#!/usr/bin/env python3
"""Verifier for ledger-extract.tsv.

Recomputes the census from the wizardwork file manifest and compares it
field-for-field against the artifact.  Exit code 0 = artifact correct,
nonzero = wrong.
"""
import csv
import statistics
import sys
from collections import defaultdict

MANIFEST = "/root/troupe-standup/wizard-work/ledger/wizardwork-file-manifest.tsv"
OUT = "/root/troupe-standup/wizard-work/ledger/ledger-extract.tsv"
HEADER = ["extension", "file_count", "bytes_total", "bytes_mean",
          "bytes_median", "bytes_min", "bytes_max"]


def norm_ext(ext):
    return "(no ext)" if ext == "" else ext


def expected_rows():
    counts = defaultdict(int)
    sizes = defaultdict(list)
    with open(MANIFEST, newline="") as f:
        for line in f:
            parts = line.rstrip("\n").split("\t")
            if len(parts) < 3:
                continue
            try:
                size = int(parts[1])
            except ValueError:
                continue
            ext = norm_ext(parts[2])
            counts[ext] += 1
            sizes[ext].append(size)
    rows = []
    for ext, szs in sizes.items():
        total = sum(szs)
        rows.append((ext, counts[ext], total,
                     total / counts[ext], statistics.median(szs),
                     min(szs), max(szs)))
    rows.sort(key=lambda r: (-r[1], r[0]))
    return rows


def main():
    expected = expected_rows()
    try:
        with open(OUT, newline="") as f:
            act = list(csv.DictReader(f, delimiter="\t"))
    except Exception as e:
        print("CHECK FAIL: cannot read %s: %r" % (OUT, e))
        sys.exit(1)

    if not act:
        print("CHECK FAIL: artifact is empty")
        sys.exit(1)

    if list(act[0].keys()) != HEADER:
        print("CHECK FAIL: header %r" % (list(act[0].keys()),))
        sys.exit(1)

    if len(act) != len(expected):
        print("CHECK FAIL: row count %d != expected %d"
              % (len(act), len(expected)))
        sys.exit(1)

    for i, (a, e) in enumerate(zip(act, expected), 1):
        ext, cnt, total, mean, med, mn, mx = e
        exp = {"extension": ext,
               "file_count": str(cnt),
               "bytes_total": str(total),
               "bytes_mean": "%.1f" % mean,
               "bytes_median": "%.1f" % med,
               "bytes_min": str(mn),
               "bytes_max": str(mx)}
        if a != exp:
            print("CHECK FAIL: row %d %r != %r" % (i, a, exp))
            sys.exit(1)

    print("CHECK PASS: %d extension rows | top=%s count=%s"
          % (len(act), expected[0][0], expected[0][1]))
    sys.exit(0)


if __name__ == "__main__":
    main()