#!/usr/bin/env python3
"""Copy ciphertext into the isolated recovery project; never read an age key."""
import argparse
import hashlib
import json
import os
from pathlib import Path

from ledger_archive import Refused, checkpoint, digest, private_file

PROJECT = "1d37ea63-8c8f-44e1-80e1-2de862579ba7"
BUCKET = "railiance-email-connect-archives"


def mirror(client, archive, receipt):
    private_file(archive)
    expected = digest(archive)
    size = archive.stat().st_size
    if expected != receipt["ciphertext_sha256"] or size != receipt["ciphertext_bytes"]:
        raise Refused("mirror_source_differs")
    key = "archives/" + receipt["object_key"]
    try:
        with archive.open("rb") as source:
            created = client.put_object(Bucket=BUCKET, Key=key, Body=source,
                                        IfNoneMatch="*", Metadata={"sha256": expected})
        version = created.get("VersionId")
    except Exception as error:
        if getattr(error, "response", {}).get("ResponseMetadata", {}).get("HTTPStatusCode") != 412:
            raise
        current = client.head_object(Bucket=BUCKET, Key=key)
        if current.get("Metadata", {}).get("sha256") != expected or current.get("ContentLength") != size:
            raise Refused("mirror_existing_object_differs")
        version = current.get("VersionId")
    if not version or version == "null":
        raise Refused("versioned_mirror_required")
    result = client.get_object(Bucket=BUCKET, Key=key, VersionId=version)
    hashed, count = hashlib.sha256(), 0
    with result["Body"] as stream:
        while block := stream.read(1024**2):
            count += len(block)
            if count > size:
                raise Refused("mirror_readback_exceeds_size")
            hashed.update(block)
    if (result.get("VersionId") != version or count != size
            or hashed.hexdigest() != expected):
        raise Refused("mirror_readback_differs")
    # Recovery needs a receipt even if both node and workstation are lost.
    record = dict(receipt, recovery_mirror={"bucket": BUCKET, "object_key": key,
                                          "version_id": version, "project_id": PROJECT,
                                          "hash_readback_verified": True})
    payload = json.dumps(record, sort_keys=True).encode()
    receipt_key = key + "." + version + "." + hashlib.sha256(payload).hexdigest() + ".receipt.json"
    try:
        saved = client.put_object(Bucket=BUCKET, Key=receipt_key, Body=payload, IfNoneMatch="*")
        receipt_version = saved.get("VersionId")
    except Exception as error:
        if getattr(error, "response", {}).get("ResponseMetadata", {}).get("HTTPStatusCode") != 412:
            raise
        receipt_version = client.head_object(Bucket=BUCKET, Key=receipt_key).get("VersionId")
    if not receipt_version or receipt_version == "null":
        raise Refused("versioned_mirror_receipt_required")
    saved = client.get_object(Bucket=BUCKET, Key=receipt_key, VersionId=receipt_version)
    with saved["Body"] as stream:
        if stream.read(len(payload) + 1) != payload:
            raise Refused("mirror_receipt_readback_differs")
    return dict(record["recovery_mirror"], receipt_key=receipt_key,
                receipt_version_id=receipt_version)


def main():
    import boto3
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument("--archive", type=Path, required=True)
    parser.add_argument("--primary-receipt", type=Path, required=True)
    parser.add_argument("--output", type=Path, required=True)
    args = parser.parse_args()
    private_file(args.primary_receipt)
    key = os.environ["AWS_ACCESS_KEY_ID"].split("@", 1)[0] + "@" + PROJECT
    client = boto3.client("s3", endpoint_url="https://s3.nl-ams.scw.cloud", region_name="nl-ams",
                          aws_access_key_id=key, aws_secret_access_key=os.environ["AWS_SECRET_ACCESS_KEY"])
    checkpoint(args.output, mirror(client, args.archive, json.loads(args.primary_receipt.read_text())))


if __name__ == "__main__":
    try:
        main()
    except Exception as error:
        print(json.dumps({"status": "failed", "failure_type": type(error).__name__}))
        raise SystemExit(1) from None