"""The REST door for lessons — the half the web UI can actually reach (#3734).

WHY THIS EXISTS AT ALL

Milestone 385 built the lesson kind through the MCP tools, which is the surface
an agent uses. The Vue app speaks REST, so until this blueprint existed a lesson
was a record a person could not create, read, edit or retire from the UI — rule
27's "no UI, no ship" failing at the door rather than in the view.

WHAT THESE PIN

Three things a second door tends to get wrong, and one that is specific to this
kind:

  - PARITY. Both doors go through services/lessons.py, so the composed
    document is identical whichever one wrote it. A REST door that composed its
    own title would produce lessons that rank differently from the agent's, and
    the document IS what ranks.

  - ACL (rule 78). Share-aware resolve, write as the owner — the pattern
    routes/snippets.py sets — so a shared editor isn't rejected by the
    owner-scoped service.

  - THE TRIGGER IS REFUSED WHEN EMPTY. This is the kind-specific one and the
    reason the door is not a thin wrapper. The service will happily store a
    lesson with no trigger: it saves, it reads correctly in every listing, and
    it never surfaces. There is nothing to notice afterwards — it looks exactly
    like a lesson that works. So the door refuses it at both create and update
    rather than handing back a record that looks finished.

  - THE REVERSE DIRECTION. `taught-by/<id>` answers "what was learned from this
    record", which the task body calls the direction that gets forgotten and
    arguably the more useful one.
"""
import inspect

import pytest


# ── parity: one composer, two doors ──────────────────────────────────────────


def test_both_doors_share_one_serializer():
    """A payload shape spelled once per door answers the two of them
    differently the first time a field is added."""
    from scribe.mcp.tools import lessons as mcp_lessons
    from scribe.services import lessons as lessons_svc

    assert mcp_lessons._to_dict is lessons_svc.lesson_to_dict


def test_the_rest_door_composes_nothing_itself():
    """Asserted on structure (rule 167). The document is what ranks, so a door
    that built its own title would produce lessons that rank differently from
    the ones the agent writes."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes)
    # It may CALL the service's composer (the dedup gate needs the document),
    # but it must not assemble a title or a trigger line itself.
    assert "trigger_title" not in src
    assert "**When to apply:**" not in src
    assert "lessons_svc.lesson_document" in src, (
        "the dedup gate must hash the same document the service will store"
    )


def test_the_door_is_registered():
    """A blueprint nobody registers is a file, not a door."""
    from scribe import app as app_module

    src = inspect.getsource(app_module)
    assert "from scribe.routes.lessons import lessons_bp" in src
    assert "app.register_blueprint(lessons_bp)" in src


def test_the_blueprint_is_mounted_where_the_client_looks():
    from scribe.routes.lessons import lessons_bp

    assert lessons_bp.url_prefix == "/api/lessons"


def test_the_reverse_lookup_is_registered_before_the_id_route():
    """Quart matches in registration order. The int converter protects
    `taught-by` today, but the ordering is what keeps that true if the
    converter is ever widened — the same care snippets' `/duplicates` takes."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes)
    assert src.index('"/taught-by/<int:record_id>"') < src.index(
        '"/<int:lesson_id>"'
    )


# ── the trigger is not optional at this door ─────────────────────────────────


def test_create_refuses_a_lesson_with_no_trigger():
    """The kind-specific guard. A triggerless lesson saves and never surfaces,
    and nothing about the stored record shows it."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes.create_lesson_route)
    assert "when_to_apply is required" in src
    assert "never reaches anyone" in src, (
        "the refusal must say WHY, or the next person reads it as a nag and "
        "removes it"
    )


def test_update_refuses_to_clear_the_trigger():
    """The other half. Creating without one is refused; emptying one later
    would reach the same broken state by a different path."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes.update_lesson_route)
    assert "cannot be cleared" in src


def test_the_subject_is_required_too():
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes.create_lesson_route)
    assert "what is required" in src


# ── ACL: rule 78's pattern, not a bare owner filter ──────────────────────────


@pytest.mark.parametrize(
    "handler", ["update_lesson_route", "delete_lesson_route"]
)
def test_writes_check_permission_and_act_as_the_owner(handler):
    """Resolve share-aware, then write as the owner — otherwise a shared
    editor is rejected by the owner-scoped service."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(getattr(routes, handler))
    assert "can_write_note" in src, f"{handler} does not check write permission"
    assert "note.user_id" in src, (
        f"{handler} writes as the caller rather than as the owner, which "
        f"rejects a legitimately shared editor (rule 78)"
    )


def test_no_handler_builds_its_own_owner_filter():
    """Rule 78's actual failure mode: a route assembling its own
    `Note.user_id == uid` clause instead of going through the service and the
    access helpers. Passing `user_id=uid` INTO a service is the correct call
    and is not what this looks for."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes)
    assert "Note.user_id" not in src
    assert "select(" not in src, (
        "a route composing its own query has bypassed the access helpers"
    )


def test_delete_trashes_recoverably():
    """Every kind's delete is a trash, and the batch id is what restores it."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes.delete_lesson_route)
    assert "trash_svc.delete" in src
    assert "deleted_batch_id" in src


# ── the reverse direction ────────────────────────────────────────────────────


def test_the_reverse_lookup_reads_the_indexed_mirror():
    """Not by scanning bodies: `data[taught_by]` is JSONB with a GIN index
    (0070), which is the whole reason step 4 put the list there."""
    from scribe.services import lessons as lessons_svc

    src = inspect.getsource(lessons_svc.lessons_taught_by)
    assert "path_exists" in src
    assert "SOURCES_KEY" in src


def test_the_reverse_lookup_is_share_aware():
    """It renders beside a record the caller can already see, so a lesson
    someone shared with them belongs in the list exactly as their own does."""
    from scribe.services import lessons as lessons_svc

    src = inspect.getsource(lessons_svc.lessons_taught_by)
    assert "readable_notes_clause" in src
    assert "deleted_at" in src


def test_the_reverse_lookup_refuses_a_nonsense_id_rather_than_interpolating():
    """The jsonpath is built by formatting, so the id has to be an int before
    it gets near the expression."""
    from scribe.services import lessons as lessons_svc

    src = inspect.getsource(lessons_svc.lessons_taught_by)
    assert "int(record_id)" in src


@pytest.mark.asyncio
async def test_a_bad_id_returns_nothing_and_raises_nothing():
    from scribe.services.lessons import lessons_taught_by

    assert await lessons_taught_by(1, 0) == []
    assert await lessons_taught_by(1, -3) == []
    assert await lessons_taught_by(1, "not a number") == []


# ── the serializer speaks the vocabulary the caller wrote with ───────────────


def test_the_payload_reads_back_the_composed_fields():
    """A caller that wrote `when_to_apply` reads `when_to_apply` back, not a
    body it has to parse."""
    from tests.helpers import fake_lesson
    from scribe.services.lessons import compose_body, compose_title, lesson_to_dict

    what = "Read the job log before waiting longer"
    trigger = "a CI run has sat in_progress longer than its suite takes"
    note = fake_lesson(
        id=7,
        title=compose_title(what, trigger),
        body=compose_body("The work is usually done.", trigger, [4181]),
        data={"what": what, "when_to_apply": trigger, "taught_by": [4181]},
        project_id=None,
        created_at=None,
        updated_at=None,
    )
    out = lesson_to_dict(note)
    assert out["what"] == what
    assert out["when_to_apply"] == trigger
    assert out["learned_from"] == [4181]
    # The insight comes back WITHOUT the lines compose_body added, so an edit
    # form round-trips instead of accumulating a copy of them per save.
    assert out["insight"] == "The work is usually done."
    assert "**When to apply:**" not in out["insight"]


def test_the_rest_guards_can_fail():
    """Rule 167: shown turning red once."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes)
    assert "a phrase that is definitely not in this module" not in src
    assert "lessons_bp" in src