VARROA_METHODS_DISPLAY <- c(
  "Nat. Totenfall" = "natuerlicher_totenfall",
  "Alkoholwäsche"  = "alkoholwaesche",
  "Puderzucker"    = "puderzucker"
)

screen_varroa_ui <- function(id) {
  ns <- NS(id)
  bslib::navset_card_tab(
    bslib::nav_panel("Kontrolle",
      shiny::div(class = "p-2",
        section_card(NULL,
          shiny::div(class = "row g-2 py-2",
            shiny::div(class = "col-4",
              shiny::dateInput(ns("count_date_from"), "Von", value = Sys.Date() - 3L, language = "de", weekstart = 1)
            ),
            shiny::div(class = "col-4",
              shiny::dateInput(ns("count_date_to"), "Bis", value = Sys.Date(), language = "de", weekstart = 1)
            ),
            shiny::div(class = "col-4",
              shiny::textInput(ns("count_time"), "Uhrzeit",
                value = format(Sys.time(), "%H:%M"), placeholder = "HH:MM")
            )
          )
        ),
        btn_group_row(ns, "count_method", "Methode", VARROA_METHODS_DISPLAY),
        stepper_row(ns, "count_val", "Anzahl / Wert"),
        shiny::uiOutput(ns("milben_pro_tag_ui")),
        section_card(NULL,
          shiny::div(class = "py-2",
            shiny::div(
              class = "bk-check d-flex justify-content-between align-items-center py-2 border-bottom",
              shiny::tags$label(class = "fw-semibold", `for` = ns("is_ctrl"), "Nachkontrolle zu Behandlung?"),
              shiny::checkboxInput(ns("is_ctrl"), NULL, value = FALSE)
            ),
            shiny::uiOutput(ns("ctrl_extra_ui")),
            shiny::textAreaInput(ns("count_notes"), "Notizen", rows = 2, width = "100%")
          )
        ),
        shiny::div(class = "d-grid mt-2",
          shiny::actionButton(ns("save_count"), "Kontrolle speichern", class = "btn btn-primary btn-lg")
        )
      )
    ),
    bslib::nav_panel("Behandlung",
      shiny::div(class = "p-2",
        section_card(NULL,
          shiny::div(class = "row g-2 py-2",
            shiny::div(class = "col-6",
              shiny::dateInput(ns("treat_date"), "Datum", value = Sys.Date(), language = "de", weekstart = 1)
            ),
            shiny::div(class = "col-6",
              shiny::textInput(ns("treat_time"), "Uhrzeit",
                value = format(Sys.time(), "%H:%M"), placeholder = "HH:MM")
            ),
            shiny::div(class = "col-12",
              shiny::selectizeInput(ns("treat_product"), "Mittel *",
                choices = c("Mittel wählen…" = "", VARROA_PRODUCTS),
                options = list(create = TRUE, placeholder = "Mittel wählen…")
              )
            )
          )
        ),
        section_card(NULL,
          shiny::div(class = "py-2",
            shiny::uiOutput(ns("treat_method_ui")),
            shiny::textInput(ns("treat_dosage"), "Dosierung", placeholder = "2,3 g / Volk"),
            shiny::textAreaInput(ns("treat_notes"), "Notizen", rows = 2, width = "100%")
          )
        ),
        shiny::div(class = "d-grid mt-2",
          shiny::actionButton(ns("save_treat"), "Behandlung speichern", class = "btn btn-warning btn-lg")
        )
      )
    )
  )
}

screen_varroa_server <- function(id, db, nav) {
  moduleServer(id, function(input, output, session) {
    ns <- session$ns

    count_method <- btn_group_server("count_method", ns, input, output,
      VARROA_METHODS_DISPLAY, default = "natuerlicher_totenfall")
    count_val    <- stepper_server("count_val", input, output)

    observeEvent(nav$screen, {
      if (nav$screen == "varroa") {
        count_val(NA_integer_)
        shiny::updateCheckboxInput(session, "is_ctrl", value = FALSE)
        shiny::updateDateInput(session, "count_date_from", value = Sys.Date() - 3L)
        shiny::updateDateInput(session, "count_date_to",   value = Sys.Date())
        shiny::updateTextInput(session, "count_time", value = format(Sys.time(), "%H:%M"))
        shiny::updateTextInput(session, "treat_time", value = format(Sys.time(), "%H:%M"))
      }
    }, ignoreInit = TRUE)

    output$milben_pro_tag_ui <- renderUI({
      v     <- count_val()
      d_von <- input$count_date_from
      d_bis <- input$count_date_to
      if (is.na(v) || is.null(d_von) || is.null(d_bis)) return(NULL)
      days <- as.numeric(as.Date(d_bis) - as.Date(d_von))
      if (days < 0) return(shiny::p(class = "text-danger small py-1", "Bis-Datum liegt vor Von-Datum."))
      mpt <- round(v / max(1, days), 1)
      cls <- if (mpt < 1) "text-success" else if (mpt < 3) "text-warning" else "text-danger"
      shiny::div(
        class = paste("text-center py-2 fw-bold fs-4", cls),
        paste0(mpt, " Milben/Tag"),
        shiny::tags$div(class = "text-muted fw-normal small",
          paste0(v, " Milben über ", days, " Tage"))
      )
    })

    output$ctrl_extra_ui <- renderUI({
      req(isTRUE(input$is_ctrl), nav$colony_id)
      treats <- db_varroa_treatments_list(db, nav$colony_id)
      if (nrow(treats) == 0)
        return(shiny::p(class = "text-muted small py-2", "Keine Behandlungen erfasst."))
      shiny::tagList(
        shiny::selectInput(ns("ctrl_treatment"), "Zur Behandlung",
          choices = setNames(treats$id, paste(treats$date, treats$product))
        ),
        shiny::textInput(ns("ctrl_result"), "Ergebnis / Befund")
      )
    })

    output$treat_method_ui <- renderUI({
      product <- input$treat_product
      methods <- if (!is.null(product) && product != "") VARROA_APPLICATION_METHODS[[product]] else NULL
      if (!is.null(methods)) {
        shiny::selectizeInput(ns("treat_method"), "Anwendung",
          choices = c("Anwendung wählen…" = "", methods),
          options = list(create = TRUE, placeholder = "Anwendung wählen…")
        )
      } else {
        shiny::textInput(ns("treat_method"), "Anwendung", placeholder = "z. B. Träufeln")
      }
    })

    observeEvent(input$save_count, {
      req(nav$colony_id, !is.na(count_val()))
      db_varroa_counts_insert(db,
        colony_id = nav$colony_id,
        date_from = input$count_date_from,
        date      = input$count_date_to,
        method    = count_method() %||% "natuerlicher_totenfall",
        count     = count_val(),
        notes     = input$count_notes,
        time      = input$count_time %||% NA
      )
      if (isTRUE(input$is_ctrl) && !is.null(input$ctrl_treatment)) {
        db_varroa_controls_insert(db,
          treatment_id = as.integer(input$ctrl_treatment),
          colony_id    = nav$colony_id,
          date         = input$count_date,
          result       = input$ctrl_result %||% "",
          notes        = input$count_notes
        )
      }
      count_val(NA_integer_)
      shiny::updateTextAreaInput(session, "count_notes", value = "")
      shiny::updateCheckboxInput(session, "is_ctrl", value = FALSE)
      nav$screen <- "colony"
    })

    observeEvent(input$save_treat, {
      req(nav$colony_id, nchar(trimws(input$treat_product)) > 0)
      db_varroa_treatments_insert(db,
        colony_id = nav$colony_id,
        date      = input$treat_date,
        product   = trimws(input$treat_product),
        method    = input$treat_method,
        dosage    = input$treat_dosage,
        notes     = input$treat_notes,
        time      = input$treat_time %||% NA
      )
      nav$screen <- "colony"
    })
  })
}