import urllib
from contextlib import suppress
from dataclasses import dataclass
from datetime import timedelta
from decimal import Decimal
from typing import Any, Dict, Iterable, List, Optional
from urllib.parse import urlencode

from django.conf import settings
from django.core.exceptions import ValidationError
from django.core.validators import URLValidator
from django.http import HttpRequest, HttpResponse, HttpResponseRedirect
from django.shortcuts import render
from django.urls import reverse
from django.utils.timesince import timesince
from django.utils.timezone import now as timezone_now
from django.utils.translation import gettext as _

from confirmation.models import Confirmation, confirmation_url
from confirmation.settings import STATUS_USED
from zerver.actions.create_realm import do_change_realm_subdomain
from zerver.actions.realm_settings import (
    do_change_realm_org_type,
    do_change_realm_plan_type,
    do_deactivate_realm,
    do_scrub_realm,
    do_send_realm_reactivation_email,
)
from zerver.decorator import require_server_admin
from zerver.forms import check_subdomain_available
from zerver.lib.exceptions import JsonableError
from zerver.lib.realm_icon import realm_icon_url
from zerver.lib.request import REQ, has_request_variables
from zerver.lib.subdomains import get_subdomain_from_hostname
from zerver.lib.validator import check_bool, check_string_in, to_decimal, to_non_negative_int
from zerver.models import (
    MultiuseInvite,
    PreregistrationRealm,
    PreregistrationUser,
    Realm,
    RealmReactivationStatus,
    UserProfile,
    get_org_type_display_name,
    get_realm,
)
from zerver.views.invite import get_invitee_emails_set

if settings.BILLING_ENABLED:
    from corporate.lib.stripe import approve_sponsorship as do_approve_sponsorship
    from corporate.lib.stripe import (
        attach_discount_to_realm,
        downgrade_at_the_end_of_billing_cycle,
        downgrade_now_without_creating_additional_invoices,
        get_discount_for_realm,
        get_latest_seat_count,
        make_end_of_cycle_updates_if_needed,
        switch_realm_from_standard_to_plus_plan,
        update_billing_method_of_current_plan,
        update_sponsorship_status,
        void_all_open_invoices,
    )
    from corporate.models import (
        Customer,
        CustomerPlan,
        get_current_plan_by_realm,
        get_customer_by_realm,
    )


def get_plan_name(plan_type: int) -> str:
    return {
        Realm.PLAN_TYPE_SELF_HOSTED: "self-hosted",
        Realm.PLAN_TYPE_LIMITED: "limited",
        Realm.PLAN_TYPE_STANDARD: "standard",
        Realm.PLAN_TYPE_STANDARD_FREE: "open source",
        Realm.PLAN_TYPE_PLUS: "plus",
    }[plan_type]


def get_confirmations(
    types: List[int], object_ids: Iterable[int], hostname: Optional[str] = None
) -> List[Dict[str, Any]]:
    lowest_datetime = timezone_now() - timedelta(days=30)
    confirmations = Confirmation.objects.filter(
        type__in=types, object_id__in=object_ids, date_sent__gte=lowest_datetime
    )
    confirmation_dicts = []
    for confirmation in confirmations:
        realm = confirmation.realm
        content_object = confirmation.content_object

        type = confirmation.type
        expiry_date = confirmation.expiry_date

        assert content_object is not None
        if hasattr(content_object, "status"):
            if content_object.status == STATUS_USED:
                link_status = "Link has been used"
            else:
                link_status = "Link has not been used"
        else:
            link_status = ""

        now = timezone_now()
        if expiry_date is None:
            expires_in = "Never"
        elif now < expiry_date:
            expires_in = timesince(now, expiry_date)
        else:
            expires_in = "Expired"

        url = confirmation_url(confirmation.confirmation_key, realm, type)
        confirmation_dicts.append(
            {
                "object": confirmation.content_object,
                "url": url,
                "type": type,
                "link_status": link_status,
                "expires_in": expires_in,
            }
        )
    return confirmation_dicts


VALID_MODIFY_PLAN_METHODS = [
    "downgrade_at_billing_cycle_end",
    "downgrade_now_without_additional_licenses",
    "downgrade_now_void_open_invoices",
    "upgrade_to_plus",
]

VALID_STATUS_VALUES = [
    "active",
    "deactivated",
]

VALID_BILLING_METHODS = [
    "send_invoice",
    "charge_automatically",
]


@dataclass
class PlanData:
    customer: Optional["Customer"] = None
    current_plan: Optional["CustomerPlan"] = None
    licenses: Optional[int] = None
    licenses_used: Optional[int] = None


@require_server_admin
@has_request_variables
def support(
    request: HttpRequest,
    realm_id: Optional[int] = REQ(default=None, converter=to_non_negative_int),
    plan_type: Optional[int] = REQ(default=None, converter=to_non_negative_int),
    discount: Optional[Decimal] = REQ(default=None, converter=to_decimal),
    new_subdomain: Optional[str] = REQ(default=None),
    status: Optional[str] = REQ(default=None, str_validator=check_string_in(VALID_STATUS_VALUES)),
    billing_method: Optional[str] = REQ(
        default=None, str_validator=check_string_in(VALID_BILLING_METHODS)
    ),
    sponsorship_pending: Optional[bool] = REQ(default=None, json_validator=check_bool),
    approve_sponsorship: bool = REQ(default=False, json_validator=check_bool),
    modify_plan: Optional[str] = REQ(
        default=None, str_validator=check_string_in(VALID_MODIFY_PLAN_METHODS)
    ),
    scrub_realm: bool = REQ(default=False, json_validator=check_bool),
    query: Optional[str] = REQ("q", default=None),
    org_type: Optional[int] = REQ(default=None, converter=to_non_negative_int),
) -> HttpResponse:
    context: Dict[str, Any] = {}

    if "success_message" in request.session:
        context["success_message"] = request.session["success_message"]
        del request.session["success_message"]

    if settings.BILLING_ENABLED and request.method == "POST":
        # We check that request.POST only has two keys in it: The
        # realm_id and a field to change.
        keys = set(request.POST.keys())
        if "csrfmiddlewaretoken" in keys:
            keys.remove("csrfmiddlewaretoken")
        if len(keys) != 2:
            raise JsonableError(_("Invalid parameters"))

        assert realm_id is not None
        realm = Realm.objects.get(id=realm_id)

        acting_user = request.user
        assert isinstance(acting_user, UserProfile)
        if plan_type is not None:
            current_plan_type = realm.plan_type
            do_change_realm_plan_type(realm, plan_type, acting_user=acting_user)
            msg = f"Plan type of {realm.string_id} changed from {get_plan_name(current_plan_type)} to {get_plan_name(plan_type)} "
            context["success_message"] = msg
        elif org_type is not None:
            current_realm_type = realm.org_type
            do_change_realm_org_type(realm, org_type, acting_user=acting_user)
            msg = f"Org type of {realm.string_id} changed from {get_org_type_display_name(current_realm_type)} to {get_org_type_display_name(org_type)} "
            context["success_message"] = msg
        elif discount is not None:
            current_discount = get_discount_for_realm(realm) or 0
            attach_discount_to_realm(realm, discount, acting_user=acting_user)
            context[
                "success_message"
            ] = f"Discount of {realm.string_id} changed to {discount}% from {current_discount}%."
        elif new_subdomain is not None:
            old_subdomain = realm.string_id
            try:
                check_subdomain_available(new_subdomain)
            except ValidationError as error:
                context["error_message"] = error.message
            else:
                do_change_realm_subdomain(realm, new_subdomain, acting_user=acting_user)
                request.session[
                    "success_message"
                ] = f"Subdomain changed from {old_subdomain} to {new_subdomain}"
                return HttpResponseRedirect(
                    reverse("support") + "?" + urlencode({"q": new_subdomain})
                )
        elif status is not None:
            if status == "active":
                do_send_realm_reactivation_email(realm, acting_user=acting_user)
                context[
                    "success_message"
                ] = f"Realm reactivation email sent to admins of {realm.string_id}."
            elif status == "deactivated":
                do_deactivate_realm(realm, acting_user=acting_user)
                context["success_message"] = f"{realm.string_id} deactivated."
        elif billing_method is not None:
            if billing_method == "send_invoice":
                update_billing_method_of_current_plan(
                    realm, charge_automatically=False, acting_user=acting_user
                )
                context[
                    "success_message"
                ] = f"Billing method of {realm.string_id} updated to pay by invoice."
            elif billing_method == "charge_automatically":
                update_billing_method_of_current_plan(
                    realm, charge_automatically=True, acting_user=acting_user
                )
                context[
                    "success_message"
                ] = f"Billing method of {realm.string_id} updated to charge automatically."
        elif sponsorship_pending is not None:
            if sponsorship_pending:
                update_sponsorship_status(realm, True, acting_user=acting_user)
                context["success_message"] = f"{realm.string_id} marked as pending sponsorship."
            else:
                update_sponsorship_status(realm, False, acting_user=acting_user)
                context["success_message"] = f"{realm.string_id} is no longer pending sponsorship."
        elif approve_sponsorship:
            do_approve_sponsorship(realm, acting_user=acting_user)
            context["success_message"] = f"Sponsorship approved for {realm.string_id}"
        elif modify_plan is not None:
            if modify_plan == "downgrade_at_billing_cycle_end":
                downgrade_at_the_end_of_billing_cycle(realm)
                context[
                    "success_message"
                ] = f"{realm.string_id} marked for downgrade at the end of billing cycle"
            elif modify_plan == "downgrade_now_without_additional_licenses":
                downgrade_now_without_creating_additional_invoices(realm)
                context[
                    "success_message"
                ] = f"{realm.string_id} downgraded without creating additional invoices"
            elif modify_plan == "downgrade_now_void_open_invoices":
                downgrade_now_without_creating_additional_invoices(realm)
                voided_invoices_count = void_all_open_invoices(realm)
                context[
                    "success_message"
                ] = f"{realm.string_id} downgraded and voided {voided_invoices_count} open invoices"
            elif modify_plan == "upgrade_to_plus":
                switch_realm_from_standard_to_plus_plan(realm)
                context["success_message"] = f"{realm.string_id} upgraded to Plus"
        elif scrub_realm:
            do_scrub_realm(realm, acting_user=acting_user)
            context["success_message"] = f"{realm.string_id} scrubbed."

    if query:
        key_words = get_invitee_emails_set(query)

        users = set(UserProfile.objects.filter(delivery_email__in=key_words))
        realms = set(Realm.objects.filter(string_id__in=key_words))

        for key_word in key_words:
            try:
                URLValidator()(key_word)
                parse_result = urllib.parse.urlparse(key_word)
                hostname = parse_result.hostname
                assert hostname is not None
                if parse_result.port:
                    hostname = f"{hostname}:{parse_result.port}"
                subdomain = get_subdomain_from_hostname(hostname)
                with suppress(Realm.DoesNotExist):
                    realms.add(get_realm(subdomain))
            except ValidationError:
                users.update(UserProfile.objects.filter(full_name__iexact=key_word))

        # full_names can have , in them
        users.update(UserProfile.objects.filter(full_name__iexact=query))

        context["users"] = users
        context["realms"] = realms

        confirmations: List[Dict[str, Any]] = []

        preregistration_user_ids = [
            user.id for user in PreregistrationUser.objects.filter(email__in=key_words)
        ]
        confirmations += get_confirmations(
            [Confirmation.USER_REGISTRATION, Confirmation.INVITATION],
            preregistration_user_ids,
            hostname=request.get_host(),
        )

        preregistration_realm_ids = [
            user.id for user in PreregistrationRealm.objects.filter(email__in=key_words)
        ]
        confirmations += get_confirmations(
            [Confirmation.REALM_CREATION],
            preregistration_realm_ids,
            hostname=request.get_host(),
        )

        multiuse_invite_ids = [
            invite.id for invite in MultiuseInvite.objects.filter(realm__in=realms)
        ]
        confirmations += get_confirmations([Confirmation.MULTIUSE_INVITE], multiuse_invite_ids)

        realm_reactivation_status_objects = RealmReactivationStatus.objects.filter(realm__in=realms)
        confirmations += get_confirmations(
            [Confirmation.REALM_REACTIVATION], [obj.id for obj in realm_reactivation_status_objects]
        )

        context["confirmations"] = confirmations

        # We want a union of all realms that might appear in the search result,
        # but not necessary as a separate result item.
        # Therefore, we do not modify the realms object in the context.
        all_realms = realms.union(
            [
                confirmation["object"].realm
                for confirmation in confirmations
                # For confirmations, we only display realm details when the type is USER_REGISTRATION
                # or INVITATION.
                if confirmation["type"] in (Confirmation.USER_REGISTRATION, Confirmation.INVITATION)
            ]
            + [user.realm for user in users]
        )
        plan_data: Dict[int, PlanData] = {}
        for realm in all_realms:
            current_plan = get_current_plan_by_realm(realm)
            plan_data[realm.id] = PlanData(
                customer=get_customer_by_realm(realm),
                current_plan=current_plan,
            )
            if current_plan is not None:
                new_plan, last_ledger_entry = make_end_of_cycle_updates_if_needed(
                    current_plan, timezone_now()
                )
                if last_ledger_entry is not None:
                    if new_plan is not None:
                        plan_data[realm.id].current_plan = new_plan
                    else:
                        plan_data[realm.id].current_plan = current_plan
                    plan_data[realm.id].licenses = last_ledger_entry.licenses
                    plan_data[realm.id].licenses_used = get_latest_seat_count(realm)
        context["plan_data"] = plan_data

    def get_realm_owner_emails_as_string(realm: Realm) -> str:
        return ", ".join(
            realm.get_human_owner_users()
            .order_by("delivery_email")
            .values_list("delivery_email", flat=True)
        )

    def get_realm_admin_emails_as_string(realm: Realm) -> str:
        return ", ".join(
            realm.get_human_admin_users(include_realm_owners=False)
            .order_by("delivery_email")
            .values_list("delivery_email", flat=True)
        )

    context["get_realm_owner_emails_as_string"] = get_realm_owner_emails_as_string
    context["get_realm_admin_emails_as_string"] = get_realm_admin_emails_as_string
    context["get_discount_for_realm"] = get_discount_for_realm
    context["get_org_type_display_name"] = get_org_type_display_name
    context["realm_icon_url"] = realm_icon_url
    context["Confirmation"] = Confirmation
    context["sorted_realm_types"] = sorted(
        Realm.ORG_TYPES.values(), key=lambda d: d["display_order"]
    )

    return render(request, "analytics/support.html", context=context)