from __future__ import annotations

from datetime import datetime
from typing import List, Optional

from fastapi import APIRouter, HTTPException
from fastapi.responses import Response
from pydantic import BaseModel

from app.db import get_pool
from app.routers.models import _bump_all_domain_versions

router = APIRouter(tags=["api_keys"])


class ApiKeyIn(BaseModel):
    name: str
    key_value: str
    note: Optional[str] = None


class ApiKeyUpdate(BaseModel):
    name: Optional[str] = None
    key_value: Optional[str] = None
    note: Optional[str] = None


class ApiKeyOut(BaseModel):
    id: int
    name: str
    key_value: str  # 返回脱敏值，不暴露明文
    note: Optional[str]
    model_count: int = 0
    created_at: datetime
    updated_at: datetime


def _mask_key(v: str) -> str:
    """脱敏：保留前6位和后4位，中间替换为 ••••••••"""
    if len(v) <= 10:
        return '••••••••'
    return v[:6] + '••••••••' + v[-4:]


class BatchAssignIn(BaseModel):
    """批量将某个 api_key 绑定到一批模型"""
    api_key_id: Optional[int] = None   # None 表示清除绑定
    model_ids: List[int]


@router.get("/api-keys", response_model=List[ApiKeyOut])
async def list_api_keys() -> List[ApiKeyOut]:
    pool = get_pool()
    rows = await pool.fetch(
        """
        SELECT k.id, k.name, k.key_value, k.note, k.created_at, k.updated_at,
               COUNT(m.id) AS model_count
        FROM api_keys k
        LEFT JOIN models m ON m.api_key_id = k.id
        GROUP BY k.id
        ORDER BY k.created_at DESC
        """
    )
    return [ApiKeyOut(**{**dict(r), "key_value": _mask_key(r["key_value"])}) for r in rows]


@router.post("/api-keys", response_model=ApiKeyOut, status_code=201)
async def create_api_key(body: ApiKeyIn) -> ApiKeyOut:
    pool = get_pool()
    row = await pool.fetchrow(
        """
        INSERT INTO api_keys (name, key_value, note)
        VALUES ($1, $2, $3)
        RETURNING id, name, key_value, note, created_at, updated_at
        """,
        body.name, body.key_value, body.note,
    )
    return ApiKeyOut(**dict(row))


@router.put("/api-keys/{key_id}", response_model=ApiKeyOut)
async def update_api_key(key_id: int, body: ApiKeyUpdate) -> ApiKeyOut:
    pool = get_pool()
    existing = await pool.fetchrow(
        "SELECT id, name, key_value, note, created_at, updated_at FROM api_keys WHERE id = $1",
        key_id,
    )
    if existing is None:
        raise HTTPException(status_code=404, detail="API Key 不存在")
    new_name = body.name if body.name is not None else existing["name"]
    new_value = body.key_value if body.key_value is not None else existing["key_value"]
    new_note = body.note if body.note is not None else existing["note"]
    key_value_changed = new_value != existing["key_value"]
    async with pool.acquire() as conn:
        async with conn.transaction():
            row = await conn.fetchrow(
                """
                UPDATE api_keys SET name = $1, key_value = $2, note = $3, updated_at = NOW()
                WHERE id = $4
                RETURNING id, name, key_value, note, created_at, updated_at
                """,
                new_name, new_value, new_note, key_id,
            )
            # key 值本身变了 → 通知所有绑定了此 key 的客户端
            if key_value_changed:
                await _bump_all_domain_versions(conn)
    return ApiKeyOut(**dict(row))


@router.delete("/api-keys/{key_id}", status_code=204, response_model=None)
async def delete_api_key(key_id: int) -> Response:
    pool = get_pool()
    result = await pool.execute("DELETE FROM api_keys WHERE id = $1", key_id)
    if result == "DELETE 0":
        raise HTTPException(status_code=404, detail="API Key 不存在")
    return Response(status_code=204)


@router.post("/api-keys/batch-assign", status_code=200)
async def batch_assign_api_key(body: BatchAssignIn) -> dict:
    """批量将指定 api_key 绑定到一批模型（api_key_id=None 则清除绑定）"""
    if not body.model_ids:
        return {"updated": 0}

    pool = get_pool()

    if body.api_key_id is not None:
        key_row = await pool.fetchrow("SELECT id FROM api_keys WHERE id = $1", body.api_key_id)
        if key_row is None:
            raise HTTPException(status_code=404, detail="API Key 不存在")

    async with pool.acquire() as conn:
        async with conn.transaction():
            result = await conn.execute(
                "UPDATE models SET api_key_id = $1 WHERE id = ANY($2::bigint[])",
                body.api_key_id, body.model_ids,
            )
            updated = int(result.split()[-1]) if result else 0
            if updated > 0:
                await _bump_all_domain_versions(conn)

    return {"updated": updated}