"""Pure, offline tests for target_revenue.attestation (WP-0006-T06).

`_find_conversion_prefix` needs no database — it is a pure function over
(initial_target_amount, entries), like fold.py. Full `publish_attestation`
persistence/idempotency is covered by the Docker-gated tests in
tests/test_ledger_hosting.py, since it requires a real Connection.
"""

from __future__ import annotations

from conftest import golden_entries, golden_manifest

from target_revenue import attestation


def test_find_conversion_prefix_matches_golden_phase_full_sequence():
    manifest = golden_manifest()
    entries = golden_entries()
    initial_amount = manifest["phase"]["initial_target"]["amount"]

    found = attestation._find_conversion_prefix(initial_amount, entries)

    assert found is not None
    prefix, conversion_timestamp = found
    assert prefix == entries  # golden phase converts exactly at the last entry
    assert conversion_timestamp == entries[-1]["recognized_at"]


def test_find_conversion_prefix_returns_none_when_never_converted():
    manifest = golden_manifest()
    partial_entries = golden_entries()[:4]  # Outstanding Target still 45000
    initial_amount = manifest["phase"]["initial_target"]["amount"]

    assert attestation._find_conversion_prefix(initial_amount, partial_entries) is None


def test_find_conversion_prefix_finds_earliest_crossing_not_the_last_entry():
    """If a later entry (e.g. an unrelated remission-credit added after
    conversion already occurred) exists, the crossing point must still be
    the earliest one — not the last entry in the list."""
    manifest = golden_manifest()
    entries = golden_entries()
    initial_amount = manifest["phase"]["initial_target"]["amount"]

    extra = {**entries[-1], "id": "trsl:entry:example0010999", "amount": 1}
    extended = entries + [extra]

    found = attestation._find_conversion_prefix(initial_amount, extended)
    assert found is not None
    prefix, conversion_timestamp = found
    assert prefix == entries  # not `extended` — crossing already happened before `extra`
    assert conversion_timestamp == entries[-1]["recognized_at"]