"""Multi-file session merge tests (T03)."""

import os
import sys

sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

from session_memory.adapters.common import Normalized  # noqa: E402
from session_memory.core.schema import Session, SessionEvent  # noqa: E402
from session_memory.core.store import Store  # noqa: E402


def _part(native, kinds, base_blob="b"):
    uid = Session.make_uid("claude", native)
    s = Session(session_uid=uid, flavor="claude", native_session_id=native)
    events, blobs = [], {}
    for i, k in enumerate(kinds):
        ref = f"blob://{native}/{i}"
        events.append(SessionEvent(session_uid=uid, seq=i, parent_seq=(i - 1 if i else None),
                                   kind=k, ts=f"2026-06-06T10:0{i}:00Z", payload_ref=ref))
        blobs[ref] = f"{base_blob}-{k}-{i}"
    return Normalized(session=s, events=events, blobs=blobs)


def test_second_file_appends_not_overwrites(tmp_path):
    st = Store(str(tmp_path / "m.db"), str(tmp_path / "blobs"))
    uid = Session.make_uid("claude", "s1")

    # file 1: 3 events (seq 0..2)
    n1 = _part("s1", ["user_msg", "assistant_msg", "tool_call"])
    added1 = st.ingest(n1)
    assert added1 == 3
    assert st.count_events(uid) == 3

    # file 2 for the SAME session: repeats event 0 + adds 2 new (continuation)
    n2 = _part("s1", ["user_msg", "edit", "completion"])
    # make the first event identical to file1's first event so it dedups
    n2.events[0].kind = "user_msg"
    n2.events[0].ts = "2026-06-06T10:00:00Z"
    n2.blobs[n2.events[0].payload_ref] = "b-user_msg-0"
    added2 = st.ingest(n2)

    # only the 2 genuinely-new events appended; total grows additively
    assert added2 == 2
    assert st.count_events(uid) == 5
    seqs = [e.seq for e in st.get_events(uid)]
    assert seqs == [0, 1, 2, 3, 4]  # contiguous, offset


def test_reingest_same_bundle_is_idempotent(tmp_path):
    st = Store(str(tmp_path / "m.db"), str(tmp_path / "blobs"))
    uid = Session.make_uid("claude", "s2")
    n = _part("s2", ["user_msg", "assistant_msg"])
    assert st.ingest(n) == 2
    assert st.ingest(n) == 0          # nothing new on re-run
    assert st.count_events(uid) == 2


def test_appended_event_parent_remapped_within_part(tmp_path):
    st = Store(str(tmp_path / "m.db"), str(tmp_path / "blobs"))
    uid = Session.make_uid("claude", "s3")
    st.ingest(_part("s3", ["user_msg", "assistant_msg"]))   # seq 0,1
    st.ingest(_part("s3", ["x_unused"]) if False else _part("s3", ["thinking", "edit"]))  # new 2,3
    events = {e.seq: e for e in st.get_events(uid)}
    # the 'edit' (seq 3) had parent_seq=0 within its part -> remapped to its part's first new seq (2)
    assert events[3].parent_seq == 2