# module_buchungen.R

buchungenUI <- function(id) {
  ns <- NS(id)
  tagList(
    useShinyjs(), 
    h3("Hauptbuchungen"),
    reactableOutput(ns("buchungen_table")),
    hr(),
    h3("Details / Gegenbuchungen"),
    reactableOutput(ns("details_table")),
    h3("Anhänge"),
    uiOutput(ns("attachments_ui")),
    fileInput(ns("anhang"), NULL, multiple = TRUE, 
      accept = c(".pdf", ".jpg", ".png", ".xlsx", ".docx"),
      width = "100%"),
    br(),
    actionBttn(ns("add_trans"), "Transaktion hinzu", size = "sm", style = "material-flat", color = "warning"),
    actionBttn(ns("del_trans"), "Transaktion Löschen", size = "sm", style = "material-flat", color = "danger"),
    actionBttn(ns("add_detail"), "Detail hinzu", size = "sm", style = "material-flat", color = "success"),
    
    # Das UI-Element des Moduls (auch wenn es leer ist)
    postingModuleUI(ns("posting_modal"))
  )
}

buchungenServer <- function(id, conn, r_global) {
  moduleServer(id, function(input, output, session) {
    ns <- session$ns
    
    # ── Reactive Variablen ─────────────────────────────────────────────────────
    postings_data      <- reactiveVal(read_buch_tabelle(conn))
    details_data       <- reactiveVal(NULL)
    selected_trans_id  <- reactiveVal(NULL)
    current_main_idx   <- reactiveVal(NULL)
    reset_trigger      <- reactiveVal(0)
    modal_trigger      <- reactiveVal(list(post_id = NULL, counter = 0))
    highlighted_valuta <- reactiveVal(NULL)
    
    update_db_trigger <- postingModuleServer(
      "posting_modal", conn, selected_trans_id, modal_trigger
    )
    
    # ── Filter ─────────────────────────────────────────────────────────────────
    aktiver_filter <- reactive(r_global$buchungen_filter)
    
    gefilterte_daten <- reactive({
      d <- postings_data()
      f <- aktiver_filter()
      if      (f == "alle")               d
      else if (f == "giro")               d |> filter(grepl("0130", account_name))
      else if (f == "monat")              d |> filter(
        floor_date(as.Date(valuta), "month") == floor_date(Sys.Date(), "month")
      )
      else if (startsWith(f, "contact:")) d |> filter(contact_id == as.integer(sub("contact:", "", f)))
      else if (startsWith(f, "project:")) d |> filter(project_id == as.integer(sub("project:", "", f)))
      else if (startsWith(f, "account:")) d |> filter(account_id == as.integer(sub("account:", "", f)))
      else d
    })
    
    observeEvent(aktiver_filter(), {
      current_main_idx(NULL)
      selected_trans_id(NULL)
      details_data(NULL)
    })
    
    # ── Sprung von anderem Modul ───────────────────────────────────────────────
    observeEvent(r_global$jump_to_entry_id, ignoreInit = TRUE, {
      req(r_global$jump_to_entry_id)
      t_id <- r_global$jump_to_entry_id
      
      # Daten neu laden
      postings_data(read_buch_tabelle(conn))
      
      # Zeile suchen
      idx <- which(gefilterte_daten()$entry_id == t_id)[1]
      req(!is.na(idx))
      
      current_main_idx(idx)
      selected_trans_id(t_id)
      details_data(read_buch_tabelle(conn, trans_id = t_id))
      highlighted_valuta(gefilterte_daten()[idx, "valuta"])
      
      reset_trigger(isolate(reset_trigger()) + 1)
      scroll_to_row(ns("buchungen_table"), idx)
      
      # Sprungziel zurücksetzen
      r_global$jump_to_entry_id <- NULL
    })
    
    # ── Haupttabelle rendern ───────────────────────────────────────────────────
    output$buchungen_table <- renderReactable({
      reset_trigger()
      f_reactable(
        daten            = gefilterte_daten(),
        coldefs          = coldef_entries_tabelle,
        selection        = "single",
        hoehe            = "60vh",
        defaultSelected  = current_main_idx(),
        highlight_valuta = highlighted_valuta()
      )
    })
    
    # ── Details laden ──────────────────────────────────────────────────────────
    sel_details <- reactive(getReactableState("buchungen_table", "selected"))
    
    observeEvent(sel_details(), ignoreInit = TRUE, {
      req(sel_details())
      highlighted_valuta(gefilterte_daten()[sel_details(), "valuta"])
      current_main_idx(sel_details())
      t_id <- gefilterte_daten()[sel_details(), "entry_id"] |> pull()
      selected_trans_id(t_id)
      details_data(read_buch_tabelle(conn, trans_id = t_id))
    })
    
    output$details_table <- renderReactable({
      req(details_data())
      f_reactable(
        details_data(),
        coldefs   = coldef_entries_tabelle,
        selection = "single",
        hoehe     = NULL
      )
    })
    
    # ── Detail hinzufügen ──────────────────────────────────────────────────────
    observeEvent(input$add_detail, {
      req(selected_trans_id())
      modal_trigger(list(post_id = NULL, counter = modal_trigger()$counter + 1))
    })
    
    # ── Detail editieren ───────────────────────────────────────────────────────
    sel_detail <- reactive(getReactableState("details_table", "selected"))
    
    observeEvent(sel_detail(), ignoreInit = TRUE, {
      p_id <- details_data()$id[sel_detail()]
      modal_trigger(list(post_id = p_id, counter = modal_trigger()$counter + 1))
    })
    
    # ── DB-Update durch Modal ──────────────────────────────────────────────────
    observeEvent(update_db_trigger(), ignoreInit = TRUE, {
      req(selected_trans_id())
      details_data(read_buch_tabelle(conn, trans_id = selected_trans_id()))
      postings_data(read_buch_tabelle(conn))
      updateReactable("buchungen_table", data = gefilterte_daten())
    })
    
    # ── Neue Transaktion ───────────────────────────────────────────────────────
    observeEvent(input$add_trans, {
      new_t_id <- max_id(conn, "entries") + 1
      dbxInsert(conn, "entries", data.frame(id = new_t_id))
      p_id1 <- max_id(conn, "postings") + 1
      p_id2 <- p_id1 + 1
      dbxInsert(conn, "postings", data.frame(
        id         = c(p_id1, p_id2),
        entry_id   = c(new_t_id, new_t_id),
        amount     = c(0, 0),
        account_id = c(0, 0),
        valuta     = c(Sys.Date(), Sys.Date())
      ))
      
      # Filter zurücksetzen damit neue Transaktion sichtbar ist
      r_global$buchungen_filter <- "alle"
      
      postings_data(read_buch_tabelle(conn))
      selected_trans_id(new_t_id)
      details_data(read_buch_tabelle(conn, trans_id = new_t_id))
      
      neue_zeile <- which(postings_data()$id == p_id1)
      current_main_idx(neue_zeile)
      reset_trigger(isolate(reset_trigger()) + 1)
      scroll_to_row(ns("buchungen_table"), neue_zeile)
    })
    
    # ── Transaktion löschen ────────────────────────────────────────────────────
    observeEvent(input$del_trans, ignoreInit = TRUE, {
      req(selected_trans_id())
      dbxDelete(conn, "postings", where = data.frame(entry_id = selected_trans_id()))
      dbxDelete(conn, "entries",  where = data.frame(id = selected_trans_id()))
      postings_data(read_buch_tabelle(conn))
      current_main_idx(NULL)
      selected_trans_id(NULL)
      details_data(NULL)
      updateReactable("buchungen_table", data = gefilterte_daten())
    })
    
    # ── Anhänge ────────────────────────────────────────────────────────────────
    output$attachments_ui <- renderUI({
      req(selected_trans_id())
      att <- dbxSelect(conn, paste0(
        "SELECT * FROM attachments WHERE entry_id = ", selected_trans_id()
      ))
      if (nrow(att) == 0) return(p("Keine Anhänge vorhanden."))
      
      tagList(lapply(seq_len(nrow(att)), function(i) {
        ext      <- tools::file_ext(att$original_name[i])
        filename <- paste0("attachments/", att$id[i], ".", ext)
        
        observeEvent(input[[paste0("open_att_", att$id[i])]], {
          showModal(modalDialog(
            tags$iframe(src = filename, width = "100%", height = "600px", 
              style = "border:none;"),
            title     = att$original_name[i],
            size      = "l",
            easyClose = TRUE,
            footer    = modalButton("Schließen")
          ))
        }, ignoreInit = TRUE, once = FALSE)
        
        div(
          actionLink(ns(paste0("open_att_", att$id[i])), att$original_name[i]),
          actionLink(ns(paste0("del_att_", att$id[i])), "✕",
            style = "color:red; margin-left:8px;")
        )
      }))
    })
  })
}