"use client";

import {
  useMemo,
  useState,
  useTransition,
  type ChangeEventHandler,
} from "react";
import { Pencil, Plus, Trash2 } from "lucide-react";
import { toast } from "sonner";

import { Button } from "@/components/ui/button";
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
  DialogTrigger,
} from "@/components/ui/dialog";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { updateFamilyAction } from "./actions";
import { InvitationStatus } from "./invitation-status";
import type { FamilyInvitationView } from "@/lib/family-invitation-view";

type EditableParent = {
  id: string;
  firstName: string;
  lastName: string;
  email: string;
  invitation?: FamilyInvitationView;
};

type EditableChild = {
  id: string;
  firstName: string;
  lastName: string;
};

type DraftParent = EditableParent & {
  kind: "existing" | "new";
};

type DraftChild = EditableChild & {
  kind: "existing" | "new";
};

type EditableFamily = {
  id: string;
  name: string;
  parents: EditableParent[];
  children: EditableChild[];
};

export function EditFamilyDialog({ family }: { family: EditableFamily }) {
  const [open, setOpen] = useState(false);
  const [isPending, startTransition] = useTransition();
  const initialParents = useMemo(
    () =>
      family.parents.map((parent) => ({
        ...parent,
        kind: "existing" as const,
      })),
    [family.parents],
  );
  const initialChildren = useMemo(
    () =>
      family.children.map((child) => ({
        ...child,
        kind: "existing" as const,
      })),
    [family.children],
  );
  const [parents, setParents] = useState<DraftParent[]>(initialParents);
  const [children, setChildren] = useState<DraftChild[]>(initialChildren);
  const [removedChildIds, setRemovedChildIds] = useState<string[]>([]);

  function resetState() {
    setParents(initialParents);
    setChildren(initialChildren);
    setRemovedChildIds([]);
  }

  function addParent() {
    if (parents.length >= 2) return;
    setParents((current) => [
      ...current,
      {
        id: `new-parent-${crypto.randomUUID()}`,
        firstName: "",
        lastName: "",
        email: "",
        kind: "new",
      },
    ]);
  }

  function removeNewParent(parent: DraftParent) {
    if (parent.kind !== "new") return;
    setParents((current) => current.filter((item) => item.id !== parent.id));
  }

  function addChild() {
    setChildren((current) => [
      ...current,
      {
        id: `new-child-${crypto.randomUUID()}`,
        firstName: "",
        lastName: "",
        kind: "new",
      },
    ]);
  }

  function removeChild(child: DraftChild) {
    setChildren((current) => current.filter((item) => item.id !== child.id));
    if (child.kind === "existing") {
      setRemovedChildIds((current) => [...current, child.id]);
    }
  }

  function handleSubmit(formData: FormData) {
    const payload = {
      familyId: family.id,
      familyName: String(formData.get("familyName") ?? ""),
      parents: parents
        .filter((parent) => parent.kind === "existing")
        .map((parent) => ({
          id: parent.id,
          firstName: String(formData.get(`parentFirstName_${parent.id}`) ?? ""),
          lastName: String(formData.get(`parentLastName_${parent.id}`) ?? ""),
          email: String(formData.get(`parentEmail_${parent.id}`) ?? ""),
        })),
      newParents: parents
        .filter((parent) => parent.kind === "new")
        .map((parent) => ({
          firstName: String(formData.get(`parentFirstName_${parent.id}`) ?? ""),
          lastName: String(formData.get(`parentLastName_${parent.id}`) ?? ""),
          email: String(formData.get(`parentEmail_${parent.id}`) ?? ""),
        })),
      children: children
        .filter((child) => child.kind === "existing")
        .map((child) => ({
          id: child.id,
          firstName: String(formData.get(`childFirstName_${child.id}`) ?? ""),
          lastName: String(formData.get(`childLastName_${child.id}`) ?? ""),
        })),
      newChildren: children
        .filter((child) => child.kind === "new")
        .map((child) => ({
          firstName: String(formData.get(`childFirstName_${child.id}`) ?? ""),
          lastName: String(formData.get(`childLastName_${child.id}`) ?? ""),
        })),
      removedChildIds,
    };

    startTransition(async () => {
      const result = await updateFamilyAction(payload);
      if (result.error) {
        toast.error(result.error);
        return;
      }

      if (result.warning) toast.warning(result.warning);
      else toast.success("Familie aktualisiert. Geänderte E-Mail-Adressen müssen über einen neuen Einladungslink bestätigt werden.");
      setOpen(false);
      setRemovedChildIds([]);
    });
  }

  return (
    <Dialog
      open={open}
      onOpenChange={(nextOpen) => {
        if (isPending) return;
        resetState();
        setOpen(nextOpen);
      }}
    >
      <DialogTrigger asChild>
        <Button variant="ghost" size="sm" className="h-8 gap-1">
          <Pencil className="h-3.5 w-3.5" />
          <span className="hidden sm:inline">Details</span>
        </Button>
      </DialogTrigger>
      <DialogContent className="max-h-[90vh] overflow-y-auto sm:max-w-2xl">
        <form
          onSubmit={(event) => {
            event.preventDefault();
            handleSubmit(new FormData(event.currentTarget));
          }}
        >
          <DialogHeader>
            <DialogTitle>Familie bearbeiten</DialogTitle>
            <DialogDescription>
              Aktualisiere Haushalt, Elternteile und Kinder.
            </DialogDescription>
          </DialogHeader>

          <fieldset disabled={isPending} className="grid gap-6 py-4">
            <div className="grid gap-2">
              <Label htmlFor={`familyName-${family.id}`}>Familienname</Label>
              <Input
                id={`familyName-${family.id}`}
                name="familyName"
                defaultValue={family.name}
                required
              />
            </div>

            <fieldset className="grid gap-3">
              <div className="flex items-center justify-between gap-3">
                <legend className="text-[11px] font-semibold uppercase text-[var(--ink-muted)] [letter-spacing:0.12em]">
                  Elternteile
                </legend>
                {parents.length < 2 && (
                  <Button
                    type="button"
                    variant="pill"
                    size="sm"
                    className="h-8 gap-1"
                    onClick={addParent}
                    disabled={isPending}
                  >
                    <Plus className="h-3.5 w-3.5" />
                    Elternteil hinzufügen
                  </Button>
                )}
              </div>

              {parents.map((parent, index) => (
                <div
                  key={parent.id}
                  className="rounded-lg border border-[var(--hairline)] bg-[var(--surface-2)] p-3"
                >
                  <div className="mb-3 flex items-center justify-between gap-3">
                    <p className="text-[11px] font-semibold uppercase text-[var(--ink-muted)] [letter-spacing:0.12em]">
                      Elternteil {index + 1}
                    </p>
                    {parent.kind === "new" && (
                      <Button
                        type="button"
                        variant="ghost"
                        size="sm"
                        className="h-7 gap-1 px-2 text-[var(--danger)] hover:bg-[var(--danger-soft)] hover:text-[var(--danger)]"
                        onClick={() => removeNewParent(parent)}
                        disabled={isPending}
                      >
                        <Trash2 className="h-3.5 w-3.5" />
                        Entfernen
                      </Button>
                    )}
                  </div>
                  <div className="grid gap-3 sm:grid-cols-2">
                    <Field
                      id={`parentFirstName-${parent.id}`}
                      name={`parentFirstName_${parent.id}`}
                      label="Vorname"
                      defaultValue={parent.firstName}
                    />
                    <Field
                      id={`parentLastName-${parent.id}`}
                      name={`parentLastName_${parent.id}`}
                      label="Nachname"
                      defaultValue={parent.lastName}
                    />
                  </div>
                  <div className="mt-3">
                    <Field
                      id={`parentEmail-${parent.id}`}
                      name={`parentEmail_${parent.id}`}
                      label="E-Mail-Adresse"
                      type="email"
                      defaultValue={parent.email}
                      onChange={(event) => {
                        const email = event.target.value;
                        setParents((current) =>
                          current.map((item) =>
                            item.id === parent.id ? { ...item, email } : item,
                          ),
                        );
                      }}
                    />
                  </div>
                  {parent.kind === "existing" && parent.invitation && (
                    <InvitationStatus
                      userId={parent.id}
                      name={`${parent.firstName} ${parent.lastName}`}
                      invitation={parent.invitation}
                      blocked={
                        parent.email !==
                        family.parents.find((item) => item.id === parent.id)
                          ?.email
                      }
                    />
                  )}
                  {parent.kind === "existing" &&
                    parent.invitation?.status !== "active" &&
                    parent.email !==
                      family.parents.find((item) => item.id === parent.id)
                        ?.email && (
                      <p className="mt-2 text-xs text-[var(--ink-soft)]">
                        Beim Speichern wird eine neue Einladung an die geänderte
                        Adresse versendet.
                      </p>
                    )}
                </div>
              ))}
            </fieldset>

            <fieldset className="grid gap-3">
              <div className="flex items-center justify-between gap-3">
                <legend className="text-[11px] font-semibold uppercase text-[var(--ink-muted)] [letter-spacing:0.12em]">
                  Kinder
                </legend>
                <Button
                  type="button"
                  variant="pill"
                  size="sm"
                  className="h-8 gap-1"
                  onClick={addChild}
                  disabled={isPending}
                >
                  <Plus className="h-3.5 w-3.5" />
                  Kind hinzufügen
                </Button>
              </div>

              {children.length === 0 ? (
                <p className="rounded-lg border border-dashed border-[var(--hairline)] bg-[var(--surface-2)] px-4 py-5 text-sm italic text-[var(--ink-faint)]">
                  Keine Kinder verknüpft.
                </p>
              ) : (
                children.map((child, index) => (
                  <div
                    key={child.id}
                    className="rounded-lg border border-[var(--hairline)] bg-[var(--surface-2)] p-3"
                  >
                    <div className="mb-3 flex items-center justify-between gap-3">
                      <p className="text-[11px] font-semibold uppercase text-[var(--ink-muted)] [letter-spacing:0.12em]">
                        Kind {index + 1}
                      </p>
                      <Button
                        type="button"
                        variant="ghost"
                        size="sm"
                        className="h-7 gap-1 px-2 text-[var(--danger)] hover:bg-[var(--danger-soft)] hover:text-[var(--danger)]"
                        onClick={() => removeChild(child)}
                        disabled={isPending}
                      >
                        <Trash2 className="h-3.5 w-3.5" />
                        Entfernen
                      </Button>
                    </div>
                    <div className="grid gap-3 sm:grid-cols-2">
                      <Field
                        id={`childFirstName-${child.id}`}
                        name={`childFirstName_${child.id}`}
                        label="Vorname"
                        defaultValue={child.firstName}
                      />
                      <Field
                        id={`childLastName-${child.id}`}
                        name={`childLastName_${child.id}`}
                        label="Nachname"
                        defaultValue={child.lastName}
                      />
                    </div>
                  </div>
                ))
              )}
            </fieldset>
          </fieldset>

          <DialogFooter>
            <Button type="submit" disabled={isPending}>
              {isPending ? "Speichert..." : "Speichern"}
            </Button>
          </DialogFooter>
        </form>
      </DialogContent>
    </Dialog>
  );
}

function Field({
  id,
  name,
  label,
  type = "text",
  defaultValue,
  onChange,
}: {
  id: string;
  name: string;
  label: string;
  type?: string;
  defaultValue: string;
  onChange?: ChangeEventHandler<HTMLInputElement>;
}) {
  return (
    <div className="grid gap-2">
      <Label htmlFor={id}>{label}</Label>
      <Input
        id={id}
        name={name}
        type={type}
        defaultValue={defaultValue}
        onChange={onChange}
        required
      />
    </div>
  );
}