#!/usr/bin/env python3
"""Add nominal STEP-derived metal bounding projections on Dwgs.User only.

Not silkscreen, a courtyard, or a case cutout. See db9-mechanical-notes.md for
source attribution, selected face subsets and the user-confirmed male/female
external-geometry equivalence. No module height or case-wall thickness assumed.
"""
import json
from pathlib import Path
import uuid
import pcbnew as p

ROOT=Path(__file__).resolve().parent
PCB=ROOT/"serial-carrier.kicad_pcb"
NS=uuid.UUID("ba7274a8-c35d-46bc-908d-cd86708fc6c4")


def main():
    lock=ROOT/"~serial-carrier.kicad_pcb.lck"
    if lock.exists():
        raise SystemExit("Close PCB Editor before refreshing the CAD envelopes")
    before=PCB.read_bytes()
    project=ROOT/"serial-carrier.kicad_pro"
    project_before=project.read_bytes()
    board=p.LoadBoard(str(PCB))
    u2=next(f for f in board.GetFootprints() if f.GetReference()=="U2")
    assert u2.GetOrientationDegrees()==0, "Review transform for rotated module"
    x0,y0=p.ToMM(u2.GetPosition().x),p.ToMM(u2.GetPosition().y)
    data=json.loads((ROOT/"reference/db9-cad/measurements.json").read_text())
    owned={str(uuid.uuid5(NS,str(i))) for i in range(64)}
    for drawing in list(board.GetDrawings()):
        if drawing.m_Uuid.AsString() in owned:
            board.Delete(drawing)
    count=0

    def point(x,y):
        # STEP/Eagle axes +Y toward connector; KiCad local Y is downward.
        return p.VECTOR2I(p.FromMM(x0+x-1.905),p.FromMM(y0+2.667-y))

    def add(item):
        nonlocal count
        assert count<64
        item.SetLayer(p.Dwgs_User)
        item.SetUuid(p.KIID(str(uuid.uuid5(NS,str(count)))))
        board.Add(item)
        count+=1

    for feature in ("front_flange_exposed_faces", "shell_outer_including_root_and_lip",
                    "left_front_hex_post", "right_front_hex_post"):
        xmin,ymin,_,xmax,ymax,_=data[feature]["bounds"]
        rect=p.PCB_SHAPE(board)
        rect.SetShape(p.SHAPE_T_RECT)
        rect.SetStart(point(xmin,ymax)); rect.SetEnd(point(xmax,ymin))
        rect.SetWidth(p.FromMM(0.1))
        add(rect)
    for axis in data["front_lock_axes"]:
        x=axis["location"][0]
        # These mark front-facing Y axes, not holes through the carrier PCB.
        line=p.PCB_SHAPE(board)
        line.SetShape(p.SHAPE_T_SEGMENT)
        line.SetStart(point(x,26.907)); line.SetEnd(point(x,32.707))
        line.SetWidth(p.FromMM(0.08))
        add(line)
    label=p.PCB_TEXT(board)
    label.SetText("CAD METAL ENVELOPES - NOT CASE CUTOUT")
    label.SetPosition(p.VECTOR2I(p.FromMM(x0+13.97),p.FromMM(y0-17.67)))
    label.SetTextSize(p.VECTOR2I(p.FromMM(0.65),p.FromMM(0.65)))
    label.SetTextThickness(p.FromMM(0.1))
    add(label)
    for drawing in board.GetDrawings():
        if not isinstance(drawing,p.PCB_TEXT):
            continue
        value=drawing.GetText()
        if value.startswith("DE-9 OUT /"):
            drawing.SetPosition(p.VECTOR2I(p.FromMM(x0+13.97),p.FromMM(y0-20.67)))
        elif value=="82 x 80 mm / 2 copper layers":
            drawing.SetPosition(p.VECTOR2I(p.FromMM(141),p.FromMM(91)))
        elif value.startswith("Nominal RS-232 metal verified;"):
            drawing.SetPosition(p.VECTOR2I(p.FromMM(141),p.FromMM(93.5)))
    temp=ROOT/"serial-carrier-envelope-tmp.kicad_pcb"
    try:
        assert p.SaveBoard(str(temp),board,True)
        if lock.exists() or PCB.read_bytes()!=before:
            raise RuntimeError("PCB changed or reopened; refusing overwrite")
        assert project.read_bytes()==project_before
        temp.replace(PCB)
    finally:
        temp.unlink(missing_ok=True)
    print(f"Added {count} nominal CAD projection graphics on Dwgs.User; no copper/project changes")


if __name__=="__main__":
    main()