engine/genesis.py

"""NEMOCITY genesis — epoch 0, exactly as specified in ARCHITECTURE.md.

Roads, then buildings, then a note; all at t = CITY_EPOCH_S, wish_id
"genesis", seeds crc32-derived. These values are a cross-component contract
(web/mock/world.json is generated from this list); do NOT edit them.

Validity is asserted at import: every footprint on empty non-water in-bounds
cells, every building touching a road, bridge cells on water and nothing else.
"""

from __future__ import annotations

import copy
import zlib

from . import constants as C


def _seed(i: int) -> int:
    return zlib.crc32(f"genesis:{i}".encode()) & 0x7FFFFFFF


def _ev(i: int, tool: str, args: dict) -> dict:
    return {
        "id": f"e_{i:06d}", "wish_id": "genesis", "tool": tool,
        "args": args, "seed": _seed(i), "t": float(C.CITY_EPOCH_S),
    }


def _col(cx: int, cz0: int, cz1: int) -> list[list[int]]:
    return [[cx, cz] for cz in range(cz0, cz1 + 1)]


def _row(cz: int, cx0: int, cx1: int, skip: tuple[int, ...] = ()) -> list[list[int]]:
    return [[cx, cz] for cx in range(cx0, cx1 + 1) if cx not in skip]


def _road(i: int, name: str, klass: str, cells: list[list[int]]) -> dict:
    return _ev(i, "lay_road", {"cells": cells, "klass": klass, "name": name})


def _bld(i: int, kind: str, name: str, cx: int, cz: int, floors: int,
         hue: int, variant: int) -> dict:
    spec = C.BUILDINGS[kind]
    return _ev(i, "place_building", {
        "kind": kind, "name": name, "cx": cx, "cz": cz,
        "w": spec["w"], "d": spec["d"], "floors": floors,
        "hue": hue, "variant": variant,
    })


GENESIS_FEATURES: list[dict] = [
    # roads (1st Ave skips the river cells; the Old Bridge — street class, the
    # bottleneck by design — carries the only crossing)
    _road(0, "Main St", "avenue", _col(0, -12, 12)),
    _road(1, "1st Ave", "avenue", _row(0, -12, 16, skip=(8, 9))),
    _road(2, "Old Bridge", "street", [[8, 0], [9, 0]]),
    _road(3, "River Rd", "street", _col(13, -6, 6)),
    _road(4, "Elm St", "street", _row(-5, -8, 0)),
    _road(5, "2nd St", "street", _col(-5, -5, 3)),
    # downtown west of the river
    _bld(6, "town_hall", "City Hall", -2, -3, 2, 44, 0),
    _bld(7, "office", "Meridian Office", 1, -2, 5, 210, 3),
    _bld(8, "cafe", "Corner Cafe", 1, 1, 1, 18, 1),
    _bld(9, "market", "Main St Market", -1, 1, 1, 35, 2),
    _bld(10, "park", "Founders Park", -4, 1, 0, 110, 0),
    # Elm / 2nd St housing cluster
    _bld(11, "house", "Elm Cottage", -1, -6, 2, 28, 4),
    _bld(12, "house", "Rose Cottage", -4, -6, 1, 350, 5),
    _bld(13, "house", "Sage House", -6, -4, 1, 95, 6),
    # east of the river — jobs/homes that force bridge commutes from day one
    _bld(14, "factory", "Riverside Works", 14, -3, 1, 24, 0),
    _bld(15, "warehouse", "East Depot", 14, 1, 1, 210, 1),
    _bld(16, "house", "Ferry House", 14, 3, 1, 205, 7),
    _bld(17, "house", "River Cottage", 14, -5, 2, 16, 2),
    _ev(18, "note", {"text": "Nemocity is listening. Ask for a building.",
                     "kind": "milestone"}),
]


def genesis_features() -> list[dict]:
    """Deep copy of the genesis event list (safe to mutate / load)."""
    return copy.deepcopy(GENESIS_FEATURES)


def genesis_world():
    """A fresh World seeded with the genesis events."""
    from .world import World

    return World.load(genesis_features())


def _validate() -> None:
    water = {
        (cx, cz)
        for cz in range(C.COORD_MIN, C.COORD_MAX + 1)
        for cx in C.river_cols(cz)
    }
    road: set[tuple[int, int]] = set()
    for ev in GENESIS_FEATURES:
        if ev["tool"] != "lay_road":
            continue
        name = ev["args"]["name"]
        for cx, cz in ev["args"]["cells"]:
            assert C.COORD_MIN <= cx <= C.COORD_MAX and C.COORD_MIN <= cz <= C.COORD_MAX, \
                f"genesis: road cell off-grid in {name}"
            on_water = (cx, cz) in water
            assert on_water == (name == "Old Bridge"), \
                f"genesis: {name} cell ({cx},{cz}) water mismatch"
            road.add((cx, cz))
    occupied: set[tuple[int, int]] = set(road)
    for ev in GENESIS_FEATURES:
        if ev["tool"] != "place_building":
            continue
        a = ev["args"]
        cells = [
            (a["cx"] + dx, a["cz"] + dz)
            for dx in range(a["w"]) for dz in range(a["d"])
        ]
        for c in cells:
            assert C.COORD_MIN <= c[0] <= C.COORD_MAX and C.COORD_MIN <= c[1] <= C.COORD_MAX, \
                f"genesis: {a['name']} off-grid"
            assert c not in water, f"genesis: {a['name']} on water at {c}"
            assert c not in occupied, f"genesis: {a['name']} overlaps at {c}"
        touches = any(
            (cx + dx, cz + dz) in road
            for cx, cz in cells
            for dx, dz in ((0, -1), (1, 0), (0, 1), (-1, 0))
        )
        assert touches, f"genesis: {a['name']} touches no road"
        occupied.update(cells)


_validate()