# module_posting.R

postingModuleUI <- function(id) {
  ns <- NS(id)
  tagList() # Das UI wird dynamisch via showModal erzeugt
}

postingModuleServer <- function(id, conn, r_trans_id, r_trigger_list) {
  moduleServer(id, function(input, output, session) {
    ns <- session$ns
    
    # Dieser Trigger signalisiert dem Hauptmodul: "Daten haben sich geändert!"
    db_updated <- reactiveVal(0)
    
    # Hilfsvariablen für den aktuellen Edit-Status
    current_record <- reactiveVal()
    current_trans  <- reactiveVal()
    
    # Beobachte den Trigger aus dem Hauptmodul
    observeEvent(r_trigger_list(), {
      req(r_trans_id())
      
      # 1. Daten laden
      t_id <- r_trans_id()
      p_id <- r_trigger_list()$post_id
      
      trans_data <- dbxSelect(conn, paste0("SELECT * FROM entries WHERE id=", t_id))
      current_trans(trans_data)
      
      if (!is.null(p_id)) {
        record <- read_posting(conn, p_id)
      } else {
        # Logik für neuen Eintrag
        new_p_id <- max_id(conn, "postings") + 1
        wertstellung <- dbxSelect(conn, paste0("SELECT max(valuta) from Postings WHERE entry_id=", t_id)) %>% pull()
        
        record <- leer_df_from_table(conn, "postings")
        record[1, "id"] <- new_p_id
        record$entry_id <- t_id
        record$account_id <- 0
        record$valuta <- wertstellung
        record$booking_date <- wertstellung
      }
      current_record(record)
      
      # 2. Modal anzeigen
      showModal(modalDialog(
        title = paste("Buchung bearbeiten - Transaktion", t_id),
        f_airdatepicker_UI(ns("valuta"), "Wertstellung", record$valuta),
        f_airdatepicker_UI(ns("buchungsdatum"), "Buchungsdatum", record$booking_date),
        selectizeInput(ns("kontakt"), "Kontakt:", selected = trans_data$contact_id, choices = get_contact_choices(conn), width = "100%"),
        selectizeInput(ns("konto"), "Kontoname:", selected = record$account_id, choices = get_account_choices(conn), width = "100%"),
        selectizeInput(ns("projekt"), "Projektname", selected = record$project_id, choices = get_project_choices(conn), width = "100%"),
        splitLayout(cellWidths = c("70%", "30%"), 
          numericInput(ns("amount"), "Betrag:", value = record$amount, width = "100%"),
          numericInput(ns("coin_share_amount"), "Münzen:", value = record$coin_share_amount, width = "100%")
        ),
        textAreaInput(ns("trans_notiz"), label = "Notiz (Transaktion)", value = trans_data$note, width = "100%"),
        
        footer = tagList(
          modalButton("Abbrechen"),
          actionBttn(ns("delete"), "Löschen", style = "minimal", color = "danger"),
          actionBttn(ns("confirm"), "Bestätigen", style = "minimal", color = "success")
        ),
        easyClose = TRUE
      ))
    })
    
    # Speichern
    observeEvent(input$confirm, {
      req(current_record(), current_trans())
      
      # Daten aus UI einsammeln
      rec <- current_record()
      tra <- current_trans()
      
      tra$contact_id <- input$kontakt
      tra$note       <- input$trans_notiz
      rec$amount     <- input$amount
      rec$account_id <- input$konto
      rec$project_id <- input$projekt
      rec$valuta     <- as.character(input$valuta)
      rec$booking_date <- as.character(input$buchungsdatum)
      rec$coin_share_amount <- input$coin_share_amount
      
      # Validierung
      ok <- !is.na(rec$amount) && rec$account_id > 0
      
      if (ok) {
        dbxUpsert(conn, "postings", records = rec, where_cols = "id")
        dbxUpsert(conn, "entries", records = tra, where_cols = "id")
        removeModal()
        db_updated(db_updated() + 1) # Hauptmodul triggern
      } else {
        showNotification("Eingabe ungültig", type = "error")
      }
    })
    
    # Löschen
    observeEvent(input$delete, {
      rec <- current_record()
      anz <- dbxSelect(conn, paste0("SELECT count(*) FROM postings WHERE entry_id=", rec$entry_id)) %>% pull()
      
      if (anz > 1) {
        dbxDelete(conn, "postings", where = data.frame(id = rec$id))
        removeModal()
        db_updated(db_updated() + 1)
      } else {
        showNotification("Letzter Teil kann nicht gelöscht werden.", type = "error")
      }
    })
    
    return(db_updated)
  })
}