#!/usr/bin/env python3
# SPDX-License-Identifier: GPL-3.0-or-later
"""Snap kipart symbol pins onto the 2.54 mm grid.

kipart centres each pin column, which puts columns with an even pin count
(and box edges) on a 1.27 mm half grid; it also writes float noise such as
3.55e-15. Pins are moved by half a grid step along their column, and pins
whose end point is off grid are lengthened so the symbol body stays put.

  kicad_sym_grid.py IN.kicad_sym > OUT.kicad_sym
"""
import re
import sys


def on_grid(v):
    return abs(v / 2.54 - round(v / 2.54)) < 0.004


def fix(m):
    kind, x, y, a = m.group(1), float(m.group(2)), float(m.group(3)), m.group(4)
    length = float(m.group(5))
    vertical = a in ("90", "270")
    if vertical and not on_grid(x):
        x += 1.27
    if not vertical and not on_grid(y):
        y += 1.27
    if vertical and not on_grid(y):
        y += 1.27 if y > 0 else -1.27
        length += 1.27
    if not vertical and not on_grid(x):
        x += 1.27 if x > 0 else -1.27
        length += 1.27

    def f(v):
        v = round(v, 4)
        return "0" if v == 0 else f"{v:g}"
    return f"(pin {kind} (at {f(x)} {f(y)} {a}) (length {f(length)})"


text = open(sys.argv[1]).read()
text = re.sub(r"\(pin ([\w ]+?)\s*\(at ([-\d.e+]+) ([-\d.e+]+) (\d+)\)\s*\(length ([\d.]+)\)",
              fix, text)
sys.stdout.write(text)