lineage_render_node <- function(ns, co, all_cols) {
  children <- all_cols[
    !is.na(all_cols$parent_colony_id) & all_cols$parent_colony_id == co$id, ]
  children <- children[order(children$name), ]

  is_closed  <- !is.na(co$closed_at)
  apiary_lbl <- co$apiary_name %||% "–"
  queen_lbl  <- if (!is.na(co$queen_year) && co$queen_year != "")
    paste0(" · Kgn. ", co$queen_year) else ""

  card <- shiny::div(
    class = paste("card tap-card mb-2", if (is_closed) "opacity-60 border-secondary" else ""),
    onclick = sprintf("Shiny.setInputValue('%s', %d, {priority:'event'})", ns("select"), co$id),
    bslib::card_body(
      class = "d-flex justify-content-between align-items-center py-2 px-3",
      shiny::div(
        shiny::tags$strong(class = if (is_closed) "text-muted" else "", co$name),
        shiny::tags$p(class = "text-muted small mb-0",
          paste0(apiary_lbl, queen_lbl))
      ),
      shiny::HTML(colony_status_badge(co$status))
    )
  )

  if (nrow(children) == 0) {
    card
  } else {
    shiny::tagList(
      card,
      shiny::div(
        class = "ms-4 ps-2 border-start border-2 border-secondary-subtle mb-1",
        lapply(seq_len(nrow(children)), function(i)
          lineage_render_node(ns, children[i, ], all_cols))
      )
    )
  }
}

screen_lineage_ui <- function(id) {
  ns <- NS(id)
  shiny::div(
    shiny::div(
      class = "d-flex gap-2 mb-3",
      shiny::checkboxInput(ns("show_closed"), "Eingegangene Völker anzeigen", value = FALSE)
    ),
    shiny::uiOutput(ns("tree"))
  )
}

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

    all_cols <- reactive({
      req(nav$screen == "lineage")
      db_colonies_list(db, include_closed = TRUE)
    })

    output$tree <- renderUI({
      cols <- all_cols()
      if (!isTRUE(input$show_closed))
        cols <- cols[is.na(cols$closed_at), ]

      if (nrow(cols) == 0)
        return(shiny::p(class = "text-muted", "Keine Völker vorhanden."))

      all_ids <- cols$id
      is_root <- is.na(cols$parent_colony_id) | !(cols$parent_colony_id %in% all_ids)
      roots   <- cols[is_root, ]
      roots   <- roots[order(roots$apiary_name, roots$name), ]

      cur_apiary <- NULL
      out <- list()
      for (i in seq_len(nrow(roots))) {
        ro <- roots[i, ]
        ap <- ro$apiary_name %||% "–"
        if (!identical(ap, cur_apiary)) {
          out <- c(out, list(shiny::tags$p(class = "text-muted small fw-semibold mt-3 mb-1", ap)))
          cur_apiary <- ap
        }
        out <- c(out, list(lineage_render_node(ns, ro, cols)))
      }
      shiny::tagList(out)
    })

    observeEvent(input$select, {
      id   <- as.integer(input$select)
      cols <- isolate(all_cols())
      co   <- cols[cols$id == id, ]
      if (nrow(co) > 0) nav$apiary_id <- co$apiary_id[1]
      nav$colony_id <- id
      nav$screen    <- "colony"
    })
  })
}