"""
Wiki.js GraphQL client for Library Desk.

Provides async Wiki.js operations via GraphQL API:
- Page CRUD (create, read, update, delete)
- Search and listing
- Tag management
- Multi-tenancy via path namespaces
"""

import httpx
from typing import Optional, List, Dict, Any
import logging

logger = logging.getLogger(__name__)


class WikiJSClient:
    """
    Wiki.js GraphQL API client.

    Documentation: https://docs.requarks.io/dev/api
    Authentication: API token (JWT) generated from Wiki.js admin panel
    """

    def __init__(self, base_url: str, api_token: str):
        """
        Initialize Wiki.js client.

        Args:
            base_url: Wiki.js base URL (e.g., "http://wiki:3000")
            api_token: Wiki.js API token (JWT from admin panel)
        """
        self.base_url = base_url.rstrip("/")
        self.graphql_url = f"{self.base_url}/graphql"
        self.api_token = api_token
        self.client = httpx.AsyncClient(timeout=30.0)
        auth_mode = "with API token" if api_token else "without auth (open API)"
        logger.info(f"Initialized Wiki.js client: {base_url} ({auth_mode})")

    async def close(self):
        """Close HTTP client"""
        await self.client.aclose()

    def _get_headers(self) -> Dict[str, str]:
        """Get request headers, optionally including auth token."""
        headers = {"Content-Type": "application/json"}
        if self.api_token:
            headers["Authorization"] = f"Bearer {self.api_token}"
        return headers

    async def _execute_query(
        self,
        query: str,
        variables: Optional[Dict] = None
    ) -> Dict[str, Any]:
        """
        Execute GraphQL query.

        Args:
            query: GraphQL query string
            variables: Query variables

        Returns:
            Query result data

        Raises:
            Exception: If query fails or returns errors
        """
        payload = {
            "query": query,
            "variables": variables or {}
        }

        headers = self._get_headers()

        try:
            response = await self.client.post(
                self.graphql_url,
                headers=headers,
                json=payload
            )
            response.raise_for_status()
            result = response.json()

            if "errors" in result:
                logger.error(f"GraphQL errors: {result['errors']}")
                raise Exception(f"GraphQL errors: {result['errors']}")

            return result.get("data", {})

        except httpx.HTTPStatusError as e:
            logger.error(f"HTTP error: {e.response.status_code} - {e.response.text}")
            raise
        except Exception as e:
            logger.error(f"GraphQL query failed: {e}", exc_info=True)
            raise

    async def _fetch_pages(self, limit: int) -> List[Dict[str, Any]]:
        """
        Fetch a raw page listing from the GraphQL API (no client-side filtering).

        Args:
            limit: Maximum pages to request from the API

        Returns:
            List of page objects with tags normalized to a list
        """
        query = """
        query ListPages($limit: Int, $orderBy: PageOrderBy) {
            pages {
                list(limit: $limit, orderBy: $orderBy) {
                    id
                    path
                    title
                    description
                    tags
                    createdAt
                    updatedAt
                    isPublished
                }
            }
        }
        """

        variables = {
            "limit": limit,
            "orderBy": "TITLE"
        }

        data = await self._execute_query(query, variables)
        pages = data.get("pages", {}).get("list", [])

        # Ensure tags is always a list
        for page in pages:
            if "tags" not in page or page["tags"] is None:
                page["tags"] = []

        return pages

    async def _fetch_all_pages(self, initial_limit: int = 100) -> List[Dict[str, Any]]:
        """
        Fetch ALL pages from the GraphQL API.

        The Wiki.js 2.x `pages.list` query only supports a `limit` argument
        (no offset - verified via GraphQL introspection). Crucially, the
        limit is applied BEFORE Wiki.js's own visibility filtering, so a
        response with fewer pages than requested does NOT mean the listing
        is complete (observed live: limit=100 -> 43 pages, limit=500 ->
        140 pages). Exhaustive listing therefore grows the limit until the
        returned page count stops increasing.

        Args:
            initial_limit: Page count for the first request

        Returns:
            Complete list of page objects
        """
        max_limit = 100_000  # Safety cap against pathological growth
        limit = max(initial_limit, 1)
        previous_count: Optional[int] = None

        while True:
            pages = await self._fetch_pages(limit)
            # Complete when a grown limit yields no new pages (fixed point)
            if previous_count is not None and len(pages) == previous_count:
                return pages
            if limit >= max_limit:
                return pages
            previous_count = len(pages)
            limit = min(limit * 2, max_limit)

    @staticmethod
    def _filter_pages(
        pages: List[Dict[str, Any]],
        path_prefix: str = "",
        tags: Optional[List[str]] = None
    ) -> List[Dict[str, Any]]:
        """Apply client-side path-prefix and tag filters to a page listing."""
        if path_prefix:
            # Normalize paths to have leading slash for consistent comparison
            normalized_prefix = "/" + path_prefix.lstrip("/")
            pages = [
                p for p in pages
                if ("/" + p["path"].lstrip("/")).startswith(normalized_prefix)
            ]

        # Filter by tags (dossiers)
        if tags:
            pages = [
                p for p in pages
                if any(tag in (p.get("tags") or []) for tag in tags)
            ]

        return pages

    async def list_pages(
        self,
        path_prefix: str = "",
        tags: Optional[List[str]] = None,
        limit: int = 50
    ) -> List[Dict[str, Any]]:
        """
        List pages with optional filtering.

        Multi-tenancy: Use path_prefix to filter by user namespace.

        Args:
            path_prefix: Filter by path prefix (e.g., "/users/jpmschweitzer")
            tags: Filter by tags (e.g., ["projects"])
            limit: Maximum results (applied AFTER filtering)

        Returns:
            List of page objects
        """
        if path_prefix or tags:
            # The API limit applies before our client-side filters, so a
            # small limit would drop matching pages that sort late. Fetch
            # everything, filter, then apply the limit.
            pages = self._filter_pages(
                await self._fetch_all_pages(),
                path_prefix=path_prefix,
                tags=tags
            )
            return pages[:limit]

        return await self._fetch_pages(limit)

    async def list_all_pages(
        self,
        path_prefix: str = "",
        tags: Optional[List[str]] = None,
        batch_size: int = 100
    ) -> List[Dict[str, Any]]:
        """
        List ALL pages with pagination support.

        Fetches pages in growing batches until all are retrieved (Wiki.js
        `pages.list` has no offset argument), then applies filters.

        Args:
            path_prefix: Filter by path prefix (e.g., "users/jpmschweitzer")
            tags: Filter by tags
            batch_size: Page count for the first request

        Returns:
            Complete list of page objects
        """
        all_pages = self._filter_pages(
            await self._fetch_all_pages(initial_limit=batch_size),
            path_prefix=path_prefix,
            tags=tags
        )

        logger.info(f"list_all_pages: found {len(all_pages)} pages (prefix: {path_prefix or 'all'})")
        return all_pages

    async def get_taxonomy_structure(
        self,
        user_namespace: str,
        limit: int = 500
    ) -> Dict[str, List[str]]:
        """
        Get the existing taxonomy structure for a user namespace.

        Returns a dict mapping top-level categories to their subcategories.
        This helps the LLM choose existing paths rather than creating new ones.

        Args:
            user_namespace: User namespace (e.g., "users/jpmschweitzer")
            limit: Maximum pages to fetch

        Returns:
            Dict like {"reference": ["political-entities", "tech"], "places": ["the-netherlands"]}
        """
        from collections import defaultdict

        pages = await self.list_pages(path_prefix=user_namespace, limit=limit)

        # Extract structure: category -> set of subcategories
        structure: Dict[str, set] = defaultdict(set)
        prefix = user_namespace.strip("/") + "/"

        for page in pages:
            path = page.get("path", "")
            if not path.startswith(prefix):
                continue

            # Get relative path within user namespace
            rel_path = path[len(prefix):]
            parts = rel_path.split("/")

            if len(parts) >= 1:
                category = parts[0]
                if len(parts) >= 2:
                    # Has subcategory (e.g., reference/political-entities/nato)
                    structure[category].add(parts[1])
                else:
                    # Just ensure category exists in structure
                    structure[category]  # Access to ensure key exists

        # Convert sets to sorted lists
        return {cat: sorted(list(subs)) for cat, subs in sorted(structure.items())}

    async def get_page(self, page_id: int) -> Optional[Dict[str, Any]]:
        """
        Get single page by ID.

        Args:
            page_id: Page ID

        Returns:
            Page object or None if not found
        """
        query = """
        query GetPage($id: Int!) {
            pages {
                single(id: $id) {
                    id
                    path
                    title
                    description
                    content
                    tags {
                        tag
                    }
                    createdAt
                    updatedAt
                    isPublished
                    editor
                }
            }
        }
        """

        try:
            # Ensure page_id is int (GraphQL requires Int, not String)
            data = await self._execute_query(query, {"id": int(page_id)})
            page = data.get("pages", {}).get("single")

            # Extract tag strings from tag objects
            if page and "tags" in page and page["tags"]:
                page["tags"] = [t["tag"] for t in page["tags"]]
            elif page:
                page["tags"] = []

            return page
        except Exception as e:
            logger.error(f"Failed to get page {page_id}: {e}")
            return None

    async def create_page(
        self,
        path: str,
        title: str,
        content: str,
        description: str = "",
        tags: Optional[List[str]] = None,
        is_published: bool = True,
        is_private: bool = False,
        editor: str = "markdown"
    ) -> Dict[str, Any]:
        """
        Create new page.

        Multi-tenancy: Ensure path starts with user namespace.

        Args:
            path: Page path (e.g., "/users/jpmschweitzer/projects/library-desk")
            title: Page title
            content: Page content (markdown)
            description: Short description
            tags: List of tags (for dossier organization)
            is_published: Whether page is published
            is_private: Whether page is private
            editor: Editor type (markdown, wysiwyg, etc.)

        Returns:
            Created page object

        Raises:
            Exception: If creation fails
        """
        mutation = """
        mutation CreatePage(
            $content: String!,
            $description: String!,
            $editor: String!,
            $isPublished: Boolean!,
            $isPrivate: Boolean!,
            $locale: String!,
            $path: String!,
            $tags: [String]!,
            $title: String!
        ) {
            pages {
                create(
                    content: $content,
                    description: $description,
                    editor: $editor,
                    isPublished: $isPublished,
                    isPrivate: $isPrivate,
                    locale: $locale,
                    path: $path,
                    tags: $tags,
                    title: $title
                ) {
                    responseResult {
                        succeeded
                        errorCode
                        message
                    }
                    page {
                        id
                        path
                        title
                    }
                }
            }
        }
        """

        variables = {
            "path": path,
            "title": title,
            "content": content,
            "description": description,
            "tags": tags or [],
            "isPublished": is_published,
            "isPrivate": is_private,
            "editor": editor,
            "locale": "en"
        }

        data = await self._execute_query(mutation, variables)
        result = data.get("pages", {}).get("create", {})

        if not result.get("responseResult", {}).get("succeeded"):
            error = result.get("responseResult", {})
            raise Exception(f"Failed to create page: {error}")

        logger.info(f"Created page: {path}")
        return result.get("page")

    async def update_page(
        self,
        page_id: int,
        content: Optional[str] = None,
        title: Optional[str] = None,
        description: Optional[str] = None,
        tags: Optional[List[str]] = None,
        is_published: Optional[bool] = None
    ) -> Dict[str, Any]:
        """
        Update existing page.

        Args:
            page_id: Page ID
            content: New content (optional)
            title: New title (optional)
            description: New description (optional)
            tags: New tags (optional)
            is_published: Published status (optional)

        Returns:
            Updated page object

        Raises:
            Exception: If update fails
        """
        mutation = """
        mutation UpdatePage(
            $id: Int!,
            $content: String,
            $title: String,
            $description: String,
            $tags: [String],
            $isPublished: Boolean
        ) {
            pages {
                update(
                    id: $id,
                    content: $content,
                    title: $title,
                    description: $description,
                    tags: $tags,
                    isPublished: $isPublished
                ) {
                    responseResult {
                        succeeded
                        errorCode
                        message
                    }
                    page {
                        id
                        updatedAt
                    }
                }
            }
        }
        """

        # Wiki.js 2.x requires `tags` on the update mutation (the server
        # unconditionally maps over it; omitting it fails with "Cannot read
        # properties of undefined (reading 'map')"). Preserve the page's
        # current tags when the caller does not supply any.
        if tags is None:
            current = await self.get_page(page_id)
            tags = (current or {}).get("tags") or []

        variables = {"id": page_id, "tags": tags}
        if content is not None:
            variables["content"] = content
        if title is not None:
            variables["title"] = title
        if description is not None:
            variables["description"] = description
        if is_published is not None:
            variables["isPublished"] = is_published

        data = await self._execute_query(mutation, variables)
        result = data.get("pages", {}).get("update", {})

        if not result.get("responseResult", {}).get("succeeded"):
            error = result.get("responseResult", {})
            raise Exception(f"Failed to update page: {error}")

        logger.info(f"Updated page: {page_id}")
        return result.get("page")

    async def delete_page(self, page_id: int):
        """
        Delete page.

        Args:
            page_id: Page ID

        Raises:
            Exception: If deletion fails
        """
        mutation = """
        mutation DeletePage($id: Int!) {
            pages {
                delete(id: $id) {
                    responseResult {
                        succeeded
                        errorCode
                        message
                    }
                }
            }
        }
        """

        data = await self._execute_query(mutation, {"id": page_id})
        result = data.get("pages", {}).get("delete", {})

        if not result.get("responseResult", {}).get("succeeded"):
            error = result.get("responseResult", {})
            raise Exception(f"Failed to delete page: {error}")

        logger.info(f"Deleted page: {page_id}")

    async def search_pages(
        self,
        query: str,
        path_prefix: Optional[str] = None
    ) -> List[Dict[str, Any]]:
        """
        Search pages by content.

        Args:
            query: Search query
            path_prefix: Optional path prefix filter

        Returns:
            List of matching pages
        """
        gql_query = """
        query SearchPages($query: String!) {
            pages {
                search(query: $query) {
                    results {
                        id
                        path
                        title
                        description
                    }
                }
            }
        }
        """

        data = await self._execute_query(gql_query, {"query": query})
        results = data.get("pages", {}).get("search", {}).get("results", [])

        # Filter by path prefix if provided. Wiki.js returns paths WITHOUT a
        # leading slash while get_wikijs_namespace() produces one WITH it, so
        # compare slash-normalized (the mismatch made this filter reject every
        # result, returning an empty search for every tenant).
        if path_prefix:
            prefix = path_prefix.lstrip("/")
            results = [r for r in results if r["path"].lstrip("/").startswith(prefix)]

        return results

    async def get_page_tree(self, path: str = "/") -> List[Dict[str, Any]]:
        """
        Get page tree structure.

        Args:
            path: Root path

        Returns:
            Tree structure of pages
        """
        query = """
        query GetPageTree($parent: Int, $mode: String!) {
            pages {
                tree(parent: $parent, mode: $mode) {
                    id
                    path
                    title
                    isFolder
                    pageId
                }
            }
        }
        """

        try:
            data = await self._execute_query(
                query,
                {"parent": 0, "mode": "all"}
            )
            return data.get("pages", {}).get("tree", [])
        except Exception as e:
            logger.error(f"Failed to get page tree: {e}")
            return []

    async def move_page(
        self,
        page_id: int,
        new_path: str,
        locale: str = "en"
    ) -> bool:
        """
        Move/rename page.

        Args:
            page_id: Page ID
            new_path: New page path
            locale: Page locale

        Returns:
            True if successful
        """
        mutation = """
        mutation MovePage($id: Int!, $destinationPath: String!, $destinationLocale: String!) {
            pages {
                move(id: $id, destinationPath: $destinationPath, destinationLocale: $destinationLocale) {
                    responseResult {
                        succeeded
                        errorCode
                        message
                    }
                }
            }
        }
        """

        try:
            data = await self._execute_query(
                mutation,
                {
                    "id": page_id,
                    "destinationPath": new_path,
                    "destinationLocale": locale
                }
            )
            result = data.get("pages", {}).get("move", {})
            success = result.get("responseResult", {}).get("succeeded", False)

            if success:
                logger.info(f"Moved page {page_id} to {new_path}")
            return success

        except Exception as e:
            logger.error(f"Failed to move page: {e}")
            return False