#!/usr/bin/env python3

import sys

import yaml

from datetime import datetime, timezone

def earliest_if_within_two_hours(timestamps):

if not timestamps:

raise ValueError("No timestamps provided")

# Parse timestamps into aware datetime objects

times = [datetime.fromisoformat(t.replace("Z", "+00:00")) for t in timestamps]

times.sort()

earliest = times[0]

latest = times[-1]

# Check the span

diff_seconds = (latest - earliest).total_seconds()

if diff_seconds > 2 * 3600: # 2 hours

raise ValueError("Timestamps are not within 2 hours of each other")

# Return earliest *string*, matching input format

return earliest.isoformat().replace("+00:00", "Z")

def strict_merge(a, b, path=""):

"""Recursively merge dictionary b into a, erroring on mismatched values."""

if not isinstance(a, dict) or not isinstance(b, dict):

# If they are not both dicts, they must match exactly:

if a != b:

raise ValueError(f"Conflict at {path}: {a!r} != {b!r}")

return a # values identical, no change

for key in b:

sub_path = f"{path}.{key}" if path else key

if key not in a:

a[key] = b[key]

else:

a[key] = strict_merge(a[key], b[key], sub_path)

return a

def main():

if len(sys.argv) < 3:

print("Usage: merge_yaml.py out.yaml file1.yaml file2.yaml ...")

sys.exit(1)

output_file = sys.argv[1]

input_files = sys.argv[2:]

merged = {}

timestamps = []

for filename in input_files:

with open(filename) as f:

data = yaml.load(f, Loader=yaml.FullLoader) or {}

# Pop the timestamps, they are not going to be equal

timestamps.append(data.pop("timestamp", None))

merged = strict_merge(merged, data)

# Make sure timestamps are within one hour of each other then use the earliest

merged["timestamp"] = earliest_if_within_two_hours(timestamps=timestamps)

with open(output_file, "w") as out:

yaml.dump(merged, out)

print(f"Successfully merged into {output_file}")

if __name__ == "__main__":

main()