"""
Ukweli — API Key Management
GET    /api-keys          -> list caller's keys
POST   /api-keys          -> generate a new key (secret shown ONCE)
DELETE /api-keys/{id}     -> revoke a key
"""

from __future__ import annotations

import logging
from datetime import datetime, timezone

from fastapi import APIRouter, Depends, HTTPException, status
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.api.auth import (
    AuthContext,
    generate_api_key_pair,
    hash_api_secret,
    require_auth,
)
from app.db.session import get_db_session
from app.models.auth import ApiKey, AuthAuditLog
from app.models.enums import APIKeyStatus, AuthEventType, AuthTier
from app.models.schemas import (
    ApiKeyCreateRequest,
    ApiKeyCreateResponse,
    ApiKeyListResponse,
    ApiKeyOut,
)

logger = logging.getLogger("ukweli.api.api_keys")
router = APIRouter(prefix="/api-keys", tags=["API Keys"])


def _to_out(rec: ApiKey) -> ApiKeyOut:
    return ApiKeyOut(
        id=rec.id,
        key_id=rec.key_id,
        name=rec.name,
        description=rec.description,
        tier=rec.tier,
        quota_per_day=rec.quota_per_day,
        requests_today=rec.requests_today,
        last_used_at=rec.last_used_at,
        status=rec.status,
        created_at=rec.created_at,
        expires_at=rec.expires_at,
    )


@router.get("", response_model=ApiKeyListResponse)
async def list_api_keys(
    db: AsyncSession = Depends(get_db_session),
    auth: AuthContext = Depends(require_auth),
) -> ApiKeyListResponse:
    """List the caller's API keys.  Requires registered tier."""
    if auth.user is None:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="API key management requires a registered account.",
        )

    result = await db.execute(
        select(ApiKey)
        .where(ApiKey.user_id == auth.user.id)
        .order_by(ApiKey.created_at.desc())
    )
    keys = [_to_out(k) for k in result.scalars().all()]
    return ApiKeyListResponse(keys=keys, total=len(keys))


@router.post("", response_model=ApiKeyCreateResponse, status_code=status.HTTP_201_CREATED)
async def create_api_key(
    payload: ApiKeyCreateRequest,
    db: AsyncSession = Depends(get_db_session),
    auth: AuthContext = Depends(require_auth),
) -> ApiKeyCreateResponse:
    """
    Issue a new API key.  The **secret** is returned in plaintext exactly
    once — we only store its bcrypt hash.
    """
    if auth.user is None:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="API key management requires a registered account.",
        )

    key_id, secret = generate_api_key_pair()
    rec = ApiKey(
        user_id=auth.user.id,
        key_id=key_id,
        secret_hash=hash_api_secret(secret),
        name=payload.name,
        description=payload.description,
        tier=AuthTier.API.value,
        quota_per_day=10000,
        status=APIKeyStatus.ACTIVE.value,
        requests_today_reset_at=datetime.now(timezone.utc),
    )
    db.add(rec)
    await db.flush()

    # Audit
    db.add(
        AuthAuditLog(
            event_type=AuthEventType.API_KEY_CREATED.value,
            user_id=auth.user.id,
            api_key_id=rec.id,
            fingerprint=auth.fingerprint,
            success=True,
        )
    )

    logger.info("API key created: user=%s key_id=%s", auth.user.id, key_id)

    return ApiKeyCreateResponse(
        id=rec.id,
        key_id=key_id,
        secret=secret,
        name=rec.name,
        description=rec.description,
        tier=rec.tier,
        quota_per_day=rec.quota_per_day,
        created_at=rec.created_at,
    )


@router.delete("/{key_id}", status_code=status.HTTP_204_NO_CONTENT)
async def revoke_api_key(
    key_id: str,
    db: AsyncSession = Depends(get_db_session),
    auth: AuthContext = Depends(require_auth),
):
    """Revoke an API key.  Idempotent."""
    if auth.user is None:
        raise HTTPException(
            status_code=status.HTTP_403_FORBIDDEN,
            detail="API key management requires a registered account.",
        )

    result = await db.execute(
        select(ApiKey).where(
            ApiKey.key_id == key_id, ApiKey.user_id == auth.user.id
        )
    )
    rec = result.scalar_one_or_none()
    if rec is None:
        raise HTTPException(
            status_code=status.HTTP_404_NOT_FOUND,
            detail="API key not found.",
        )

    if rec.status != APIKeyStatus.REVOKED.value:
        rec.status = APIKeyStatus.REVOKED.value
        db.add(
            AuthAuditLog(
                event_type=AuthEventType.API_KEY_REVOKED.value,
                user_id=auth.user.id,
                api_key_id=rec.id,
                fingerprint=auth.fingerprint,
                success=True,
            )
        )
        logger.info("API key revoked: id=%s", rec.id)

    return None