from fastapi import APIRouter
from fastapi.responses import JSONResponse
from typing import Dict, Any, List

from core.registry.tasks_registry import TASKS


# =====================================================
# INTERNAL HELPERS
# =====================================================

def _serialize_task(task) -> Dict[str, Any]:
    """
    Convert TaskDefinition → API-safe metadata.
    Must NOT import task modules.
    """

    return {
        "name": getattr(task, "name", None),
        "description": getattr(task, "description", ""),
        "category": getattr(task, "category", "general"),
        "module": getattr(task, "module", None),
        "callable": getattr(task, "callable_name", "run"),
        "async": getattr(task, "async_task", False),
        "enabled": getattr(task, "enabled", True),
    }


def _group_tasks(tasks: List[Any]) -> Dict[str, List[Dict[str, Any]]]:
    """
    Groups tasks by category for UI rendering.
    """

    grouped: Dict[str, List[Dict[str, Any]]] = {}

    for task in tasks:
        category = getattr(task, "category", "general")
        grouped.setdefault(category, []).append(_serialize_task(task))

    return grouped


# =====================================================
# DOCS ROUTER BUILDER (V11)
# =====================================================

def build_docs_router() -> APIRouter:
    """
    Builds dynamic documentation endpoints.

    Provides:
        /docs/tasks      → flat task list
        /docs/catalog    → grouped tasks
        /docs/health     → docs status
    """

    router = APIRouter(
        prefix="/docs",
        tags=["Documentation"],
    )

    # -------------------------------------------------
    # List all tasks
    # -------------------------------------------------
    @router.get("/tasks")
    async def list_tasks():
        return JSONResponse(
            [_serialize_task(task) for task in TASKS]
        )

    # -------------------------------------------------
    # Categorized task catalog
    # -------------------------------------------------
    @router.get("/catalog")
    async def task_catalog():
        return JSONResponse(_group_tasks(TASKS))

    # -------------------------------------------------
    # Docs health endpoint
    # -------------------------------------------------
    @router.get("/health")
    async def docs_health():
        return {
            "status": "ok",
            "service": "docs",
            "tasks_registered": len(TASKS),
        }

    return router