from typing import List, Optional, cast

import orjson
from django.core.exceptions import ValidationError
from django.db import IntegrityError
from django.http import HttpRequest, HttpResponse
from django.utils.translation import gettext as _

from zerver.actions.custom_profile_fields import (
    check_remove_custom_profile_field_value,
    do_remove_realm_custom_profile_field,
    do_update_user_custom_profile_data_if_changed,
    try_add_realm_custom_profile_field,
    try_add_realm_default_custom_profile_field,
    try_reorder_realm_custom_profile_fields,
    try_update_realm_custom_profile_field,
)
from zerver.decorator import human_users_only, require_realm_admin
from zerver.lib.exceptions import JsonableError
from zerver.lib.external_accounts import validate_external_account_field_data
from zerver.lib.request import REQ, has_request_variables
from zerver.lib.response import json_success
from zerver.lib.types import ProfileDataElementUpdateDict, ProfileFieldData, Validator
from zerver.lib.users import validate_user_custom_profile_data
from zerver.lib.validator import (
    check_bool,
    check_capped_string,
    check_dict,
    check_dict_only,
    check_int,
    check_list,
    check_string,
    check_union,
    validate_select_field_data,
)
from zerver.models import CustomProfileField, Realm, UserProfile
from zerver.models.custom_profile_fields import custom_profile_fields_for_realm


def list_realm_custom_profile_fields(
    request: HttpRequest, user_profile: UserProfile
) -> HttpResponse:
    fields = custom_profile_fields_for_realm(user_profile.realm_id)
    return json_success(request, data={"custom_fields": [f.as_dict() for f in fields]})


hint_validator = check_capped_string(CustomProfileField.HINT_MAX_LENGTH)
name_validator = check_capped_string(CustomProfileField.NAME_MAX_LENGTH)


def validate_field_name_and_hint(name: str, hint: str) -> None:
    if not name.strip():
        raise JsonableError(_("Label cannot be blank."))

    try:
        hint_validator("hint", hint)
        name_validator("name", name)
    except ValidationError as error:
        raise JsonableError(error.message)


def validate_custom_field_data(field_type: int, field_data: ProfileFieldData) -> None:
    try:
        if field_type == CustomProfileField.SELECT:
            # Choice type field must have at least have one choice
            if len(field_data) < 1:
                raise JsonableError(_("Field must have at least one choice."))
            validate_select_field_data(field_data)
        elif field_type == CustomProfileField.EXTERNAL_ACCOUNT:
            validate_external_account_field_data(field_data)
    except ValidationError as error:
        raise JsonableError(error.message)


def validate_display_in_profile_summary_field(
    field_type: int, display_in_profile_summary: bool
) -> None:
    if not display_in_profile_summary:
        return

    # The LONG_TEXT field type doesn't make sense visually for profile
    # field summaries. The USER field type will require some further
    # client support.
    if field_type in (CustomProfileField.LONG_TEXT, CustomProfileField.USER):
        raise JsonableError(_("Field type not supported for display in profile summary."))


def is_default_external_field(field_type: int, field_data: ProfileFieldData) -> bool:
    if field_type != CustomProfileField.EXTERNAL_ACCOUNT:
        return False
    if field_data["subtype"] == "custom":
        return False
    return True


def validate_custom_profile_field(
    name: str,
    hint: str,
    field_type: int,
    field_data: ProfileFieldData,
    display_in_profile_summary: bool,
) -> None:
    # Validate field data
    validate_custom_field_data(field_type, field_data)

    if not is_default_external_field(field_type, field_data):
        # If field is default external field then we will fetch all data
        # from our default field dictionary, so no need to validate name or hint
        # Validate field name, hint if not default external account field
        validate_field_name_and_hint(name, hint)

    field_types = [i[0] for i in CustomProfileField.FIELD_TYPE_CHOICES]
    if field_type not in field_types:
        raise JsonableError(_("Invalid field type."))

    validate_display_in_profile_summary_field(field_type, display_in_profile_summary)


def validate_custom_profile_field_update(
    field: CustomProfileField,
    display_in_profile_summary: Optional[bool] = None,
    field_data: Optional[ProfileFieldData] = None,
    name: Optional[str] = None,
    hint: Optional[str] = None,
) -> None:
    if name is None:
        name = field.name
    if hint is None:
        hint = field.hint
    if field_data is None:
        if field.field_data == "":
            # We're passing this just for validation, sinec the function won't
            # accept a string. This won't change the actual value.
            field_data = {}
        else:
            field_data = orjson.loads(field.field_data)
    if display_in_profile_summary is None:
        display_in_profile_summary = field.display_in_profile_summary

    assert field_data is not None
    validate_custom_profile_field(
        name,
        hint,
        field.field_type,
        field_data,
        display_in_profile_summary,
    )


check_profile_field_data: Validator[ProfileFieldData] = check_dict(
    value_validator=check_union([check_dict(value_validator=check_string), check_string])
)


def update_only_display_in_profile_summary(
    existing_field: CustomProfileField,
    requested_field_data: Optional[ProfileFieldData] = None,
    requested_name: Optional[str] = None,
    requested_hint: Optional[str] = None,
) -> bool:
    if (
        (requested_name is not None and requested_name != existing_field.name)
        or (requested_hint is not None and requested_hint != existing_field.hint)
        or (
            requested_field_data is not None
            and requested_field_data != orjson.loads(existing_field.field_data)
        )
    ):
        return False
    return True


def display_in_profile_summary_limit_reached(
    realm: Realm, profile_field_id: Optional[int] = None
) -> bool:
    query = CustomProfileField.objects.filter(realm=realm, display_in_profile_summary=True)
    if profile_field_id is not None:
        query = query.exclude(id=profile_field_id)
    return query.count() >= CustomProfileField.MAX_DISPLAY_IN_PROFILE_SUMMARY_FIELDS


@require_realm_admin
@has_request_variables
def create_realm_custom_profile_field(
    request: HttpRequest,
    user_profile: UserProfile,
    name: str = REQ(default="", converter=lambda var_name, x: x.strip()),
    hint: str = REQ(default=""),
    field_data: ProfileFieldData = REQ(default={}, json_validator=check_profile_field_data),
    field_type: int = REQ(json_validator=check_int),
    display_in_profile_summary: bool = REQ(default=False, json_validator=check_bool),
    required: bool = REQ(default=False, json_validator=check_bool),
) -> HttpResponse:
    if display_in_profile_summary and display_in_profile_summary_limit_reached(user_profile.realm):
        raise JsonableError(
            _("Only 2 custom profile fields can be displayed in the profile summary.")
        )

    validate_custom_profile_field(name, hint, field_type, field_data, display_in_profile_summary)
    try:
        if is_default_external_field(field_type, field_data):
            field_subtype = field_data["subtype"]
            assert isinstance(field_subtype, str)
            field = try_add_realm_default_custom_profile_field(
                realm=user_profile.realm,
                field_subtype=field_subtype,
                display_in_profile_summary=display_in_profile_summary,
                required=required,
            )
            return json_success(request, data={"id": field.id})
        else:
            field = try_add_realm_custom_profile_field(
                realm=user_profile.realm,
                name=name,
                field_data=field_data,
                field_type=field_type,
                hint=hint,
                display_in_profile_summary=display_in_profile_summary,
                required=required,
            )
            return json_success(request, data={"id": field.id})
    except IntegrityError:
        raise JsonableError(_("A field with that label already exists."))


@require_realm_admin
def delete_realm_custom_profile_field(
    request: HttpRequest, user_profile: UserProfile, field_id: int
) -> HttpResponse:
    try:
        field = CustomProfileField.objects.get(id=field_id)
    except CustomProfileField.DoesNotExist:
        raise JsonableError(_("Field id {id} not found.").format(id=field_id))

    do_remove_realm_custom_profile_field(realm=user_profile.realm, field=field)
    return json_success(request)


@require_realm_admin
@has_request_variables
def update_realm_custom_profile_field(
    request: HttpRequest,
    user_profile: UserProfile,
    field_id: int,
    name: Optional[str] = REQ(default=None, converter=lambda var_name, x: x.strip()),
    hint: Optional[str] = REQ(default=None),
    field_data: Optional[ProfileFieldData] = REQ(
        default=None, json_validator=check_profile_field_data
    ),
    required: Optional[bool] = REQ(default=None, json_validator=check_bool),
    display_in_profile_summary: Optional[bool] = REQ(default=None, json_validator=check_bool),
) -> HttpResponse:
    realm = user_profile.realm
    try:
        field = CustomProfileField.objects.get(realm=realm, id=field_id)
    except CustomProfileField.DoesNotExist:
        raise JsonableError(_("Field id {id} not found.").format(id=field_id))

    if display_in_profile_summary and display_in_profile_summary_limit_reached(
        user_profile.realm, field.id
    ):
        raise JsonableError(
            _("Only 2 custom profile fields can be displayed in the profile summary.")
        )

    if (
        field.field_type == CustomProfileField.EXTERNAL_ACCOUNT
        # HACK: Allow changing the display_in_profile_summary property
        # of default external account types, but not any others.
        #
        # TODO: Make the name/hint/field_data parameters optional, and
        # explicitly require that the client passes None for all of them for this case.
        # Right now, for name/hint/field_data we allow the client to send the existing
        # values for the respective fields. After this TODO is done, we will only allow
        # the client to pass None values if the field is unchanged.
        and is_default_external_field(field.field_type, orjson.loads(field.field_data))
        and not update_only_display_in_profile_summary(field, field_data, name, hint)
    ):
        raise JsonableError(_("Default custom field cannot be updated."))

    validate_custom_profile_field_update(field, display_in_profile_summary, field_data, name, hint)
    try:
        try_update_realm_custom_profile_field(
            realm=realm,
            field=field,
            name=name,
            hint=hint,
            field_data=field_data,
            display_in_profile_summary=display_in_profile_summary,
            required=required,
        )
    except IntegrityError:
        raise JsonableError(_("A field with that label already exists."))
    return json_success(request)


@require_realm_admin
@has_request_variables
def reorder_realm_custom_profile_fields(
    request: HttpRequest,
    user_profile: UserProfile,
    order: List[int] = REQ(json_validator=check_list(check_int)),
) -> HttpResponse:
    try_reorder_realm_custom_profile_fields(user_profile.realm, order)
    return json_success(request)


@human_users_only
@has_request_variables
def remove_user_custom_profile_data(
    request: HttpRequest,
    user_profile: UserProfile,
    data: List[int] = REQ(json_validator=check_list(check_int)),
) -> HttpResponse:
    for field_id in data:
        check_remove_custom_profile_field_value(user_profile, field_id)
    return json_success(request)


check_profile_data_element_update_dict = cast(
    Validator[ProfileDataElementUpdateDict],
    check_dict_only(
        [
            ("id", check_int),
            ("value", check_union([check_string, check_list(check_int)])),
        ]
    ),
)


@human_users_only
@has_request_variables
def update_user_custom_profile_data(
    request: HttpRequest,
    user_profile: UserProfile,
    data: List[ProfileDataElementUpdateDict] = REQ(
        json_validator=check_list(
            check_profile_data_element_update_dict,
        )
    ),
) -> HttpResponse:
    validate_user_custom_profile_data(user_profile.realm.id, data)
    do_update_user_custom_profile_data_if_changed(user_profile, data)
    # We need to call this explicitly otherwise constraints are not check
    return json_success(request)