"""tokens 路由：token CRUD + 签发 + 吊销 + 日志"""

import hashlib
import json
import secrets
from datetime import datetime, timezone

from fastapi import APIRouter, Depends, HTTPException, Query, status
from pydantic import BaseModel

from ..core.db import get_pool
from ..core.deps import current_admin
from ..core.redis import cache_delete

router = APIRouter(prefix="/api/tokens", tags=["tokens"])


class TokenCreate(BaseModel):
    client_id: str
    service_scope: str  # MCP 服务地址（如 http://10.100.154.100:8001/mcp），后端反查服务名入库
    description: str | None = None
    expires_at: datetime | None = None  # null = 永不过期


class TokenUpdate(BaseModel):
    description: str | None = None
    expires_at: datetime | None = None


class RevokeReq(BaseModel):
    reason: str | None = None


def _row_to_dict(row) -> dict:
    return {
        "token_id": row["token_id"],
        "token_prefix": row["token_prefix"],
        "token_plain": row["token_plain"],
        "client_id": row["client_id"],
        "service_scope": row["service_scope"],
        "service_url": row["service_url"],
        "status": row["status"],
        "expires_at": row["expires_at"].isoformat() if row["expires_at"] else None,
        "description": row["description"],
        "created_at": row["created_at"].isoformat() if row["created_at"] else None,
        "created_by": row["created_by"],
        "revoked_at": row["revoked_at"].isoformat() if row["revoked_at"] else None,
        "revoke_reason": row["revoke_reason"],
        "last_used_at": row["last_used_at"].isoformat() if row["last_used_at"] else None,
        "last_used_svc": row["last_used_svc"],
    }


@router.get("")
async def list_tokens(
    client_id: str | None = Query(None),
    status: str | None = Query(None),
    service_scope: str | None = Query(None),
    admin: dict = Depends(current_admin),
):
    pool = await get_pool()
    query = "SELECT * FROM mcp_token WHERE 1=1"
    params: list = []
    if client_id:
        query += f" AND client_id = ${len(params)+1}"
        params.append(client_id)
    if status:
        query += f" AND status = ${len(params)+1}"
        params.append(status)
    if service_scope:
        query += f" AND service_scope = ${len(params)+1}"
        params.append(service_scope)
    query += " ORDER BY token_id DESC"
    rows = await pool.fetch(query, *params)
    return {"total": len(rows), "tokens": [_row_to_dict(r) for r in rows]}


@router.post("", status_code=status.HTTP_201_CREATED)
async def create_token(req: TokenCreate, admin: dict = Depends(current_admin)):
    pool = await get_pool()

    # 动态校验 service_scope：传入 MCP 服务地址，反查服务名（必须是已注册的 active 服务）
    svc_row = await pool.fetchrow(
        "SELECT service_name, service_url FROM mcp_service WHERE service_url = $1 AND status = 'active'",
        req.service_scope.strip(),
    )
    if svc_row is None:
        raise HTTPException(400, f"service_scope '{req.service_scope}' 不是已注册的活跃服务")
    service_name = svc_row["service_name"]

    # client_id + service_scope 唯一校验：同一客户端同一服务不允许重复签发
    existing = await pool.fetchval(
        "SELECT 1 FROM mcp_token WHERE client_id = $1 AND service_scope = $2 AND status = 'active'",
        req.client_id, service_name,
    )
    if existing:
        raise HTTPException(400, f"client_id '{req.client_id}' 已存在服务于 '{service_name}' 的活跃 Token，请先吊销旧 Token")

    # 生成明文 token：仅此一次返回
    plain = secrets.token_urlsafe(32)
    token_hash = hashlib.sha256(plain.encode()).hexdigest()
    token_prefix = plain[:12] + "…"

    row = await pool.fetchrow(
        """INSERT INTO mcp_token (token_hash, token_plain, token_prefix, client_id, service_scope, service_url, status,
                                  expires_at, description, created_by)
           VALUES ($1, $2, $3, $4, $5, $6, 'active', $7, $8, $9)
           RETURNING token_id, token_prefix, client_id, service_scope, service_url, status,
                     expires_at, description, created_at, created_by""",
        token_hash, plain, token_prefix, req.client_id, service_name, svc_row["service_url"],
        req.expires_at, req.description, admin.get("username", "admin"),
    )

    # 审计日志
    await pool.execute(
        "INSERT INTO mcp_token_log (token_id, event, detail) VALUES ($1, 'issued', $2)",
        row["token_id"],
        json.dumps({"client_id": req.client_id, "service_scope": service_name, "service_url": svc_row["service_url"]}),
    )

    return {
        "token": plain,  # 明文仅此一次
        "token_id": row["token_id"],
        "token_prefix": row["token_prefix"],
        "client_id": row["client_id"],
        "service_scope": row["service_scope"],
        "service_url": row["service_url"],
        "message": "请立即保存此 token，之后无法再次查看",
    }


@router.patch("/{token_id}")
async def update_token(
    token_id: int,
    req: TokenUpdate,
    admin: dict = Depends(current_admin),
):
    pool = await get_pool()
    existing = await pool.fetchrow("SELECT token_id FROM mcp_token WHERE token_id = $1", token_id)
    if existing is None:
        raise HTTPException(404, "token 不存在")

    updates, params = [], []
    if req.description is not None:
        updates.append(f"description = ${len(params)+1}")
        params.append(req.description)
    if req.expires_at is not None:
        updates.append(f"expires_at = ${len(params)+1}")
        params.append(req.expires_at)
    if not updates:
        raise HTTPException(400, "无更新字段")

    params.append(token_id)
    await pool.execute(
        f"UPDATE mcp_token SET {', '.join(updates)} WHERE token_id = ${len(params)}",
        *params,
    )
    return {"success": True, "token_id": token_id}


@router.put("/{token_id}/revoke")
async def revoke_token(
    token_id: int,
    req: RevokeReq = RevokeReq(),
    admin: dict = Depends(current_admin),
):
    """吊销 token：软删除，status 改为 revoked。吊销后才可删除。"""
    pool = await get_pool()
    row = await pool.fetchrow(
        "SELECT token_id, status, token_hash FROM mcp_token WHERE token_id = $1", token_id
    )
    if row is None:
        raise HTTPException(404, "token 不存在")
    if row["status"] == "revoked":
        raise HTTPException(400, "token 已吊销")

    await pool.execute(
        "UPDATE mcp_token SET status = 'revoked', revoked_at = now(), revoke_reason = $2 WHERE token_id = $1",
        token_id, req.reason,
    )
    await pool.execute(
        "INSERT INTO mcp_token_log (token_id, event, detail) VALUES ($1, 'revoked', $2)",
        token_id, json.dumps({"reason": req.reason, "by": admin.get("username")}),
    )
    await cache_delete(f"mcp:tok:{row['token_hash']}", f"mcp:tok:miss:{row['token_hash']}")
    return {"success": True, "token_id": token_id, "status": "revoked"}


@router.put("/{token_id}/enable")
async def enable_token(
    token_id: int,
    admin: dict = Depends(current_admin),
):
    """启用 token：将已吊销的 token 恢复为 active。"""
    pool = await get_pool()
    row = await pool.fetchrow(
        "SELECT token_id, status, token_hash FROM mcp_token WHERE token_id = $1", token_id
    )
    if row is None:
        raise HTTPException(404, "token 不存在")
    if row["status"] == "active":
        raise HTTPException(400, "token 已是启用状态")

    await pool.execute(
        "UPDATE mcp_token SET status = 'active', revoked_at = NULL, revoke_reason = NULL WHERE token_id = $1",
        token_id,
    )
    await pool.execute(
        "INSERT INTO mcp_token_log (token_id, event, detail) VALUES ($1, 'enabled', $2)",
        token_id, json.dumps({"by": admin.get("username")}),
    )
    await cache_delete(f"mcp:tok:{row['token_hash']}", f"mcp:tok:miss:{row['token_hash']}")
    return {"success": True, "token_id": token_id, "status": "active"}


@router.delete("/{token_id}")
async def delete_token(
    token_id: int,
    admin: dict = Depends(current_admin),
):
    """删除 token：物理删除，仅允许删除已吊销的 token。"""
    pool = await get_pool()
    row = await pool.fetchrow(
        "SELECT token_id, status, token_hash FROM mcp_token WHERE token_id = $1", token_id
    )
    if row is None:
        raise HTTPException(404, "token 不存在")
    if row["status"] != "revoked":
        raise HTTPException(400, "仅可删除已吊销的 token，请先吊销")

    await pool.execute("DELETE FROM mcp_token_log WHERE token_id = $1", token_id)
    await pool.execute("DELETE FROM mcp_token WHERE token_id = $1", token_id)
    await cache_delete(f"mcp:tok:{row['token_hash']}", f"mcp:tok:miss:{row['token_hash']}")
    return {"success": True, "token_id": token_id}


@router.get("/{token_id}/logs")
async def token_logs(token_id: int, limit: int = 50, admin: dict = Depends(current_admin)):
    pool = await get_pool()
    rows = await pool.fetch(
        """SELECT log_id, event, service, client_ip, occurred_at, detail
           FROM mcp_token_log WHERE token_id = $1
           ORDER BY occurred_at DESC LIMIT $2""",
        token_id, limit,
    )
    return {
        "total": len(rows),
        "logs": [
            {
                "log_id": r["log_id"],
                "event": r["event"],
                "service": r["service"],
                "client_ip": r["client_ip"],
                "occurred_at": r["occurred_at"].isoformat() if r["occurred_at"] else None,
                "detail": r["detail"],
            }
            for r in rows
        ],
    }