"""6 x 3.5 mm through-hole tactile switch, APEM MJTP1243 and MJTP1250 (top-operated, two terminals). The body is centred on the origin,
its underside on the board's top face (the XY plane); the body's 6.0 length and the two terminals lie along X (6.5 apart), its 3.5 depth
along Y. Dimensions from APEM's MJTP series sheet, in the README."""
from steve import Model

kind = "1243"  # Type (MJTP1243 or MJTP1250)

# Each entry: (height to the actuator's top L1, overall height to the terminals' tips L).
#   APEM "MJTP Series 6mm Thru-Hole Mtg. Tact Switches", catalogue section M (pages M3 to M7, PDF dated 2021-09-05/2023-04-20; the
#   mm.digikey.com copy), page M6, MJTP1243 & MJTP1250, table: MJTP1243 L1 .169 (4,3), L .307 (7,8); MJTP1250 L1 .197 (5,0),
#   L .335 (8,5).
TYPES = {
    "1243": (4.3, 7.8),
    "1250": (5.0, 8.5),
}
# Page M6, the MJTP1243 & MJTP1250 drawing, in inches (mm); the mm values are used:
BODY_L = 6.0       # .236 (6.0), the body's length (front view)
BODY_W = 3.5       # .138 (3.5), its depth (side view)
TOP = 3.5          # .138 (3.5), the board to the cover's top
EAR_H = 0.3        # .012 (0.3), the two end bosses above the cover's top
ACT_L = 3.0        # .118 (3.0), the actuator's length (front view)
ACT_W = 1.5        # .059 (1.5), its depth (side view)
TAIL = 3.5         # .138 (3.5), the terminals' tips below the board
PITCH = 6.5        # .256 (6.5), the terminals' centres at the tips
OVER = 7.9         # .311 (7.9), over the terminals' bends
LEAD_W = 1.0       # .039 (1.0), the terminals' width (side view)
LEAD_T = 0.3       # .012 (0.3), their thickness
BEND_START = 0.7   # .028 (0.7), the board to where the terminal starts to bend out
BEND_APEX = 1.8    # .071 (1.8), the board to the bend's outermost point
BEND_END = 2.8     # .110 (2.8), the board to where the terminal is straight again
# Proportions, for looks only (the drawing doesn't dimension them; scaled from the drawing, README): the cover's thickness, the end
# bosses' size, the corner feet's recesses, and where the terminals leave the housing.
COVER_T = 0.3
EAR_L = 1.0
EAR_W = 2.0
RECESS_L = 2.2
RECESS_W = 2.5
RECESS_H = 0.4
LEAD_TOP = 0.8

if kind not in TYPES:
    raise ValueError(f"no type {kind!r}: {', '.join(TYPES)}")
height, overall = TYPES[kind]
if abs(height + TAIL - overall) > 0.05:
    raise ValueError("L1 and L disagree with the 3.5 tail")
hx, hy = BODY_L / 2, BODY_W / 2
housing_top = TOP - COVER_T

# model.box takes the box's centre; the XZ plane's normal is -Y, so a sketch on it extrudes towards -Y.
model = Model()
model.box("housing", BODY_L, BODY_W, housing_top - RECESS_H, at=(0, 0, (housing_top + RECESS_H) / 2), op="new", body="housing_body",
          name="Housing")
# Four corner feet: the underside is recessed RECESS_L along X and RECESS_W along Y (front and side views).
foot_l = (BODY_L - RECESS_L) / 2
foot_w = (BODY_W - RECESS_W) / 2
for i, (sx, sy) in enumerate(((1, 1), (-1, 1), (-1, -1), (1, -1))):
    model.box(f"foot_{i + 1}", foot_l, foot_w, RECESS_H + 0.01, at=(sx * (hx - foot_l / 2), sy * (hy - foot_w / 2), (RECESS_H + 0.01) / 2),
              op="join", body="housing_body", name="Foot")
# The two end bosses stand on the cover; they are moulded with the housing, through the cover's end notches.
for i, sx in enumerate((1, -1)):
    model.box(f"ear_{i + 1}", EAR_L, EAR_W, COVER_T + EAR_H + 0.01, at=(sx * (hx - EAR_L / 2), 0, housing_top - 0.01 + (COVER_T + EAR_H + 0.01) / 2),
              op="join", body="housing_body", name="End boss")
# Cover: a plate over the housing with the ends notched round the bosses and an opening for the actuator.
model.box("cover", BODY_L, BODY_W, COVER_T, at=(0, 0, housing_top + COVER_T / 2), op="new", body="cover_body", name="Cover")
for i, sx in enumerate((1, -1)):
    model.box(f"cover_notch_{i + 1}", EAR_L + 0.02, EAR_W, COVER_T + 0.2, at=(sx * (hx - EAR_L / 2 + 0.01), 0, housing_top + COVER_T / 2),
              op="cut", body="cover_body", name="Boss notch")
model.box("cover_opening", ACT_L, ACT_W, COVER_T + 0.2, at=(0, 0, housing_top + COVER_T / 2), op="cut", body="cover_body",
          name="Actuator opening")
# Actuator: from the housing's top, through the cover, up to L1.
model.box("actuator", ACT_L, ACT_W, height - housing_top, at=(0, 0, (height + housing_top) / 2), op="new", body="actuator_body",
          name="Actuator")


def outline(points, t):
    """A closed outline around a polyline of straight segments, t thick (mitred corners)."""
    import math

    def offset(sign):
        out = []
        for i, (x, y) in enumerate(points):
            normals = []
            segments = ([(points[i - 1], points[i])] if i else []) + ([(points[i], points[i + 1])] if i + 1 < len(points) else [])
            for a, b in segments:
                dx, dy = b[0] - a[0], b[1] - a[1]
                n = math.hypot(dx, dy)
                normals.append((-dy / n, dx / n))
            if len(normals) == 1:
                nx, ny = normals[0]
                k = 1.0
            else:
                nx, ny = normals[0][0] + normals[1][0], normals[0][1] + normals[1][1]
                n = math.hypot(nx, ny)
                nx, ny = nx / n, ny / n
                k = 1 / (nx * normals[0][0] + ny * normals[0][1])
            out.append((x + sign * nx * k * t / 2, y + sign * ny * k * t / 2))
        return out
    return offset(1) + offset(-1)[::-1]


# Terminals 1 (-X) and 2 (+X): a strip 1.0 wide and 0.3 thick down the housing's end face from LEAD_TOP, out to the bends' 7.9 overall
# at 1.8 below the board, back in to the 6.5 pitch at 2.8 and straight down to the tip; drawn as an outline in the XZ plane (the strip's
# centre line offset by half the thickness) and extruded along Y.
x_face = hx + LEAD_T / 2
x_pin = PITCH / 2
x_apex = OVER / 2 - LEAD_T / 2
for _ in range(4):  # the mitred outer corner reaches past half the thickness: move the bend in until it sits at OVER / 2
    path = [(x_face, LEAD_TOP), (x_face, -BEND_START), (x_apex, -BEND_APEX), (x_pin, -BEND_END), (x_pin, -TAIL)]
    x_apex -= max(x for x, z in outline(path, LEAD_T)) - OVER / 2
path = [(x_face, LEAD_TOP), (x_face, -BEND_START), (x_apex, -BEND_APEX), (x_pin, -BEND_END), (x_pin, -TAIL)]
leads = []
for i, sx in enumerate((-1, 1)):
    pts = [(sx * x, z) for x, z in path]
    model.plane(f"lead_{i + 1}_plane", on="XZ", offset=-LEAD_W / 2, name=f"Terminal {i + 1}")
    with model.sketch(f"lead_{i + 1}_sketch", on=f"lead_{i + 1}_plane", name=f"Terminal {i + 1}") as sk:
        sk.polyline(f"lead_{i + 1}_outline", outline(pts, LEAD_T), closed=True)
    model.extrude(f"lead_{i + 1}", f"lead_{i + 1}_sketch", distance=LEAD_W, op="new", body=f"lead_{i + 1}_body", name=f"Terminal {i + 1}")
    leads.append(f"lead_{i + 1}_body")
# Materials (page M3): the case and actuator black thermoplastic (pa6 for both, the sheet names no resin), the cover PET film
# (pet; the sheet also lists tin plated brass or stainless steel for covers and brackets), the terminals silver plated brass (brass).
model.material("pa6", bodies=["housing_body"], color="#26272a")
model.material("pet", bodies=["cover_body"], color="#1c1d20")
model.material("pa6", bodies=["actuator_body"], color="#202124")
model.material("brass", bodies=leads, color="#d6d8db")
result = model.result()