import base64
import copy
import hashlib
from datetime import UTC, datetime
from uuid import uuid4

import pytest

from k1link.device_plugins.vesc.archive import Archive


def backup():
    uid = "01" * 12
    configs = {}
    for name, command in (("motor", 14), ("application", 17)):
        raw = bytes([command]) + b"test-synthetic-config"
        configs[name] = {"encoding": "base64", "payload": base64.b64encode(raw).decode(),
                         "bytes": len(raw), "sha256": hashlib.sha256(raw).hexdigest(),
                         "signature_hex": raw[1:5].hex()}
    return {"schema": "missioncore.vesc.config-backup/v1", "operation_id": "op_" + uuid4().hex,
            "device_id": "vesc_" + hashlib.sha256(("uuid:" + uid).encode()).hexdigest()[:32],
            "identity": {"uuid": uid, "version": "6.06"}, "configs": configs,
            "observed_at": datetime.now(UTC).isoformat()}


def test_immutable_versions_survive_restart_and_do_not_cross_node_scope(tmp_path):
    archive = Archive(tmp_path / "archive")
    value = backup()
    archive.add("node-a", value)
    archive.add("node-a", copy.deepcopy(value))
    reopened = Archive(tmp_path / "archive")
    assert len(reopened.listing("node-a", value["device_id"])["items"]) == 1
    assert reopened.read("node-a", value["device_id"], value["operation_id"]) == value
    assert reopened.listing("node-b", value["device_id"])["items"] == []
    with pytest.raises(ValueError):
        reopened.read("node-b", value["device_id"], value["operation_id"])
    changed = copy.deepcopy(value)
    changed["observed_at"] = datetime.now(UTC).isoformat()
    with pytest.raises(ValueError, match="immutable"):
        reopened.add("node-a", changed)


def test_corrupt_or_misattributed_payload_is_never_archived(tmp_path):
    archive = Archive(tmp_path / "archive")
    value = backup()
    value["configs"]["motor"]["sha256"] = "0" * 64
    with pytest.raises(ValueError, match="integrity"):
        archive.add("a", value)
    value = backup()
    value["device_id"] = "vesc_" + "0" * 32
    with pytest.raises(ValueError, match="mismatch"):
        archive.add("a", value)
    assert archive.export("a", 0)["items"] == []


def test_bounded_replication_replays_without_losing_versions_and_paginates(tmp_path):
    board, core = Archive(tmp_path / "board"), Archive(tmp_path / "core")
    values = [backup() for _ in range(53)]
    for value in values:
        board.add("local", value)
    after = 0
    while True:
        batch = board.export("local", after)
        assert len(batch["items"]) <= 4
        assert core.receive("paired-node", batch) == batch["next"]
        assert core.receive("paired-node", batch) == batch["next"]
        if batch["next"] == after:
            break
        after = batch["next"]
    page = core.listing("paired-node", values[0]["device_id"])
    assert len(page["items"]) == 50 and page["next"]
    older = core.listing("paired-node", values[0]["device_id"], int(page["next"]))
    assert len(older["items"]) == 3 and older["next"] is None
    assert len({item["id"] for item in page["items"] + older["items"]}) == 53