;;; ---------------------------------------------------------------------
;;;  PLLENTAB-bgol.lsp
;;;  Command:  PLEN
;;;
;;;  PURPOSE
;;;  Computes the total length of all selected lines/polylines, grouped
;;;  and summed by layer, and writes a simple tabulated summary of
;;;  per-layer totals directly into the drawing at a user-picked point.
;;;  Useful for quantity takeoffs (e.g. total road length, total pipe
;;;  length by diameter/layer).
;;;
;;;  USAGE
;;;    1. Load this file (APPLOAD or drag-drop onto the drawing window).
;;;    2. Type   PLEN   at the command line and press Enter.
;;;    3. Select the LINE / LWPOLYLINE entities to total.
;;;    4. Pick a point in the drawing for the results table.
;;;    5. A table of layer name vs. total length is drawn as TEXT rows
;;;       on layer "BGOL-PLEN".
;;;
;;;  NOTES
;;;    - This is an original, independently written implementation.
;;;      It is INSPIRED by the general idea of per-layer length
;;;      summary utilities common in CAD/survey drafting workflows,
;;;      but the code, command name and file name here are new and are
;;;      NOT copied from, nor identical to, any specific third-party
;;;      product.
;;;
;;;  ---------------------------------------------------------------------
;;;  Developed and shared for the CAD community by:  BGol Community
;;;  Community website:                              https://bgol.in/
;;;  License:  Open-source & free to use, modify, and share for all.
;;;            Provided "as is", without warranty of any kind.
;;;  ---------------------------------------------------------------------

(vl-load-com)

(defun BGOL:PLEN-EnsureLayer (lname / )
  (if (not (tblsearch "LAYER" lname))
    (entmake (list '(0 . "LAYER")
                   '(100 . "AcDbSymbolTableRecord")
                   '(100 . "AcDbLayerTableRecord")
                   (cons 2 lname)
                   '(70 . 0)
                   '(62 . 5)          ; blue
                   '(6 . "Continuous")))
  )
)

(defun BGOL:PLEN-MakeText (pt str ht lname / dxfdata)
  (setq dxfdata (list '(0 . "TEXT")
                       '(100 . "AcDbEntity")
                       (cons 8 lname)
                       '(100 . "AcDbText")
                       (cons 10 pt)
                       (cons 40 ht)
                       (cons 1 str)
                 )
  )
  (entmakex dxfdata)
)

(defun BGOL:PLEN-GetLen (obj / res)
  (setq res (vl-catch-all-apply
              '(lambda () (vlax-curve-getDistAtParam obj (vlax-curve-getEndParam obj)))
              '()))
  (if (vl-catch-all-error-p res) 0.0 res)
)

(defun C:PLEN ( / ss n i ename obj layer len entry layertotals pt th
                  rowht row grandtotal k)
  (BGOL:PLEN-EnsureLayer "BGOL-PLEN")
  (princ "\nSelect lines/polylines to total by layer: ")
  (setq ss (ssget '((-4 . "<OR") (0 . "LINE") (0 . "LWPOLYLINE") (-4 . "OR>"))))
  (if ss
    (progn
      (setq n (sslength ss))
      (setq layertotals '())
      (setq grandtotal 0.0)
      (setq i 0)
      (while (< i n)
        (setq ename (ssname ss i))
        (setq obj (vlax-ename->vla-object ename))
        (setq layer (cdr (assoc 8 (entget ename))))
        (setq len (BGOL:PLEN-GetLen obj))
        (setq grandtotal (+ grandtotal len))
        (setq entry (assoc layer layertotals))
        (if entry
          (setq layertotals (subst (cons layer (+ (cdr entry) len)) entry layertotals))
          (setq layertotals (append layertotals (list (cons layer len))))
        )
        (setq i (1+ i))
      )
      (setq pt (getpoint "\nSpecify point for results table: "))
      (if pt
        (progn
          (setq th 2.5)
          (setq rowht (* th 1.8))
          (setq row (list (car pt) (cadr pt) (caddr pt)))
          (BGOL:PLEN-MakeText row "LAYER LENGTH SUMMARY (PLEN)" th "BGOL-PLEN")
          (setq row (list (car row) (- (cadr row) rowht) (caddr row)))
          (BGOL:PLEN-MakeText row "Layer                Total Length" th "BGOL-PLEN")
          (setq k 0)
          (foreach entry layertotals
            (setq row (list (car row) (- (cadr row) rowht) (caddr row)))
            (BGOL:PLEN-MakeText row
              (strcat (car entry) "   " (rtos (cdr entry) 2 3))
              th "BGOL-PLEN")
            (setq k (1+ k))
          )
          (setq row (list (car row) (- (cadr row) rowht) (caddr row)))
          (BGOL:PLEN-MakeText row (strcat "GRAND TOTAL: " (rtos grandtotal 2 3)) th "BGOL-PLEN")
          (princ (strcat "\nPLEN: totals for " (itoa (length layertotals)) " layer(s) placed in drawing."))
        )
        (princ "\nNo point specified; table not placed.")
      )
    )
    (princ "\nNo lines or polylines selected.")
  )
  (princ)
)

(princ "\nPLLENTAB-bgol.lsp loaded. Type PLEN to total selected line lengths by layer.")
(princ "\n  -- Free & open-source, courtesy of BGol Community (https://bgol.in/) --")
(princ)