#!/usr/bin/env python3
"""Place a neutral `waxseed` actor at the centre of every wax blob on every map.

Reads the resource plane straight out of each map.bin, finds blob centroids by
flood fill, and appends the actors to map.yaml. Idempotent: strips previously
placed waxseed entries first.
"""
import os, re, struct, glob

MAPS = glob.glob(os.path.join(os.path.dirname(__file__), '..', 'mods', 'vinylgod', 'maps', '*'))


def resource_cells(path):
    d = open(path, 'rb').read()
    fmt, w, h = d[0], *struct.unpack_from('<HH', d, 1)
    tiles_off, heights_off, res_off = struct.unpack_from('<III', d, 5)
    assert fmt == 2 and heights_off == 0, path
    cells = set()
    for x in range(w):
        for y in range(h):
            if d[res_off + 2 * (x * h + y)] != 0:
                cells.add((x, y))
    return cells


def blobs(cells):
    """Flood-fill into connected blobs, return list of (cx, cy)."""
    seen, out = set(), []
    for start in sorted(cells):
        if start in seen:
            continue
        stack, blob = [start], []
        seen.add(start)
        while stack:
            x, y = stack.pop()
            blob.append((x, y))
            for n in ((x+1, y), (x-1, y), (x, y+1), (x, y-1)):
                if n in cells and n not in seen:
                    seen.add(n)
                    stack.append(n)
        if len(blob) >= 6:  # ignore specks
            out.append((round(sum(p[0] for p in blob) / len(blob)),
                        round(sum(p[1] for p in blob) / len(blob))))
    return out


for mapdir in sorted(MAPS):
    my, mb = os.path.join(mapdir, 'map.yaml'), os.path.join(mapdir, 'map.bin')
    if not (os.path.exists(my) and os.path.exists(mb)):
        continue
    centres = blobs(resource_cells(mb))
    s = open(my).read()
    s = re.sub(r'\n\twaxseed\d+: waxseed\n\t\tOwner: Neutral\n\t\tLocation: \d+,\d+', '', s)
    if 'Actors:' not in s:
        s = s.rstrip() + '\n\nActors:\n'
    block = ''.join(f'\n\twaxseed{i}: waxseed\n\t\tOwner: Neutral\n\t\tLocation: {x},{y}'
                    for i, (x, y) in enumerate(centres))
    # append to the Actors section (it is the last block in our generated maps)
    head, _, tail = s.partition('Actors:')
    lines = tail.split('\n')
    cut = len(lines)
    for i, ln in enumerate(lines):
        if ln and not ln.startswith('\t') and i > 0:  # next top-level key
            cut = i
            break
    tail = '\n'.join(lines[:cut]).rstrip() + block + '\n' + '\n'.join(lines[cut:])
    open(my, 'w').write(head + 'Actors:' + tail)
    print(f'{os.path.basename(mapdir)}: {len(centres)} seep(s) at {centres}')