from http import HTTPStatus
import pkg_resources
import warnings

from flask import Blueprint, current_app, jsonify, make_response, request
from flask_restful import Api, Resource

from server.app.util.constants import (
    Axis,
    DiffExpMode,
    JSON_NaN_to_num_warning_msg,
)
from server.app.util.errors import (
    FilterError,
    InteractiveError,
    JSONEncodingValueError,
    PrepareError,
)

"""
Sort order for routes
1. Initialize
2. Data & Metadata
3. Computation
"""


class SchemaAPI(Resource):
    def get(self):
        return make_response(
            jsonify({"schema": current_app.data.schema}), HTTPStatus.OK
        )


class ConfigAPI(Resource):
    def get(self):
        config = {
            "config": {
                "features": [
                    {
                        "method": "POST",
                        "path": "/cluster/",
                        **current_app.data.features["cluster"],
                    },
                    {
                        "method": "POST",
                        "path": "/layout/obs",
                        **current_app.data.features["layout"]["obs"],
                    },
                    {
                        "method": "POST",
                        "path": "/layout/var",
                        **current_app.data.features["layout"]["var"],
                    },
                    {
                        "method": "POST",
                        "path": "/diffexp/",
                        **current_app.data.features["diffexp"],
                    },
                ],
                "displayNames": {
                    "engine": f"cellxgene Scanpy engine version {pkg_resources.get_distribution('cellxgene').version}",
                    "dataset": current_app.config["DATASET_TITLE"],
                },
                "parameters": {
                    "max_category_items": current_app.data.max_category_items
                },
                "library_versions": {
                    "scanpy": pkg_resources.get_distribution("scanpy").version,
                    "cellxgene": pkg_resources.get_distribution("cellxgene").version,
                    "anndata": pkg_resources.get_distribution("cellxgene").version
                }
            }
        }
        return make_response(jsonify(config), HTTPStatus.OK)


class AnnotationsObsAPI(Resource):
    def get(self):
        fields = request.args.getlist("annotation-name", None)
        preferred_mimetype = request.accept_mimetypes.best_match(
            ["application/octet-stream"]
        )
        try:
            if preferred_mimetype == "application/octet-stream":
                return make_response(current_app.data.annotation_to_fbs_matrix("obs", fields),
                                     HTTPStatus.OK,
                                     {"Content-Type": "application/octet-stream"})
            else:
                return make_response(f"Unsupported MIME type '{request.accept_mimetypes}'", HTTPStatus.NOT_ACCEPTABLE)
        except KeyError:
            return make_response(f"Error bad key in {fields}", HTTPStatus.BAD_REQUEST)
        except ValueError as e:
            return make_response(str(e), HTTPStatus.INTERNAL_SERVER_ERROR)


class AnnotationsVarAPI(Resource):
    def get(self):
        fields = request.args.getlist("annotation-name", None)
        preferred_mimetype = request.accept_mimetypes.best_match(
            ["application/octet-stream"]
        )
        try:
            if preferred_mimetype == "application/octet-stream":
                return make_response(current_app.data.annotation_to_fbs_matrix("var", fields),
                                     HTTPStatus.OK,
                                     {"Content-Type": "application/octet-stream"})
            else:
                return make_response(f"Unsupported MIME type '{request.accept_mimetypes}'", HTTPStatus.NOT_ACCEPTABLE)
        except KeyError:
            return make_response(f"Error bad key in {fields}", HTTPStatus.BAD_REQUEST)
        except ValueError as e:
            return make_response(str(e), HTTPStatus.INTERNAL_SERVER_ERROR)


class DataVarAPI(Resource):
    def put(self):
        preferred_mimetype = request.accept_mimetypes.best_match(
            ["application/octet-stream"]
        )
        try:
            if preferred_mimetype == "application/octet-stream":
                filter_json = request.get_json()
                filter = filter_json["filter"] if filter_json else None
                return make_response(
                    current_app.data.data_frame_to_fbs_matrix(
                        filter, axis=Axis.VAR
                    ),
                    HTTPStatus.OK,
                    {"Content-Type": "application/octet-stream"})
            else:
                return make_response(f"Unsupported MIME type '{request.accept_mimetypes}'", HTTPStatus.NOT_ACCEPTABLE)
        except FilterError as e:
            return make_response(e.message, HTTPStatus.BAD_REQUEST)
        except ValueError as e:
            return make_response(str(e), HTTPStatus.INTERNAL_SERVER_ERROR)


class DiffExpObsAPI(Resource):
    def post(self):
        args = request.get_json()
        # confirm mode is present and legal
        try:
            mode = DiffExpMode(args["mode"])
        except KeyError:
            return make_response("Error: mode is required", HTTPStatus.BAD_REQUEST)
        except ValueError:
            return make_response(
                f"Error: invalid mode option {args['mode']}", HTTPStatus.BAD_REQUEST
            )
        # Validate filters
        if mode == DiffExpMode.VAR_FILTER or "varFilter" in args:
            # not NOT_IMPLEMENTED
            return make_response(
                "mode=varfilter not implemented", HTTPStatus.NOT_IMPLEMENTED
            )
        if mode == DiffExpMode.TOP_N and "count" not in args:
            return make_response(
                "mode=topN requires a count parameter", HTTPStatus.BAD_REQUEST
            )

        if "set1" not in args:
            return make_response("set1 is required.", HTTPStatus.BAD_REQUEST)
        if Axis.VAR in args["set1"]["filter"]:
            return make_response(
                "Var filter not allowed for set1", HTTPStatus.BAD_REQUEST
            )
        # set2
        if "set2" not in args:
            return make_response(
                "Set2 as inverse of set1 is not implemented", HTTPStatus.NOT_IMPLEMENTED
            )
        if Axis.VAR in args["set2"]["filter"]:
            return make_response(
                "Var filter not allowed for set2", HTTPStatus.BAD_REQUEST
            )

        set1_filter = args["set1"]["filter"]
        set2_filter = args.get("set2", {"filter": {}})["filter"]

        # TODO: implement varfilter mode

        # mode=topN
        count = args.get("count", None)
        try:
            diffexp = current_app.data.diffexp_topN(
                set1_filter,
                set2_filter,
                count,
                current_app.data.features["diffexp"]["interactiveLimit"],
            )
            return make_response(
                diffexp, HTTPStatus.OK, {"Content-Type": "application/json"}
            )
        except (ValueError, FilterError) as e:
            return make_response(e.message, HTTPStatus.BAD_REQUEST)
        except InteractiveError:
            return make_response("Non-interactive request", HTTPStatus.FORBIDDEN)
        except JSONEncodingValueError as e:
            # JSON encoding failure, usually due to bad data
            warnings.warn(JSON_NaN_to_num_warning_msg)
            return make_response(str(e), HTTPStatus.INTERNAL_SERVER_ERROR)
        except ValueError as e:
            return make_response(str(e), HTTPStatus.INTERNAL_SERVER_ERROR)


class LayoutObsAPI(Resource):
    def get(self):
        preferred_mimetype = request.accept_mimetypes.best_match(
            ["application/octet-stream"]
        )
        try:
            if preferred_mimetype == "application/octet-stream":
                return make_response(current_app.data.layout_to_fbs_matrix(),
                                     HTTPStatus.OK,
                                     {"Content-Type": "application/octet-stream"})
            else:
                return make_response(f"Unsupported MIME type '{request.accept_mimetypes}'", HTTPStatus.NOT_ACCEPTABLE)
        except PrepareError as e:
            return make_response(e.message, HTTPStatus.INTERNAL_SERVER_ERROR)
        except ValueError as e:
            return make_response(str(e), HTTPStatus.INTERNAL_SERVER_ERROR)


def get_api_resources():
    bp = Blueprint("api", __name__, url_prefix="/api/v0.2")
    api = Api(bp)
    # Initialization routes
    api.add_resource(SchemaAPI, "/schema")
    api.add_resource(ConfigAPI, "/config")
    # Data routes
    api.add_resource(AnnotationsObsAPI, "/annotations/obs")
    api.add_resource(AnnotationsVarAPI, "/annotations/var")
    api.add_resource(DataVarAPI, "/data/var")
    # Computation routes
    api.add_resource(DiffExpObsAPI, "/diffexp/obs")
    api.add_resource(LayoutObsAPI, "/layout/obs")
    return api