// Five MENU TO — simplified port of Harbour menuto.prg
// Compiles via gengo to native binary

STATIC aPrompts := {}

// @row, col PROMPT text → collects menu items
FUNCTION __AtPrompt(nRow, nCol, cPrompt, cMsg)
   AAdd(aPrompts, {nRow, nCol, cPrompt, cMsg})
   SetPos(nRow, nCol)
   DevOut(cPrompt)
   RETURN .F.

// MENU TO nChoice → displays menu, returns selection
FUNCTION __MenuTo(nStart)
   LOCAL n, nKey, nLen, q, lExit

   nLen := Len(aPrompts)
   IF nLen = 0
      RETURN 0
   ENDIF

   n := nStart
   IF n < 1
      n := 1
   ENDIF
   IF n > nLen
      n := nLen
   ENDIF

   SetCursor(0)
   lExit := .F.

   DO WHILE !lExit

      // Highlight current item (reverse video)
      SetPos(aPrompts[n][1], aPrompts[n][2])
      DevOut(Chr(27) + "[7m" + aPrompts[n][3] + Chr(27) + "[0m")

      // Show message if any
      IF aPrompts[n][4] != NIL .AND. Len(aPrompts[n][4]) > 0
         SetPos(MaxRow(), 0)
         DevOut(PadR(aPrompts[n][4], MaxCol() + 1))
      ENDIF

      // Wait for key
      nKey := Inkey(0)

      // Unhighlight current
      q := n
      SetPos(aPrompts[q][1], aPrompts[q][2])
      DevOut(aPrompts[q][3])

      DO CASE
      CASE nKey = 24 .OR. nKey = 4    // Down or Right
         n++
         IF n > nLen
            n := 1
         ENDIF
      CASE nKey = 5 .OR. nKey = 19    // Up or Left
         n--
         IF n < 1
            n := nLen
         ENDIF
      CASE nKey = 1                    // Home
         n := 1
      CASE nKey = 6                    // End
         n := nLen
      CASE nKey = 13 .OR. nKey = 10    // Enter (CR or LF)
         lExit := .T.
      CASE nKey = 27                   // ESC
         n := 0
         lExit := .T.
      ENDCASE
   ENDDO

   // Clear message line
   SetPos(MaxRow(), 0)
   DevOut(Space(MaxCol() + 1))

   SetCursor(1)

   // Clear prompts for next use
   aPrompts := {}

   RETURN n

// AChoice — array-based menu selection
FUNCTION AChoice(nTop, nLeft, nBottom, nRight, aItems)
   LOCAL n := 1, nKey, nLen, nVisible, nOffset, r, i, lExit

   nLen := Len(aItems)
   IF nLen = 0
      RETURN 0
   ENDIF

   nVisible := nBottom - nTop + 1
   nOffset := 0
   lExit := .F.

   SetCursor(0)

   DO WHILE !lExit

      // Draw visible items
      FOR r := 1 TO nVisible
         i := nOffset + r
         SetPos(nTop + r - 1, nLeft)
         IF i <= nLen
            IF i = n
               DevOut(Chr(27) + "[7m" + PadR(aItems[i], nRight - nLeft + 1) + Chr(27) + "[0m")
            ELSE
               DevOut(PadR(aItems[i], nRight - nLeft + 1))
            ENDIF
         ELSE
            DevOut(Space(nRight - nLeft + 1))
         ENDIF
      NEXT

      nKey := Inkey(0)

      DO CASE
      CASE nKey = 24     // Down
         IF n < nLen
            n++
            IF n > nOffset + nVisible
               nOffset++
            ENDIF
         ENDIF
      CASE nKey = 5      // Up
         IF n > 1
            n--
            IF n <= nOffset
               nOffset := n - 1
            ENDIF
         ENDIF
      CASE nKey = 3      // PgDn
         n += nVisible
         IF n > nLen
            n := nLen
         ENDIF
         nOffset := n - nVisible
         IF nOffset < 0
            nOffset := 0
         ENDIF
      CASE nKey = 18     // PgUp
         n -= nVisible
         IF n < 1
            n := 1
         ENDIF
         nOffset := n - 1
         IF nOffset < 0
            nOffset := 0
         ENDIF
      CASE nKey = 1      // Home
         n := 1
         nOffset := 0
      CASE nKey = 6      // End
         n := nLen
         nOffset := nLen - nVisible
         IF nOffset < 0
            nOffset := 0
         ENDIF
      CASE nKey = 13     // Enter
         lExit := .T.
      CASE nKey = 27     // ESC
         n := 0
         lExit := .T.
      ENDCASE
   ENDDO

   SetCursor(1)
   RETURN n