"""VC migration e2e test (TASK-06-05, R-VC-MIG-01 — CRITICAL).

The highest-severity v0.4 risk: a v0.3 VC MUST verify against a Postgres
store with the v0.3 public key archived as superseded. This test seeds
SQLite with a v0.3 issuer key + credential, runs the migration, and
verifies through the HTTP endpoint.

Requires a live Postgres instance. Skips gracefully when PRAXIS_PG_DSN is
unset.
"""

from __future__ import annotations

import asyncio
import json
import os
import uuid
from pathlib import Path

import pytest
from fastapi.testclient import TestClient

pytestmark = pytest.mark.skipif(
    "PRAXIS_PG_DSN" not in os.environ,
    reason="PRAXIS_PG_DSN not set — VC migration e2e test skipped (R-VC-MIG-01).",
)


@pytest.fixture
async def _e2e_env(tmp_path, monkeypatch):
    """Set up a fresh SQLite store + Postgres pool + run migration."""
    import server.__main__ as m
    from db.store import PraxisStore
    from db.pg_migrate import apply_pg_migrations
    from db.pg_store import PgStore
    from server.vc.issuer import build_vc_payload, sign, issue_credential
    from server.vc.issuer_keys import init_issuer_key, _load_root_key
    from server.vc.migrate_keys import migrate_issuer_keys

    # Fresh SQLite store in a temp dir.
    sqlite_path = tmp_path / "praxis-e2e.db"
    monkeypatch.setenv("PRAXIS_DB_PATH", str(sqlite_path))
    sqlite_store = PraxisStore(str(sqlite_path))
    await sqlite_store.init()

    # Seed SQLite with a v0.3 issuer key + a v0.3-issued credential.
    root_key = _load_root_key()
    v03_kp = await init_issuer_key(sqlite_store, root_key)
    v03_cred_id = await issue_credential(
        sqlite_store,
        signing_key=v03_kp.signing_key,
        key_id=v03_kp.key_id,
        learner_id="learner-e2e-v03",
        path="cs-refund",
        scenarios_passed=["sc-1"],
        rubric_score=4.0,
        completed_weeks=6,
        evidence=[],
    )

    # Connect to Postgres + apply migrations + clean tables.
    import asyncpg
    pool = await asyncpg.create_pool(
        dsn=os.environ["PRAXIS_PG_DSN"], min_size=1, max_size=3, command_timeout=10
    )
    await apply_pg_migrations(pool)
    async with pool.acquire() as conn:
        await conn.execute(
            "TRUNCATE operators, issued_credentials, mastery_gate_events, "
            "cohort_aggregates, issuer_keys RESTART IDENTITY CASCADE"
        )

    pg_store = PgStore(pool)

    yield {
        "sqlite_store": sqlite_store,
        "pg_store": pg_store,
        "pool": pool,
        "v03_kp": v03_kp,
        "v03_cred_id": v03_cred_id,
        "root_key": root_key,
    }

    await pool.close()


@pytest.mark.asyncio
async def test_v03_vc_verifies_after_migration(_e2e_env):
    """R-VC-MIG-01: v0.3 VC verifies against Postgres with archived key."""
    env = _e2e_env
    from server.vc.migrate_keys import migrate_issuer_keys
    from server.vc.verification import verify_credential

    # Run the migration.
    result = await migrate_issuer_keys(
        env["sqlite_store"], env["pg_store"], env["root_key"]
    )
    assert result["archived_key_id"] == env["v03_kp"].key_id
    assert result["new_key_id"] is not None

    # Verify Postgres has 1 superseded + 1 active key.
    active = await env["pg_store"].get_active_signing_key_row()
    assert active is not None
    assert active["id"] == result["new_key_id"]
    archived = await env["pg_store"].get_public_key_row(env["v03_kp"].key_id)
    assert archived is not None
    assert archived["status"] == "superseded"

    # R-VC-MIG-01 CRITICAL: verify the v0.3 credential through the
    # two-store path (G-011: credential in SQLite, key in Postgres).
    res = await verify_credential(
        env["sqlite_store"], env["v03_cred_id"],
        pg_store=env["pg_store"], sqlite_store=env["sqlite_store"],
    )
    assert res is not None
    assert res["valid"] is True, (
        "R-VC-MIG-01 FAIL: v0.3 VC did not verify against archived superseded key"
    )
    assert res["status"] == "active"


@pytest.mark.asyncio
async def test_migration_idempotent_e2e(_e2e_env):
    """Re-running the migration is a no-op."""
    env = _e2e_env
    from server.vc.migrate_keys import migrate_issuer_keys
    await migrate_issuer_keys(env["sqlite_store"], env["pg_store"], env["root_key"])
    result = await migrate_issuer_keys(env["sqlite_store"], env["pg_store"], env["root_key"])
    assert result["archived_key_id"] is None
    assert result["new_key_id"] is None


@pytest.mark.asyncio
async def test_g027_first_boot_no_v03_key(_e2e_env):
    """G-027: fresh deploy with no v0.3 key → skip archive, fresh key only."""
    env = _e2e_env
    # Use a fresh SQLite store with NO v0.3 key.
    from db.store import PraxisStore
    from server.vc.migrate_keys import migrate_issuer_keys
    import tempfile
    fresh_path = Path(tempfile.mkdtemp()) / "fresh.db"
    fresh_store = PraxisStore(str(fresh_path))
    await fresh_store.init()
    result = await migrate_issuer_keys(fresh_store, env["pg_store"], env["root_key"])
    assert result["archived_key_id"] is None
    assert result["new_key_id"] is not None


@pytest.mark.asyncio
async def test_v04_vc_verifies_after_migration(_e2e_env):
    """A newly-issued v0.4 VC verifies against the active key in Postgres."""
    env = _e2e_env
    from server.vc.migrate_keys import migrate_issuer_keys
    from server.vc.verification import verify_credential
    from server.vc.issuer import issue_credential
    from server.vc.issuer_keys import get_active_signing_key

    await migrate_issuer_keys(env["sqlite_store"], env["pg_store"], env["root_key"])
    # Issue a v0.4 credential using the active Postgres key.
    kp, _enc = await get_active_signing_key(env["pg_store"], env["root_key"])
    v04_cred_id = await issue_credential(
        env["sqlite_store"],
        signing_key=kp.signing_key,
        key_id=kp.key_id,
        learner_id="learner-e2e-v04",
        path="cs-refund",
        scenarios_passed=["sc-1", "sc-2"],
        rubric_score=4.5,
        completed_weeks=6,
        evidence=[],
    )
    # The credential is in SQLite; the key is in Postgres. Verify via the
    # two-store path.
    res = await verify_credential(
        env["sqlite_store"], v04_cred_id,
        pg_store=env["pg_store"], sqlite_store=env["sqlite_store"],
    )
    assert res is not None
    assert res["valid"] is True


@pytest.mark.asyncio
async def test_tampered_v03_vc_fails_e2e(_e2e_env):
    """Tamper detection: a modified v0.3 credential fails verification."""
    env = _e2e_env
    from server.vc.migrate_keys import migrate_issuer_keys
    from server.vc.verification import verify_credential

    await migrate_issuer_keys(env["sqlite_store"], env["pg_store"], env["root_key"])
    # Fetch the v0.3 credential and tamper with its payload.
    row = await env["sqlite_store"].get_credential(env["v03_cred_id"])
    assert row is not None
    doc = json.loads(row["vc_payload_json"])
    doc["credentialSubject"]["rubricScore"] = 1.0  # tamper
    await env["sqlite_store"].set_credential_status(env["v03_cred_id"], "active")
    # Overwrite the payload in SQLite with the tampered version.
    import aiosqlite
    async with aiosqlite.connect(env["sqlite_store"].db_path) as db:
        await db.execute(
            "UPDATE issued_credentials SET vc_payload_json = ? WHERE id = ?",
            (json.dumps(doc, sort_keys=True, separators=(",", ":")), env["v03_cred_id"]),
        )
        await db.commit()
    res = await verify_credential(
        env["sqlite_store"], env["v03_cred_id"],
        pg_store=env["pg_store"], sqlite_store=env["sqlite_store"],
    )
    assert res is not None
    assert res["valid"] is False