"""
Wiki router for Library Desk API.

Endpoints for wiki page and dossier management.
All operations are scoped to user namespaces for multi-tenancy.
"""

from fastapi import APIRouter, HTTPException, Depends, Query, BackgroundTasks
from typing import Optional
import logging

from src.models.wiki import (
    WikiPage, WikiPageList, WikiPageCreate, WikiPageUpdate, WikiPageMove,
    WikiOperationResponse, WikiSearchResponse,
    DossierList, WikiSearchResult,
    WikiSmartCreateRequest, WikiSmartCreateResponse
)
from src.services.wiki_service import WikiService
from src.services.graph_service import GraphService
from src.services.vector_service import VectorService
from src.core.dependencies import (
    WikiJSDep, Neo4jDep, QdrantDep, OllamaDep,
    verify_api_key, get_settings, get_hybrid_rag_service, get_ingestion_service,
    RequiredUserQuery
)
from src.services.wiki_page_writer import WikiPageWriter
from src.services.entity_linking_utils import apply_bidirectional_entity_linking
from src.config import Settings

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/wiki", tags=["Wiki"])


# Dependency to get wiki service
def get_wiki_service(wiki_client: WikiJSDep) -> WikiService:
    """Get wiki service instance."""
    return WikiService(wiki_client)


# Dependency to get graph service
def get_graph_service(neo4j_client: Neo4jDep, wiki_client: WikiJSDep) -> GraphService:
    """Get graph service instance."""
    return GraphService(neo4j_client, wiki_client)


# Dependency to get vector service
def get_vector_service(
    qdrant_client: QdrantDep,
    wiki_client: WikiJSDep,
    ollama_client: OllamaDep
) -> VectorService:
    """Get vector service instance."""
    return VectorService(qdrant_client, wiki_client, ollama_client)


# Page operations
@router.get("/pages", response_model=WikiPageList)
async def list_pages(
    user: RequiredUserQuery,
    tag: Optional[str] = Query(default=None, description="Filter by tag (dossier)"),
    limit: int = Query(default=50, ge=1, le=200, description="Maximum pages to return"),
    wiki_service: WikiService = Depends(get_wiki_service),
    api_key: str = Depends(verify_api_key)
):
    """
    List wiki pages for a user.

    Optionally filter by tag (dossier). Pages are scoped to user's namespace.

    **Example:** `/wiki/pages?user=jpmschweitzer&tag=projects&limit=20`
    """
    try:
        return await wiki_service.list_pages(user=user, tag=tag, limit=limit)
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Failed to list pages: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


@router.get("/pages/{page_id}", response_model=WikiPage)
async def get_page(
    page_id: int,
    user: RequiredUserQuery,
    wiki_service: WikiService = Depends(get_wiki_service),
    api_key: str = Depends(verify_api_key)
):
    """
    Get a single wiki page by ID.

    Access is restricted to pages within the user's namespace.

    **Example:** `/wiki/pages/123?user=jpmschweitzer`
    """
    try:
        page = await wiki_service.get_page(page_id=page_id, user=user)
        if not page:
            raise HTTPException(status_code=404, detail=f"Page {page_id} not found or access denied")
        return page
    except HTTPException:
        raise
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Failed to get page {page_id}: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


@router.post("/pages", response_model=WikiPage, status_code=201)
async def create_page(
    page_data: WikiPageCreate,
    background_tasks: BackgroundTasks,
    wiki_service: WikiService = Depends(get_wiki_service),
    graph_service: GraphService = Depends(get_graph_service),
    vector_service: VectorService = Depends(get_vector_service),
    api_key: str = Depends(verify_api_key)
):
    """
    Create a new wiki page.

    The page will be created in the user's namespace. If path doesn't start
    with namespace, it will be automatically prefixed.

    **Auto-updates knowledge graph and vector embeddings**: After creating
    the page, the graph and vectors are automatically updated in the
    background to extract entities/relationships and generate semantic embeddings.

    **Example Request:**
    ```json
    {
        "title": "Library Desk Architecture",
        "path": "/projects/library-desk/architecture",
        "content": "# Architecture\\n\\nThis describes...",
        "description": "Architecture documentation",
        "tags": ["projects", "architecture"],
        "user": "<tenant>"
    }
    ```

    The `user` field is REQUIRED (no default tenant).
    """
    try:
        page = await wiki_service.create_page(page_data)

        user = page_data.user

        # Schedule BOTH graph and vector updates in background (non-blocking)
        background_tasks.add_task(
            graph_service.update_from_page,
            page_id=page.id,
            user=user
        )
        background_tasks.add_task(
            vector_service.update_from_page,
            page_id=page.id,
            user=user
        )

        logger.info(f"Page {page.id} created, graph and vector updates scheduled")
        return page

    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Failed to create page: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


@router.post("/pages/smart-create", response_model=WikiSmartCreateResponse, status_code=201)
async def smart_create_page(
    request: WikiSmartCreateRequest,
    background_tasks: BackgroundTasks,
    wiki_client: WikiJSDep,
    neo4j_client: Neo4jDep,
    qdrant_client: QdrantDep,
    ollama_client: OllamaDep,
    settings: Settings = Depends(get_settings),
    api_key: str = Depends(verify_api_key)
):
    """
    Create wiki page with intelligent research.

    Combines HybridRAG search with LLM content generation to create
    rich, well-researched wiki pages in a single API call.

    **Process:**
    1. Runs HybridRAG search on the topic (wiki + graph + web)
    2. Uses LLM to synthesize findings into structured wiki content
    3. Creates the page with proper attribution/sources
    4. Indexes into vectors + knowledge graph (background)
    5. Applies bidirectional entity linking (background)

    **Example Request:**
    ```json
    {
        "topic": "Docker orchestration patterns",
        "path": "/technology/containers/docker-orchestration",
        "tags": ["technology", "devops", "containers"],
        "user": "jpmschweitzer",
        "include_web_research": true,
        "include_wiki_search": true
    }
    ```

    **Returns:**
    - Created page with ID, path, content
    - Research summary (wiki/web/graph result counts)
    - Entity linking statistics (forward/backward links)
    """
    try:
        user = request.user

        # Build services. HybridRAG comes from the single wiring point in
        # dependencies so it includes volatile_service (a previous inline
        # copy here lacked it).
        wiki_service = WikiService(wiki_client)
        vector_service = VectorService(qdrant_client, wiki_client, ollama_client)
        graph_service = GraphService(neo4j_client, wiki_client)
        hybrid_rag_service = get_hybrid_rag_service()
        wiki_page_writer = WikiPageWriter(ollama_client=ollama_client, settings=settings)

        # Step 1-5: Research + Generate + Create page
        page, research_data = await wiki_service.smart_create_page(
            topic=request.topic,
            user=user,
            path=request.path,
            tags=request.tags,
            hybrid_rag_service=hybrid_rag_service,
            wiki_page_writer=wiki_page_writer,
            include_web=request.include_web_research,
            include_wiki=request.include_wiki_search
        )

        # Schedule graph and vector updates in background
        background_tasks.add_task(
            graph_service.update_from_page,
            page_id=page.id,
            user=user
        )
        background_tasks.add_task(
            vector_service.update_from_page,
            page_id=page.id,
            user=user
        )

        # Schedule bidirectional entity linking in background
        async def run_entity_linking():
            ingestion_service = get_ingestion_service()
            return await apply_bidirectional_entity_linking(
                page_id=page.id,
                page_title=page.title,
                user=user,
                neo4j_client=neo4j_client,
                wiki_service=wiki_service,
                ingestion_service=ingestion_service
            )

        background_tasks.add_task(run_entity_linking)

        logger.info(
            f"Smart page created: id={page.id}, path={page.path}, "
            f"sources={research_data['sources_used']}"
        )

        return WikiSmartCreateResponse(
            page=page,
            research_summary=research_data["research_summary"],
            sources_used=research_data["sources_used"],
            search_id=research_data["search_id"],
            entity_linking={"forward_links": 0, "backward_links": 0, "pages_updated": 0}
            # Note: entity_linking stats are 0 here as it runs in background
        )

    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Failed to smart create page: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


@router.put("/pages/{page_id}", response_model=WikiPage)
async def update_page(
    page_id: int,
    page_data: WikiPageUpdate,
    background_tasks: BackgroundTasks,
    user: RequiredUserQuery,
    wiki_service: WikiService = Depends(get_wiki_service),
    graph_service: GraphService = Depends(get_graph_service),
    vector_service: VectorService = Depends(get_vector_service),
    api_key: str = Depends(verify_api_key)
):
    """
    Update an existing wiki page.

    Only pages within the user's namespace can be updated.
    Partial updates are supported - only provided fields will be updated.

    **Auto-updates knowledge graph and vector embeddings**: After updating
    the page, the graph and vectors are automatically refreshed in the
    background to reflect the changes.

    **Example Request:**
    ```json
    {
        "title": "Updated Title",
        "tags": ["projects", "updated"]
    }
    ```
    """
    try:
        page = await wiki_service.update_page(
            page_id=page_id,
            page_data=page_data,
            user=user
        )

        # Schedule BOTH graph and vector updates in background (non-blocking)
        background_tasks.add_task(
            graph_service.update_from_page,
            page_id=page_id,
            user=user,
            force_refresh=True  # Force refresh on updates
        )
        background_tasks.add_task(
            vector_service.update_from_page,
            page_id=page_id,
            user=user,
            force_refresh=True  # Force refresh on updates
        )

        logger.info(f"Page {page_id} updated, graph and vector refresh scheduled")
        return page

    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Failed to update page {page_id}: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


@router.delete("/pages/{page_id}", response_model=WikiOperationResponse)
async def delete_page(
    page_id: int,
    background_tasks: BackgroundTasks,
    user: RequiredUserQuery,
    wiki_service: WikiService = Depends(get_wiki_service),
    vector_service: VectorService = Depends(get_vector_service),
    graph_service: GraphService = Depends(get_graph_service),
    api_key: str = Depends(verify_api_key)
):
    """
    Delete a wiki page.

    Only pages within the user's namespace can be deleted.
    This operation cannot be undone.

    **Auto-cleanup**: Vector chunks and graph nodes for this page are
    automatically deleted in the background.
    """
    try:
        success = await wiki_service.delete_page(page_id=page_id, user=user)

        # Schedule vector cleanup in background
        background_tasks.add_task(
            vector_service.delete_page_chunks,
            page_id=page_id,
            user=user
        )

        # Schedule graph cleanup in background
        background_tasks.add_task(
            graph_service.delete_page,
            page_id=page_id,
            user=user
        )

        logger.info(f"Page {page_id} deleted, vector and graph cleanup scheduled")
        return WikiOperationResponse(
            success=success,
            message=f"Page {page_id} deleted successfully",
            page_id=page_id
        )
    except ValueError as e:
        raise HTTPException(status_code=404, detail=str(e))
    except Exception as e:
        logger.error(f"Failed to delete page {page_id}: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


@router.post("/pages/{page_id}/move", response_model=WikiOperationResponse)
async def move_page(
    page_id: int,
    move_data: WikiPageMove,
    user: RequiredUserQuery,
    wiki_service: WikiService = Depends(get_wiki_service),
    api_key: str = Depends(verify_api_key)
):
    """
    Move or rename a wiki page.

    The new path must be within the user's namespace.

    **Example Request:**
    ```json
    {
        "new_path": "/projects/library-desk/docs/architecture"
    }
    ```
    """
    try:
        success = await wiki_service.move_page(
            page_id=page_id,
            new_path=move_data.new_path,
            user=user
        )
        if not success:
            raise HTTPException(status_code=500, detail="Failed to move page")

        return WikiOperationResponse(
            success=True,
            message=f"Page {page_id} moved successfully",
            page_id=page_id,
            page_path=move_data.new_path
        )
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except HTTPException:
        raise
    except Exception as e:
        logger.error(f"Failed to move page {page_id}: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


# Search operations
@router.get("/search", response_model=WikiSearchResponse)
async def search_pages(
    user: RequiredUserQuery,
    q: str = Query(..., min_length=1, description="Search query"),
    limit: int = Query(default=20, ge=1, le=100, description="Maximum results"),
    wiki_service: WikiService = Depends(get_wiki_service),
    api_key: str = Depends(verify_api_key)
):
    """
    Search wiki pages within user's namespace.

    **Example:** `/wiki/search?q=architecture&user=jpmschweitzer&limit=10`
    """
    try:
        results = await wiki_service.search_pages(
            query=q,
            user=user,
            limit=limit
        )

        return WikiSearchResponse(
            results=[
                WikiSearchResult(
                    id=r.id,
                    path=r.path,
                    title=r.title,
                    description=r.description,
                    relevance=None
                )
                for r in results
            ],
            query=q,
            total=len(results)
        )
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Search failed: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


# Dossier operations
@router.get("/dossiers", response_model=DossierList)
async def list_dossiers(
    user: RequiredUserQuery,
    wiki_service: WikiService = Depends(get_wiki_service),
    api_key: str = Depends(verify_api_key)
):
    """
    List all dossiers (unique tags) for a user.

    Dossiers are tag-based collections of pages.

    **Example:** `/wiki/dossiers?user=jpmschweitzer`
    """
    try:
        return await wiki_service.list_dossiers(user=user)
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Failed to list dossiers: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")


@router.get("/dossiers/{dossier_name}/pages", response_model=WikiPageList)
async def get_dossier_pages(
    dossier_name: str,
    user: RequiredUserQuery,
    limit: int = Query(default=100, ge=1, le=500, description="Maximum pages"),
    wiki_service: WikiService = Depends(get_wiki_service),
    api_key: str = Depends(verify_api_key)
):
    """
    Get all pages in a dossier.

    Returns pages tagged with the dossier name.

    **Example:** `/wiki/dossiers/projects/pages?user=jpmschweitzer`
    """
    try:
        return await wiki_service.get_dossier_pages(
            dossier_name=dossier_name,
            user=user,
            limit=limit
        )
    except ValueError as e:
        raise HTTPException(status_code=400, detail=str(e))
    except Exception as e:
        logger.error(f"Failed to get dossier pages: {e}", exc_info=True)
        raise HTTPException(status_code=500, detail="Internal server error")