read_buch_tabelle <- function(conn, trans_id = NULL){
  if(!is.null(trans_id)){
    postings <- tbl(conn, "postings") %>%
      filter(entry_id == trans_id)
  } else {
    postings <- tbl(conn, "postings")
  }
  entries     <- tbl(conn, "entries")
  accounts    <- tbl(conn, "accounts")
  projects    <- tbl(conn, "projects")
  contacts    <- tbl(conn, "contacts")
  attachments <- tbl(conn, "attachments")
  
  # Anzahl Attachments pro entry_id vorberechnen
  attachment_counts <- attachments %>%
    group_by(entry_id) %>%
    summarise(n_attachments = n(), .groups = "drop")
  
  result <- postings |>
    left_join(entries,           by = c("entry_id" = "id")) |>
    left_join(contacts,          by = c("contact_id" = "id")) |>
    left_join(accounts,          by = c("account_id" = "id")) |>
    left_join(projects,          by = c("project_id" = "id")) |>
    left_join(attachment_counts, by = "entry_id") |>
    select(id, valuta, account_name, projektname, display_name, amount, entry_id, n_attachments, account_id) |>
    collect() %>%
    mutate(
      saldo         = 0,
      n_attachments = tidyr::replace_na(n_attachments, 0L)
    ) %>%
    arrange(valuta, entry_id)
}

read_posting <- function(conn, id){
  dbxSelect(conn, paste0("SELECT * FROM postings WHERE id =", id))
}


coldef_entries_tabelle <- 
  list(
    id = colDef(name = "ID", width = 80),
    valuta = colDef(name = "Wertstellung", width = 120),
    account_name = colDef(name = "Kontoname", width = 200),
    projektname = colDef(name = "Projektname", width = 150),
    display_name = colDef(name = "Kontakt", width = 250),
    account_id    = colDef(show = FALSE),
    entry_id    = colDef(show = FALSE),
    amount = colDef(name = "Betrag", width = 120, 
      format = colFormat(prefix = "", separators = TRUE, digits = 2),
      style = function(value) {
        color <- if (value < 0) "#e06666" else "#2b2b2b" # Rot bei negativ, sonst dunkelgrau
        list(color = color, fontWeight = "bold")        # Gibt CSS-Styles zurück
      }
    ),
    n_attachments = colDef(
      name = "Anhänge",
      filterMethod = JS("function(rows, columnId, filterValue) {
    const val = parseFloat(filterValue);
    if (isNaN(val)) return rows;  // kein gültiger Wert → alles zeigen
    return rows.filter(row => row.values[columnId] > val);
  }")
    ),
    entry_id = colDef(name ="trans_id", width = 120),
    saldo = colDef(
      name = "Saldo",
      width = 140,
      html = TRUE,
      cell = JS("
    function(cellInfo, state) {
      const page = state.page || 0
      const pageSize = state.pageSize || state.sortedData.length
      const globalIndex = page * pageSize + cellInfo.viewIndex

      let total = 0
      for (let i = 0; i <= globalIndex && i < state.sortedData.length; i++) {
        total += Number(state.sortedData[i].amount || 0)
      }

      const color = total < 0 ? '#e06666' : '#2b2b2b'

      return `<span style='color:${color}; font-weight:bold'>
                ${total.toLocaleString('de-DE', {
                  minimumFractionDigits: 2,
                  maximumFractionDigits: 2
                })}
              </span>`
    }
  ")
    )
  )