from fastapi import APIRouter, Depends, HTTPException, Query
from pydantic import BaseModel
from typing import Optional, List
from sqlalchemy.ext.asyncio import AsyncSession
from sqlalchemy import select
from app.database import get_db
from app.api.v1.admin import require_admin
from app.services.credit import CreditService
from app.models.credit_package import CreditPackage, SubscriptionPlan
from app.models.user_credit import UserCredit
from app.models.user import User
import uuid

router = APIRouter()


class PackageForm(BaseModel):
    name: str
    name_en: str
    credits: int
    price: float
    price_usd: Optional[float] = None
    original_price: Optional[float] = None
    is_active: bool = True
    sort_order: int = 0


class PlanForm(BaseModel):
    name: str
    name_en: str
    credits_per_month: int
    price: float
    price_usd: Optional[float] = None
    duration_days: int = 30
    is_active: bool = True
    sort_order: int = 0


class AdjustCreditsForm(BaseModel):
    user_id: str
    credits: float
    reason: str = ""


@router.get("/credit-packages")
async def list_packages(
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    result = await db.execute(
        select(CreditPackage).order_by(CreditPackage.sort_order)
    )
    return [{
        "id": str(p.id),
        "name": p.name,
        "name_en": p.name_en,
        "credits": p.credits,
        "price": p.price,
        "price_usd": p.price_usd,
        "original_price": p.original_price,
        "is_active": p.is_active,
        "sort_order": p.sort_order,
    } for p in result.scalars().all()]


@router.post("/credit-packages")
async def create_package(
    data: PackageForm,
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    pkg = CreditPackage(**data.model_dump())
    db.add(pkg)
    await db.flush()
    return {"id": str(pkg.id), "status": "ok"}


@router.put("/credit-packages/{pkg_id}")
async def update_package(
    pkg_id: str,
    data: PackageForm,
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    try:
        uid = uuid.UUID(pkg_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="无效ID")
    result = await db.execute(select(CreditPackage).where(CreditPackage.id == uid))
    pkg = result.scalar_one_or_none()
    if not pkg:
        raise HTTPException(status_code=404, detail="次数包不存在")
    for k, v in data.model_dump().items():
        setattr(pkg, k, v)
    await db.flush()
    return {"status": "ok"}


@router.delete("/credit-packages/{pkg_id}")
async def delete_package(
    pkg_id: str,
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    try:
        uid = uuid.UUID(pkg_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="无效ID")
    result = await db.execute(select(CreditPackage).where(CreditPackage.id == uid))
    pkg = result.scalar_one_or_none()
    if not pkg:
        raise HTTPException(status_code=404, detail="次数包不存在")
    await db.delete(pkg)
    await db.flush()
    return {"status": "ok"}


@router.get("/subscription-plans")
async def list_plans(
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    result = await db.execute(
        select(SubscriptionPlan).order_by(SubscriptionPlan.sort_order)
    )
    return [{
        "id": str(p.id),
        "name": p.name,
        "name_en": p.name_en,
        "credits_per_month": p.credits_per_month,
        "price": p.price,
        "price_usd": p.price_usd,
        "duration_days": p.duration_days,
        "is_active": p.is_active,
        "sort_order": p.sort_order,
    } for p in result.scalars().all()]


@router.post("/subscription-plans")
async def create_plan(
    data: PlanForm,
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    plan = SubscriptionPlan(**data.model_dump())
    db.add(plan)
    await db.flush()
    return {"id": str(plan.id), "status": "ok"}


@router.put("/subscription-plans/{plan_id}")
async def update_plan(
    plan_id: str,
    data: PlanForm,
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    try:
        uid = uuid.UUID(plan_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="无效ID")
    result = await db.execute(select(SubscriptionPlan).where(SubscriptionPlan.id == uid))
    plan = result.scalar_one_or_none()
    if not plan:
        raise HTTPException(status_code=404, detail="订阅套餐不存在")
    for k, v in data.model_dump().items():
        setattr(plan, k, v)
    await db.flush()
    return {"status": "ok"}


@router.delete("/subscription-plans/{plan_id}")
async def delete_plan(
    plan_id: str,
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    try:
        uid = uuid.UUID(plan_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="无效ID")
    result = await db.execute(select(SubscriptionPlan).where(SubscriptionPlan.id == uid))
    plan = result.scalar_one_or_none()
    if not plan:
        raise HTTPException(status_code=404, detail="订阅套餐不存在")
    await db.delete(plan)
    await db.flush()
    return {"status": "ok"}


@router.get("/user-credits")
async def list_user_credits(
    page: int = Query(1, ge=1),
    size: int = Query(20, ge=1, le=100),
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    offset = (page - 1) * size
    result = await db.execute(
        select(UserCredit).order_by(UserCredit.updated_at.desc()).offset(offset).limit(size)
    )
    items = result.scalars().all()

    from sqlalchemy import func
    count_result = await db.execute(select(func.count(UserCredit.id)))
    total = count_result.scalar() or 0

    enriched = []
    for uc in items:
        user_result = await db.execute(select(User).where(User.id == uc.user_id))
        user = user_result.scalar_one_or_none()
        enriched.append({
            "id": str(uc.id),
            "user_id": str(uc.user_id),
            "username": user.username if user else "N/A",
            "balance": uc.balance,
            "total_purchased": uc.total_purchased,
            "total_used": uc.total_used,
            "subscription_plan_id": str(uc.subscription_plan_id) if uc.subscription_plan_id else None,
            "subscription_expires_at": uc.subscription_expires_at.isoformat() if uc.subscription_expires_at else None,
            "free_trial_used": uc.free_trial_used,
            "updated_at": uc.updated_at.isoformat() if uc.updated_at else None,
        })

    return {"items": enriched, "total": total, "page": page, "size": size}


class AdjustForm(BaseModel):
    user_id: str
    credits: float
    reason: str = ""


@router.post("/user-credits/adjust")
async def adjust_credits(
    data: AdjustForm,
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    svc = CreditService(db)
    try:
        uid = uuid.UUID(data.user_id)
    except ValueError:
        raise HTTPException(status_code=400, detail="无效用户ID")
    balance = await svc.add_credits(
        user_id=uid,
        credits=data.credits,
        source="admin_grant",
        description=data.reason or f"管理员调整: {data.credits:+.1f} 次",
    )
    return {"status": "ok", "balance": balance}


@router.get("/credit-consumptions")
async def list_consumptions(
    page: int = Query(1, ge=1),
    size: int = Query(20, ge=1, le=200),
    user_id: str = Query(None),
    result_type: str = Query(None),
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    from app.models.credit_consumption import CreditConsumption
    from sqlalchemy import select, func, desc

    conditions = []
    if user_id:
        try:
            conditions.append(CreditConsumption.user_id == uuid.UUID(user_id))
        except ValueError:
            pass
    if result_type:
        conditions.append(CreditConsumption.result_type == result_type)

    stmt = select(CreditConsumption).where(*conditions).order_by(
        desc(CreditConsumption.created_at)
    ).offset((page - 1) * size).limit(size)
    result = await db.execute(stmt)
    items = result.scalars().all()

    count_stmt = select(func.count(CreditConsumption.id)).where(*conditions)
    count_result = await db.execute(count_stmt)
    total = count_result.scalar() or 0

    return {
        "items": [{
            "id": str(c.id),
            "user_id": str(c.user_id),
            "result_type": c.result_type,
            "credits_change": c.credits_change,
            "balance_after": c.balance_after,
            "source": c.source,
            "description": c.description,
            "created_at": c.created_at.isoformat() if c.created_at else None,
        } for c in items],
        "total": total,
        "page": page,
        "size": size,
    }


@router.get("/credit-stats")
async def credit_stats(
    _: dict = Depends(require_admin),
    db: AsyncSession = Depends(get_db),
):
    svc = CreditService(db)
    return await svc.get_stats()