import logging
import time
import uuid
from decimal import Decimal
from typing import Optional

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

from open_webui.env import GLOBAL_LOG_LEVEL
from open_webui.models.subscriptions import (
    SubscriptionPlanModel,
    SubscriptionPlanForm,
    UpdateSubscriptionPlanForm,
    UserSubscriptionWithPlanModel,
    UpdateUserSubscriptionForm,
    SubscriptionUsageLogModel,
    RedemptionCodeModel,
    CreateRedemptionCodeForm,
    UpdateRedemptionCodeForm,
    SubscriptionPlans,
    UserSubscriptions,
    SubscriptionUsageLogs,
    RedemptionCodes,
)
from open_webui.models.users import UserModel, Users
from open_webui.utils.auth import get_verified_user, get_admin_user

log = logging.getLogger(__name__)
log.setLevel(GLOBAL_LOG_LEVEL)

router = APIRouter()

PAGE_ITEM_COUNT = 30


####################
# Subscription Plans API
####################


@router.get("/plans", response_model=list[SubscriptionPlanModel])
async def get_subscription_plans(
    include_inactive: bool = False,
    user: UserModel = Depends(get_verified_user),
):
    """
    Get all subscription plans.
    """
    # only admin can see inactive plans
    if include_inactive and user.role != "admin":
        include_inactive = False

    return SubscriptionPlans.get_all_plans(include_inactive=include_inactive)


@router.get("/plans/{plan_id}", response_model=SubscriptionPlanModel)
async def get_subscription_plan(
    plan_id: str,
    _: UserModel = Depends(get_verified_user),
):
    """
    Get a specific subscription plan.
    """
    plan = SubscriptionPlans.get_plan_by_id(plan_id)
    if not plan:
        raise HTTPException(status_code=404, detail="Plan not found")
    return plan


@router.post("/plans", response_model=SubscriptionPlanModel)
async def create_subscription_plan(
    form_data: SubscriptionPlanForm,
    _: UserModel = Depends(get_admin_user),
):
    """
    Create a new subscription plan (admin only).
    """
    existing = SubscriptionPlans.get_plan_by_id(form_data.id)
    if existing:
        raise HTTPException(status_code=400, detail="Plan ID already exists")

    return SubscriptionPlans.create_plan(form_data)


@router.put("/plans/{plan_id}", response_model=SubscriptionPlanModel)
async def update_subscription_plan(
    plan_id: str,
    form_data: UpdateSubscriptionPlanForm,
    _: UserModel = Depends(get_admin_user),
):
    """
    Update a subscription plan (admin only).
    """
    plan = SubscriptionPlans.update_plan(plan_id, form_data)
    if not plan:
        raise HTTPException(status_code=404, detail="Plan not found")
    return plan


@router.delete("/plans/{plan_id}")
async def delete_subscription_plan(
    plan_id: str,
    _: UserModel = Depends(get_admin_user),
):
    """
    Delete a subscription plan (admin only).
    """
    plan = SubscriptionPlans.get_plan_by_id(plan_id)
    if not plan:
        raise HTTPException(status_code=404, detail="Plan not found")

    if plan.is_default:
        raise HTTPException(status_code=400, detail="Cannot delete default plan")

    if not SubscriptionPlans.delete_plan(plan_id):
        raise HTTPException(status_code=500, detail="Failed to delete plan")

    return {"success": True}


####################
# User Subscription API
####################


@router.get("/me", response_model=UserSubscriptionWithPlanModel)
async def get_my_subscription(
    user: UserModel = Depends(get_verified_user),
):
    """
    Get current user's subscription status.
    """
    subscription = UserSubscriptions.get_with_plan(user.id)

    if not subscription:
        # initialize free subscription
        UserSubscriptions.init_free_subscription(user.id)
        subscription = UserSubscriptions.get_with_plan(user.id)

    if not subscription:
        raise HTTPException(status_code=500, detail="Failed to get subscription")

    return subscription


class UsageResponse(BaseModel):
    total: int
    results: list[SubscriptionUsageLogModel]


@router.get("/me/usage", response_model=UsageResponse)
async def get_my_usage(
    page: int = 1,
    limit: int = PAGE_ITEM_COUNT,
    user: UserModel = Depends(get_verified_user),
):
    """
    Get current user's usage history.
    """
    offset = (page - 1) * limit
    total, logs = SubscriptionUsageLogs.get_by_user_id(user.id, offset=offset, limit=limit)
    return UsageResponse(total=total, results=logs)


class RedeemRequest(BaseModel):
    code: str


@router.post("/redeem", response_model=UserSubscriptionWithPlanModel)
async def redeem_code(
    form_data: RedeemRequest,
    user: UserModel = Depends(get_verified_user),
):
    """
    Redeem a redemption code.
    """
    RedemptionCodes.redeem_code(form_data.code, user.id)
    return UserSubscriptions.get_with_plan(user.id)


####################
# Admin Subscription Management API
####################


class AdminSubscriptionsResponse(BaseModel):
    total: int
    results: list[UserSubscriptionWithPlanModel]


@router.get("/admin/subscriptions", response_model=AdminSubscriptionsResponse)
async def get_all_subscriptions(
    query: Optional[str] = None,
    page: int = 1,
    limit: int = PAGE_ITEM_COUNT,
    _: UserModel = Depends(get_admin_user),
):
    """
    Get all user subscriptions (admin only).
    """
    offset = (page - 1) * limit
    total, subs = UserSubscriptions.get_all_subscriptions(query=query, offset=offset, limit=limit)

    # add username to results
    user_ids = [sub.user_id for sub in subs]
    users = Users.get_users_by_user_ids(user_ids)
    user_map = {u.id: u.name for u in users}

    for sub in subs:
        setattr(sub, "username", user_map.get(sub.user_id, ""))

    return AdminSubscriptionsResponse(total=total, results=subs)


@router.get("/admin/subscriptions/{user_id}", response_model=UserSubscriptionWithPlanModel)
async def get_user_subscription(
    user_id: str,
    _: UserModel = Depends(get_admin_user),
):
    """
    Get a specific user's subscription (admin only).
    """
    subscription = UserSubscriptions.get_with_plan(user_id)
    if not subscription:
        raise HTTPException(status_code=404, detail="Subscription not found")
    return subscription


@router.put("/admin/subscriptions/{user_id}", response_model=UserSubscriptionWithPlanModel)
async def update_user_subscription(
    user_id: str,
    form_data: UpdateUserSubscriptionForm,
    _: UserModel = Depends(get_admin_user),
):
    """
    Update a user's subscription (admin only).
    """
    existing = UserSubscriptions.get_by_user_id(user_id)
    if not existing:
        raise HTTPException(status_code=404, detail="Subscription not found")

    if form_data.plan_id:
        plan = SubscriptionPlans.get_plan_by_id(form_data.plan_id)
        if not plan:
            raise HTTPException(status_code=400, detail="Invalid plan ID")

    UserSubscriptions.update_subscription(user_id, form_data)
    return UserSubscriptions.get_with_plan(user_id)


####################
# Redemption Codes API
####################


class RedemptionCodesResponse(BaseModel):
    total: int
    results: list[RedemptionCodeModel]


@router.get("/redemption_codes", response_model=RedemptionCodesResponse)
async def get_redemption_codes(
    keyword: Optional[str] = None,
    page: int = 1,
    limit: int = PAGE_ITEM_COUNT,
    _: UserModel = Depends(get_admin_user),
):
    """
    Get all redemption codes (admin only).
    """
    offset = (page - 1) * limit
    total, codes = RedemptionCodes.get_codes(keyword=keyword, offset=offset, limit=limit)

    # add username to results
    user_ids = {code.user_id for code in codes if code.user_id}
    if user_ids:
        users = Users.get_users_by_user_ids(user_ids)
        user_map = {u.id: u.name for u in users}
        for code in codes:
            if code.user_id:
                setattr(code, "username", user_map.get(code.user_id, ""))

    return RedemptionCodesResponse(total=total, results=codes)


class CreateRedemptionCodesResponse(BaseModel):
    total: int
    codes: list[str]


@router.post("/redemption_codes", response_model=CreateRedemptionCodesResponse)
async def create_redemption_codes(
    form_data: CreateRedemptionCodeForm,
    _: UserModel = Depends(get_admin_user),
):
    """
    Create redemption codes (admin only).
    """
    # validate plan exists
    plan = SubscriptionPlans.get_plan_by_id(form_data.plan_id)
    if not plan:
        raise HTTPException(status_code=400, detail="Invalid plan ID")

    # validate form data
    if form_data.redemption_type == "duration":
        if not form_data.duration_days:
            raise HTTPException(status_code=400, detail="duration_days is required for duration type")
    elif form_data.redemption_type == "upgrade":
        if not form_data.upgrade_days:
            raise HTTPException(status_code=400, detail="upgrade_days is required for upgrade type")
    else:
        raise HTTPException(status_code=400, detail="Invalid redemption_type")

    now = int(time.time())

    # check expiration
    if form_data.expired_at and form_data.expired_at < now:
        raise HTTPException(status_code=400, detail="Expiration time must be in the future")

    codes = []
    for _ in range(form_data.count):
        code = RedemptionCodeModel(
            code=uuid.uuid4().hex[:16].upper(),
            purpose=form_data.purpose,
            redemption_type=form_data.redemption_type,
            plan_id=form_data.plan_id,
            duration_days=form_data.duration_days,
            upgrade_days=form_data.upgrade_days,
            expired_at=form_data.expired_at,
            created_at=now,
        )
        codes.append(code)

    RedemptionCodes.insert_codes(codes)

    return CreateRedemptionCodesResponse(
        total=len(codes),
        codes=[code.code for code in codes]
    )


@router.put("/redemption_codes/{code}", response_model=RedemptionCodeModel)
async def update_redemption_code(
    code: str,
    form_data: UpdateRedemptionCodeForm,
    _: UserModel = Depends(get_admin_user),
):
    """
    Update a redemption code (admin only).
    """
    existing = RedemptionCodes.get_code(code)
    if not existing:
        raise HTTPException(status_code=404, detail="Code not found")

    if existing.received_at:
        raise HTTPException(status_code=400, detail="Cannot update a code that has been used")

    updated = RedemptionCodes.update_code(code, form_data)
    if not updated:
        raise HTTPException(status_code=500, detail="Failed to update code")

    return updated


@router.delete("/redemption_codes/{code}")
async def delete_redemption_code(
    code: str,
    _: UserModel = Depends(get_admin_user),
):
    """
    Delete a redemption code (admin only).
    """
    if not RedemptionCodes.delete_code(code):
        raise HTTPException(status_code=404, detail="Code not found")

    return {"success": True}


####################
# Statistics API
####################


class SubscriptionStatsRequest(BaseModel):
    start_time: int
    end_time: int
    query: Optional[str] = None


@router.post("/statistics")
async def get_subscription_statistics(
    form_data: SubscriptionStatsRequest,
    _: UserModel = Depends(get_admin_user),
):
    """
    Get subscription usage statistics (admin only).
    """
    from collections import defaultdict

    # query user ids if needed
    user_ids = None
    if form_data.query:
        users = Users.get_users(filter={"query": form_data.query})["users"]
        user_map = {user.id: user.name for user in users}
        user_ids = list(user_map.keys())
        if not user_ids:
            return {
                "total_messages": 0,
                "model_usage": [],
                "user_usage": [],
            }
    else:
        users = Users.get_users()["users"]
        user_map = {user.id: user.name for user in users}

    # get usage logs
    logs = SubscriptionUsageLogs.get_by_time_range(
        form_data.start_time, form_data.end_time, user_ids
    )

    # build stats
    total_messages = len(logs)
    model_usage = defaultdict(int)
    user_usage = defaultdict(int)

    for log in logs:
        if log.model_id:
            model_usage[log.model_id] += 1
        user_key = f"{log.user_id}:{user_map.get(log.user_id, log.user_id)}"
        user_usage[user_key] += 1

    return {
        "total_messages": total_messages,
        "model_usage": [
            {"name": model, "value": count}
            for model, count in model_usage.items()
        ],
        "user_usage": [
            {"name": user.split(":", 1)[1], "value": count}
            for user, count in user_usage.items()
        ],
    }