from typing import Dict, Optional
from services.data.db_utils import translate_run_key, translate_task_key
from services.ui_backend_service.data import unpack_processed_value
from services.utils import handle_exceptions
from .utils import (
    format_response_list,
    get_pathspec_from_request,
    query_param_enabled,
    web_response,
    DBPagination,
    DBResponse,
)
from services.ui_backend_service.data.cache.card_cache_manager import wait_until_card_is_ready, CARD_API_HTML_WAIT_TIME
from services.ui_backend_service.data.cache.card_cache_manager import list_cards as list_cards_from_cache
import time
from aiohttp import web
import asyncio


class CardsApi(object):
    def __init__(self, app, db, cache=None):
        self.db = db
        self.cache = getattr(cache, "card_cache", None)
        app.router.add_route(
            "GET",
            "/flows/{flow_id}/runs/{run_number}/steps/{step_name}/tasks/{task_id}/cards",
            self.get_cards_list_for_task,
        )
        app.router.add_route(
            "GET",
            "/flows/{flow_id}/runs/{run_number}/steps/{step_name}/tasks/{task_id}/cards/{hash}",
            self.get_card_content_by_hash,
        )
        app.router.add_route(
            "GET",
            "/flows/{flow_id}/runs/{run_number}/steps/{step_name}/tasks/{task_id}/cards/{hash}/data",
            self.get_card_data_by_hash,
        )

    async def get_task_by_request(self, request):
        flow_id, run_number, step_name, task_id, _ = get_pathspec_from_request(request)

        run_id_key, run_id_value = translate_run_key(run_number)
        task_id_key, task_id_value = translate_task_key(task_id)

        conditions = [
            "flow_id = %s",
            "{run_id_key} = %s".format(run_id_key=run_id_key),
            "step_name = %s",
            "{task_id_key} = %s".format(task_id_key=task_id_key),
        ]
        values = [flow_id, run_id_value, step_name, task_id_value]
        db_response, *_ = await self.db.task_table_postgres.find_records(
            fetch_single=True,
            conditions=conditions,
            values=values,
            expanded=True,
        )
        if db_response.response_code == 200:
            return db_response.body
        return None

    @handle_exceptions
    async def get_cards_list_for_task(self, request):
        """
        ---
        description: Get all identifiers of cards for a task
        tags:
        - Card
        parameters:
          - $ref: '#/definitions/Params/Path/flow_id'
          - $ref: '#/definitions/Params/Path/run_number'
          - $ref: '#/definitions/Params/Path/step_name'
          - $ref: '#/definitions/Params/Path/task_id'
          - $ref: '#/definitions/Params/Builtin/_page'
          - $ref: '#/definitions/Params/Builtin/_limit'
          - $ref: '#/definitions/Params/Custom/invalidate'
        produces:
        - application/json
        responses:
            "200":
                description: Returns a list of cards for the specified task
                schema:
                  $ref: '#/definitions/ResponsesCardList'
            "404":
                description: Task was not found.
            "405":
                description: invalid HTTP Method
                schema:
                  $ref: '#/definitions/ResponsesError405'
        """

        task = await self.get_task_by_request(request)
        if not task:
            return web_response(404, {"data": []})

        cards = await get_card_list(self.cache, task, max_wait_time=1)

        if cards is None:
            # Handle edge: Cache failed to return anything, even errors.
            # NOTE: choice of status 200 here is quite arbitrary, as the cache returning None is usually
            # caused by a premature request, and cards are not permanently missing.
            return web_response(200, {"data": []})

        card_hashes = [
            {"id": data["id"], "hash": hash, "type": data["type"]}
            for hash, data in cards.items()
        ]
        # paginate list of cards
        limit, page, offset = get_pagination_params(request)
        _pages = max(len(card_hashes) // limit, 1)
        limited_set = card_hashes[offset:][:limit]

        response = DBResponse(200, limited_set)
        pagination = DBPagination(limit, limit * (page - 1), len(response.body), page)
        status, body = format_response_list(request, response, pagination, page, _pages)

        return web_response(status, body)

    @handle_exceptions
    async def get_card_content_by_hash(self, request):
        """
        ---
        description: Get specific card of a task
        tags:
        - Card
        parameters:
          - $ref: '#/definitions/Params/Path/flow_id'
          - $ref: '#/definitions/Params/Path/run_number'
          - $ref: '#/definitions/Params/Path/step_name'
          - $ref: '#/definitions/Params/Path/task_id'
          - $ref: '#/definitions/Params/Custom/invalidate'
        produces:
        - text/html
        responses:
            "200":
                description: Returns the HTML content of a card with the specific hash
            "404":
                description: Card was not found.
            "405":
                description: invalid HTTP Method
                schema:
                  $ref: '#/definitions/ResponsesError405'
        """
        hash = request.match_info.get("hash")
        task = await self.get_task_by_request(request)
        if not task:
            return web.Response(
                content_type="text/html", status=404, body="Task not found."
            )
        cards = await get_card_html_for_task_async(
            self.cache,
            task,
            hash,
        )
        if cards is None:
            return web.Response(
                content_type="text/html",
                status=404,
                body="Card not found for task. Possibly still being processed. Please refresh page to check again.",
            )

        if cards and hash in cards:
            return web.Response(content_type="text/html", body=cards[hash]["html"])
        else:
            return web.Response(
                content_type="text/html",
                status=404,
                body="Card not found for task.",
            )

    @handle_exceptions
    async def get_card_data_by_hash(self, request):
        """
        ---
        description: Get the data of a card created for a task. Contains any additional updates needed by the card.
        tags:
        - Card
        parameters:
          - $ref: '#/definitions/Params/Path/flow_id'
          - $ref: '#/definitions/Params/Path/run_number'
          - $ref: '#/definitions/Params/Path/step_name'
          - $ref: '#/definitions/Params/Path/task_id'
          - $ref: '#/definitions/Params/Path/hash'

        produces:
        - application/json
        responses:
            "200":
                description: Returns the data object created by the realtime card with the specific hash
            "404":
                description: Card data was not found.
            "405":
                description: invalid HTTP Method
                schema:
                  $ref: '#/definitions/ResponsesError405'
        """
        _hash = request.match_info.get("hash")
        task = await self.get_task_by_request(request)
        if not task:
            return web.Response(
                content_type="text/html", status=404, body="Task not found."
            )
        data = await get_card_data_for_task_async(
            self.cache,
            task,
            _hash,
        )

        if data is None:
            return web_response(404, {"error": "Card data not found for task"})
        else:
            return web_response(200, data)


def _card_data_from_cache(local_cache):
    data = local_cache.read_data()
    if data is None:
        return None
    return {
        "data": data["data"],
        "id": local_cache.card_id,
        "type": local_cache.card_type,
    }


async def get_card_html_for_task_async(
    cache_client,
    task,
    card_hash,
) -> Optional[Dict[str, Dict]]:
    """
    Return the card-data from the cache, or nothing.

    Example:
    --------
    {
        "id": 1,
        "hash": "abc123",
        "data": {}
    }
    """
    pathspec = "{flow_id}/{run_id}/{step_name}/{task_id}".format(
        flow_id=task.get("flow_id"),
        run_id=task.get("run_id") or task.get("run_number"),
        step_name=task.get("step_name"),
        task_id=task.get("task_name") or task.get("task_id"),
    )
    _local_cache = cache_client.cache_manager.get_local_cache(pathspec, card_hash)
    _html = await wait_until_card_is_ready(
        cache_client.cache_manager, _local_cache, max_wait_time=CARD_API_HTML_WAIT_TIME
    )
    return _html


async def get_card_data_for_task_async(
    cache_client,
    task,
    card_hash,
) -> Optional[Dict[str, Dict]]:
    """
    Return the card-data from the cache, or nothing.

    Example:
    --------
    {
        "id": 1,
        "hash": "abc123",
        "data": {}
    }
    """
    pathspec = "{flow_id}/{run_id}/{step_name}/{task_id}".format(
        flow_id=task.get("flow_id"),
        run_id=task.get("run_id") or task.get("run_number"),
        step_name=task.get("step_name"),
        task_id=task.get("task_name") or task.get("task_id"),
    )
    await cache_client.cache_manager.register(pathspec)
    _local_cache = cache_client.cache_manager.get_local_cache(pathspec, card_hash)
    if not _local_cache.read_ready():
        # Since this is a data update call we can return a 404 and the client
        # should handle calling back so we only await at registration.
        return None

    return _card_data_from_cache(_local_cache)


async def get_card_list(
    cache_client, task, max_wait_time=3
):
    pathspec = "{flow_id}/{run_id}/{step_name}/{task_id}".format(
        flow_id=task.get("flow_id"),
        run_id=task.get("run_id") or task.get("run_number"),
        step_name=task.get("step_name"),
        task_id=task.get("task_name") or task.get("task_id"),
    )
    return await list_cards_from_cache(cache_client.cache_manager, pathspec, max_wait_time)


def get_pagination_params(request):
    """extract pagination params from request"""
    # Page
    page = max(int(request.query.get("_page", 1)), 1)

    # Limit
    # Default limit is 1000, maximum is 10_000
    limit = min(int(request.query.get("_limit", 1000)), 10000)

    # Offset
    offset = limit * (page - 1)

    return limit, page, offset


class CardException(Exception):
    def __init__(
        self, msg="Failed to read card contents", id="card-error", traceback_str=None
    ):
        self.message = msg
        self.id = id
        self.traceback_str = traceback_str

    def __str__(self):
        return self.message