from fastapi import APIRouter, Header, HTTPException, Query
from typing import Optional
from datetime import datetime, timedelta
import logging
import os

from ..storage.analytics_store import AnalyticsStore
from ..utils.access_control import require_api_permission

router = APIRouter()
logger = logging.getLogger(__name__)

# Initialize analytics store, but don't crash the app if Supabase is not available.
# In environments like Hugging Face Spaces where Supabase isn't configured,
# we disable analytics gracefully instead of raising at import time.
try:
    # Only attempt to initialize Supabase analytics when credentials are present
    if os.getenv("SUPABASE_URL") and os.getenv("SUPABASE_SERVICE_KEY"):
        analytics_store: Optional[AnalyticsStore] = AnalyticsStore()
    else:
        analytics_store = None
        logger.debug(
            "AnalyticsStore: Supabase credentials not configured. "
            "Analytics endpoints will return 503."
        )
except RuntimeError as exc:
    analytics_store = None
    # Only log at warning level if credentials are configured (actual error)
    # Otherwise log at debug level (expected when Supabase is not configured)
    if os.getenv("SUPABASE_URL") and os.getenv("SUPABASE_SERVICE_KEY"):
        logger.warning(
            "AnalyticsStore initialization failed (%s). Analytics endpoints will return 503.",
            str(exc).split('\n')[0],  # Only first line
        )
    else:
        logger.debug(
            "AnalyticsStore not configured (%s). Analytics endpoints will return 503.",
            str(exc).split('\n')[0],
        )


@router.get("/overview")
async def analytics_overview(
    x_tenant_id: str = Header(None),
    days: int = Query(30, description="Number of days to look back"),
    x_user_role: str = Header("viewer")
):
    """
    Returns an overview of analytics for the dashboard.
    Includes total queries, tool usage, red-flag count, and active users.
    """

    if not x_tenant_id:
        raise HTTPException(status_code=400, detail="Missing tenant ID")
    require_api_permission(x_user_role, "view_analytics")

    # Return empty data if analytics is not configured (instead of 503)
    if analytics_store is None:
        return {
            "tenant_id": x_tenant_id,
            "overview": {
                "total_queries": 0,
                "tool_usage": {},
                "redflag_count": 0,
                "active_users": 0,
                "last_query": None,
                "rag_quality": {
                    "total_searches": 0,
                    "avg_hits_per_search": 0,
                    "avg_score": 0.0,
                    "avg_top_score": 0.0,
                    "avg_latency_ms": 0.0
                }
            }
        }

    since_timestamp = int((datetime.now() - timedelta(days=days)).timestamp()) if days else None
    
    tool_usage = analytics_store.get_tool_usage_stats(x_tenant_id, since_timestamp)
    activity = analytics_store.get_activity_summary(x_tenant_id, since_timestamp)
    rag_quality = analytics_store.get_rag_quality_metrics(x_tenant_id, since_timestamp)

    return {
        "tenant_id": x_tenant_id,
        "overview": {
            "total_queries": activity["total_queries"],
            "tool_usage": tool_usage,
            "redflag_count": activity["redflag_count"],
            "active_users": activity["active_users"],
            "last_query": activity["last_query"],
            "rag_quality": rag_quality
        }
    }


@router.get("/tool-usage")
async def analytics_tool_usage(
    x_tenant_id: str = Header(None),
    days: int = Query(30, description="Number of days to look back"),
    x_user_role: str = Header("viewer")
):
    """
    Returns how often each tool (RAG, Web, Admin, LLM) was used with detailed stats.
    Includes counts, latency, tokens, and success/error rates.
    """

    if not x_tenant_id:
        raise HTTPException(status_code=400, detail="Missing tenant ID")
    require_api_permission(x_user_role, "view_analytics")

    # Return empty data if analytics is not configured (instead of 503)
    if analytics_store is None:
        return {
            "tenant_id": x_tenant_id,
            "tool_usage": {},
            "period_days": days
        }

    since_timestamp = int((datetime.now() - timedelta(days=days)).timestamp()) if days else None
    tool_usage = analytics_store.get_tool_usage_stats(x_tenant_id, since_timestamp)

    return {
        "tenant_id": x_tenant_id,
        "tool_usage": tool_usage,
        "period_days": days
    }


@router.get("/redflags")
async def analytics_redflags(
    x_tenant_id: str = Header(None),
    limit: int = Query(50, description="Maximum number of violations to return"),
    days: int = Query(30, description="Number of days to look back"),
    x_user_role: str = Header("viewer")
):
    """
    Returns red-flag violations for this tenant.
    Includes rule details, severity, confidence, and timestamps.
    """

    if not x_tenant_id:
        raise HTTPException(status_code=400, detail="Missing tenant ID")
    require_api_permission(x_user_role, "view_analytics")

    # Return empty data if analytics is not configured (instead of 503)
    if analytics_store is None:
        return {
            "tenant_id": x_tenant_id,
            "redflags": [],
            "count": 0
        }

    since_timestamp = int((datetime.now() - timedelta(days=days)).timestamp()) if days else None
    redflags = analytics_store.get_redflag_violations(x_tenant_id, limit, since_timestamp)

    # Convert timestamps to ISO format
    for violation in redflags:
        if "timestamp" in violation:
            violation["timestamp_iso"] = datetime.fromtimestamp(violation["timestamp"]).isoformat()

    return {
        "tenant_id": x_tenant_id,
        "redflags": redflags,
        "count": len(redflags)
    }


@router.get("/activity")
async def analytics_activity(
    x_tenant_id: str = Header(None),
    days: int = Query(30, description="Number of days to look back"),
    x_user_role: str = Header("viewer")
):
    """
    Returns general tenant activity statistics.
    Includes total queries, active users, last query timestamp, and individual activity records for heatmap visualization.
    """

    if not x_tenant_id:
        raise HTTPException(status_code=400, detail="Missing tenant ID")
    require_api_permission(x_user_role, "view_analytics")

    # Return empty data if analytics is not configured (instead of 503)
    if analytics_store is None:
        return {
            "tenant_id": x_tenant_id,
            "activity": {
                "total_queries": 0,
                "active_users": 0,
                "redflag_count": 0,
                "last_query": None
            },
            "activities": [],
            "period_days": days
        }

    since_timestamp = int((datetime.now() - timedelta(days=days)).timestamp()) if days else None
    activity = analytics_store.get_activity_summary(x_tenant_id, since_timestamp)
    
    # Also fetch individual activity records for heatmap visualization
    activities = analytics_store.get_activity_records(x_tenant_id, since_timestamp)

    return {
        "tenant_id": x_tenant_id,
        "activity": activity,
        "activities": activities,  # Individual records with timestamps for heatmap
        "period_days": days
    }


@router.get("/rag-quality")
async def analytics_rag_quality(
    x_tenant_id: str = Header(None),
    days: int = Query(30, description="Number of days to look back"),
    x_user_role: str = Header("viewer")
):
    """
    Returns RAG quality metrics including recall/precision indicators.
    Includes average hits, scores, and latency.
    """

    if not x_tenant_id:
        raise HTTPException(status_code=400, detail="Missing tenant ID")
    require_api_permission(x_user_role, "view_analytics")

    # Return empty data if analytics is not configured (instead of 503)
    if analytics_store is None:
        return {
            "tenant_id": x_tenant_id,
            "rag_quality": {
                "total_searches": 0,
                "avg_hits_per_search": 0,
                "avg_score": 0.0,
                "avg_top_score": 0.0,
                "avg_latency_ms": 0.0
            },
            "period_days": days
        }

    since_timestamp = int((datetime.now() - timedelta(days=days)).timestamp()) if days else None
    rag_quality = analytics_store.get_rag_quality_metrics(x_tenant_id, since_timestamp)

    return {
        "tenant_id": x_tenant_id,
        "rag_quality": rag_quality,
        "period_days": days
    }