"""First-fit printable PCD76 bracket. Run in FreeCAD GUI via macro.

Geometry is based on a 6xx/7 mm body standoff reference; no load rating is implied.
"""
import math,time,traceback
from pathlib import Path
import FreeCAD as A, FreeCADGui as G, Part, Import, Mesh
from pivy import coin
R=Path(__file__).resolve().parent.parent
O=R/'models'/'encoder_shared76_print_v1'; O.mkdir(parents=True,exist_ok=True)
V=A.Vector
def cy(r,h,x=0,y=0,z=0): return Part.makeCylinder(r,h,V(x,y,z))
def add(doc,name,label,s,c,trans=0):
 o=doc.addObject('PartDesign::Feature',name);o.Label=label;o.Shape=s
 o.ViewObject.ShapeColor=c;o.ViewObject.LineColor=(.12,.12,.12);o.ViewObject.Transparency=trans;return o
def valid(name,s):
 if s.isNull() or not s.isValid() or len(s.Solids)!=1 or s.Volume<=0:raise RuntimeError('Invalid solid '+name)
def hexprism(x,y,z,h):
 # 7 mm across flats
 rr=7/math.sqrt(3)
 pts=[V(x+rr*math.cos(math.radians(30+i*60)),y+rr*math.sin(math.radians(30+i*60)),z) for i in range(6)];pts.append(pts[0])
 return Part.Face(Part.Wire(Part.makePolygon(pts).Edges)).extrude(V(0,0,h))
try:
 src=A.openDocument(str(R/'models'/'shared76_concept'/'Shared76.FCStd'))
 keep=['Motor','Holder','Magnet','PCB','Chip','PCBHead1','PCBHead2','PCBHead3']+['Corner%d'%i for i in range(4)]+['Rail%d'%i for i in range(2)]
 shapes={n:src.getObject(n).Shape.copy() for n in keep}
 A.closeDocument(src.Name)
 src=A.openDocument(str(R/'models'/'encoder_print_v1'/'EncoderAssembly_Fit.FCStd'))
 oldring=src.getObject('Bracket').Shape.copy().common(Part.makeBox(100,100,3.2,V(-50,-50,10.9)))
 A.closeDocument(src.Name)
 # PCB rear/base face z=11.3 with one 0.5mm shim on a 7mm standoff.
 board_shift=.4; oldring.translate(V(0,0,board_shift))
 for n in ['PCB','Chip','PCBHead1','PCBHead2','PCBHead3']: shapes[n].translate(V(0,0,board_shift))
 p=38/math.sqrt(2); frame=Part.makeBox(64,64,3.2,V(-32,-32,11.3)).cut(cy(16.8,3.22,z=11.29)).fuse(oldring)
 # U slots face outward: left opens to -X and right to +X. Both pairs differ in direction.
 for side in (-1,1):
  for y in (-p,p):
   x=side*p; start=x if side>0 else x-10
   cutter=Part.makeBox(10,4.6,3.24,V(start,y-2.3,11.28)).fuse(cy(2.3,3.24,x,y,11.28))
   frame=frame.cut(cutter)
 frame=frame.removeSplitter();valid('frame',frame)
 shim05=cy(4.5,.5).cut(cy(2.25,.52,z=-.01));valid('shim05',shim05)
 shim10=cy(4.5,1).cut(cy(2.25,1.02,z=-.01));valid('shim10',shim10)
 parts=A.newDocument('Shared76PrintParts')
 local=frame.copy();local.translate(V(0,0,-11.3));valid('flat frame',local)
 po=[add(parts,'EncoderBracket','PCD76 encoder bracket print face down',local,(.15,.45,.85)),add(parts,'Shim05','M4 shim 0.5mm',shim05,(.75,.75,.75)),add(parts,'Shim10','M4 shim 1mm',shim10,(.75,.75,.75))]
 parts.recompute(); mesh_lines=[]
 for ob in po:
  Mesh.export([ob],str(O/(ob.Name+'.stl')));Import.export([ob],str(O/(ob.Name+'.step')))
  mesh=Mesh.Mesh(str(O/(ob.Name+'.stl')));bb=mesh.BoundBox
  mesh_lines.append('%s solid=%s facets=%d volume=%.4f zmin=%.4f'%(ob.Name,mesh.isSolid(),mesh.CountFacets,mesh.Volume,bb.ZMin))
  if not mesh.isSolid() or mesh.Volume<=0 or abs(bb.ZMin)>.001:raise RuntimeError('mesh validation failed '+ob.Name)
 (O/'mesh_check.txt').write_text('\n'.join(mesh_lines)+'\n',encoding='utf8');parts.saveAs(str(O/'Shared76_Print.FCStd'))
 A.closeDocument(parts.Name)
 doc=A.newDocument('Shared76Fit');objs={}
 colors={'Motor':(.32,.34,.37),'Holder':(.98,.55,.1),'Magnet':(.8,.8,.8),'PCB':(.04,.65,.19),'Chip':(.1,.1,.1)}
 for n in keep:
  c=colors.get(n,(.84,.47,.13) if n.startswith('Corner') else (.55,.56,.6) if n.startswith('Rail') else (.8,.8,.8))
  objs[n]=add(doc,n,n,shapes[n],c,70 if n=='Motor' else 15 if n.startswith('Corner') else 0)
 objs['Frame']=add(doc,'EncoderBracket','PCD76 bracket printed part',frame,(.15,.45,.85))
 stand=[];bottomwash=[];adjust=[];topwash=[];tops=[]
 for side in (-1,1):
  for y in (-p,p):
   x=side*p; i=len(stand)
   # 3mm corner then 0.8 metal washer, then 7mm body; male 8mm long, 4.2mm nominal thread into motor.
   washer=cy(5,.8,x,y,3).cut(cy(2.15,.82,x,y,2.99))
   bottomwash.append(add(doc,'MetalWasher%d'%i,'Metal angle washer 0.8 assumed',washer,(.78,.8,.82)))
   body=hexprism(x,y,3.8,7).cut(cy(2.1,3.52,x,y,7.29))
   body=body.fuse(cy(1.95,8,x,y,-4.2)).removeSplitter();valid('standoff',body)
   stand.append(add(doc,'Standoff%d'%i,'M4 male female 7mm body 8mm male reference',body,(.82,.70,.4)))
   adj=cy(4.5,.5,x,y,10.8).cut(cy(2.25,.52,x,y,10.79))
   adjust.append(add(doc,'AdjustmentShim%d'%i,'0.5mm nominal adjustment',adj,(.72,.72,.72)))
   tw=cy(4.5,.8,x,y,14.5).cut(cy(2.15,.82,x,y,14.49))
   topwash.append(add(doc,'TopWasher%d'%i,'Top M4 washer 9x0.8 assumed',tw,(.8,.8,.8)))
   # Chosen illustrative thread penetration 3mm (female minimum reference 3.5mm).
   bolt=cy(1.9,8,x,y,7.3).fuse(cy(3.5,2.5,x,y,15.3)).removeSplitter()
   tops.append(add(doc,'TopScrew%d'%i,'M4 screw envelope length 8mm verify depth',bolt,(.8,.8,.8)))
 doc.recompute()
 # All pairs of assembled hardware/PCB/support are checked; intended face contact has zero volume.
 group=[objs[k] for k in keep]+[objs['Frame']]+stand+bottomwash+adjust+topwash+tops
 intersections=[]
 for i,a in enumerate(group):
  for b in group[i+1:]:
   if a.Name.startswith('PCBHead') and b.Name in ['PCB']: continue # heads bear on board face
   if not a.Shape.BoundBox.intersect(b.Shape.BoundBox):continue
   volume=a.Shape.common(b.Shape).Volume
   if volume>0.001:intersections.append('%s / %s %.5f mm3'%(a.Name,b.Name,volume))
 report=['Nominal gap 1.4mm: 7mm standoff body, 0.8mm motor washer, 0.5mm encoder shim.',
 'M4 male 8mm; through 3mm angle and 0.8mm metal washer, nominal motor engagement 4.2mm.',
 'M4 top shank 8mm through 0.8mm top washer + 3.2mm bracket + 0.5mm shim, female entry 3.5mm.',
 'Intersections above 0.001 mm3, selected complete simplified assembly pairs:']+(intersections or ['none'])
 (O/'geometry_check.txt').write_text('\n'.join(report)+'\n',encoding='utf8')
 # No automatic PASS if a real interference exists: keep report and let human evaluate.
 view=G.activeDocument().activeView()
 def render(top,name):
  if top:view.viewTop()
  else:view.viewAxonometric();G.updateGui();time.sleep(.5);view.getCameraNode().orientation.setValue(coin.SbRotation(.880476,.115917,-.279848,-.364705))
  G.updateGui();time.sleep(.7);view.fitAll();G.updateGui();time.sleep(.7);view.saveImage(str(O/name),1600,1200,'White')
 render(False,'assembly.png');render(True,'rear.png')
 states={o.Name:o.ViewObject.Visibility for o in doc.Objects if hasattr(o,'Shape')}
 for ob in doc.Objects:
  if hasattr(ob,'Shape'):ob.ViewObject.Visibility=False
 objs['Frame'].ViewObject.Visibility=True;render(True,'bracket.png')
 for ob in doc.Objects:
  if hasattr(ob,'Shape'):ob.ViewObject.Visibility=states[ob.Name]
 render(False,'assembly.png');doc.recompute();doc.saveAs(str(O/'Shared76_Assembly.FCStd'))
 Import.export([o for o in doc.Objects if hasattr(o,'Shape')],str(O/'Shared76_Assembly.step'))
 (O/'DONE.txt').write_text('ok\n',encoding='utf8')
except Exception:
 (O/'ERROR.txt').write_text(traceback.format_exc(),encoding='utf8');raise