import logging
from datetime import date, datetime

from django.conf import settings
from django.contrib import admin, messages
from django.http import HttpResponseRedirect
from django.utils.html import format_html
from django.utils.translation import gettext_lazy as _
from django.utils.translation import ngettext
from segno import helpers

from posts.models import FetMeeting

from .forms import (
    BankDataAdminForm,
    BillAdminForm,
    BillInlineForm,
    ResolutionAdminForm,
    WirefAdminForm,
)
from .models import BankData, Bill, Resolution, Wiref
from .utils import generate_pdf

logger = logging.getLogger(__name__)


class BillPeriodeFilter(admin.SimpleListFilter):
    title = "Periode"
    parameter_name = "period"

    __lst = ()

    def choices(self, changelist):
        # Current period.
        yield {
            "selected": self.value() is None,
            "query_string": changelist.get_query_string(remove=[self.parameter_name]),
            "display": self.__lst[0][1],
        }

        # Add all other periods.
        for lookup, title in self.__lst[1:]:
            yield {
                "selected": self.value() == str(lookup),
                "query_string": changelist.get_query_string({self.parameter_name: lookup}),
                "display": title,
            }

        # 'All' choice.
        yield {
            "selected": self.value() == "All",
            "query_string": changelist.get_query_string({self.parameter_name: "All"}),
            "display": _("All"),
        }

    def lookups(self, request, model_admin):
        qs = model_admin.get_queryset(request).order_by("-date")
        if not qs.exists():
            return None

        count = 0
        total_count = qs.count()

        # Get first period.
        start_year = qs.first().date.year

        # Check if date of first bill is in first half of year. If yes, start of period is the
        # year before.
        if qs.first().date < date(start_year, 7, 1):
            start_year -= 1

        start_date = date(start_year, 7, 1)
        end_date = date(start_year + 1, 6, 30)
        entry_qs = qs.filter(date__range=(start_date, end_date))

        # Go through all bills to get the periods.
        while count != total_count:
            # Set period if a bill exists.
            if entry_qs.exists():
                self.__lst += (
                    (
                        f"{start_year}-{start_year + 1}",
                        f"Periode {start_year}-{start_year + 1}",
                    ),
                )
                count += entry_qs.count()

            # Get bills from next period.
            start_year -= 1
            start_date = date(start_year, 7, 1)
            end_date = date(start_year + 1, 6, 30)
            entry_qs = qs.filter(date__range=(start_date, end_date))

            # If you are searching bills from 90's, something went wrong.
            if start_year < 2000:
                logger.info(
                    "Something went wrong while counting. Count: %s. Totalcounter: %s",
                    count,
                    total_count,
                )
                break

        return self.__lst

    def queryset(self, request, queryset):
        qs = queryset

        if self.value():
            try:
                period = datetime.strptime(self.value()[:4], "%Y")  # noqa: DTZ007
            except Exception:
                # If choice is 'All', return all bills.
                qs = queryset
            else:
                # Return bills from specific old period.
                start_year = period.year
                start_date = date(start_year, 7, 1)
                end_date = date(start_year + 1, 6, 30)
                qs = queryset.filter(date__range=(start_date, end_date))

        # Return bills from current period.
        else:
            tmp_qs = queryset.order_by("-date")

            # Get first period.
            start_year = tmp_qs.first().date.year

            # Check if date of first bill is in first half of year. If yes, start of period is the
            # year before.
            if tmp_qs.first().date < date(start_year, 7, 1):
                start_year -= 1

            start_date = date(start_year, 7, 1)
            end_date = date(start_year + 1, 6, 30)
            qs = queryset.filter(date__range=(start_date, end_date))

        return qs


class BillInline(admin.TabularInline):
    form = BillInlineForm
    model = Bill

    can_delete = False
    extra = 0
    max_num = 0
    readonly_fields = ("purpose", "amount", "file_field", "affiliation")
    show_change_link = True


@admin.register(BankData)
class BankDataAdmin(admin.ModelAdmin):
    form = BankDataAdminForm
    model = BankData

    inlines = (BillInline,)

    list_display = [
        "name",
        "iban",
        "bic",
        "address",
        "is_disabled",
    ]

    ordering = ["name"]

    def add_view(self, request, form_url="", extra_context=None):
        extra_context = extra_context or {}
        extra_context["help_text"] = "Fette Schriften sind Pflichtfelder."
        return super().add_view(
            request,
            form_url,
            extra_context=extra_context,
        )

    def change_view(self, request, object_id, form_url="", extra_context=None):
        extra_context = extra_context or {}
        extra_context["help_text"] = "Fette Schriften sind Pflichtfelder."
        return super().change_view(
            request,
            object_id,
            form_url,
            extra_context=extra_context,
        )


@admin.register(Bill)
class BillAdmin(admin.ModelAdmin):
    form = BillAdminForm
    model = Bill

    list_display = [
        "id",
        "only_digital",
        "amount",
        "purpose",
        "resolution",
        "status_colored",
        "bill_creator",
        "affiliation",
    ]

    actions = ["make_cleared", "make_finished"]
    autocomplete_fields = ["resolution"]
    list_filter = ["status", "affiliation", "payer", BillPeriodeFilter]
    search_fields = [
        "purpose",
        "bankdata__name",
        "bill_creator__firstname",
        "bill_creator__surname",
    ]
    show_facets = admin.ShowFacets.ALWAYS
    ordering = ["-id"]

    readonly_fields = [
        "get_bankdata_name",
        "get_bankdata_iban",
        "get_bankdata_bic",
        "get_qrcode",
    ]
    fieldsets = (
        (
            None,
            {
                "fields": (
                    "bill_creator",
                    "resolution",
                ),
            },
        ),
        (
            "Bankdaten",
            {
                "fields": (
                    "payer",
                    "bankdata",
                    ("get_bankdata_name", "get_bankdata_iban", "get_bankdata_bic"),
                    "get_qrcode",
                ),
            },
        ),
        (
            "Rechnung",
            {
                "fields": (
                    "affiliation",
                    "date",
                    "invoice",
                    "purpose",
                    "amount",
                    "only_digital",
                    "file_field",
                ),
            },
        ),
        (
            "Sonstiges",
            {
                "fields": (
                    "comment",
                    "wiref",
                    "status",
                ),
            },
        ),
    )

    def add_view(self, request, form_url="", extra_context=None):
        extra_context = extra_context or {}
        extra_context["help_text"] = "Fette Schriften sind Pflichtfelder."
        return super().add_view(
            request,
            form_url,
            extra_context=extra_context,
        )

    def change_view(self, request, object_id, form_url="", extra_context=None):
        extra_context = extra_context or {}
        extra_context["help_text"] = "Fette Schriften sind Pflichtfelder."
        return super().change_view(
            request,
            object_id,
            form_url,
            extra_context=extra_context,
        )

    def save_model(self, request, obj, form, change):
        obj.author = request.user
        super().save_model(request, obj, form, change)

    @admin.display(description="Kontoinhaber:in")
    def get_bankdata_name(self, obj):
        try:
            tmp = BankData.objects.get(id=obj.bankdata.id)
        except Exception:
            return "-"

        return f"{tmp.name}"

    @admin.display(description="IBAN")
    def get_bankdata_iban(self, obj):
        try:
            tmp = BankData.objects.get(id=obj.bankdata.id)
        except Exception:
            return "-"

        return f"{tmp.iban}"

    @admin.display(description="BIC")
    def get_bankdata_bic(self, obj):
        try:
            tmp = BankData.objects.get(id=obj.bankdata.id)
        except Exception:
            return "-"

        return f"{tmp.bic}"

    @admin.display(description="QR Code")
    def get_qrcode(self, obj):
        if obj.status != Bill.Status.CLEARED:
            return "-"

        try:
            tmp = BankData.objects.get(id=obj.bankdata.id)
        except Exception:
            return "-"

        try:
            qrcode = helpers.make_epc_qr(
                name=tmp.name,
                iban=tmp.iban,
                amount=obj.amount,
                text=obj.purpose,
                bic=tmp.bic,
                encoding="utf-8",
            )
        except Exception:
            return "Daten für QR Code ungültig"

        uri = qrcode.png_data_uri(scale=3.0)
        return format_html('<img src="{}">', uri)

    @admin.display(description="Status")
    def status_colored(self, obj):
        # TODO: if there is a status without color, set nothing.
        colors = {
            Bill.Status.SUBMITTED: "red",
            Bill.Status.CLEARED: "darkorange",
            Bill.Status.FINISHED: "green",
            Bill.Status.INCOMPLETED: "blue",
        }
        return format_html(
            '<b style="background:{color};">{status}</b>',
            color=colors[obj.status],
            status=obj.get_status_display(),
        )

    @admin.action(description="Als 'Für Überweisung freigegeben' markieren.")
    def make_cleared(self, request, queryset):
        updated = queryset.update(status=Bill.Status.CLEARED)
        self.message_user(
            request,
            ngettext(
                "%d Rechnung wurde als 'Für Überweisung freigegeben' markiert.",
                "%d Rechnungen wurden als 'Für Überweisung freigegeben' markiert.",
                updated,
            )
            % updated,
            messages.SUCCESS,
        )

    @admin.action(description="Als 'Abgeschlossen / Überwiesen' markieren.")
    def make_finished(self, request, queryset):
        updated = queryset.update(status=Bill.Status.FINISHED)
        self.message_user(
            request,
            ngettext(
                "%d Rechnung wurde als 'Abgeschlossen / Überwiesen' markiert.",
                "%d Rechnungen wurden als 'Abgeschlossen / Überwiesen' markiert.",
                updated,
            )
            % updated,
            messages.SUCCESS,
        )


@admin.register(Resolution)
class ResolutionAdmin(admin.ModelAdmin):
    form = ResolutionAdminForm
    model = Resolution

    inlines = (BillInline,)

    list_display = [
        "name",
        "id",
        "is_visible",
        "total",
    ]

    ordering = ["-id"]
    search_fields = ["name", "id"]

    readonly_fields = [
        "fetmeeting",
    ]
    fieldsets = (
        (
            None,
            {
                "fields": (
                    "name",
                    "id",
                    "date",
                    "option",
                    "is_visible",
                ),
            },
        ),
        (
            "Budget",
            {
                "fields": (
                    "budget",
                    "total",
                    "budget_remaining",
                ),
            },
        ),
        (
            "Abstimmung",
            {
                "classes": ["collapse"],
                "fields": (
                    "voting",
                    "voting_text",
                    "fetmeeting",
                ),
            },
        ),
    )

    def add_view(self, request, form_url="", extra_context=None):
        extra_context = extra_context or {}
        extra_context["help_text"] = "Fette Schriften sind Pflichtfelder."
        return super().add_view(
            request,
            form_url,
            extra_context=extra_context,
        )

    def change_view(self, request, object_id, form_url="", extra_context=None):
        extra_context = extra_context or {}
        extra_context["help_text"] = "Fette Schriften sind Pflichtfelder."
        return super().change_view(
            request,
            object_id,
            form_url,
            extra_context=extra_context,
        )

    @admin.display(description="Gesamtsumme (EUR)")
    def total(self, obj):
        total = 0
        bills = Bill.objects.filter(resolution=obj)
        for elem in bills:
            total += elem.amount

        return f"{total}"

    @admin.display(description="Fachschaftssitzung")
    def fetmeeting(self, obj):
        fetmeeting = FetMeeting.objects.get_queryset().filter(date=obj.date).first()

        if fetmeeting is not None:
            link = f"https://{settings.HOST_NAME}/posts/{fetmeeting.slug}/"
            return format_html('<a href="{}" target="_blank">Link zur Fachschaftssitzung</a>', link)

        return format_html("-")


@admin.register(Wiref)
class WirefAdmin(admin.ModelAdmin):
    form = WirefAdminForm
    model = Wiref

    inlines = (BillInline,)

    list_display = [
        "wiref_id",
        "status",
        "file_field",
        "total",
    ]

    actions = ["make_cleared", "make_finished"]
    list_filter = ["status"]
    ordering = ["-wiref_id"]

    def add_view(self, request, form_url="", extra_context=None):
        extra_context = extra_context or {}
        extra_context["help_text"] = "Fette Schriften sind Pflichtfelder."
        return super().add_view(
            request,
            form_url,
            extra_context=extra_context,
        )

    def change_view(self, request, object_id, form_url="", extra_context=None):
        extra_context = extra_context or {}
        extra_context["help_text"] = "Fette Schriften sind Pflichtfelder."
        extra_context["generate_pdf"] = True
        return super().change_view(
            request,
            object_id,
            form_url,
            extra_context=extra_context,
        )

    def response_change(self, request, obj):
        if "_generate_pdf" in request.POST:
            if generate_pdf(obj) is True:
                self.message_user(
                    request,
                    "Neues Wiref Formular wurde generiert.",
                    messages.SUCCESS,
                )
            else:
                self.message_user(
                    request,
                    "Das PDF-Dokument konnte nicht generiert werden, da der Status nicht auf "
                    "'Offen' gesetzt ist.",
                    messages.WARNING,
                )
            return HttpResponseRedirect(".")
        return super().response_change(request, obj)

    def save_model(self, request, obj, form, change):
        # set status to submitted, if a file exists and status is opened.
        if (
            change is True
            and obj.file_field != ""
            and obj.status == Wiref.Status.OPENED
            and "_generate_pdf" not in request.POST
        ):
            obj.status = Wiref.Status.SUBMITTED
        super().save_model(request, obj, form, change)

    @admin.display(description="Gesamtsumme (EUR)")
    def total(self, obj):
        total = 0
        bills = Bill.objects.filter(wiref=obj)
        for elem in bills:
            total += elem.amount

        return f"{total}"

    @admin.action(description="Als 'Überwiesen' markieren.")
    def make_finished(self, request, queryset):
        updated = queryset.update(status=Wiref.Status.TRANSFERRED)
        self.message_user(
            request,
            ngettext(
                "%d Wiref Formular wurde als 'Überwiesen' markiert.",
                "%d Wiref Formulare wurden als 'Überwiesen' markiert.",
                updated,
            )
            % updated,
            messages.SUCCESS,
        )