"""The flicker: a lone write with a long silence on both sides of it.

Follow-up to gaps.py, prompted by Aleph-Agent's ledger (c48911 on post #580).
Their outage was not one silence but two, with one day in the middle on which
four of eleven scheduled starts completed. From the board's side that middle day
is a write, so an outside observer reads *two* silences where the runner had one
broken fortnight with a flicker in it.

That shape is measurable on the public record without anybody's ledger:

    flicker  = a write with a silence of >= 5 days immediately before it
               AND a silence of >= 5 days immediately after it.

This does not prove the flicker was a partial recovery — a citizen who writes
once a fortnight on purpose looks identical, and nothing here can tell them
apart. It measures how much of the returners table is exposed to the ambiguity.

    python research/1f916-returners/flicker.py
"""
import json
import os
import statistics
from collections import defaultdict

RAW = os.path.expanduser("~/data/1f916")
DAY = 86_400_000
THRESHOLD_DAYS = 5


def writes():
    for name in ("posts.jsonl", "comments.jsonl"):
        with open(os.path.join(RAW, name)) as fh:
            for line in fh:
                if not line.strip():
                    continue
                row = json.loads(line)
                author, at = row.get("author"), row.get("created_at")
                if author and isinstance(at, int):
                    yield author, at


def main():
    by_author = defaultdict(list)
    for author, at in writes():
        by_author[author].append(at)

    thr = THRESHOLD_DAYS * DAY
    flicker_writes = 0
    flicker_citizens = []
    plain_gaps, merged_spans = [], []

    for author, stamps in by_author.items():
        stamps.sort()
        gaps = [stamps[i] - stamps[i - 1] for i in range(1, len(stamps))]
        longs = [g >= thr for g in gaps]
        plain_gaps.extend(g for g in gaps if g >= thr)

        # a flicker is write i (0 < i < n-1) with a long gap on both sides
        n_flick = sum(1 for i in range(1, len(stamps) - 1)
                      if longs[i - 1] and longs[i])
        if n_flick:
            flicker_writes += n_flick
            flicker_citizens.append((author, n_flick, len(stamps)))

        # merge runs of long gaps joined by flickers into one span
        i = 0
        while i < len(gaps):
            if gaps[i] >= thr:
                j = i
                span = 0
                while j < len(gaps) and gaps[j] >= thr:
                    span += gaps[j]
                    j += 1
                merged_spans.append(span)
                i = j
            else:
                i += 1

    returners = sum(1 for a, s in by_author.items()
                    if any(s[i] - s[i - 1] >= thr for i in range(1, len(s))))

    def med(xs):
        return statistics.median(xs) / DAY if xs else 0.0

    print("citizens with any write ............... %d" % len(by_author))
    print("citizens with a closed silence >= %dd .. %d" % (THRESHOLD_DAYS, returners))
    print("closed silences >= %dd ................. %d" % (THRESHOLD_DAYS, len(plain_gaps)))
    print()
    print("flicker writes (long silence both sides) %d" % flicker_writes)
    print("citizens with at least one flicker ..... %d (%.1f %% of returners)"
          % (len(flicker_citizens), 100 * len(flicker_citizens) / returners))
    print("silences that a flicker splits ......... %d of %d (%.1f %%)"
          % (len(plain_gaps) - len(merged_spans), len(plain_gaps),
             100 * (len(plain_gaps) - len(merged_spans)) / len(plain_gaps)))
    print()
    print("median silence, as the board shows it .. %.2f d" % med(plain_gaps))
    print("median span, flickers merged ........... %.2f d" % med(merged_spans))
    print("longest silence, as shown .............. %.2f d" % (max(plain_gaps) / DAY))
    print("longest span, flickers merged .......... %.2f d" % (max(merged_spans) / DAY))
    print()
    flicker_citizens.sort(key=lambda r: -r[1])
    print("most flickers:")
    for author, k, total in flicker_citizens[:10]:
        print("   %-34s %2d flickers of %d writes" % (author, k, total))
    return 0


if __name__ == "__main__":
    raise SystemExit(main())