"""Test the exam-bank corpus coverage grouping (/api/exam/corpus)."""
from fastapi import FastAPI
from fastapi.testclient import TestClient
from routers.exam.corpus import router
from routers.exam.dependencies import ExamContext, get_exam_context

TEACHER = "00000000-0000-0000-0000-000000000001"
INST_A = "10000000-0000-0000-0000-000000000001"


class FakeResult:
    def __init__(self, data): self.data = data


class FakeQuery:
    def __init__(self, store, table): self.store, self.table = store, table
    def select(self, *_a, **_k): return self
    def execute(self): return FakeResult(list(self.store.get(self.table, [])))


class FakeSupabase:
    def __init__(self, store): self.store = store
    def table(self, name): return FakeQuery(self.store, name)


def _client(store):
    app = FastAPI(); app.include_router(router, prefix="/api/exam")
    app.dependency_overrides[get_exam_context] = lambda: ExamContext(TEACHER, "tok", FakeSupabase(store), [INST_A])
    return TestClient(app)


def test_corpus_groups_papers_by_session_with_qp_ms_er_coverage():
    store = {
        "eb_specifications": [{"spec_code": "AQA-PHYS-8463", "exam_board_code": "AQA", "subject_code": "PHYSICS", "award_code": "8463", "first_teach": "2016"}],
        "eb_exams": [
            {"exam_code": "a", "spec_code": "AQA-PHYS-8463", "paper_code": "8463/1H", "session": "2022-Jun", "type_code": "QP", "storage_loc": "cc.examboards/a.pdf"},
            {"exam_code": "b", "spec_code": "AQA-PHYS-8463", "paper_code": "8463/1H", "session": "2022-Jun", "type_code": "MS", "storage_loc": "cc.examboards/b.pdf"},
            {"exam_code": "c", "spec_code": "AQA-PHYS-8463", "paper_code": "8463/1H", "session": "2022-Jun", "type_code": "ER", "storage_loc": None},
            {"exam_code": "d", "spec_code": "AQA-PHYS-8463", "paper_code": "8463/2H", "session": "2023-Jun", "type_code": "QP", "storage_loc": "cc.examboards/d.pdf"},
        ],
    }
    body = _client(store).get("/api/exam/corpus").json()
    assert body["totals"]["specs"] == 1 and body["totals"]["papers"] == 2
    spec = body["boards"][0]["specs"][0]
    assert spec["level"] == "GCSE" and spec["subject"] == "Physics"
    assert spec["counts"] == {"QP": 2, "MS": 1, "ER": 0}  # ER present but not stored → not counted
    p = next(p for p in spec["papers"] if p["paper_code"] == "8463/1H")
    assert p["docs"] == {"QP": True, "MS": True, "ER": False}