"""Operational diagnostics. No auth in v1 (M0/M1 only expose non-sensitive
counts and the current Alembic revision).

The `/diag/reset` endpoint is **test-only** — it requires `APP_ENV=test` and
is the bedrock of the e2e suite (clean DB + freshly minted install token).
"""

from __future__ import annotations

import logging

from flask import Blueprint, abort, jsonify
from sqlalchemy import text
from sqlalchemy.exc import SQLAlchemyError

from app.core.config import settings
from app.core.install_token import regenerate_install_token
from app.db.session import get_engine

bp = Blueprint("diag", __name__, url_prefix="/diag")
log = logging.getLogger("metamorph.diag")


@bp.get("/db")
def db_diag():
    """Return the Alembic revision and the count of public-schema tables."""
    try:
        with get_engine().connect() as conn:
            revision = conn.execute(
                text("SELECT version_num FROM alembic_version")
            ).scalar()
            table_count = conn.execute(
                text(
                    "SELECT count(*) FROM information_schema.tables "
                    "WHERE table_schema='public' AND table_type='BASE TABLE'"
                )
            ).scalar_one()
    except SQLAlchemyError as e:
        log.warning("metamorph.diag.db_unreachable", extra={"error": str(e)})
        return jsonify({"reachable": False, "error": "database_unreachable"}), 503

    return jsonify(
        {
            "reachable": True,
            "alembic_revision": revision,
            "table_count": int(table_count),
        }
    )


@bp.post("/reset")
def reset_test_state():
    """TEST-ONLY: wipe users/auth tables and mint a fresh install token.

    Refuses unless `APP_ENV=test`. Used by the Playwright suite to start each
    auth scenario from a deterministic state.
    """
    # NOTE: this endpoint is the test-suite reset hook. Allowed in `dev` too so
    # the e2e suite can run against a normal `make up` stack, but in dev it is
    # destructive — equivalent to `make clean` for the auth tables. Production
    # (APP_ENV=prod/staging) is locked out.
    if settings.APP_ENV not in ("dev", "test"):
        abort(403, description="diag/reset is only available in dev/test")
    if settings.APP_ENV == "dev":
        log.warning("metamorph.diag.reset_in_dev_environment")

    try:
        with get_engine().begin() as conn:
            # Auth + RBAC + settings reset.
            conn.execute(
                text(
                    "TRUNCATE users, refresh_tokens, invitations, invitation_groups, "
                    "user_groups, settings, groups RESTART IDENTITY CASCADE"
                )
            )
            # Mission catalogue reset (M6). Truncated before the template tables
            # below because `mission_scenarios.source_scenario_template_id` and
            # `mission_tests.source_test_template_id` are ON DELETE SET NULL — a
            # cascade-truncate of templates would attempt to null those columns
            # and stall on the constraint check. Wiping the mission tables first
            # avoids that round-trip; cascades from `missions` then take care of
            # members, scenarios, tests, mitre_tags, categories.
            conn.execute(
                text(
                    "TRUNCATE mission_test_mitre_tags, mission_tests, "
                    "mission_scenarios, mission_categories, mission_members, "
                    "missions RESTART IDENTITY CASCADE"
                )
            )
            # Template catalogue reset (M5). The MITRE truncate below cascades to
            # the polymorphic tag join, but the template rows themselves must be
            # wiped first because `scenario_template_tests.test_template_id` is
            # ON DELETE RESTRICT.
            conn.execute(
                text(
                    "TRUNCATE scenario_template_tests, scenario_templates, "
                    "test_template_mitre_tags, test_templates "
                    "RESTART IDENTITY CASCADE"
                )
            )
            # MITRE reference reset — kept in sync with `settings` so a freshly
            # reset stack has `GET /mitre/status` and `GET /mitre/tactics` agree
            # ("no data, no last_sync"). The e2e suite re-syncs via /mitre/sync
            # when it needs catalogue data.
            conn.execute(
                text(
                    "TRUNCATE mitre_technique_tactics, mitre_subtechniques, "
                    "mitre_techniques, mitre_tactics RESTART IDENTITY CASCADE"
                )
            )
    except SQLAlchemyError as e:
        log.error("metamorph.diag.reset_failed", extra={"error": str(e)})
        return jsonify({"reset": False, "error": "database_error"}), 500

    token = regenerate_install_token()

    # Clear the in-memory rate-limit counters so the e2e suite that follows can
    # log in repeatedly without hitting `/auth/login`/`/auth/refresh` limits.
    # The limiter uses `memory://` in dev (cf. `app/core/rate_limit.py`).
    try:
        from app.core.rate_limit import limiter  # noqa: PLC0415 — avoid import cycle

        if limiter.enabled:
            limiter.reset()
    except Exception as e:  # noqa: BLE001
        log.warning("metamorph.diag.rate_limit_reset_failed", extra={"error": str(e)})

    log.warning("metamorph.diag.reset_completed")
    return jsonify({"reset": True, "install_token": token})