"""Enterprise identity APIs. Public routes are explicitly enumerated in policy."""

from __future__ import annotations

import hashlib
import json
import secrets
import uuid
from datetime import UTC, datetime, timedelta
from functools import wraps
from urllib.parse import urlsplit

from flask import current_app, g, jsonify, redirect, request
from itsdangerous import BadSignature, URLSafeTimedSerializer
from sqlalchemy import text
from sqlalchemy.exc import IntegrityError, StatementError

from app import db
from app.api.system import bp
from app.core.common.identifiers import new_governance_uid
from app.core.system.enterprise_identity import (
    ClaimMapper,
    DirectorySynchronizer,
    EmergencyAccess,
    IdentityPolicyError,
    IdentityUpstreamError,
    IdpConfig,
    sanitize_audit_detail,
)
from app.core.system.identity_repository import PostgresIdentityRepository
from app.core.system.identity_sessions import SessionManager
from app.core.system.oidc import OidcClient, OidcTransport
from app.core.system.permissions import (
    IDENTITY_MANAGE,
    IDENTITY_OPERATE,
    IDENTITY_READ,
    require_permissions,
)
from app.core.system.tokens import issue_access_token
from app.models.result import failed, success


def _body() -> dict:
    value = request.get_json(silent=True)
    if not isinstance(value, dict):
        raise IdentityPolicyError("JSON object body is required")
    return value


def _required_str(data: dict, key: str, *, maximum: int = 500) -> str:
    value = data.get(key)
    if not isinstance(value, str) or not value.strip() or len(value.strip()) > maximum:
        raise IdentityPolicyError(f"{key} is required or invalid")
    return value.strip()


def _optional_str(data: dict, key: str, default: str, *, maximum: int) -> str:
    if key not in data:
        return default
    return _required_str(data, key, maximum=maximum)


def _uuid(value, field: str) -> str:
    try:
        return str(uuid.UUID(str(value)))
    except (ValueError, TypeError, AttributeError) as exc:
        raise IdentityPolicyError(f"{field} must be a UUID") from exc


def _positive_int(value, field: str, *, maximum: int = 2_147_483_647) -> int:
    if isinstance(value, bool):
        raise IdentityPolicyError(f"{field} must be a positive integer")
    try:
        result = int(value)
    except (ValueError, TypeError) as exc:
        raise IdentityPolicyError(f"{field} must be a positive integer") from exc
    if result < 1 or result > maximum:
        raise IdentityPolicyError(f"{field} must be a positive integer")
    return result


def _timestamp(value, field: str) -> datetime:
    if not isinstance(value, str):
        raise IdentityPolicyError(f"{field} must be an ISO-8601 timestamp")
    try:
        parsed = datetime.fromisoformat(value.replace("Z", "+00:00"))
    except ValueError as exc:
        raise IdentityPolicyError(f"{field} must be an ISO-8601 timestamp") from exc
    if parsed.tzinfo is None or parsed.utcoffset() is None:
        raise IdentityPolicyError(f"{field} must include a timezone")
    return parsed


def _string_array(data: dict, key: str, *, default=None) -> tuple[str, ...]:
    value = data.get(key, default)
    if not isinstance(value, list) or not value or any(not isinstance(item, str) or not item.strip() for item in value):
        raise IdentityPolicyError(f"{key} must be a non-empty string array")
    return tuple(item.strip() for item in value)


def _validate_mapping(version: str, group_rules) -> ClaimMapper:
    if not isinstance(group_rules, dict):
        raise IdentityPolicyError("group_rules must be an object")
    return ClaimMapper(version=version, group_rules=group_rules)


def _identity_input_guard(view):
    @wraps(view)
    def guarded(*args, **kwargs):
        try:
            return view(*args, **kwargs)
        except IdentityPolicyError:
            raise
        except (KeyError, TypeError, ValueError, IntegrityError, StatementError) as exc:
            db.session.rollback()
            raise IdentityPolicyError("invalid enterprise identity request") from exc

    return guarded


def _repo() -> PostgresIdentityRepository:
    return PostgresIdentityRepository(db.session)


def _config(row) -> IdpConfig:
    return IdpConfig(provider_uid=str(row["provider_uid"]), version=row["version"], issuer=row["issuer"],
                     client_id=row["client_id"], secret_ref=row["secret_ref"],
                     authorization_endpoint=row["authorization_endpoint"], token_endpoint=row["token_endpoint"],
                     jwks_uri=row["jwks_uri"], redirect_uris=tuple(row["redirect_uris"]),
                     post_login_redirect_uris=tuple(dict(row["config"]).get("post_login_redirect_uris", ())),
                     algorithms=tuple(row["algorithms"]), mapping_version=row["mapping_version"], status=row["status"])


def _load_config(provider_uid: str, *, version: int | None = None, active: bool = True):
    clause = "AND status='active'" if active else ""
    version_clause = "AND version=:version" if version is not None else ""
    return db.session.execute(text(f"""
        SELECT provider_uid::text,version,status,issuer,client_id,secret_ref,authorization_endpoint,
               token_endpoint,jwks_uri,redirect_uris,algorithms,mapping_version,config
        FROM public.identity_idp_config_versions WHERE provider_uid=CAST(:provider AS uuid) {version_clause} {clause}
        ORDER BY version DESC LIMIT 1
    """), {"provider": provider_uid, "version": version}).mappings().one_or_none()


def _audit(event_type: str, outcome: str, *, actor_uid: str | None = None,
           provider_uid: str | None = None, resource_uid: str | None = None,
           enterprise_subject: str | None = None, detail: dict | None = None) -> None:
    _repo().audit({"event_type": event_type, "outcome": outcome, "actor_uid": actor_uid,
                   "provider_uid": provider_uid, "resource_type": "enterprise_identity",
                   "resource_uid": resource_uid,
                   "subject_digest": (hashlib.sha256(enterprise_subject.encode()).hexdigest()
                                      if enterprise_subject else None),
                   "safe_detail": sanitize_audit_detail(detail or {})})


def _cookie_secure() -> bool:
    return bool(current_app.config.get("IDENTITY_COOKIE_SECURE", True))


def _origin(uri: str) -> str:
    parts = urlsplit(uri)
    return f"{parts.scheme}://{parts.netloc}"


def _browser_origin_allowed(origin: str) -> bool:
    rows = db.session.execute(text("SELECT config FROM public.identity_idp_config_versions WHERE status='active'")).scalars().all()
    allowed = {_origin(uri) for config in rows for uri in dict(config).get("post_login_redirect_uris", ())}
    allowed.update(current_app.config.get("IDENTITY_ALLOWED_TEST_ORIGINS", ()))
    return origin in allowed


@bp.errorhandler(IdentityPolicyError)
def identity_policy_error(exc):
    try:
        db.session.rollback()
        _audit("identity_policy_denied", "denied", actor_uid=getattr(g, "current_user", {}).get("id"),
               detail={"path": request.path, "reason": str(exc)[:160]})
    except Exception:  # pragma: no cover - failure reporting must not expose internals
        db.session.rollback()
    return jsonify(failed(str(exc), code=400)), 400


@bp.errorhandler(IdentityUpstreamError)
def identity_upstream_error(exc):
    db.session.rollback()
    try:
        _audit("identity_upstream_failure", "failure", actor_uid=getattr(g, "current_user", {}).get("id"),
               detail={"path": request.path})
    except Exception:  # pragma: no cover
        db.session.rollback()
    return jsonify(failed("enterprise identity provider is unavailable", code=502)), 502


@bp.route("/identity/providers", methods=["GET"])
def identity_providers():
    rows = db.session.execute(text("""
        SELECT provider_uid::text,version,issuer,config->>'display_name' display_name
        FROM public.identity_idp_config_versions WHERE status='active' ORDER BY provider_uid
    """)).mappings().all()
    return jsonify(success([{"provider_uid": row["provider_uid"], "version": row["version"],
                             "issuer": row["issuer"], "display_name": row["display_name"] or "企业单点登录"} for row in rows]))


@bp.route("/identity/authorize", methods=["POST"])
@_identity_input_guard
def identity_authorize():
    data = _body()
    provider_uid = _uuid(data.get("provider_uid"), "provider_uid")
    row = _load_config(provider_uid)
    if not row:
        raise IdentityPolicyError("active identity provider not found")
    config = _config(row)
    callback_uri = _required_str(data, "redirect_uri", maximum=2048)
    post_login_uri = _required_str(data, "post_login_uri", maximum=2048)
    if post_login_uri not in config.post_login_redirect_uris:
        raise IdentityPolicyError("post-login redirect URI is not allowlisted")
    started = OidcClient(_repo()).begin(config, callback_uri)
    serializer = URLSafeTimedSerializer(current_app.config["SECRET_KEY"], salt="oidc-flow")
    response = jsonify(success({"authorization_url": started.url, "provider_uid": config.provider_uid}))
    response.set_cookie("dataops_oidc_flow", serializer.dumps({"state": started.state, "verifier": started.code_verifier,
                                                                 "provider_uid": config.provider_uid,
                                                                 "redirect_uri": callback_uri,
                                                                 "post_login_uri": post_login_uri}),
                        httponly=True, secure=_cookie_secure(), samesite="Lax", max_age=300, path="/api/system/identity/callback")
    _audit("oidc_authorize", "success", provider_uid=config.provider_uid, detail={"redirect_uri": data["redirect_uri"]})
    return response


@bp.route("/identity/callback", methods=["GET"])
@_identity_input_guard
def identity_callback():
    serializer = URLSafeTimedSerializer(current_app.config["SECRET_KEY"], salt="oidc-flow")
    try:
        flow = serializer.loads(request.cookies.get("dataops_oidc_flow", ""), max_age=300)
    except BadSignature as exc:
        raise IdentityPolicyError("OIDC browser flow binding is invalid or expired") from exc
    if not isinstance(flow, dict) or request.args.get("state") != flow.get("state"):
        raise IdentityPolicyError("OIDC state mismatch")
    provider_uid = _uuid(flow.get("provider_uid"), "provider_uid")
    row = _load_config(provider_uid)
    if not row:
        raise IdentityPolicyError("active identity provider not found")
    row = dict(row)
    config = _config(row)
    config.validate()
    callback_uri = _required_str(flow, "redirect_uri", maximum=2048)
    verifier = _required_str(flow, "verifier", maximum=512)
    state = _required_str(flow, "state", maximum=512)
    post_login_uri = _required_str(flow, "post_login_uri", maximum=2048)
    code = request.args.get("code")
    if not isinstance(code, str) or not code or len(code) > 4096:
        raise IdentityPolicyError("OIDC authorization code is required")
    # Do not keep a database transaction open while calling the external IdP.
    db.session.rollback()
    transport = OidcTransport()
    id_token = transport.exchange_code(config, code=code, redirect_uri=callback_uri, verifier=verifier)
    jwks = transport.fetch_jwks(config)
    repo = _repo()
    try:
        claims = OidcClient(repo).verify_callback(config, state=state, redirect_uri=callback_uri,
                                                   code_verifier=verifier, id_token=id_token, jwks=jwks,
                                                   commit=False)
        mapped = ClaimMapper(version=config.mapping_version,
                             group_rules=dict(row["config"]).get("group_rules", {})).map(claims)
        link = repo.get_identity(config.provider_uid, mapped.subject, for_update=True)
        if link and link["status"] != "active":
            raise IdentityPolicyError("enterprise identity is disabled")
        scope = {"business_domain_uids": mapped.business_domain_uids, "object_types": mapped.object_types,
                 "environments": mapped.environments, "data_scopes": mapped.data_scopes}
        changed = bool(link and (sorted(link["roles"]) != sorted(mapped.roles)
                                 or dict(link["authorization_scope"]) != json.loads(json.dumps(scope))))
        user_uid = link["user_uid"] if link else new_governance_uid()
        token_version = (int(link["token_version"]) + 1 if changed else int(link["token_version"])) if link else 1
        repo.put_identity(config.provider_uid, mapped.subject, {
            "provider_uid": config.provider_uid, "user_uid": user_uid, "username": mapped.username,
            "display_name": mapped.display_name, "department": mapped.department, "groups": list(mapped.groups),
            "roles": list(mapped.roles), "authorization_scope": scope, "mapping_version": mapped.mapping_version,
            "claims_digest": mapped.claims_digest, "status": "active", "token_version": token_version,
        }, commit=False)
        if changed:
            repo.revoke_subject_sessions(config.provider_uid, mapped.subject,
                                         reason="claims_mapping_changed", commit=False)
        credentials = SessionManager(repo, secret=current_app.config["SECRET_KEY"]).create(
            subject=mapped.subject, user_uid=user_uid, roles=list(mapped.roles), identity_source="oidc",
            token_version=token_version, provider_uid=config.provider_uid, commit=False)
        exchange = secrets.token_urlsafe(40)
        repo.insert_exchange_code({"uid": new_governance_uid(),
                                   "code_hash": hashlib.sha256(exchange.encode()).hexdigest(),
                                   "session_uid": credentials.session_uid, "redirect_uri": post_login_uri,
                                   "expires_at": datetime.now(UTC) + timedelta(minutes=2)}, commit=False)
        db.session.commit()
    except IdentityPolicyError:
        db.session.rollback()
        raise
    except Exception as exc:
        db.session.rollback()
        raise IdentityPolicyError("OIDC callback persistence failed") from exc
    _audit("oidc_login", "success", provider_uid=config.provider_uid, resource_uid=user_uid,
           detail={"mapping_version": mapped.mapping_version, "claims_digest": mapped.claims_digest})
    response = redirect(f"{flow['post_login_uri']}?exchange_code={exchange}", code=302)
    response.set_cookie("dataops_refresh", credentials.refresh_token, httponly=True, secure=_cookie_secure(), samesite="Strict",
                        max_age=8 * 3600, path="/api/system/identity")
    response.delete_cookie("dataops_oidc_flow", path="/api/system/identity/callback")
    return response


@bp.route("/identity/exchange", methods=["POST"])
@_identity_input_guard
def identity_exchange():
    data = _body()
    exchange_code = _required_str(data, "exchange_code", maximum=1024)
    redirect_uri = _required_str(data, "redirect_uri", maximum=2048)
    digest = hashlib.sha256(exchange_code.encode()).hexdigest()
    row = db.session.execute(text("""
        UPDATE public.identity_exchange_codes SET status='consumed',consumed_at=CURRENT_TIMESTAMP
        WHERE code_hash=:digest AND status='pending' AND expires_at>CURRENT_TIMESTAMP
          AND redirect_uri=:redirect RETURNING session_uid::text,redirect_uri
    """), {"digest": digest, "redirect": redirect_uri}).mappings().one_or_none()
    if not row or request.headers.get("Origin") != _origin(row["redirect_uri"]):
        db.session.rollback()
        raise IdentityPolicyError("exchange code or browser origin is invalid")
    db.session.commit()
    session = _repo().get_session(row["session_uid"])
    if not session or session["status"] != "active":
        raise IdentityPolicyError("identity session is unavailable")
    token = issue_access_token(user_id=session["user_uid"], roles=list(session["roles"]), secret=current_app.config["SECRET_KEY"],
                               session_uid=session["uid"], token_version=session["token_version"], identity_source=session["identity_source"])
    return jsonify(success({"token": token, "identity_source": session["identity_source"]}))


@bp.route("/identity/refresh", methods=["POST"])
def identity_refresh():
    origin = request.headers.get("Origin", "")
    if not _browser_origin_allowed(origin):
        raise IdentityPolicyError("browser origin is not allowlisted")
    credentials = SessionManager(_repo(), secret=current_app.config["SECRET_KEY"]).refresh(request.cookies.get("dataops_refresh", ""))
    session = _repo().get_session(credentials.session_uid)
    _audit("identity_refresh", "success", actor_uid=session["user_uid"] if session else None,
           provider_uid=session.get("provider_uid") if session else None,
           resource_uid=credentials.session_uid,
           detail={"rotated_from_uid": session.get("rotated_from_uid") if session else None})
    response = jsonify(success({"token": credentials.access_token}))
    response.set_cookie("dataops_refresh", credentials.refresh_token, httponly=True, secure=_cookie_secure(), samesite="Strict",
                        max_age=8 * 3600, path="/api/system/identity")
    return response


@bp.route("/identity/logout", methods=["POST"])
@require_permissions(IDENTITY_READ)
def identity_logout():
    session_uid = g.current_user.get("sid")
    session = _repo().get_session(session_uid) if session_uid else None
    if session_uid:
        SessionManager(_repo(), secret=current_app.config["SECRET_KEY"]).revoke(session_uid)
    _audit("identity_logout", "success", actor_uid=g.current_user.get("id"),
           provider_uid=session.get("provider_uid") if session else None, resource_uid=session_uid)
    response = jsonify(success({"revoked": True}))
    response.delete_cookie("dataops_refresh", path="/api/system/identity")
    return response


@bp.route("/identity/idp-versions", methods=["GET"])
@require_permissions(IDENTITY_MANAGE)
def identity_idp_versions():
    rows = db.session.execute(text("SELECT provider_uid::text,version,status,issuer,client_id,secret_ref,redirect_uris,algorithms,mapping_version,created_at FROM public.identity_idp_config_versions ORDER BY provider_uid,version DESC")).mappings().all()
    return jsonify(success([{**dict(row), "secret_ref": "env:DATAOPS_OIDC_***"} for row in rows]))


@bp.route("/identity/idp-versions", methods=["POST"])
@require_permissions(IDENTITY_MANAGE)
@_identity_input_guard
def identity_idp_version_create():
    data = _body()
    provider_uid = _uuid(data["provider_uid"], "provider_uid") if data.get("provider_uid") else new_governance_uid()
    mapping_version = _required_str(data, "mapping_version", maximum=120)
    group_rules = data.get("group_rules")
    _validate_mapping(mapping_version, group_rules)
    config = IdpConfig(provider_uid=provider_uid, version=_positive_int(data.get("version"), "version"),
        issuer=_required_str(data, "issuer", maximum=2048), client_id=_required_str(data, "client_id", maximum=300),
        secret_ref=_required_str(data, "secret_ref", maximum=160),
        authorization_endpoint=_required_str(data, "authorization_endpoint", maximum=2048),
        token_endpoint=_required_str(data, "token_endpoint", maximum=2048),
        jwks_uri=_required_str(data, "jwks_uri", maximum=2048), redirect_uris=_string_array(data, "redirect_uris"),
        post_login_redirect_uris=_string_array(data, "post_login_redirect_uris"),
        algorithms=_string_array(data, "algorithms", default=["RS256"]), mapping_version=mapping_version).validate()
    db.session.execute(text("""
        INSERT INTO public.identity_idp_config_versions(uid,provider_uid,version,status,issuer,client_id,secret_ref,authorization_endpoint,
        token_endpoint,jwks_uri,redirect_uris,algorithms,mapping_version,config,created_by)
        VALUES(CAST(:uid AS uuid),CAST(:provider AS uuid),:version,'draft',:issuer,:client,:secret,:auth,:token,:jwks,
        CAST(:redirects AS jsonb),CAST(:algorithms AS jsonb),:mapping,CAST(:config AS jsonb),CAST(:actor AS uuid))
    """), {"uid": new_governance_uid(), "provider": config.provider_uid, "version": config.version, "issuer": config.issuer,
             "client": config.client_id, "secret": config.secret_ref, "auth": config.authorization_endpoint,
             "token": config.token_endpoint, "jwks": config.jwks_uri, "redirects": json.dumps(config.redirect_uris),
             "algorithms": json.dumps(config.algorithms), "mapping": config.mapping_version,
             "config": json.dumps({"display_name": data.get("display_name"), "group_rules": group_rules,
                                   "post_login_redirect_uris": data.get("post_login_redirect_uris", [])}), "actor": g.current_user["id"]})
    db.session.commit()
    _audit("idp_version_created", "success", actor_uid=g.current_user["id"], provider_uid=config.provider_uid)
    return jsonify(success(config.public_dict())), 201


@bp.route("/identity/idp-versions/<provider_uid>/<int:version>/<action>", methods=["POST"])
@require_permissions(IDENTITY_MANAGE)
@_identity_input_guard
def identity_idp_action(provider_uid: str, version: int, action: str):
    provider_uid = _uuid(provider_uid, "provider_uid")
    version = _positive_int(version, "version")
    row = _load_config(provider_uid, version=version, active=False)
    if not row:
        raise IdentityPolicyError("IdP configuration version not found")
    config = _config(row)
    config.validate()
    _validate_mapping(config.mapping_version, dict(row["config"]).get("group_rules"))
    if action == "dry-run":
        result = {"valid": True, "secret_available": bool(config.resolve_secret())}
        _audit("idp_dry_run", "success", actor_uid=g.current_user["id"], provider_uid=provider_uid,
               resource_uid=f"{provider_uid}:{version}", detail={"version": version})
        return jsonify(success(result))
    if action in {"activate", "rotate"}:
        config.resolve_secret()
        db.session.execute(text("UPDATE public.identity_idp_config_versions SET status='superseded' WHERE provider_uid=CAST(:p AS uuid) AND status='active'"), {"p": provider_uid})
        db.session.execute(text("UPDATE public.identity_idp_config_versions SET status='active',activated_at=CURRENT_TIMESTAMP WHERE provider_uid=CAST(:p AS uuid) AND version=:v"), {"p": provider_uid, "v": version})
        db.session.execute(text("UPDATE public.enterprise_identity_links SET token_version=token_version+1,updated_at=CURRENT_TIMESTAMP WHERE provider_uid=CAST(:p AS uuid)"), {"p": provider_uid})
        db.session.execute(text("""
            UPDATE public.identity_sessions SET status='revoked',revoke_reason='provider_configuration_changed',revoked_at=CURRENT_TIMESTAMP
            WHERE status='active' AND identity_link_uid IN
              (SELECT uid FROM public.enterprise_identity_links WHERE provider_uid=CAST(:p AS uuid))
        """), {"p": provider_uid})
    elif action == "disable":
        disabled = db.session.execute(text("UPDATE public.identity_idp_config_versions SET status='disabled',disabled_at=CURRENT_TIMESTAMP WHERE provider_uid=CAST(:p AS uuid) AND version=:v AND status='active' RETURNING provider_uid"), {"p": provider_uid, "v": version}).scalar_one_or_none()
        if not disabled:
            raise IdentityPolicyError("only the selected active IdP version can be disabled")
        db.session.execute(text("UPDATE public.enterprise_identity_links SET token_version=token_version+1,updated_at=CURRENT_TIMESTAMP WHERE provider_uid=CAST(:p AS uuid)"), {"p": provider_uid})
        db.session.execute(text("""
            UPDATE public.identity_sessions SET status='revoked',revoke_reason='provider_disabled',revoked_at=CURRENT_TIMESTAMP
            WHERE status='active' AND identity_link_uid IN
              (SELECT uid FROM public.enterprise_identity_links WHERE provider_uid=CAST(:p AS uuid))
        """), {"p": provider_uid})
    elif action == "connectivity":
        payload = OidcTransport().fetch_jwks(config)
        result = {"reachable": True, "key_count": len(payload.get("keys", []))}
        _audit("idp_connectivity", "success", actor_uid=g.current_user["id"], provider_uid=provider_uid,
               resource_uid=f"{provider_uid}:{version}", detail={"version": version, **result})
        return jsonify(success(result))
    else:
        raise IdentityPolicyError("unsupported IdP version action")
    db.session.commit()
    _audit(f"idp_{action}", "success", actor_uid=g.current_user["id"], provider_uid=provider_uid)
    return jsonify(success({"provider_uid": provider_uid, "version": version, "action": action}))


@bp.route("/identity/claims/dry-run", methods=["POST"])
@require_permissions(IDENTITY_OPERATE)
@_identity_input_guard
def identity_claims_dry_run():
    data = _body()
    mapping_version = _required_str(data, "mapping_version", maximum=120)
    claims = data.get("claims")
    if not isinstance(claims, dict):
        raise IdentityPolicyError("claims must be an object")
    mapped = _validate_mapping(mapping_version, data.get("group_rules")).map(claims)
    result = {"roles": mapped.roles, "business_domain_uids": mapped.business_domain_uids,
              "object_types": mapped.object_types, "environments": mapped.environments,
              "data_scopes": mapped.data_scopes, "mapping_version": mapped.mapping_version,
              "claims_digest": mapped.claims_digest}
    _audit("claims_dry_run", "success", actor_uid=g.current_user["id"],
           enterprise_subject=mapped.subject,
           detail={"mapping_version": mapped.mapping_version, "claims_digest": mapped.claims_digest,
                   "role_count": len(mapped.roles), "scope_count": sum(len(result[key]) for key in
                   ("business_domain_uids", "object_types", "environments", "data_scopes"))})
    return jsonify(success(result))


@bp.route("/identity/directory/delta", methods=["POST"])
@require_permissions(IDENTITY_OPERATE)
@_identity_input_guard
def identity_directory_delta():
    data = _body()
    event_type = _required_str(data, "event_type", maximum=20).upper()
    provider_uid = _uuid(data.get("provider_uid"), "provider_uid")
    params = {
        "provider_uid": provider_uid,
        "source": _required_str(data, "source", maximum=80),
        "source_event_id": _required_str(data, "source_event_id", maximum=300),
        "cursor": _required_str(data, "cursor", maximum=500),
        "cursor_sequence": _positive_int(data.get("cursor_sequence"), "cursor_sequence"),
        "event_type": event_type,
    }
    if event_type in {"JOINER", "MOVER", "RESTORE"}:
        row = _load_config(provider_uid)
        if not row:
            raise IdentityPolicyError("active identity provider not found")
        config = _config(row)
        mapped = ClaimMapper(
            version=config.mapping_version,
            group_rules=dict(row["config"]).get("group_rules", {}),
        ).map(data.get("claims", {}))
        params["subject"] = mapped.subject
        params["attributes"] = {
            "provider_uid": config.provider_uid,
            "username": mapped.username,
            "display_name": mapped.display_name,
            "department": mapped.department,
            "groups": mapped.groups,
            "roles": mapped.roles,
            "mapping_version": mapped.mapping_version,
            "claims_digest": mapped.claims_digest,
            "authorization_scope": {
                "business_domain_uids": mapped.business_domain_uids,
                "object_types": mapped.object_types,
                "environments": mapped.environments,
                "data_scopes": mapped.data_scopes,
            },
        }
    elif event_type in {"LEAVER", "DISABLE"}:
        params["subject"] = _required_str(data, "subject", maximum=500)
        params["attributes"] = {"username": data.get("username"), "roles": []}
    elif event_type in {"DEPARTMENT", "GROUP"}:
        if not isinstance(data.get("attributes"), dict):
            raise IdentityPolicyError("organization attributes must be an object")
        params["attributes"] = data["attributes"]
    else:
        raise IdentityPolicyError("unsupported directory event type")
    result = DirectorySynchronizer(_repo(), SessionManager(_repo(), secret=current_app.config["SECRET_KEY"])).apply(**params)
    _audit("directory_delta", "success", actor_uid=g.current_user["id"],
           provider_uid=provider_uid, resource_uid=params["source_event_id"],
           enterprise_subject=str(params["subject"]) if params.get("subject") else None,
           detail={"event_type": event_type, "result": result})
    return jsonify(success(result))


@bp.route("/identity/sessions", methods=["GET"])
@require_permissions(IDENTITY_OPERATE)
@_identity_input_guard
def identity_sessions():
    subject = request.args.get("subject")
    provider_uid = request.args.get("provider_uid")
    if subject and not provider_uid:
        raise IdentityPolicyError("provider_uid is required with subject")
    if provider_uid:
        provider_uid = _uuid(provider_uid, "provider_uid")
    if subject and len(subject) > 500:
        raise IdentityPolicyError("subject is invalid")
    rows = _repo().list_sessions(provider_uid, subject)
    visible = ("uid", "user_uid", "identity_source", "status", "created_at", "last_seen_at", "expires_at")
    return jsonify(success([{key: row.get(key) for key in visible} for row in rows]))


@bp.route("/identity/sessions/<session_uid>/revoke", methods=["POST"])
@require_permissions(IDENTITY_OPERATE)
@_identity_input_guard
def identity_session_revoke(session_uid: str):
    session_uid = _uuid(session_uid, "session_uid")
    data = _body()
    session = _repo().get_session(session_uid)
    reason = _optional_str(data, "reason", "operator_revoke", maximum=120)
    SessionManager(_repo(), secret=current_app.config["SECRET_KEY"]).revoke(session_uid, reason=reason)
    _audit("identity_session_revoke", "success", actor_uid=g.current_user["id"],
           provider_uid=session.get("provider_uid") if session else None, resource_uid=session_uid,
           detail={"reason_supplied": bool(data.get("reason"))})
    return jsonify(success({"session_uid": session_uid, "revoked": True}))


@bp.route("/identity/sessions/<session_uid>/risk-terminate", methods=["POST"])
@require_permissions(IDENTITY_OPERATE)
@_identity_input_guard
def identity_session_risk(session_uid: str):
    session_uid = _uuid(session_uid, "session_uid")
    data = _body()
    session = _repo().get_session(session_uid)
    reason = _optional_str(data, "reason", "risk_signal", maximum=300)
    SessionManager(_repo(), secret=current_app.config["SECRET_KEY"]).risk_revoke(session_uid, reason=reason)
    _audit("identity_session_risk_terminate", "success", actor_uid=g.current_user["id"],
           provider_uid=session.get("provider_uid") if session else None, resource_uid=session_uid,
           detail={"reason_supplied": bool(data.get("reason"))})
    return jsonify(success({"session_uid": session_uid, "revoked": True, "risk": True}))


@bp.route("/identity/emergency/requests", methods=["POST"])
@require_permissions(IDENTITY_OPERATE)
@_identity_input_guard
def identity_emergency_request():
    data = _body()
    account_uid = _uuid(data.get("account_uid"), "account_uid")
    reason = _required_str(data, "reason", maximum=2000)
    expires_at = _timestamp(data.get("expires_at"), "expires_at")
    eligible = db.session.execute(text("""
        SELECT EXISTS(
          SELECT 1 FROM public.users u JOIN public.user_roles ur ON ur.user_id=u.id
          JOIN public.roles r ON r.id=ur.role_id
          WHERE u.id=CAST(:account AS uuid) AND u.status='active' AND r.name='admin'
            AND NOT EXISTS(SELECT 1 FROM public.enterprise_identity_links l WHERE l.user_uid=u.id)
        )
    """), {"account": account_uid}).scalar()
    record = EmergencyAccess(_repo()).request(requester_uid=g.current_user["id"], account_uid=account_uid,
        reason=reason, expires_at=expires_at,
        account_is_local_active_admin=bool(eligible))
    _audit("emergency_request", "success", actor_uid=g.current_user["id"], resource_uid=record["uid"],
           detail={"account_uid": record["account_uid"], "expires_at": record["expires_at"].isoformat()})
    return jsonify(success(record)), 201


@bp.route("/identity/emergency/<request_uid>/<action>", methods=["POST"])
@require_permissions(IDENTITY_MANAGE)
@_identity_input_guard
def identity_emergency_action(request_uid: str, action: str):
    request_uid = _uuid(request_uid, "request_uid")
    service = EmergencyAccess(_repo())
    data = _body()
    if action == "approve":
        result = service.approve(request_uid, approver_uid=g.current_user["id"])
    elif action == "activate":
        result = service.activate(request_uid)
    elif action == "review":
        result = service.review(request_uid, reviewer_uid=g.current_user["id"],
                                outcome=_required_str(data, "outcome", maximum=2000))
    elif action == "close":
        result = service.close(request_uid, actor_uid=g.current_user["id"])
    else:
        raise IdentityPolicyError("unsupported emergency action")
    _audit(f"emergency_{action}", "warning" if action == "activate" else "success", actor_uid=g.current_user["id"], resource_uid=request_uid)
    return jsonify(success(result))


@bp.route("/identity/sessions/revoke-all", methods=["POST"])
@require_permissions(IDENTITY_OPERATE)
@_identity_input_guard
def identity_session_revoke_all():
    data = _body()
    provider_uid = _uuid(data.get("provider_uid"), "provider_uid")
    subject = _required_str(data, "subject", maximum=500)
    reason = _optional_str(data, "reason", "operator_revoke_all", maximum=120)
    SessionManager(_repo(), secret=current_app.config["SECRET_KEY"]).revoke_subject(
        provider_uid, subject, reason=reason
    )
    _audit("identity_session_revoke_all", "success", actor_uid=g.current_user["id"],
           provider_uid=provider_uid, enterprise_subject=subject,
           detail={"reason_supplied": bool(data.get("reason"))})
    return jsonify(success({"revoked": True}))


@bp.route("/identity/audit", methods=["GET"])
@require_permissions(IDENTITY_MANAGE)
@_identity_input_guard
def identity_audit():
    rows = db.session.execute(text("SELECT uid::text,event_type,outcome,actor_uid::text,provider_uid::text,resource_type,resource_uid,safe_detail,created_at FROM public.identity_audit_events ORDER BY created_at DESC LIMIT :limit"),
                              {"limit": _positive_int(request.args.get("limit", 100), "limit", maximum=500)}).mappings().all()
    return jsonify(success([dict(row) for row in rows]))