import csv

from django.contrib import admin
from django.http import HttpResponse
from django.core.exceptions import FieldDoesNotExist

from .models import (
    Account,
    Project,
    HonoraryCertificate,
    Library,
    ELiterature,
    Software,
    IFG,
    Travel,
    Email,
    BusinessCard,
    List,
    Literature,
)


class RequestURLBeforeInternNotesMixin:
    """
    Ensures that 'request_url' (if present) appears directly before 'intern_notes'.
    Works whether 'fields' is explicitly defined or derived from the Model/Form.
    """
    request_url_field_name = 'request_url'
    anchor_field_name = 'intern_notes'  # field to insert before or after
    insert_before = True  # set False to insert after the anchor

    def get_fields(self, request, obj=None):
        # Get the current list of fields from the parent class
        fields = list(super().get_fields(request, obj))

        req = self.request_url_field_name
        anchor = self.anchor_field_name

        # Skip modification if the model doesn't have 'request_url'
        try:
            self.model._meta.get_field(req)
        except FieldDoesNotExist:
            return fields

        # Ensure 'request_url' is included in the field list
        if req not in fields:
            fields.append(req)

        # If the anchor field exists, move 'request_url' to the desired position
        if anchor in fields and req in fields:
            # Remove and reinsert 'request_url' at the correct index
            fields = [f for f in fields if f != req]
            idx = fields.index(anchor)
            insert_at = idx if self.insert_before else idx + 1
            fields.insert(insert_at, req)

        return fields


def export_as_csv(self, request, queryset):
    meta = self.model._meta
    field_names = [field.name for field in meta.fields]

    response = HttpResponse(content_type='text/csv')
    response['Content-Disposition'] = 'attachment; filename={}.csv'.format(meta)
    writer = csv.writer(response)

    writer.writerow(field_names)
    for obj in queryset:
        row = writer.writerow([getattr(obj, field) for field in field_names])

    return response


export_as_csv.short_description = "Ausgewähltes zu CSV exportieren"

admin.site.add_action(export_as_csv)


@admin.register(Project)
class ProjectAdmin(admin.ModelAdmin):
    save_as = True
    search_fields = ('name', 'pid', 'finance_id', 'realname', 'start', 'end', 'participants_estimated',
                     'participants_real', 'cost', 'status', 'end_quartal')
    list_display = ('name', 'pid', 'finance_id', 'realname', 'start', 'end', 'participants_estimated',
                    'participants_real', 'cost', 'status', 'end_quartal')
    fields = ('realname', 'email', 'granted', 'granted_date', 'mail_state', 'end_mail_send', 'survey_mail_send',
              'survey_mail_date', 'name', 'description', 'pid', 'finance_id', 'start', 'end', 'otrs', 'plan', 'page',
              'urls', 'group', 'location', 'participants_estimated', 'participants_real', 'insurance',
              'insurance_technic', 'support', 'cost', 'account', 'granted_from', 'notes', 'intern_notes', 'status',
              'project_of_year', 'end_quartal')
    #    action = ['export_as_csv']
    date_hierarchy = 'end'
    readonly_fields = ('end_quartal', 'project_of_year', 'pid', 'finance_id')

    class Media:
        js = ('dropdown/js/otrs_link.js',)


@admin.register(BusinessCard)
class BusinessCardAdmin(RequestURLBeforeInternNotesMixin, admin.ModelAdmin):
    save_as = True
    search_fields = ('realname', 'service_id', 'granted', 'granted_date', 'project')
    list_display = ('realname', 'service_id', 'granted', 'granted_date', 'project', 'terms_accepted')
    list_display_links = ('realname', 'service_id')
    #    action = ['export_as_csv']
    date_hierarchy = 'granted_date'
    readonly_fields = ['service_id']

    class Media:
        js = ('dropdown/js/base.js', 'dropdown/js/otrs_link.js')


@admin.register(Literature)
class LiteratureAdmin(RequestURLBeforeInternNotesMixin, admin.ModelAdmin):
    save_as = True
    search_fields = ('realname', 'service_id', 'granted', 'granted_date')
    list_display = ('realname', 'service_id', 'granted', 'granted_date', 'terms_accepted')
    list_display_links = ('realname', 'service_id')
    date_hierarchy = 'granted_date'
    readonly_fields = ['service_id']

    class Media:
        js = ('dropdown/js/otrs_link.js',)


@admin.register(Account)
class AccountAdmin(admin.ModelAdmin):
    save_as = True


@admin.register(HonoraryCertificate)
class HonoraryCertificateAdmin(admin.ModelAdmin):
    save_as = True
    search_fields = ['realname', 'granted', 'project__name', 'project__pid']
    list_display = ('realname', 'granted', 'project')
    date_hierarchy = 'granted_date'
    autocomplete_fields = ['project']

    class Media:
        js = ('dropdown/js/otrs_link.js',)


@admin.register(Library, ELiterature, Software)
class LibraryAdmin(RequestURLBeforeInternNotesMixin, admin.ModelAdmin):
    save_as = True
    search_fields = ('realname', 'service_id', 'granted', 'granted_date')
    list_display = ('realname', 'service_id', 'granted', 'granted_date')
    list_display_links = ('realname', 'service_id')
    date_hierarchy = 'granted_date'
    readonly_fields = ['service_id']
    exclude = ['type']

    class Media:
        js = ('dropdown/js/otrs_link.js',)

    def get_queryset(self, request):
        return super().get_queryset(request).filter(type=self.model.TYPE)

    def formfield_for_dbfield(self, db_field, request, **kwargs):
        if db_field.name == 'library':
            kwargs['label'] = self.model.LIBRARY_LABEL
            kwargs['help_text'] = self.model.LIBRARY_HELP_TEXT

        elif db_field.name == 'duration':
            kwargs['help_text'] = self.model.DURATION_HELP_TEXT

        return super().formfield_for_dbfield(db_field, request, **kwargs)


@admin.register(IFG)
class IFGAdmin(RequestURLBeforeInternNotesMixin, admin.ModelAdmin):
    save_as = True
    search_fields = ('realname', 'service_id', 'granted', 'granted_date')
    list_display = ('realname', 'service_id', 'granted', 'granted_date')
    list_display_links = ('realname', 'service_id')
    date_hierarchy = 'granted_date'
    readonly_fields = ['service_id']

    class Media:
        js = ('dropdown/js/otrs_link.js',)


@admin.register(Travel)
class TravelAdmin(admin.ModelAdmin):
    save_as = True
    search_fields = ['realname', 'service_id', 'granted_date', 'project__name', 'project__pid']
    list_display = ('realname', 'service_id', 'granted', 'granted_date', 'project_end', 'project',
                    'project_end_quartal')
    list_display_links = ('realname', 'project')
    date_hierarchy = 'project_end'
    autocomplete_fields = ['project']
    readonly_fields = ['service_id', 'project_end', 'project_end_quartal']

    class Media:
        js = ('dropdown/js/otrs_link.js',)


@admin.register(Email)
class EmailAdmin(RequestURLBeforeInternNotesMixin, admin.ModelAdmin):
    save_as = True
    search_fields = ('realname', 'service_id', 'granted', 'granted_date')
    list_display = ('realname', 'service_id', 'granted', 'granted_date', 'terms_accepted')
    list_display_links = ('realname', 'service_id')
    date_hierarchy = 'granted_date'
    radio_fields = {'adult': admin.VERTICAL}
    readonly_fields = ['service_id']

    class Media:
        js = ('dropdown/js/base.js', 'dropdown/js/otrs_link.js')


@admin.register(List)
class ListAdmin(RequestURLBeforeInternNotesMixin, admin.ModelAdmin):
    save_as = True
    search_fields = ('realname', 'service_id', 'granted', 'granted_date')
    list_display = ('realname', 'service_id', 'granted', 'granted_date', 'terms_accepted')
    list_display_links = ('realname', 'service_id')
    date_hierarchy = 'granted_date'
    readonly_fields = ['service_id']

    class Media:
        js = ('dropdown/js/otrs_link.js',)

# commented out because of the individual registering to control displays in admin panel

# admin.site.register([
#                     Account,
#                     HonoraryCertificate,
#                     Library,
#                     IFG,
#                     Travel,
#                     Email,
#                     List,
#                     ])