from typing import Union, List, Dict, Optional, cast
import logging
import ujson

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

from zerver.decorator import require_realm_admin, human_users_only
from zerver.lib.request import has_request_variables, REQ
from zerver.lib.actions import (try_add_realm_custom_profile_field,
                                do_remove_realm_custom_profile_field,
                                try_update_realm_custom_profile_field,
                                do_update_user_custom_profile_data,
                                try_reorder_realm_custom_profile_fields,
                                notify_user_update_custom_profile_data)
from zerver.lib.response import json_success, json_error
from zerver.lib.types import ProfileFieldData
from zerver.lib.validator import (check_dict, check_list, check_int,
                                  validate_field_data, check_capped_string)

from zerver.models import (custom_profile_fields_for_realm, UserProfile, CustomProfileFieldValue,
                           CustomProfileField, custom_profile_fields_for_realm)
from zerver.lib.exceptions import JsonableError
from zerver.lib.users import validate_user_custom_profile_data

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({'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(_("Name cannot be blank."))

    error = hint_validator('hint', hint)
    if error:
        raise JsonableError(error)

    error = name_validator('name', name)
    if error:
        raise JsonableError(error)

@require_realm_admin
@has_request_variables
def create_realm_custom_profile_field(request: HttpRequest,
                                      user_profile: UserProfile,
                                      name: str=REQ(),
                                      hint: str=REQ(default=''),
                                      field_data: ProfileFieldData=REQ(default={},
                                                                       converter=ujson.loads),
                                      field_type: int=REQ(validator=check_int)) -> HttpResponse:
    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:
        return json_error(_("Invalid field type."))

    # Choice type field must have at least have one choice
    if field_type == CustomProfileField.CHOICE and len(field_data) < 1:
        return json_error(_("Field must have at least one choice."))

    error = validate_field_data(field_data)
    if error:
        return json_error(error)

    try:
        field = try_add_realm_custom_profile_field(
            realm=user_profile.realm,
            name=name,
            field_data=field_data,
            field_type=field_type,
            hint=hint,
        )
        return json_success({'id': field.id})
    except IntegrityError:
        return json_error(_("A field with that name 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:
        return json_error(_('Field id {id} not found.').format(id=field_id))

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

@require_realm_admin
@has_request_variables
def update_realm_custom_profile_field(request: HttpRequest, user_profile: UserProfile,
                                      field_id: int,
                                      name: str=REQ(),
                                      hint: str=REQ(default=''),
                                      field_data: ProfileFieldData=REQ(default={},
                                                                       converter=ujson.loads),
                                      ) -> HttpResponse:
    validate_field_name_and_hint(name, hint)
    error = validate_field_data(field_data)
    if error:
        return json_error(error)

    realm = user_profile.realm
    try:
        field = CustomProfileField.objects.get(realm=realm, id=field_id)
    except CustomProfileField.DoesNotExist:
        return json_error(_('Field id {id} not found.').format(id=field_id))

    try:
        try_update_realm_custom_profile_field(realm, field, name, hint=hint,
                                              field_data=field_data)
    except IntegrityError:
        return json_error(_('A field with that name already exists.'))
    return json_success()

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

@human_users_only
@has_request_variables
def remove_user_custom_profile_data(request: HttpRequest, user_profile: UserProfile,
                                    data: List[int]=REQ(validator=check_list(
                                                        check_int))) -> HttpResponse:
    for field_id in data:
        try:
            field = CustomProfileField.objects.get(realm=user_profile.realm, id=field_id)
        except CustomProfileField.DoesNotExist:
            return json_error(_('Field id {id} not found.').format(id=field_id))

        try:
            field_value = CustomProfileFieldValue.objects.get(field=field, user_profile=user_profile)
        except CustomProfileFieldValue.DoesNotExist:
            continue
        field_value.delete()
        notify_user_update_custom_profile_data(user_profile, {'id': field_id,
                                                              'value': None,
                                                              'rendered_value': None,
                                                              'type': field.field_type})

    return json_success()

@human_users_only
@has_request_variables
def update_user_custom_profile_data(
        request: HttpRequest,
        user_profile: UserProfile,
        data: List[Dict[str, Union[int, str, List[int]]]]=REQ(validator=check_list(
            check_dict([('id', check_int)])))) -> HttpResponse:

    validate_user_custom_profile_data(user_profile.realm.id, data)
    do_update_user_custom_profile_data(user_profile, data)
    # We need to call this explicitly otherwise constraints are not check
    return json_success()