clip(this_emoji()$emoji)
    })
    observeEvent(input$done, {
      stopApp(invisible())
    })
    observeEvent(input$cancel, {
      stopApp(invisible())
    })
  }

  runGadget(ui, server, viewer = paneViewer(500), stopOnCancel = FALSE)
}