from bson import ObjectId

from app.services.external_reply_service import (
    build_external_reply_plan,
    internet_message_id_of,
)
from app.services.message_ids import canonical_message_id, folded_message_id
from app.services.thread_service import threading_fields_from_parent


def test_build_external_reply_references_gmail_parent():
    parent = {
        "_id": ObjectId(),
        "internet_message_id": "<gmail-a@mail.gmail.com>",
        "message_id": "<gmail-a@mail.gmail.com>",
        "references": [],
        "subject": "lets try one more time",
    }
    plan = build_external_reply_plan(
        parent_external_message=parent,
        body_text="I hear you.",
        recipients=["customer@gmail.com"],
    )
    assert plan.threading.in_reply_to == "<gmail-a@mail.gmail.com>"
    assert plan.threading.references == ["<gmail-a@mail.gmail.com>"]
    assert plan.subject == "Re: lets try one more time"
    assert plan.threading.replying_to_internet_message_id == "<gmail-a@mail.gmail.com>"


def test_build_external_reply_chains_references_for_multi_round():
    parent = {
        "_id": ObjectId(),
        "internet_message_id": "<a2@gmail.com>",
        "message_id": "<a2@gmail.com>",
        "references": ["<a1@gmail.com>", "<g1@gentic.email>"],
        "subject": "Re: lets try one more time",
    }
    threading = threading_fields_from_parent(parent)
    assert threading["in_reply_to"] == "<a2@gmail.com>"
    assert threading["references"] == [
        "<a1@gmail.com>",
        "<g1@gentic.email>",
        "<a2@gmail.com>",
    ]


def test_external_reply_never_uses_internal_object_id_as_in_reply_to():
    parent = {
        "_id": ObjectId(),
        "internet_message_id": "<gmail-a@mail.gmail.com>",
        "message_id": "<gmail-a@mail.gmail.com>",
        "references": [],
        "subject": "hello",
    }
    plan = build_external_reply_plan(
        parent_external_message=parent,
        body_text="reply",
        recipients=["customer@gmail.com"],
    )
    assert str(parent["_id"]) not in (plan.threading.in_reply_to or "")
    assert all(str(parent["_id"]) not in ref for ref in plan.threading.references)


def test_handoff_bridge_reply_uses_external_parent_not_human_reply():
    """Human handoff must thread B against customer A, never private H2."""
    customer_a = {
        "_id": ObjectId(),
        "internet_message_id": "<CAHabc123@mail.gmail.com>",
        "message_id": "<CAHabc123@mail.gmail.com>",
        "message_scope": "EXTERNAL",
        "direction": "inbound",
        "references": [],
        "subject": "fresh test",
    }
    human_h2 = {
        "_id": ObjectId(),
        "internet_message_id": "<H2@gmail.com>",
        "message_id": "<H2@gmail.com>",
        "message_scope": "HANDOFF",
        "direction": "inbound",
        "in_reply_to": "<H1@gentic.email>",
        "references": ["<H1@gentic.email>"],
        "subject": "Re: fresh test",
    }
    plan = build_external_reply_plan(
        parent_external_message=customer_a,
        body_text="human said B",
        recipients=["091rabbytes@gmail.com"],
    )
    assert plan.threading.in_reply_to == "<CAHabc123@mail.gmail.com>"
    assert plan.threading.references == ["<CAHabc123@mail.gmail.com>"]
    assert human_h2["internet_message_id"] not in (plan.threading.in_reply_to or "")
    assert all(
        human_h2["internet_message_id"] not in ref for ref in plan.threading.references
    )
    assert "<H1@gentic.email>" not in plan.threading.references


def test_raw_header_restores_gmail_message_id_case():
    parent = {
        "_id": ObjectId(),
        "internet_message_id": "<cahabc123@mail.gmail.com>",
        "message_id": "<cahabc123@mail.gmail.com>",
        "raw_headers": {"message_id": "<CAHabc123@mail.gmail.com>"},
        "references": [],
        "subject": "fresh test",
    }
    plan = build_external_reply_plan(
        parent_external_message=parent,
        body_text="human said B",
        recipients=["customer@gmail.com"],
    )
    assert plan.threading.in_reply_to == "<CAHabc123@mail.gmail.com>"
    assert plan.threading.references == ["<CAHabc123@mail.gmail.com>"]


def test_gmail_message_id_case_is_preserved_for_threading():
    raw = "<CAHabc123@mail.gmail.com>"
    assert canonical_message_id(raw) == raw
    assert folded_message_id(raw) == "<cahabc123@mail.gmail.com>"
    parent = {
        "_id": ObjectId(),
        "internet_message_id": raw,
        "message_id": raw,
        "references": [],
        "subject": "fresh test",
    }
    plan = build_external_reply_plan(
        parent_external_message=parent,
        body_text="human said B",
        recipients=["customer@gmail.com"],
    )
    assert plan.threading.in_reply_to == raw
    assert internet_message_id_of(parent) == raw