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)

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)

@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:
    if not name.strip():
        return json_error(_("Name cannot be blank."))

    error = hint_validator('hint', hint)
    if error:
        return json_error(error)

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

    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:
    if not name.strip():
        return json_error(_("Name cannot be blank."))

    error = hint_validator('hint', hint)
    if error:
        return json_error(error, data={'field': '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})

    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:
    for item in data:
        field_id = item['id']
        try:
            field = CustomProfileField.objects.get(id=field_id)
        except CustomProfileField.DoesNotExist:
            return json_error(_('Field id {id} not found.').format(id=field_id))

        validators = CustomProfileField.FIELD_VALIDATORS
        field_type = field.field_type
        var_name = '{}'.format(field.name)
        value = item['value']
        if field_type in validators:
            validator = validators[field_type]
            result = validator(var_name, value)
        elif field_type == CustomProfileField.CHOICE:
            choice_field_validator = CustomProfileField.CHOICE_FIELD_VALIDATORS[field_type]
            field_data = field.field_data
            result = choice_field_validator(var_name, field_data, value)
        elif field_type == CustomProfileField.USER:
            user_field_validator = CustomProfileField.USER_FIELD_VALIDATORS[field_type]
            result = user_field_validator(user_profile.realm.id, cast(List[int], value),
                                          False)
        else:
            raise AssertionError("Invalid field type")

        if result is not None:
            return json_error(result)

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