import csv

from django.contrib import admin
from django.http import HttpResponse
from .models import ProjectRequest, ProjectsDeclined
from .forms import ProjectRequestAdminForm
from django.db import models
from django import forms
from django.contrib import messages
from .services import approve_project_request, decline_project_request
from django.contrib.admin.helpers import ActionForm


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


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(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',)

@admin.register(Literature)
class LiteratureAdmin(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']


@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(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']

    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(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']

@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(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',)


@admin.register(List)
class ListAdmin(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 ApproveActionForm(ActionForm):
    """
    Extra control rendered next to the bulk actions dropdown.
    Admin must choose an Account (Kostenstelle) when approving requests.
    """
    account_code = forms.ModelChoiceField(queryset=Account.objects.all(), required=True,
                                          label='Kostenstelle (Account)')


@admin.register(ProjectRequest)
class ProjectRequestAdmin(admin.ModelAdmin):
    """
    Admin for incoming project requests (< 1000 EUR).

    - Uses a custom ModelForm to render JSON-backed fields (checkbox multiselects).
    - Provides two bulk actions: approve (moves to Projects) and decline (moves to Projects_declined).
    - Enforces that an Account must be selected for approval.
    """
    form = ProjectRequestAdminForm
    save_as = True
    list_display = ('name', 'realname', 'email', 'start', 'end', 'cost', 'decision')
    list_filter = ('decision', 'insurance',)
    search_fields = ('name', 'realname', 'email')
    readonly_fields = ('decision', 'decision_date', 'decided_by')

    # Make text areas more comfortable to edit in admin
    formfield_overrides = {
        # Increase rows for TextField edit widgets
        models.TextField: {'widget': forms.Textarea(attrs={'rows': 5, 'cols': 80})},
    }

    # Show actions at the top (common UX in Django admin)
    actions = ['approve_selected', 'decline_selected']
    actions_on_top = True
    actions_on_bottom = False
    action_form = ApproveActionForm

    @admin.action(description='Bewilligen → nach „Projects“')
    def approve_selected(self, request, queryset):
        """
        Bulk-approve selected requests:
        - Requires an Account (Kostenstelle) chosen via ApproveActionForm.
        - Delegates the creation/move logic to the service layer.
        - Counts successes and reports via Django messages.
        """
        account_pk = request.POST.get('account_code')
        if not account_pk:
            self.message_user(
                request,
                'Bitte eine Kostenstelle auswählen.',
                level=messages.ERROR
            )
            return

        try:
            account = Account.objects.get(pk=account_pk)
        except Account.DoesNotExist:
            self.message_user(
                request,
                f'Unbekannte Kostenstelle (Account pk={account_pk}).',
                level=messages.ERROR
            )
            return

        decided_by = request.user.get_username()
        ok, failed = 0, 0

        for req in queryset:
            try:
                # Service call is atomic and locks the row (select_for_update)
                approve_project_request(req.id, decided_by, account.code)
                ok += 1
            except Exception as exc:
                failed += 1
                # Show a concise per-object error; keep details in server logs if needed
                self.message_user(
                    request,
                    f'Fehler beim Bewilligen von „{req}“: {exc}',
                    level=messages.ERROR
                )

        if ok:
            self.message_user(
                request,
                f'{ok} Antrag/Anträge bewilligt und als Project angelegt.',
                level=messages.SUCCESS
            )
        if failed:
            self.message_user(
                request,
                f'{failed} Antrag/Anträge konnten nicht bewilligt werden.',
                level=messages.WARNING
            )

    @admin.action(description='Ablehnen → nach „Projects_declined“')
    def decline_selected(self, request, queryset):
        """
        Bulk-decline selected requests:
        - Archives a minimal snapshot to Projects_declined (per ticket).
        - Delegates the move logic to the service layer.
        """
        ok, failed = 0, 0

        for req in queryset:
            try:
                decline_project_request(req.id, reason='')
                ok += 1
            except Exception as exc:
                failed += 1
                self.message_user(
                    request,
                    f'Fehler beim Ablehnen von „{req}“: {exc}',
                    level=messages.ERROR
                )

        if ok:
            self.message_user(
                request,
                f'{ok} Antrag/Anträge abgelehnt → „Projects_declined“',
                level=messages.WARNING
            )
        if failed:
            self.message_user(
                request,
                f'{failed} Antrag/Anträge konnten nicht abgelehnt werden.',
                level=messages.ERROR
            )


@admin.register(ProjectsDeclined)
class ProjectsDeclinedAdmin(admin.ModelAdmin):
    """
    Read-only-ish list of declined requests for auditing.
    """
    list_display = ('name', 'realname', 'email', 'decision_date')
    search_fields = ('name', 'realname', 'email')
    date_hierarchy = 'decision_date'

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

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