"""Stream-record -> SHOC webhook envelope mapping tests (plan Phase 5).

Pins the emitter's classification and envelope-building contract
(docs/shoc-webhook-contract.md sections 3-4) against realistic DynamoDB
stream records: event-type classification incl. the cancelled transition and
the already-cancelled no-false-cancel case, the write_origin echo guard,
exact eventSourceARN table discrimination, delivery_id/occurred_at mapping,
data null-fill + source_email_s3_key exclusion, and Decimal JSON-safety.

Also the enum golden pin: the emitted event_type set must equal the four
contract names AND the published spec's webhooks keys (lambdas/api/
openapi.json), and the classification's status/record_type value space must
stay anchored to the WO pipeline's template_parser enums.

Offline -- envelope.py has no boto3 clients and no network. Table names
default to PascalCase; set WORK_ORDERS_TABLE / COMMENTS_TABLE for kebab.
"""

import json
from datetime import datetime, timezone
from decimal import Decimal
from pathlib import Path

import pytest

from tests.support import REPO_ROOT, load_lambda_module

# Realistic stream ARNs for BOTH tables: "WorkOrders" is a leading substring
# of "WorkOrderComments", which is exactly the trap the exact-segment parse
# in envelope._table_name exists to avoid.
WO_STREAM_ARN = (
    "arn:aws:dynamodb:us-east-1:011934824531:table/WorkOrders"
    "/stream/2026-07-23T00:00:00.000"
)
COMMENTS_STREAM_ARN = (
    "arn:aws:dynamodb:us-east-1:011934824531:table/WorkOrderComments"
    "/stream/2026-07-23T00:00:00.000"
)

CONTRACT_EVENT_TYPES = {
    "work_order.created",
    "work_order.updated",
    "work_order.cancelled",
    "work_order.comment_added",
}


@pytest.fixture(scope="module")
def envelope():
    return load_lambda_module("wo", "shoc_emitter/envelope")


def _record(arn, event_name, new_image=None, old_image=None, **meta):
    """Build a stream record; ``meta`` overrides event_id / creation."""
    stream = {
        "ApproximateCreationDateTime": meta.get("creation", 1784642602.0),
        "SequenceNumber": meta.get("sequence_number", "100"),
        "StreamViewType": "NEW_AND_OLD_IMAGES",
    }
    if new_image is not None:
        stream["NewImage"] = new_image
    if old_image is not None:
        stream["OldImage"] = old_image
    return {
        "eventID": meta.get("event_id", "4b7c2f0e-0001"),
        "eventName": event_name,
        "eventSource": "aws:dynamodb",
        "eventSourceARN": arn,
        "dynamodb": stream,
    }


def _wo_image(**overrides):
    image = {
        "work_order_id": {"S": "11144580730"},
        "wo_status": {"S": "new"},
        "description": {"S": "Dock door 14 won't close"},
        "record_type": {"S": "new_work_order"},
        "created_at": {"S": "2026-07-16T14:03:22.114208+00:00"},
        "updated_at": {"S": "2026-07-16T14:03:22.114208+00:00"},
    }
    image.update(overrides)
    return image


def _comment_image(**overrides):
    image = {
        "work_order_id": {"S": "11144580730"},
        "comment_id": {"S": "11144580730#2026-04-27T23:51:48#a1b2c3d4e5f6"},
        "record_type": {"S": "comment"},
        "commenter": {"S": "APM Technician"},
        "text": {"S": "Vendor dispatched, ETA tomorrow AM."},
        "created_at": {"S": "2026-04-27T23:51:48"},
        "ingested_at": {"S": "2026-07-16T14:05:00+00:00"},
    }
    image.update(overrides)
    return image


# --- Classification ----------------------------------------------------------


def test_workorders_insert_is_created(envelope):
    event = envelope.build_event(_record(WO_STREAM_ARN, "INSERT", _wo_image()))
    assert event["event_type"] == "work_order.created"


def test_workorders_modify_is_updated(envelope):
    event = envelope.build_event(
        _record(
            WO_STREAM_ARN,
            "MODIFY",
            _wo_image(wo_status={"S": "assigned"}),
            _wo_image(wo_status={"S": "new"}),
        )
    )
    assert event["event_type"] == "work_order.updated"


def test_cancelled_transition_is_cancelled(envelope):
    event = envelope.build_event(
        _record(
            WO_STREAM_ARN,
            "MODIFY",
            _wo_image(wo_status={"S": "cancelled"}),
            _wo_image(wo_status={"S": "assigned"}),
        )
    )
    assert event["event_type"] == "work_order.cancelled"


def test_already_cancelled_modify_is_updated_not_cancelled(envelope):
    # OLD already cancelled + NEW cancelled: any later touch to a cancelled
    # WO must NOT re-emit a cancelled event (no false cancels on retries).
    event = envelope.build_event(
        _record(
            WO_STREAM_ARN,
            "MODIFY",
            _wo_image(wo_status={"S": "cancelled"}),
            _wo_image(wo_status={"S": "cancelled"}),
        )
    )
    assert event["event_type"] == "work_order.updated"


def test_comment_insert_is_comment_added(envelope):
    event = envelope.build_event(
        _record(COMMENTS_STREAM_ARN, "INSERT", _comment_image())
    )
    assert event["event_type"] == "work_order.comment_added"
    assert set(event["data"]) == set(envelope.COMMENT_DATA_FIELDS)


@pytest.mark.parametrize(
    "overrides",
    [
        {"text": {"S": ""}},
        {"text": {"S": "   \t\n"}},
        {"_drop": "text"},
    ],
    ids=["empty", "whitespace-only", "missing"],
)
def test_blank_comment_text_is_skipped(envelope, overrides):
    image = _comment_image()
    if overrides.get("_drop") == "text":
        del image["text"]
    else:
        image.update(overrides)
    record = _record(COMMENTS_STREAM_ARN, "INSERT", image)
    assert envelope.build_event(record) is None
    assert envelope.is_blank_comment_skip(record) is True


def test_non_blank_comment_is_not_blank_skip(envelope):
    record = _record(COMMENTS_STREAM_ARN, "INSERT", _comment_image())
    assert envelope.build_event(record) is not None
    assert envelope.is_blank_comment_skip(record) is False


def test_remove_is_skipped(envelope):
    assert envelope.build_event(_record(WO_STREAM_ARN, "REMOVE")) is None
    assert envelope.build_event(_record(COMMENTS_STREAM_ARN, "REMOVE")) is None
    assert (
        envelope.is_blank_comment_skip(_record(COMMENTS_STREAM_ARN, "REMOVE")) is False
    )


def test_comment_modify_is_skipped(envelope):
    record = _record(COMMENTS_STREAM_ARN, "MODIFY", _comment_image(), _comment_image())
    assert envelope.build_event(record) is None


def test_shoc_write_origin_echo_guard_skips(envelope):
    record = _record(
        WO_STREAM_ARN,
        "INSERT",
        _wo_image(write_origin={"S": "shoc-write-api"}),
    )
    assert envelope.build_event(record) is None
    # Any OTHER write_origin value is not an echo and must still deliver.
    record = _record(
        WO_STREAM_ARN,
        "INSERT",
        _wo_image(write_origin={"S": "email-processor"}),
    )
    assert envelope.build_event(record) is not None


# --- eventSourceARN table discrimination -------------------------------------


def test_table_discrimination_is_exact_segment_not_substring(envelope):
    # The WorkOrders stream must classify as a WO state event and the
    # WorkOrderComments stream as a comment event -- never cross-parsed even
    # though "WorkOrders" is a leading substring of "WorkOrderComments".
    wo_event = envelope.build_event(_record(WO_STREAM_ARN, "INSERT", _wo_image()))
    assert wo_event["event_type"] == "work_order.created"
    comment_event = envelope.build_event(
        _record(COMMENTS_STREAM_ARN, "INSERT", _comment_image())
    )
    assert comment_event["event_type"] == "work_order.comment_added"

    # Superstring table names must not substring-match either known table.
    for table in ("WorkOrdersLegacy", "WorkOrderCommentsArchive", "XWorkOrders"):
        arn = (
            f"arn:aws:dynamodb:us-east-1:011934824531:table/{table}"
            "/stream/2026-07-23T00:00:00.000"
        )
        assert envelope.build_event(_record(arn, "INSERT", _wo_image())) is None

    # A malformed / missing ARN skips rather than raises (total function).
    assert envelope.build_event(_record("", "INSERT", _wo_image())) is None


def test_kebab_table_names_via_env(monkeypatch):
    """PLAT-11: classification follows WORK_ORDERS_TABLE / COMMENTS_TABLE."""
    import sys

    monkeypatch.setenv("WORK_ORDERS_TABLE", "work-orders")
    monkeypatch.setenv("COMMENTS_TABLE", "work-order-comments")
    sys.modules.pop("wo_shoc_emitter_envelope", None)
    kebab_envelope = load_lambda_module("wo", "shoc_emitter/envelope")
    wo_arn = (
        "arn:aws:dynamodb:us-east-1:011934824531:table/work-orders"
        "/stream/2026-08-07T00:00:00.000"
    )
    comments_arn = (
        "arn:aws:dynamodb:us-east-1:011934824531:table/work-order-comments"
        "/stream/2026-08-07T00:00:00.000"
    )
    assert (
        kebab_envelope.build_event(_record(wo_arn, "INSERT", _wo_image()))["event_type"]
        == "work_order.created"
    )
    assert (
        kebab_envelope.build_event(_record(comments_arn, "INSERT", _comment_image()))[
            "event_type"
        ]
        == "work_order.comment_added"
    )
    # Legacy PascalCase ARNs must not match kebab env names.
    assert (
        kebab_envelope.build_event(_record(WO_STREAM_ARN, "INSERT", _wo_image()))
        is None
    )
    # Restore cached module for later tests that expect PascalCase defaults.
    sys.modules.pop("wo_shoc_emitter_envelope", None)
    monkeypatch.delenv("WORK_ORDERS_TABLE", raising=False)
    monkeypatch.delenv("COMMENTS_TABLE", raising=False)
    load_lambda_module("wo", "shoc_emitter/envelope")


# --- Envelope fields ---------------------------------------------------------


def test_envelope_constant_fields_and_delivery_id(envelope):
    record = _record(WO_STREAM_ARN, "INSERT", _wo_image(), event_id="evt-abc-123")
    event = envelope.build_event(record)
    assert event["schema_version"] == 1
    assert event["source"] == "procurement-ingest/workorder-shoc-emitter"
    assert event["replay"] is False
    # delivery_id is the stream record eventID: unique per source event and
    # stable across ESM retries (the receiver's idempotency key).
    assert event["delivery_id"] == "evt-abc-123"


def test_occurred_at_from_decimal_creation_time(envelope):
    # ApproximateCreationDateTime arrives as epoch seconds; via the low-level
    # stream API it deserializes as Decimal -- must still map to an aware
    # ISO-8601 +00:00 instant.
    creation = Decimal("1784642602")
    record = _record(WO_STREAM_ARN, "INSERT", _wo_image(), creation=creation)
    event = envelope.build_event(record)
    expected = datetime.fromtimestamp(1784642602.0, tz=timezone.utc).isoformat()
    assert event["occurred_at"] == expected
    assert event["occurred_at"].endswith("+00:00")


def test_data_null_fills_absent_fields_and_excludes_s3_key(envelope):
    image = {
        "work_order_id": {"S": "11144580730"},
        "wo_status": {"S": "unknown"},
        # Internal pointer: must never leave the account via the webhook.
        "source_email_s3_key": {"S": "inbound/2026/07/abc.eml"},
    }
    event = envelope.build_event(_record(WO_STREAM_ARN, "INSERT", image))
    assert set(event["data"]) == set(envelope.WO_DATA_FIELDS)
    assert "source_email_s3_key" not in event["data"]
    assert event["data"]["work_order_id"] == "11144580730"
    for field in set(envelope.WO_DATA_FIELDS) - {"work_order_id", "wo_status"}:
        assert event["data"][field] is None


def test_decimal_image_values_become_json_safe(envelope):
    image = _wo_image(
        severity={"N": "3"},
        priority={"N": "2.5"},
    )
    event = envelope.build_event(_record(WO_STREAM_ARN, "INSERT", image))
    assert event["data"]["severity"] == 3
    assert isinstance(event["data"]["severity"], int)
    assert event["data"]["priority"] == 2.5
    assert isinstance(event["data"]["priority"], float)
    # The whole envelope must serialize -- this is the raw body that gets
    # signed and POSTed.
    json.dumps(event)


# --- Enum golden pin ---------------------------------------------------------


def test_event_type_set_matches_contract_and_openapi_webhooks(envelope):
    scenarios = [
        _record(WO_STREAM_ARN, "INSERT", _wo_image()),
        _record(
            WO_STREAM_ARN,
            "MODIFY",
            _wo_image(wo_status={"S": "assigned"}),
            _wo_image(wo_status={"S": "new"}),
        ),
        _record(
            WO_STREAM_ARN,
            "MODIFY",
            _wo_image(wo_status={"S": "cancelled"}),
            _wo_image(wo_status={"S": "assigned"}),
        ),
        _record(COMMENTS_STREAM_ARN, "INSERT", _comment_image()),
    ]
    emitted = {envelope.build_event(record)["event_type"] for record in scenarios}
    assert emitted == CONTRACT_EVENT_TYPES

    # The published read-API spec documents the same four outbound webhook
    # events; emitter and spec must move together.
    spec_path = Path(REPO_ROOT) / "lambdas" / "api" / "openapi.json"
    spec = json.loads(spec_path.read_text(encoding="utf-8"))
    assert set(spec["webhooks"]) == emitted


def test_status_and_record_type_value_space_anchored_to_template_parser(envelope):
    # The WO pipeline's template_parser enums are the wo_status/record_type
    # value space the stream carries (prompts.py mirrors them for the AI
    # path). The cancelled-transition trigger value must be a real status,
    # and the contract's record_type enum must be exactly the pipeline's
    # email-type enum -- widen either side only in a PR that updates both.
    template_parser = load_lambda_module("wo", "email_processor/template_parser")
    assert envelope.CANCELLED_STATUS in template_parser.VALID_STATUSES
    assert template_parser.VALID_EMAIL_TYPES == {
        "new_work_order",
        "update",
        "comment",
        "cancellation",
    }