"""Both records show the lesson → rule link in the web UI (milestone 440, #4635).

The frontend has no component test runner, so these read the source — and
each is written against something the backend owns, so a drift on either
side fails here rather than rendering a page that quietly reads wrong:

- the client's judgment and link-state unions are the service's and the
  model's own values, so a renamed state cannot leave a branch that never
  matches;
- the lesson page branches on every judgment, with the unjudged answer as
  the fall-through, so "not yet judged" is stated rather than left blank;
- the write-level list the pages hide controls by is the server's
  PERMISSION_RANK from editor up, which is the drift that had the snippet
  page hiding its edit controls from shared editors (`"edit"` is not a level
  the server sends).
"""
from __future__ import annotations

import inspect
import re
from pathlib import Path

from scribe.models.lesson_rule_link import LINK_STATES
from scribe.services import lesson_rules as links_svc
from scribe.services.access import PERMISSION_RANK

FRONTEND = Path(__file__).resolve().parents[1] / "frontend" / "src"


def _read(rel: str) -> str:
    return (FRONTEND / rel).read_text()


def _union(source: str, name: str) -> set[str]:
    """The string members of `export type <name> = "a" | "b" …;`."""
    m = re.search(rf"export type {name}\s*=\s*([^;]+);", source)
    assert m, f"type {name} not found"
    return set(re.findall(r'"([^"]+)"', m.group(1)))


def _template(view: str) -> str:
    return view[view.index("<template>"):view.rindex("</template>")]


def test_the_client_judgment_union_is_the_services_three_answers():
    assert _union(_read("api/lessons.ts"), "RuleJudgment") == {
        links_svc.LINKED, links_svc.NO_RULE, links_svc.UNJUDGED,
    }


def test_the_client_link_states_are_the_models():
    assert _union(_read("api/lessons.ts"), "LinkState") == set(LINK_STATES)


def test_the_lesson_page_answers_all_three_judgments():
    """`linked` and `no_rule` are tested by name; `unjudged` is the v-else
    that closes the same chain, so a fourth state the server might add reads
    as unjudged rather than as nothing."""
    tpl = _template(_read("views/LessonDetailView.vue"))
    linked = tpl.index(f"lesson.rule_judgment === '{links_svc.LINKED}'")
    no_rule = tpl.index(f"lesson.rule_judgment === '{links_svc.NO_RULE}'")
    assert linked < no_rule
    after = tpl[no_rule:]
    # The no-rule answer renders its reason, and the chain closes on a v-else.
    para_end = after.index("</p>")
    assert "lesson.no_rule?.why" in after[:para_end]
    closing = after[para_end + len("</p>"):]
    assert re.match(r"\s*<p v-else\b", closing), "the unjudged branch is not the chain's v-else"
    assert "Not yet judged" in closing[:closing.index("</p>")]


def test_the_panel_is_gated_on_the_judgment_being_attached():
    """An absent `rule_judgment` is "the links could not be read" — never
    "no rule" — so the panel must not render a state for it."""
    tpl = _template(_read("views/LessonDetailView.vue"))
    assert '<section v-if="lesson.rule_judgment"' in tpl


def test_both_pages_link_through_to_the_other_record():
    lesson_tpl = _read("views/LessonDetailView.vue")
    assert re.search(r'path:\s*"/rules",\s*query:\s*\{\s*rule:', lesson_tpl)
    rule_tpl = _template(_read("components/rules/RuleEditorSlideOver.vue"))
    assert ':to="`/lessons/${l.id}`"' in rule_tpl


def test_the_kind_and_state_markers_reuse_rule_chip():
    """No new chip style where `.rule-chip` serves: both components load the
    shared sheet and neither re-declares the class in its own block."""
    for rel in (
        "views/LessonDetailView.vue",
        "components/rules/RuleEditorSlideOver.vue",
        "views/LessonEditorView.vue",
    ):
        src = _read(rel)
        assert 'class="rule-chip' in _template(src), rel
        assert '<style src="@/assets/rules-shared.css" />' in src, rel
        scoped = src[src.index("<style scoped>"):]
        scoped = scoped[:scoped.index("</style>")]
        assert ".rule-chip" not in scoped, f"{rel} re-spells the chip"


def test_the_write_levels_are_the_servers():
    src = _read("utils/permission.ts")
    m = re.search(r"WRITE_LEVELS[^=]*=\s*\[([^\]]*)\]", src)
    assert m, "WRITE_LEVELS not found"
    client = set(re.findall(r'"([^"]+)"', m.group(1)))
    server = {p for p, rank in PERMISSION_RANK.items() if rank >= PERMISSION_RANK["editor"]}
    assert client == server


def test_no_page_spells_its_own_write_check():
    """The helper exists so pages agree; a page comparing against a share
    level by hand is the copy that drifted to `"edit"`. Matched on the names
    only a share level uses — `admin` and `owner` are also user roles, and
    `role === "admin"` is not this."""
    offenders = [
        str(p.relative_to(FRONTEND))
        for p in [*FRONTEND.rglob("*.vue"), *FRONTEND.rglob("*.ts")]
        if p != FRONTEND / "utils" / "permission.ts"
        and re.search(r'[!=]==\s*"(?:viewer|editor|edit)"', p.read_text())
    ]
    assert offenders == []


# ── #4658: the web editor records the answer ─────────────────────────────────


def _payload_fn(view: str) -> str:
    start = view.index("function answerPayload(")
    return view[start:view.index("\n}\n", start)]


def test_the_editor_sends_the_answer_under_the_names_both_routes_read():
    """Rule 33's contract check: a field the form sends under another name is
    dropped without an error, and the lesson saves unjudged."""
    from scribe.routes import lessons as routes

    body = _payload_fn(_read("views/LessonEditorView.vue"))
    assert "rule_ids:" in body and "no_rule:" in body
    for route in (routes.create_lesson_route, routes.update_lesson_route):
        src = inspect.getsource(route)
        assert 'data.get("rule_ids")' in src or 'data["rule_ids"]' in src, route.__name__
        assert 'data.get("no_rule")' in src, route.__name__


def test_the_editor_offers_the_three_answers():
    tpl = _template(_read("views/LessonEditorView.vue"))
    offered = set(re.findall(r'v-model="answer" type="radio" value="([a-z_]+)"', tpl))
    assert offered == {"rules", "no_rule", "open"}


def test_leaving_it_open_after_linking_clears_the_links_rather_than_nothing():
    """`rule_ids` omitted leaves the links alone; an empty list is what turns a
    linked lesson back into an open one. The editor must send the list."""
    body = _payload_fn(_read("views/LessonEditorView.vue"))
    assert "{ rule_ids: [] }" in body


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

    src = inspect.getsource(routes)
    assert src.index('"/rule-candidates"') < src.index('"/<int:lesson_id>"')
    assert "/api/lessons/rule-candidates" in _read("api/lessons.ts")


def test_the_candidates_route_keeps_unavailable_apart_from_none():
    """The service returns None when the search could not run. The route has
    to pass that through as null, not coerce it to an empty list, because
    "nothing resembles it" is a claim the editor shows to the writer."""
    from scribe.routes import lessons as routes

    src = inspect.getsource(routes.lesson_rule_candidates_route)
    assert 'jsonify({"candidates": candidates})' in src
    assert "or []" not in src