from datetime import datetime

from django.conf import settings


class QueryError(Exception):
    pass


def parse_size(query_params, sizes):
    if "size" in query_params:
        size = query_params["size"]
        if size not in sizes:
            message = "Size is not permitted"
            message_class = "danger"
            return {"message": message, "class": message_class}
        size = int(size)
    else:
        size = 15

    return size


def parse_index(user, query_params, raise_error=False):
    if "index" in query_params:
        index = query_params["index"]
        if index == "main":
            index = settings.INDEX_MAIN
        else:
            if not user.has_perm(f"core.index_{index}"):
                message = f"Not permitted to search by this index: {index}"
                if raise_error:
                    raise QueryError(message)
                message_class = "danger"
                return {
                    "message": message,
                    "class": message_class,
                }
            if index == "meta":
                index = settings.INDEX_META
            elif index == "internal":
                index = settings.INDEX_INT
            elif index == "restricted":
                if not user.has_perm("core.restricted_sources"):
                    message = f"Not permitted to search by this index: {index}"
                    if raise_error:
                        raise QueryError(message)
                    message_class = "danger"
                    return {
                        "message": message,
                        "class": message_class,
                    }
                index = settings.INDEX_RESTRICTED
            else:
                message = f"Index is not valid: {index}"
                if raise_error:
                    raise QueryError(message)
                message_class = "danger"
                return {
                    "message": message,
                    "class": message_class,
                }
    else:
        index = settings.INDEX_MAIN
    return index


def parse_source(user, query_params, raise_error=False):
    source = None
    if "source" in query_params:
        source = query_params["source"]

        if source in settings.SOURCES_RESTRICTED:
            if not user.has_perm("core.restricted_sources"):
                message = f"Access denied: {source}"
                if raise_error:
                    raise QueryError(message)
                message_class = "danger"
                return {"message": message, "class": message_class}
        elif source not in settings.MAIN_SOURCES:
            message = f"Invalid source: {source}"
            if raise_error:
                raise QueryError(message)
            message_class = "danger"
            return {"message": message, "class": message_class}

        if source == "all":
            source = None  # the next block will populate it

    if source:
        sources = [source]
    else:
        sources = list(settings.MAIN_SOURCES)
        if user.has_perm("core.restricted_sources"):
            for source_iter in settings.SOURCES_RESTRICTED:
                sources.append(source_iter)

    if "all" in sources:
        sources.remove("all")

    return sources


def parse_sort(query_params):
    sort = None
    if "sorting" in query_params:
        sorting = query_params["sorting"]
        if sorting not in ("asc", "desc", "none"):
            message = "Invalid sort"
            message_class = "danger"
            return {"message": message, "class": message_class}
        if sorting == "asc":
            sort = "ascending"
        elif sorting == "desc":
            sort = "descending"
    return sort


def parse_date_time(query_params):
    if set({"from_date", "to_date", "from_time", "to_time"}).issubset(
        query_params.keys()
    ):
        from_ts = f"{query_params['from_date']}T{query_params['from_time']}Z"
        to_ts = f"{query_params['to_date']}T{query_params['to_time']}Z"
        from_ts = datetime.strptime(from_ts, "%Y-%m-%dT%H:%MZ")
        to_ts = datetime.strptime(to_ts, "%Y-%m-%dT%H:%MZ")

        return (from_ts, to_ts)
    return (None, None)


def parse_sentiment(query_params):
    sentiment = None
    if "check_sentiment" in query_params:
        if "sentiment_method" not in query_params:
            message = "No sentiment method"
            message_class = "danger"
            return {"message": message, "class": message_class}
        if "sentiment" in query_params:
            sentiment = query_params["sentiment"]
            try:
                sentiment = float(sentiment)
            except ValueError:
                message = "Sentiment is not a float"
                message_class = "danger"
                return {"message": message, "class": message_class}
        sentiment_method = query_params["sentiment_method"]

        return (sentiment_method, sentiment)