"""REST API for accessing the crashreports statistics."""
import zipfile

from rest_framework import generics
from rest_framework import serializers
from rest_framework.exceptions import NotFound
from rest_framework.response import Response
from rest_framework.views import APIView

from django.core.exceptions import ObjectDoesNotExist
from django.db import connection
from django.db.models.expressions import F

from django_filters.rest_framework import (
    DjangoFilterBackend,
    DateFilter,
    FilterSet,
    CharFilter,
    BooleanFilter,
)

from crashreport_stats.models import (
    Version,
    VersionDaily,
    RadioVersion,
    RadioVersionDaily,
)
from crashreports.models import Device, Crashreport, HeartBeat, LogFile
from crashreports.permissions import (
    HasRightsOrIsDeviceOwnerDeviceCreation,
    HasStatsAccess,
)
from . import raw_querys


def dictfetchall(cursor):
    """Return all rows from a cursor as a dict."""
    desc = cursor.description
    return [
        dict(zip([col[0] for col in desc], row)) for row in cursor.fetchall()
    ]


class DeviceUpdateHistory(APIView):
    """View the update history of a specific device."""

    permission_classes = (HasRightsOrIsDeviceOwnerDeviceCreation,)

    def get(self, request, uuid, format=None):
        """Get the update history of a device.

        Args:
            request: Http request
            uuid: The UUID of the device
            format: Optional response format parameter

        Returns: The update history of the requested device.

        """
        cursor = connection.cursor()
        raw_querys.execute_device_update_history_query(cursor, {"uuid": uuid})
        res = dictfetchall(cursor)
        return Response(res)


class DeviceReportHistory(APIView):
    """View the report history of a specific device."""

    permission_classes = (HasRightsOrIsDeviceOwnerDeviceCreation,)

    def get(self, request, uuid, format=None):
        """Get the report history of a device.

        Args:
            request: Http request
            uuid: The UUID of the device
            format: Optional response format parameter

        Returns: The report history of the requested device.

        """
        cursor = connection.cursor()
        raw_querys.execute_device_report_history(cursor, {"uuid": uuid})
        res = dictfetchall(cursor)
        return Response(res)


class Status(APIView):
    """View the number of devices, crashreports and heartbeats."""

    permission_classes = (HasStatsAccess,)

    def get(self, request, format=None):
        """Get the number of devices, crashreports and heartbeats.

        Args:
            request: Http request
            format: Optional response format parameter

        Returns: The number of devices, crashreports and heartbeats.

        """
        num_devices = Device.objects.count()
        num_crashreports = Crashreport.objects.count()
        num_heartbeats = HeartBeat.objects.count()
        return Response(
            {
                "devices": num_devices,
                "crashreports": num_crashreports,
                "heartbeats": num_heartbeats,
            }
        )


class DeviceStat(APIView):
    """View an overview of the statistics of a device."""

    permission_classes = (HasRightsOrIsDeviceOwnerDeviceCreation,)

    def get(self, request, uuid, format=None):
        """Get some general statistics for a device.

        Args:
            request: Http request
            uuid:  The UUID of the device
            format: Optional response format parameter

        Returns: Some general information of the device in a dictionary.

        """
        device = Device.objects.filter(uuid=uuid)
        last_active = (
            HeartBeat.objects.filter(device=device).order_by("-date")[0].date
        )
        heartbeats = HeartBeat.objects.filter(device=device).count()
        crashreports = (
            Crashreport.objects.filter(device=device)
            .filter(boot_reason__in=Crashreport.CRASH_BOOT_REASONS)
            .count()
        )
        crashes_per_day = (
            crashreports * 1.0 / heartbeats if heartbeats > 0 else 0
        )
        smpls = (
            Crashreport.objects.filter(device=device)
            .filter(boot_reason__in=Crashreport.SMPL_BOOT_REASONS)
            .count()
        )
        smpl_per_day = smpls * 1.0 / heartbeats if heartbeats > 0 else 0
        return Response(
            {
                "uuid": uuid,
                "last_active": last_active,
                "heartbeats": heartbeats,
                "crashreports": crashreports,
                "crashes_per_day": crashes_per_day,
                "smpls": smpls,
                "smpl_per_day": smpl_per_day,
                "board_date": device[0].board_date,
            }
        )


class LogFileDownload(APIView):
    """View for downloading log files."""

    permission_classes = (HasRightsOrIsDeviceOwnerDeviceCreation,)

    def get(self, request, id_logfile, format=None):
        """Get a logfile.

        Args:
            request: Http request
            id_logfile: The id of the log file
            format: Optional response format parameter

        Returns: The log file with the corresponding id.

        """
        try:
            logfile = LogFile.objects.get(id=id_logfile)
        except ObjectDoesNotExist:
            raise NotFound(detail="Logfile does not exist.")
        zip_file = zipfile.ZipFile(logfile.logfile.path)
        ret = {}
        for file in zip_file.filelist:
            file_open = zip_file.open(file)
            ret[file.filename] = file_open.read()
        return Response(ret)


class _VersionStatsFilter(FilterSet):
    first_seen_before = DateFilter(
        field_name="first_seen_on", lookup_expr="lte"
    )
    first_seen_after = DateFilter(field_name="first_seen_on", lookup_expr="gte")
    released_before = DateFilter(field_name="released_on", lookup_expr="lte")
    released_after = DateFilter(field_name="released_on", lookup_expr="gte")


class _VersionStatsSerializer(serializers.ModelSerializer):
    permission_classes = (HasStatsAccess,)


class _VersionStatsListView(generics.ListAPIView):
    permission_classes = (HasStatsAccess,)
    filter_backends = (DjangoFilterBackend,)


class _DailyVersionStatsFilter(FilterSet):
    date_start = DateFilter(field_name="date", lookup_expr="gte")
    date_end = DateFilter(field_name="date", lookup_expr="lte")


class _DailyVersionStatsSerializer(serializers.ModelSerializer):
    permission_classes = (HasStatsAccess,)


class _DailyVersionStatsListView(generics.ListAPIView):
    permission_classes = (HasStatsAccess,)
    filter_backends = (DjangoFilterBackend,)


class VersionSerializer(_VersionStatsSerializer):
    """Serializer for the Version class."""

    class Meta:  # noqa: D106
        model = Version
        fields = "__all__"


class VersionFilter(_VersionStatsFilter):
    """Filter for Version instances."""

    class Meta:  # noqa: D106
        model = Version
        fields = "__all__"


class VersionListView(_VersionStatsListView):
    """View for listing versions."""

    queryset = Version.objects.all().order_by("-heartbeats")
    filter_class = VersionFilter
    serializer_class = VersionSerializer


class VersionDailyFilter(_DailyVersionStatsFilter):
    """Filter for VersionDaily instances."""

    version__build_fingerprint = CharFilter()
    version__is_official_release = BooleanFilter()
    version__is_beta_release = BooleanFilter()

    class Meta:  # noqa: D106
        model = VersionDaily
        fields = "__all__"


class VersionDailySerializer(_DailyVersionStatsSerializer):
    """Serializer for VersionDaily instances."""

    build_fingerprint = serializers.CharField()

    class Meta:  # noqa: D106
        model = VersionDaily
        fields = "__all__"


class VersionDailyListView(_DailyVersionStatsListView):
    """View for listing VersionDaily instances."""

    queryset = (
        VersionDaily.objects.annotate(
            build_fingerprint=F("version__build_fingerprint")
        )
        .all()
        .order_by("date")
    )
    filter_class = VersionDailyFilter
    filter_fields = (
        "version__build_fingerprint",
        "version__is_official_release",
        "version__is_beta_release",
    )
    serializer_class = VersionDailySerializer


class RadioVersionSerializer(_VersionStatsSerializer):
    """Serializer for RadioVersion instances."""

    class Meta:  # noqa: D106
        model = RadioVersion
        fields = "__all__"


class RadioVersionFilter(_VersionStatsFilter):
    """Filter for RadioVersion instances."""

    class Meta:  # noqa: D106
        model = RadioVersion
        fields = "__all__"


class RadioVersionListView(_VersionStatsListView):
    """View for listing RadioVersion instances."""

    queryset = RadioVersion.objects.all().order_by("-heartbeats")
    serializer_class = RadioVersionSerializer
    filter_class = RadioVersionFilter


class RadioVersionDailyFilter(_DailyVersionStatsFilter):
    """Filter for RadioVersionDaily instances."""

    version__radio_version = CharFilter()
    version__is_official_release = BooleanFilter()
    version__is_beta_release = BooleanFilter()

    class Meta:  # noqa: D106
        model = RadioVersionDaily
        fields = "__all__"


class RadioVersionDailySerializer(_DailyVersionStatsSerializer):
    """Serializer for RadioVersionDaily instances."""

    radio_version = serializers.CharField()

    class Meta:  # noqa: D106
        model = RadioVersionDaily
        fields = "__all__"


class RadioVersionDailyListView(_DailyVersionStatsListView):
    """View for listing RadioVersionDaily instances."""

    queryset = (
        RadioVersionDaily.objects.annotate(
            radio_version=F("version__radio_version")
        )
        .all()
        .order_by("date")
    )
    filter_class = RadioVersionDailyFilter
    filter_fields = (
        "version__radio_version",
        "version__is_official_release",
        "version__is_beta_release",
    )
    serializer_class = RadioVersionDailySerializer