"""
Site inspections router.
Handles site-wide inspection lifecycle:
  - Start site inspection (crawl + inspect all pages)
  - SSE stream for real-time progress
  - Get site inspection result
  - List site inspections (history)
  - Trigger single page inspection within a site

IMPORTANT: Static paths (/site-inspections) must be registered BEFORE
dynamic paths (/site-inspections/{id}) to avoid routing conflicts.
"""

import json
import logging

import httpx
from fastapi import APIRouter, HTTPException, Query
from sse_starlette.sse import EventSourceResponse

from app.core.database import get_db
from app.core.redis import get_redis
from app.models.site_schemas import (
    StartSiteInspectionRequest,
    StartSiteInspectionResponse,
    InspectPageRequest,
)
from app.services.site_inspection_service import SiteInspectionService

logger = logging.getLogger(__name__)

router = APIRouter()


def _get_service() -> SiteInspectionService:
    """Get SiteInspectionService instance."""
    db = get_db()
    redis = get_redis()
    return SiteInspectionService(db=db, redis=redis)


# ============================================================
# POST /api/site-inspections -- Start site inspection
# ============================================================

@router.post("/site-inspections", status_code=202)
async def start_site_inspection(request: StartSiteInspectionRequest):
    """
    Start a new site-wide inspection.
    Returns 202 Accepted with site_inspection_id immediately.
    Crawling and inspection run asynchronously in the background.
    """
    url = str(request.url)

    # Validate URL scheme
    if not url.startswith(("http://", "https://")):
        raise HTTPException(
            status_code=422,
            detail="유효한 URL을 입력해주세요 (http:// 또는 https://로 시작해야 합니다)",
        )

    service = _get_service()

    try:
        site_inspection_id = await service.start_site_inspection(
            url=url,
            max_pages=request.max_pages,
            max_depth=request.max_depth,
            concurrency=request.concurrency,
            accessibility_standard=request.accessibility_standard,
        )
    except httpx.HTTPStatusError as e:
        raise HTTPException(
            status_code=400,
            detail=f"해당 URL에 접근할 수 없습니다 (HTTP {e.response.status_code})",
        )
    except httpx.TimeoutException:
        raise HTTPException(
            status_code=400,
            detail="해당 URL에 접근할 수 없습니다 (응답 시간 초과)",
        )
    except httpx.RequestError:
        raise HTTPException(
            status_code=400,
            detail="해당 URL에 접근할 수 없습니다",
        )
    except Exception as e:
        logger.error("Failed to start site inspection: %s", str(e))
        raise HTTPException(
            status_code=400,
            detail="사이트 검사를 시작할 수 없습니다",
        )

    return StartSiteInspectionResponse(
        site_inspection_id=site_inspection_id,
        status="crawling",
        root_url=url,
        stream_url=f"/api/site-inspections/{site_inspection_id}/stream",
    )


# ============================================================
# GET /api/site-inspections -- List site inspections (history)
# IMPORTANT: This MUST be before /{site_inspection_id} routes
# ============================================================

@router.get("/site-inspections")
async def list_site_inspections(
    page: int = Query(default=1, ge=1),
    limit: int = Query(default=20, ge=1, le=100),
):
    """Get paginated site inspection history."""
    service = _get_service()
    result = await service.get_site_inspection_list(
        page=page,
        limit=limit,
    )
    return result


# ============================================================
# GET /api/site-inspections/{site_inspection_id}/stream -- SSE
# ============================================================

@router.get("/site-inspections/{site_inspection_id}/stream")
async def stream_site_progress(site_inspection_id: str):
    """
    Stream site inspection progress via Server-Sent Events.

    Events:
      - crawl_progress: { pages_found, current_url }
      - crawl_complete: { total_pages, pages: [...] }
      - page_start: { page_url, page_index }
      - page_progress: { page_url, category, progress, current_step }
      - page_complete: { page_url, inspection_id, score, grade }
      - aggregate_update: { pages_inspected, pages_total, overall_score }
      - complete: { status, aggregate_scores }
      - error: { message }
    """

    async def event_generator():
        redis = get_redis()
        pubsub = redis.pubsub()
        channel = f"site-inspection:{site_inspection_id}:events"

        await pubsub.subscribe(channel)

        try:
            # Send initial connected event
            yield {
                "event": "connected",
                "data": json.dumps({
                    "site_inspection_id": site_inspection_id,
                    "message": "SSE 연결 완료",
                }, ensure_ascii=False),
            }

            # Listen for Pub/Sub messages
            async for message in pubsub.listen():
                if message["type"] == "message":
                    event_data = json.loads(message["data"])
                    event_type = event_data.pop("event_type", "progress")

                    yield {
                        "event": event_type,
                        "data": json.dumps(event_data, ensure_ascii=False),
                    }

                    # End stream on complete or error
                    if event_type in ("complete", "error"):
                        break

        except Exception as e:
            logger.error(
                "SSE stream error for site %s: %s",
                site_inspection_id, str(e),
            )
            yield {
                "event": "error",
                "data": json.dumps({
                    "site_inspection_id": site_inspection_id,
                    "status": "error",
                    "message": "스트리밍 중 오류가 발생했습니다",
                }, ensure_ascii=False),
            }
        finally:
            await pubsub.unsubscribe(channel)
            await pubsub.aclose()

    return EventSourceResponse(
        event_generator(),
        media_type="text/event-stream",
    )


# ============================================================
# GET /api/site-inspections/{site_inspection_id} -- Get result
# ============================================================

@router.get("/site-inspections/{site_inspection_id}")
async def get_site_inspection(site_inspection_id: str):
    """Get site inspection result by ID."""
    service = _get_service()
    result = await service.get_site_inspection(site_inspection_id)

    if result is None:
        raise HTTPException(
            status_code=404,
            detail="사이트 검사 결과를 찾을 수 없습니다",
        )

    # Remove MongoDB _id field if present
    result.pop("_id", None)
    return result


# ============================================================
# POST /api/site-inspections/{site_inspection_id}/inspect-page
# -- Trigger single page inspection
# ============================================================

@router.post("/site-inspections/{site_inspection_id}/inspect-page")
async def inspect_page(
    site_inspection_id: str,
    request: InspectPageRequest,
):
    """
    Trigger inspection for a specific page within a site inspection.
    Useful for re-inspecting a single page or manually triggering
    inspection of a page that failed previously.
    """
    page_url = str(request.url)
    service = _get_service()

    inspection_id = await service.inspect_single_page(
        site_inspection_id=site_inspection_id,
        page_url=page_url,
    )

    if inspection_id is None:
        raise HTTPException(
            status_code=404,
            detail="사이트 검사 또는 해당 페이지를 찾을 수 없습니다",
        )

    return {
        "site_inspection_id": site_inspection_id,
        "page_url": page_url,
        "inspection_id": inspection_id,
        "status": "completed",
    }