#! python3
# shared logic for C-1 (bend radius -> KDS 24 14 21 Table 4.5-1). Pure geometry, no document edits.
import math
import Rhino
from Rhino.Geometry import Arc, Line, Point3d, Vector3d, PolyCurve, PolylineCurve, ArcCurve, Curve, Brep, PipeCapMode
from Rhino.Geometry.Intersect import Intersection

BASE = r"D:\★Pier 자료\프로그램\Pier_T\검토파일"
NOMINAL = {13: 12.7, 16: 15.9, 19: 19.1, 22: 22.2, 25: 25.4, 29: 28.6, 32: 31.8, 35: 34.9}


def required_rc(dia):
    """Minimum centreline bend radius: inner diameter >= 3.5db (D19+) / 2db (<=D16), db nominal, tube d = integer dia."""
    d = int("".join(ch for ch in dia if ch.isdigit()))
    nom = NOMINAL[d]
    inner_r = 1.75 * nom if d >= 19 else 1.0 * nom
    return math.ceil((inner_r + d / 2.0) * 100.0) / 100.0, d


def _is_straight(c):
    if isinstance(c, PolylineCurve):
        return True
    return c.IsLinear(1e-6)


def plan_curve(poly, dia):
    """Return (new_polycurve or None, info). info['short'] = number of short arcs, info['status'] ok|complex|unchanged."""
    req, d = required_rc(dia)
    n = poly.SegmentCount
    segs = [poly.SegmentCurve(i).DuplicateCurve() for i in range(n)]
    short = []
    for i, s in enumerate(segs):
        ok, arc = s.TryGetArc()
        if ok and not s.IsLinear() and arc.Radius < req - 1e-6 and math.degrees(arc.Angle) < 179.0:
            short.append(i)
    info = {"short": len(short), "req": req, "status": "unchanged"}
    if not short:
        return None, info
    # each short arc needs straight neighbours (or curve ends) and tangent continuity
    for i in short:
        for j in (i - 1, i + 1):
            if 0 <= j < n and not _is_straight(segs[j]):
                info["status"] = "complex"
                return None, info
            if 0 <= j < n and j in short:
                info["status"] = "complex"
                return None, info
    new = list(segs)
    for i in short:
        ok, arc = segs[i].TryGetArc()
        p0, p1 = arc.StartPoint, arc.EndPoint
        t0 = segs[i].TangentAtStart
        t1 = segs[i].TangentAtEnd
        t0.Unitize()
        t1.Unitize()
        ok2, a, b = Intersection.LineLine(Line(p0, p0 + t0 * 1e5), Line(p1 - t1 * 1e5, p1))
        if not ok2:
            info["status"] = "complex"
            return None, info
        corner = Line(p0, p0 + t0 * 1e5).PointAt(a)
        theta = math.acos(max(-1.0, min(1.0, t0 * t1)))
        tl = req * math.tan(theta / 2.0)
        ns = corner - t0 * tl
        ne = corner + t1 * tl
        mid_arc = Arc(ns, t0, ne)
        if not mid_arc.IsValid:
            info["status"] = "complex"
            return None, info
        new[i] = ArcCurve(mid_arc)
        if i - 1 >= 0:
            pc = new[i - 1].DuplicateCurve()
            new[i - 1] = _retarget(pc, end=ns)
        if i + 1 < n:
            nc = new[i + 1].DuplicateCurve()
            new[i + 1] = _retarget(nc, start=ne)
    pc = PolyCurve()
    for s in new:
        if s is None:
            info["status"] = "complex"
            return None, info
        pc.Append(s)
    info["status"] = "ok"
    return pc, info


def _retarget(c, start=None, end=None):
    if isinstance(c, PolylineCurve):
        pts = [c.Point(i) for i in range(c.PointCount)]
        if start is not None:
            pts[0] = start
        if end is not None:
            pts[-1] = end
        return PolylineCurve(pts)
    a = start if start is not None else c.PointAtStart
    b = end if end is not None else c.PointAtEnd
    return Rhino.Geometry.LineCurve(a, b)


def make_pipe(curve, d, tol):
    r = d / 2.0
    res = Brep.CreatePipe(curve, r, False, PipeCapMode.Flat, True, tol, Rhino.RhinoMath.ToRadians(1.0))
    return res