from fastapi import APIRouter, HTTPException, Depends, Query
from app.database import get_supabase
from app.dependencies import get_current_user
from app.models import CampaignCreate, CampaignResponse
from typing import List, Optional
import uuid
import logging

logger = logging.getLogger(__name__)
router = APIRouter(prefix="/campaigns", tags=["Campaigns"])


# ── Helpers ───────────────────────────────────────────────────────────────────

def _check_campaigns_access(user_id: str, supabase):
    sub = supabase.table("subscriptions").select("plan").eq("user_id", user_id).eq("status", "active").execute()
    plan = sub.data[0]["plan"] if sub.data else "free"
    if plan not in ("starter", "business", "agency", "enterprise"):
        raise HTTPException(status_code=402, detail="Campaigns require Starter plan or higher")
    return plan


def _get_user_company_id(user_id: str, supabase) -> str:
    result = supabase.table("companies").select("id").eq("owner_id", user_id).execute()
    if not result.data:
        raise HTTPException(status_code=404, detail="Company not found")
    return result.data[0]["id"]


def _verify_chatbot_ownership(chatbot_id: str, company_id: str, supabase):
    chatbot = supabase.table("chatbots").select("id").eq("id", chatbot_id).eq("company_id", company_id).execute()
    if not chatbot.data:
        raise HTTPException(status_code=404, detail="Chatbot not found")


# ── Endpoints ─────────────────────────────────────────────────────────────────

@router.get("", response_model=List[CampaignResponse])
async def list_campaigns(
    chatbot_id: Optional[str] = Query(None),
    page: int = Query(1, ge=1),
    limit: int = Query(20, ge=1, le=100),
    user=Depends(get_current_user),
):
    supabase = get_supabase()
    _check_campaigns_access(user.id, supabase)
    company_id = _get_user_company_id(user.id, supabase)

    chatbots_q = supabase.table("chatbots").select("id").eq("company_id", company_id)
    if chatbot_id:
        chatbots_q = chatbots_q.eq("id", chatbot_id)
    chatbots = chatbots_q.execute()
    chatbot_ids = [c["id"] for c in (chatbots.data or [])]
    if not chatbot_ids:
        return []

    offset = (page - 1) * limit
    result = supabase.table("campaigns").select("*").in_("chatbot_id", chatbot_ids) \
        .order("created_at", desc=True).range(offset, offset + limit - 1).execute()
    return [CampaignResponse(**c) for c in (result.data or [])]


@router.post("", response_model=CampaignResponse, status_code=201)
async def create_campaign(data: CampaignCreate, user=Depends(get_current_user)):
    supabase = get_supabase()
    _check_campaigns_access(user.id, supabase)
    company_id = _get_user_company_id(user.id, supabase)
    _verify_chatbot_ownership(data.chatbot_id, company_id, supabase)

    # Count Telegram subscribers for this chatbot
    subscribers = supabase.table("channel_sessions").select("id", count="exact") \
        .eq("chatbot_id", data.chatbot_id).eq("channel", "telegram").execute()
    recipients_count = subscribers.count or 0

    campaign_data = {
        "id": str(uuid.uuid4()),
        "chatbot_id": data.chatbot_id,
        "title": data.title,
        "message": data.message,
        "status": "draft",
        "recipients_count": recipients_count,
        "sent_count": 0,
    }
    result = supabase.table("campaigns").insert(campaign_data).execute()
    if not result.data:
        raise HTTPException(status_code=500, detail="Failed to create campaign")
    return CampaignResponse(**result.data[0])


@router.post("/{campaign_id}/send", response_model=CampaignResponse)
async def send_campaign(campaign_id: str, user=Depends(get_current_user)):
    """Broadcast the campaign message to all Telegram subscribers of the chatbot."""
    supabase = get_supabase()
    _check_campaigns_access(user.id, supabase)
    company_id = _get_user_company_id(user.id, supabase)

    campaign = supabase.table("campaigns").select("*, chatbots(company_id)") \
        .eq("id", campaign_id).execute()
    if not campaign.data:
        raise HTTPException(status_code=404, detail="Campaign not found")
    c = campaign.data[0]
    if c.get("chatbots", {}).get("company_id") != company_id:
        raise HTTPException(status_code=403, detail="Not authorized")
    if c["status"] == "sent":
        raise HTTPException(status_code=400, detail="Campaign already sent")

    chatbot_id = c["chatbot_id"]

    # Get the Telegram bot token for this chatbot
    conn = supabase.table("channel_connections").select("bot_token") \
        .eq("chatbot_id", chatbot_id).eq("channel", "telegram").eq("is_active", True).execute()
    if not conn.data or not conn.data[0].get("bot_token"):
        raise HTTPException(status_code=400, detail="No active Telegram connection for this chatbot")
    bot_token = conn.data[0]["bot_token"]

    # Get all Telegram subscribers (channel_sessions)
    sessions = supabase.table("channel_sessions").select("external_id") \
        .eq("chatbot_id", chatbot_id).eq("channel", "telegram").execute()
    subscribers = sessions.data or []

    # Mark as sending
    supabase.table("campaigns").update({"status": "sending"}).eq("id", campaign_id).execute()

    # Broadcast
    from app.services.telegram_service import send_message as tg_send
    sent = 0
    for sub in subscribers:
        try:
            # external_id format is "tg:{token_prefix}:{chat_id}"
            parts = sub["external_id"].split(":")
            if len(parts) >= 3:
                chat_id = int(parts[2])
                await tg_send(bot_token, chat_id, c["message"])
                sent += 1
        except Exception as e:
            logger.warning(f"Failed to send campaign to {sub['external_id']}: {e}")

    # Mark as sent
    from datetime import datetime, timezone
    supabase.table("campaigns").update({
        "status": "sent",
        "sent_count": sent,
        "recipients_count": len(subscribers),
        "sent_at": datetime.now(timezone.utc).isoformat(),
    }).eq("id", campaign_id).execute()

    updated = supabase.table("campaigns").select("*").eq("id", campaign_id).execute()
    return CampaignResponse(**updated.data[0])


@router.delete("/{campaign_id}")
async def delete_campaign(campaign_id: str, user=Depends(get_current_user)):
    supabase = get_supabase()
    _check_campaigns_access(user.id, supabase)
    company_id = _get_user_company_id(user.id, supabase)

    campaign = supabase.table("campaigns").select("*, chatbots(company_id)") \
        .eq("id", campaign_id).execute()
    if not campaign.data:
        raise HTTPException(status_code=404, detail="Campaign not found")
    if campaign.data[0].get("chatbots", {}).get("company_id") != company_id:
        raise HTTPException(status_code=403, detail="Not authorized")
    if campaign.data[0]["status"] == "sending":
        raise HTTPException(status_code=400, detail="Cannot delete a campaign that is currently sending")

    supabase.table("campaigns").delete().eq("id", campaign_id).execute()
    return {"success": True}