library(shiny)
library(shinyjs)
library(shinyTree)
library(reactable)
library(dplyr)
library(DBI)

# ── UI ────────────────────────────────────────────────────────────────────────
accountsUI <- function(id) {
  ns <- NS(id)
  tagList(
    useShinyjs(),
    sidebarLayout(
      sidebarPanel(
        width = 3,
        h4("Konten"),
        shinyTree(ns("account_tree"), checkbox = FALSE, search = FALSE)
      ),
      mainPanel(
        width = 9,
        # Accounts-Felder
        wellPanel(
          fluidRow(
            column(12,
              actionButton(ns("new_account"), "Konto neu", 
                class = "btn-success", icon = icon("plus")),
              hr()
            )
          ),
          fluidRow(
            column(4,
              textInput(ns("account_name"), "Kontoname"),
              textInput(ns("bank_name"),    "Bank")
            ),
            column(4,
              numericInput(ns("hibiscus_id"), "Hibiscus Account ID", value = NA),
              numericInput(ns("budget_id"),   "Budget ID",           value = NA)
            ),
            column(4,
              # ID read-only anzeigen
              disabled(numericInput(ns("account_id"), "ID", value = NA)),
              br(),
              actionButton(ns("save_account"), "Speichern",
                class = "btn-primary", icon = icon("save")),
              textOutput(ns("save_status"))
            )
          )
        ),
        # Buchungen
        h4("Buchungen"),
        reactableOutput(ns("postings_table"))
      )
    )
  )
}

# ── Server ----
accountsServer <- function(id, conn, r_global) {
  moduleServer(id, function(input, output, session) {
    ns <- session$ns
    # ── Refresh-Trigger ----
    refresh <- reactiveVal(0)
    
    # ── Kontendaten ----
    accounts <- reactive({
      refresh()
      dbReadTable(conn, "accounts") %>% arrange(account_name)
    })
    
    # ── Baum aufbauen ----
    tree_data <- reactive({
      refresh()
      build_account_tree(conn)
    })

    output$account_tree <- renderTree({  
      tree_data() 
      })
    
    # ── Gewähltes Konto ────────────────────────────────────────────────────────
    selected_name <- reactive({
      sel <- get_selected(input$account_tree, format = "names")
      cat("raw selected:", paste(sel, collapse=", "), "\n")
      if (length(sel) == 0) return(NULL)
      name <- sub(" \\(\\d+\\)$", "", sel[[1]])
      cat("cleaned name:", name, "\n")
      name
    })
    
    selected_account <- reactive({
      req(selected_name())
      df <- accounts()
      df[df$account_name == selected_name(), ]
    })
    
    # ── Inputs befüllen ----
    observeEvent(selected_account(), {
      acc <- selected_account()
      req(nrow(acc) > 0)
      updateNumericInput(session, "account_id",   value = acc$id)
      updateTextInput(session,    "account_name", value = acc$account_name)
      updateTextInput(session,    "bank_name",    value = acc$bank_name %||% "")
      updateNumericInput(session, "hibiscus_id",  value = acc$hibiscus_account_id)
      updateNumericInput(session, "budget_id",    value = acc$budget_id)
    })
    
    # ── Neu-Button ----
    observeEvent(input$new_account, {
      neue_id <- max_id(conn, "accounts") + 1L
      updateNumericInput(session, "account_id",   value = neue_id)
      updateTextInput(session,    "account_name", value = "")
      updateTextInput(session,    "bank_name",    value = "")
      updateNumericInput(session, "hibiscus_id",  value = NA)
      updateNumericInput(session, "budget_id",    value = 0)
    })
    
    # ── Buchungsanzahl für gewähltes Konto ----
    has_postings <- reactive({
      req(input$account_id)
      count <- tbl(conn, "postings") %>%
        filter(account_id == !!input$account_id) %>%
        count() %>%
        pull(n)
      count > 0
    })
    
    # ── Lösch-Button sperren/freigeben ----
    observe({
      req(input$account_id)
      if (has_postings()) {
        shinyjs::disable("delete_account")
        shinyjs::runjs(sprintf(
          "$('#%s').attr('title', 'Konto hat Buchungen und kann nicht gelöscht werden')",
          ns("delete_account")
        ))
      } else {
        shinyjs::enable("delete_account")
        shinyjs::runjs(sprintf(
          "$('#%s').removeAttr('title')",
          ns("delete_account")
        ))
      }
    })
    
    # ── Speichern (upsert ----
    observeEvent(input$save_account, {
      record <- data.frame(
        id                  = input$account_id,
        account_name        = input$account_name,
        bank_name           = input$bank_name,
        hibiscus_account_id = input$hibiscus_id,
        budget_id           = input$budget_id,
        stringsAsFactors    = FALSE
      )
      
      dbxUpsert(conn, "accounts", record, where_cols = c("id"))
      refresh(refresh() + 1)
      
      output$save_status <- renderText("✓ Gespeichert")
      shinyjs::delay(2000, output$save_status <- renderText(""))
    })
    
    # ── Löschen ----
    observeEvent(input$delete_account, {
      req(input$account_id)
      showModal(modalDialog(
        title  = "Konto löschen",
        paste0("Konto '", input$account_name, "' wirklich löschen?"),
        footer = tagList(
          modalButton("Abbrechen"),
          actionButton(ns("delete_confirm"), "Ja, löschen", class = "btn-danger")
        )
      ))
    })
    
    observeEvent(input$delete_confirm, {
      dbxDelete(conn, "accounts", data.frame(id = input$account_id))
      removeModal()
      refresh(refresh() + 1)
      
      output$save_status <- renderText("✓ Gelöscht")
      shinyjs::delay(2000, output$save_status <- renderText(""))
      
      updateNumericInput(session, "account_id",   value = NA)
      updateTextInput(session,    "account_name", value = "")
      updateTextInput(session,    "bank_name",    value = "")
      updateNumericInput(session, "hibiscus_id",  value = NA)
      updateNumericInput(session, "budget_id",    value = NA)
    })
    
    # ── Buchungen laden (read-only ----
    postings_data <- reactive({
      req(selected_account())
      acc <- selected_account()
      req(nrow(acc) > 0)
      refresh()
      read_buch_tabelle(conn) %>%
        filter(account_id == acc$id)
    })
    
    # ── Reactable ----
    output$postings_table <- renderReactable({
      req(postings_data())
      
      reactable(
        postings_data() %>% 
          select(valuta, projektname, display_name, amount, n_attachments),
        striped       = TRUE,
        highlight     = TRUE,
        selection     = "single",
        onClick       = "select",
        defaultSorted = list(valuta = "desc"),
        columns       = list(
          valuta        = colDef(name = "Datum",   maxWidth = 100),
          projektname   = colDef(name = "Projekt", maxWidth = 120),
          display_name  = colDef(name = "Kontakt"),
          amount        = colDef(
            name     = "Betrag",
            maxWidth = 110,
            align    = "right",
            format   = colFormat(currency = "EUR", separators = TRUE, locales = "de-DE")
          ),
          n_attachments = colDef(name = "Anhänge", maxWidth = 80, align = "center")
        )
      )
    })
    
    # ── Sprung zu Buchungen via r_global ----
    sel <- reactive(getReactableState("postings_table", "selected"))
    
    observeEvent(sel(), ignoreInit = TRUE, {
      req(sel(), postings_data())
      entry_id <- postings_data()$entry_id[sel()]
      # In accountsServer vor dem Sprung:
      r_global$nav_history <- c(r_global$nav_history, list(list(
        tab          = "konten",
        account_name = selected_name()
      )))
      r_global$jump_to_entry_id <- entry_id
      r_global$active_tab       <- "buchungen"
      r_global$jump_to_entry_id <- entry_id
      r_global$active_tab       <- "buchungen"
    })
    
    # ── Rückgabe ───────────────────────────────────────────────────────────────
    return(list(
      selected_account = selected_account
    ))
  })
}

# ── Hilfsfunktion ──────────────────────────────────────────────────────────────
`%||%` <- function(a, b) if (is.na(a) || is.null(a) || a == "") b else a