from datetime import datetime, timezone
from types import SimpleNamespace

import pytest
from bson import ObjectId

from app.services.handoff_delivery import enqueue_handoff_delivery
from app.services.handoff_mirror_policy import (
    GENERATED_BY_AGENT,
    GENERATED_BY_HANDOFF_BRIDGE,
    MESSAGE_ORIGIN_AGENT,
    MESSAGE_ORIGIN_HUMAN_OWNER,
    RELAY_STATUS_BLOCKED,
    should_mirror_to_human,
)
from app.services import human_handoff_service
from app.services.human_handoff_service import (
    MESSAGE_SCOPE_EXTERNAL,
    MESSAGE_SCOPE_HANDOFF,
    build_handoff_subject,
    maybe_trigger_handoff,
    process_human_reply,
    resolve_handoff_from_inbound,
)
from app.services.mailbox_scope import apply_external_scope
from app.services.external_reply_service import build_external_reply_plan


class FakeCursor:
    def __init__(self, items):
        self.items = items

    def sort(self, *_args, **_kwargs):
        return self

    async def to_list(self, length=None):
        return list(self.items)[:length]


class FakeCollection:
    def __init__(self, items=None):
        self.items = list(items or [])
        self.inserted = []
        self.updated = []

    async def find_one(self, query, projection=None):
        for item in self.items:
            if _matches(item, query):
                return item
        return None

    def find(self, query=None):
        query = query or {}
        return FakeCursor([item for item in self.items if _matches(item, query)])

    async def insert_one(self, document):
        document = dict(document)
        document.setdefault("_id", ObjectId())
        self.items.append(document)
        self.inserted.append(document)
        return SimpleNamespace(inserted_id=document["_id"])

    async def update_one(self, query, update, upsert=False):
        self.updated.append((query, update, upsert))
        existing = await self.find_one(query)
        if existing is None and upsert:
            inserted = {"_id": ObjectId(), **query, **update.get("$setOnInsert", {})}
            self.items.append(inserted)
            return SimpleNamespace(upserted_id=inserted["_id"], modified_count=0)
        if existing is not None:
            existing.update(update.get("$set", {}))
            return SimpleNamespace(upserted_id=None, modified_count=1)
        return SimpleNamespace(upserted_id=None, modified_count=0)

    async def find_one_and_update(self, query, update, **kwargs):
        existing = await self.find_one(query)
        if existing is None:
            return None
        existing.update(update.get("$set", {}))
        return existing


def _matches(document, query):
    for key, expected in query.items():
        if key == "$or":
            if not any(_matches(document, clause) for clause in expected):
                return False
            continue
        if key == "$ne":
            continue
        actual = document.get(key)
        if isinstance(expected, dict):
            if "$ne" in expected and actual == expected["$ne"]:
                return False
            if "$in" in expected and actual not in expected["$in"]:
                return False
            continue
        if actual != expected:
            return False
    return True


def test_external_mailbox_filter_excludes_handoff_scope():
    match = {"account_id": "account-1", "mailbox": "inbox"}
    apply_external_scope(match)
    assert match["$or"] == [
        {"message_scope": "EXTERNAL"},
        {"message_scope": {"$exists": False}},
    ]


def test_bridge_plan_never_references_private_ids():
    customer = {
        "_id": ObjectId(),
        "internet_message_id": "<A@gmail.com>",
        "message_id": "<A@gmail.com>",
        "message_scope": MESSAGE_SCOPE_EXTERNAL,
        "references": [],
        "subject": "Invoice 42",
    }
    private_id = "<H1@gentic.email>"
    plan = build_external_reply_plan(
        parent_external_message=customer,
        body_text="Approved",
        recipients=["customer@gmail.com"],
    )
    assert plan.threading.in_reply_to == "<A@gmail.com>"
    assert private_id not in plan.threading.references
    assert plan.subject == "Re: Invoice 42"
    assert "handoff" not in plan.subject.lower()


@pytest.mark.asyncio
async def test_existing_handoff_is_sticky_without_reevaluating_rules():
    external_thread_id = ObjectId()
    source_id = ObjectId()
    handoff = {
        "_id": ObjectId(),
        "account_id": "account-1",
        "external_thread_id": external_thread_id,
        "status": "ACTIVE",
        "rule_name": "Finance approvals",
    }
    database = SimpleNamespace(
        human_handoffs=FakeCollection([handoff]),
        human_handoff_rules=FakeCollection(
            [
                {
                    "_id": ObjectId(),
                    "name": "Finance approvals",
                    "priority": 1,
                    "labels": ["Finance"],
                    "email_types": ["transactional"],
                    "instructions": "only invoices",
                    "active": True,
                    "created_at": datetime.now(timezone.utc),
                }
            ]
        ),
        handoff_delivery_jobs=FakeCollection(),
    )
    message = {
        "_id": source_id,
        "message_scope": MESSAGE_SCOPE_EXTERNAL,
        "direction": "inbound",
        "sender": {"address": "customer@example.com"},
        "subject": "Hello there",
        "body_text": "just checking in",
        "snippet": "just checking in",
    }

    result = await maybe_trigger_handoff(
        database,
        account_id="account-1",
        agent_email="agent@gentic.email",
        external_message=message,
        external_thread_id=external_thread_id,
    )

    assert result["_id"] == handoff["_id"]
    assert database.handoff_delivery_jobs.items
    assert (
        database.handoff_delivery_jobs.items[0]["kind"] == "MIRROR_TO_HUMAN"
    )


@pytest.mark.asyncio
async def test_duplicate_delivery_jobs_share_an_idempotency_key():
    database = SimpleNamespace(handoff_delivery_jobs=FakeCollection())
    handoff_id = ObjectId()
    source_id = ObjectId()
    first = await enqueue_handoff_delivery(
        database,
        kind="MIRROR_TO_HUMAN",
        account_id="account-1",
        handoff_id=handoff_id,
        source_message_id=source_id,
        agent_email="agent@gentic.email",
    )
    second = await enqueue_handoff_delivery(
        database,
        kind="MIRROR_TO_HUMAN",
        account_id="account-1",
        handoff_id=handoff_id,
        source_message_id=source_id,
        agent_email="agent@gentic.email",
    )
    assert first["idempotency_key"] == second["idempotency_key"]
    assert len(database.handoff_delivery_jobs.items) == 1


@pytest.mark.asyncio
async def test_human_reply_resolves_only_to_private_handoff():
    parent_id = ObjectId()
    thread_id = ObjectId()
    handoff = {
        "_id": ObjectId(),
        "account_id": "account-1",
        "handoff_thread_id": thread_id,
        "human_email": "owner@example.com",
        "agent_email": "agent@gentic.email",
        "status": "ACTIVE",
    }
    database = SimpleNamespace(
        messages=FakeCollection(
            [
                {
                    "_id": parent_id,
                    "message_scope": MESSAGE_SCOPE_HANDOFF,
                    "message_id": "<H1@gentic.email>",
                    "message_id_folded": "<h1@gentic.email>",
                }
            ]
        ),
        mailbox_entries=FakeCollection(
            [
                {
                    "account_id": "account-1",
                    "message_id": parent_id,
                    "message_scope": MESSAGE_SCOPE_HANDOFF,
                    "thread_id": thread_id,
                }
            ]
        ),
        human_handoffs=FakeCollection([handoff]),
    )

    resolved = await resolve_handoff_from_inbound(
        database,
        account_id="account-1",
        agent_email="agent@gentic.email",
        sender_address="owner@example.com",
        in_reply_to="<H1@gentic.email>",
        references=["<H1@gentic.email>"],
    )
    assert resolved["_id"] == handoff["_id"]


def test_human_echo_and_agent_mirror_policy():
    assert should_mirror_to_human(
        {
            "message_scope": MESSAGE_SCOPE_EXTERNAL,
            "direction": "outbound",
            "generated_by": GENERATED_BY_HANDOFF_BRIDGE,
            "message_origin": MESSAGE_ORIGIN_HUMAN_OWNER,
            "generated_from_handoff_message_id": ObjectId(),
        }
    ) is False
    assert should_mirror_to_human(
        {
            "message_scope": MESSAGE_SCOPE_EXTERNAL,
            "direction": "outbound",
            "generated_by": GENERATED_BY_AGENT,
            "message_origin": MESSAGE_ORIGIN_AGENT,
        }
    ) is True


def test_private_subject_stays_off_the_external_plane():
    private = build_handoff_subject(
        sender_name="Parth Dixit",
        external_sender="customer@example.com",
        external_subject="Invoice 42",
    )
    assert private.startswith("handoff · Parth Dixit ·")
    assert "Invoice 42" in private
    assert "Finance approvals" not in private


@pytest.mark.asyncio
async def test_first_matching_rule_creates_a_new_linked_handoff():
    external_thread_id = ObjectId()
    source_id = ObjectId()
    rule = {
        "_id": ObjectId(),
        "account_id": "account-1",
        "name": "Finance approvals",
        "priority": 1,
        "owner_email": "owner@example.com",
        "owner_name": "Owner",
        "labels": ["All mail"],
        "email_types": ["all"],
        "instructions": "",
        "active": True,
        "allow_replies": True,
        "created_at": datetime.now(timezone.utc),
    }
    database = SimpleNamespace(
        human_handoffs=FakeCollection(),
        human_handoff_rules=FakeCollection([rule]),
        handoff_delivery_jobs=FakeCollection(),
        email_threads=FakeCollection(),
    )
    message = {
        "_id": source_id,
        "message_scope": MESSAGE_SCOPE_EXTERNAL,
        "direction": "inbound",
        "sender": {"name": "Parth Dixit", "address": "customer@example.com"},
        "subject": "Invoice 42",
        "body_text": "please review this invoice",
        "snippet": "please review this invoice",
    }

    result = await maybe_trigger_handoff(
        database,
        account_id="account-1",
        agent_email="agent@gentic.email",
        external_message=message,
        external_thread_id=external_thread_id,
    )

    assert result["rule_name"] == "Finance approvals"
    assert result["external_thread_id"] == external_thread_id
    assert result["handoff_thread_id"]
    assert result["private_subject"].startswith("handoff · Parth Dixit ·")
    assert database.handoff_delivery_jobs.items[0]["kind"] == "MIRROR_TO_HUMAN"


@pytest.mark.asyncio
async def test_maybe_trigger_does_not_echo_human_origin_messages():
    database = SimpleNamespace(
        human_handoffs=FakeCollection(
            [
                {
                    "_id": ObjectId(),
                    "account_id": "account-1",
                    "external_thread_id": ObjectId(),
                    "status": "ACTIVE",
                }
            ]
        ),
        handoff_delivery_jobs=FakeCollection(),
    )
    result = await maybe_trigger_handoff(
        database,
        account_id="account-1",
        agent_email="agent@gentic.email",
        external_message={
            "_id": ObjectId(),
            "message_scope": MESSAGE_SCOPE_EXTERNAL,
            "direction": "outbound",
            "generated_by": GENERATED_BY_HANDOFF_BRIDGE,
            "message_origin": MESSAGE_ORIGIN_HUMAN_OWNER,
            "generated_from_handoff_message_id": ObjectId(),
            "sender": {"address": "agent@gentic.email"},
        },
        external_thread_id=database.human_handoffs.items[0]["external_thread_id"],
    )
    assert result is None
    assert database.handoff_delivery_jobs.items == []


@pytest.mark.asyncio
async def test_leaked_private_subject_blocks_human_relay(monkeypatch):
    stored = {}

    async def store(_database, **kwargs):
        stored.update(kwargs)
        return {"_id": ObjectId(), **kwargs}

    enqueued = []

    async def enqueue(*args, **kwargs):
        enqueued.append(kwargs)
        return {}

    class BrokenStorage:
        async def get(self, *_args, **_kwargs):
            raise RuntimeError("raw mime unavailable")

    monkeypatch.setattr(human_handoff_service, "store_handoff_message", store)
    monkeypatch.setattr(human_handoff_service, "enqueue_handoff_delivery", enqueue)
    monkeypatch.setattr(human_handoff_service, "get_raw_mime_storage", lambda: BrokenStorage())

    database = SimpleNamespace(messages=FakeCollection(), human_handoffs=FakeCollection())
    await process_human_reply(
        database,
        account_id="account-1",
        agent_email="agent@gentic.email",
        handoff={
            "_id": ObjectId(),
            "handoff_thread_id": ObjectId(),
            "allow_replies": True,
        },
        parsed={
            "sender": {"name": "Owner", "address": "owner@example.com"},
            "to": [{"address": "agent@gentic.email"}],
            "subject": "Re: Finance approvals · handoff · customer@example.com · Invoice 42",
            "message_id": "<H2@gmail.com>",
            "in_reply_to": "<H1@gentic.email>",
            "references": ["<H1@gentic.email>"],
            "attachments": [],
            "raw_headers": {},
        },
        body_text=(
            "Finance approvals · handoff · customer@example.com · Invoice 42\n"
            "Please approve"
        ),
        body_html=None,
        raw_mime={"bucket": "mail", "name": "raw.eml"},
        delivery_key="delivery-1",
    )
    assert stored["relay_status"] == RELAY_STATUS_BLOCKED
    assert enqueued == []