from typing import Any, cast

from django import forms
from django.contrib import admin, messages
from django.core import mail
from django.db.models import Value
from django.db.models.functions import Concat, LPad, Now
from django.db.models.query import QuerySet
from django.http import HttpRequest

from .certification_emails import all_certification_emails
from .forms import CertificationForm
from .models import (
    AbstractAudit,
    Certification,
    CertificationAudit,
    CertificationDefinition,
    CertificationVersion,
    CertificationVersionAnnotated,
    CmsRedRiverVeteransScholarship,
    Department,
    InstructorOrVendor,
    SpecialProgram,
    Waiver,
    WaiverAudit,
)


class AlwaysChangedModelForm(forms.models.ModelForm):
    """By always returning true even unchanged inlines will get validated and saved."""

    def has_changed(self) -> bool:
        return True


class AbstractAuditInline(admin.TabularInline):
    extra = 0
    form = AlwaysChangedModelForm

    def get_formset(
        self, request: HttpRequest, obj: AbstractAudit | None = None, **kwargs: Any
    ) -> type[
        "forms.models.BaseInlineFormSet[AbstractAudit, Any, forms.models.ModelForm[Any]]"
    ]:
        formset = super().get_formset(request, obj, **kwargs)
        formset.form.base_fields["user"].initial = request.user
        return formset


@admin.register(Department)
class DepartmentAdmin(admin.ModelAdmin):
    search_fields = ["name"]
    list_display = [
        "name",
        "parent",
        "has_mailing_list",
        "shop_lead_flag",
        "list_reply_to_address",
    ]


class CertificationVersionInline(admin.TabularInline):
    model = CertificationVersion
    extra = 1

    readonly_fields = (
        "semantic_version",
        "is_latest",
        "is_current",
    )

    @admin.display(description="Latest", boolean=True)
    def is_latest(self, obj: CertificationVersionAnnotated) -> bool:
        return obj.is_latest

    @admin.display(description="Current", boolean=True)
    def is_current(self, obj: CertificationVersionAnnotated) -> bool:
        return obj.is_current


@admin.register(CertificationDefinition)
class CertificationDefinitionAdmin(admin.ModelAdmin):
    search_fields = ["name"]
    list_display = [
        "name",
        "department",
        "latest_semantic_version",
    ]
    list_filter = ["department"]
    show_facets = admin.ShowFacets.ALWAYS
    inlines = [CertificationVersionInline]

    @admin.display(description="Latest Version")
    def latest_semantic_version(self, obj: CertificationDefinition) -> str:
        return str(obj.latest_version().semantic_version())


class CertificationAuditInline(AbstractAuditInline):
    model = CertificationAudit


@admin.register(Certification)
class CertificationAdmin(admin.ModelAdmin):
    form = CertificationForm
    search_fields = [
        "name",
        "certification_version__definition__name",
        "certification_version__definition__department__name",
    ]
    date_hierarchy = "date"
    autocomplete_fields = ["member"]
    exclude = ["shop_lead_notified"]
    inlines = [CertificationAuditInline]

    def get_queryset(self, request: HttpRequest) -> QuerySet[Certification]:
        qs = super().get_queryset(request)
        return qs.prefetch_related("certification_version__definition__department")

    @admin.display(
        description="Certification Name",
        ordering="certification_version__definition__name",
    )
    def certification_name(self, obj: Certification) -> str:
        return obj.certification_version.definition.name

    @admin.display(
        description="Certification Version",
        ordering=(
            Concat(
                LPad("certification_version__major", 4, Value("0")),
                LPad("certification_version__minor", 4, Value("0")),
                LPad("certification_version__patch", 4, Value("0")),
                "certification_version__prerelease",
                "certification_version__approval_date",
            )
        ),
    )
    def certification_semantic_version(self, obj: Certification) -> str:
        return str(obj.certification_version.semantic_version())

    @admin.display(description="Current", boolean=True)
    def is_current(self, obj: Certification) -> bool:
        return cast(CertificationVersionAnnotated, obj.certification_version).is_current

    @admin.display(
        description="Department",
        ordering="certification_version__definition__department",
    )
    def certification_department(self, obj: Certification) -> Department:
        return obj.certification_version.definition.department

    @admin.display(description="Latest Audit")
    def latest_audit(self, obj: Certification) -> CertificationAudit:
        return obj.audits.latest()

    list_display = [
        "name",
        "certification_name",
        "certification_semantic_version",
        "is_current",
        "certification_department",
        "date",
        "shop_lead_notified",
        "certified_by",
        "latest_audit",
    ]
    list_display_links = [
        "name",
        "certification_name",
    ]
    list_filter = [
        "certification_version__definition__department",
        ("shop_lead_notified", admin.EmptyFieldListFilter),
        ("audits", admin.EmptyFieldListFilter),
    ]
    show_facets = admin.ShowFacets.ALWAYS

    actions = ["send_notifications"]

    @admin.action(
        description="Notify Shop Leads and Members of selected certifications"
    )
    def send_notifications(
        self, request: HttpRequest, queryset: QuerySet[Certification]
    ) -> None:
        try:
            emails = list(all_certification_emails(queryset))

            with mail.get_connection() as conn:
                conn.send_messages(emails)

            for cert in queryset:
                cert.shop_lead_notified = Now()
                cert.save()

            self.message_user(
                request,
                f"{len(emails)} notifications sent for {len(queryset)} certifications",
                messages.SUCCESS,
            )
        except Exception as e:
            self.message_user(
                request,
                f"Failed to send notifications! {e}",
                messages.ERROR,
            )
            raise


@admin.register(InstructorOrVendor)
class InstructorOrVendorAdmin(admin.ModelAdmin):
    search_fields = ["name"]
    list_display = [
        "name",
        "instructor_agreement_date",
        "w9_date",
        "phone",
        "email_address",
    ]


@admin.register(SpecialProgram)
class SpecialProgramAdmin(admin.ModelAdmin):
    search_fields = ["program_name"]
    list_display = [
        "program_name",
        "discount_percent",
        "discount_code",
        "membership_code",
        "start_date",
        "end_date",
        "program_amount",
        "program_status",
    ]


class WaiverAuditInline(AbstractAuditInline):
    model = WaiverAudit


@admin.register(Waiver)
class WaiverAdmin(admin.ModelAdmin):
    search_fields = ["name"]
    list_display = [
        "name",
        "date",
        "emergency_contact_name",
        "emergency_contact_number",
        "waiver_version",
        "guardian_name",
        "guardian_relation",
        "guardian_date",
        "latest_audit",
    ]
    list_filter = [
        "waiver_version",
        ("audits", admin.EmptyFieldListFilter),
    ]
    show_facets = admin.ShowFacets.ALWAYS
    inlines = [WaiverAuditInline]

    @admin.display(description="Latest Audit")
    def latest_audit(self, obj: Waiver) -> WaiverAudit:
        return obj.audits.latest()


admin.site.register(CmsRedRiverVeteransScholarship)