"use client";

import { useState, type FormEvent } from "react";
import { useRouter } from "next/navigation";
import type { Faq } from "@/types/cms";
import { Button } from "@/components/ui/button";
import { Input, Textarea } from "@/components/ui/input";
import { useConfirmDialog } from "@/components/ui/confirm-dialog";
import { useToast } from "@/components/ui/toast";
import { cardClasses } from "@/components/ui/styles";
import { cn } from "@/lib/utils";
import { clientFetch } from "@/lib/api/client";

interface FaqFormState {
  question: string;
  answer: string;
  display_order: string;
  is_active: boolean;
}

const EMPTY_FORM: FaqFormState = { question: "", answer: "", display_order: "0", is_active: true };

export function FaqManager({ faqs }: { faqs: Faq[] }) {
  const router = useRouter();
  const [showCreate, setShowCreate] = useState(false);
  const [createForm, setCreateForm] = useState<FaqFormState>(EMPTY_FORM);
  const [editingId, setEditingId] = useState<number | null>(null);
  const [editForm, setEditForm] = useState<FaqFormState>(EMPTY_FORM);
  const [error, setError] = useState<string | null>(null);
  const [isSubmitting, setIsSubmitting] = useState(false);
  const [deletingId, setDeletingId] = useState<number | null>(null);
  const { confirm, dialog } = useConfirmDialog();
  const { toast } = useToast();

  function toPayload(form: FaqFormState) {
    return {
      question: form.question,
      answer: form.answer,
      display_order: form.display_order ? Number(form.display_order) : 0,
      is_active: form.is_active,
    };
  }

  async function handleCreate(formEvent: FormEvent<HTMLFormElement>) {
    formEvent.preventDefault();
    setError(null);
    setIsSubmitting(true);

    const res = await clientFetch("/api/admin/cms/faqs", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(toPayload(createForm)),
    });

    setIsSubmitting(false);
    const body = await res.json().catch(() => null);

    if (!res.ok) {
      const message = body?.message ?? "Failed to create FAQ.";
      setError(message);
      toast(message, "error");
      return;
    }

    setShowCreate(false);
    setCreateForm(EMPTY_FORM);
    toast("FAQ created successfully.", "success");
    router.refresh();
  }

  async function handleUpdate(formEvent: FormEvent<HTMLFormElement>, id: number) {
    formEvent.preventDefault();
    setError(null);
    setIsSubmitting(true);

    const res = await clientFetch(`/api/admin/cms/faqs/${id}`, {
      method: "PUT",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(toPayload(editForm)),
    });

    setIsSubmitting(false);
    const body = await res.json().catch(() => null);

    if (!res.ok) {
      const message = body?.message ?? "Failed to update FAQ.";
      setError(message);
      toast(message, "error");
      return;
    }

    setEditingId(null);
    toast("FAQ updated successfully.", "success");
    router.refresh();
  }

  async function handleDelete(id: number) {
    if (!(await confirm("Delete this FAQ?"))) return;

    setError(null);
    setDeletingId(id);
    const res = await clientFetch(`/api/admin/cms/faqs/${id}`, { method: "DELETE" });
    setDeletingId(null);
    const body = await res.json().catch(() => null);

    if (!res.ok) {
      const message = body?.message ?? "Failed to delete FAQ.";
      setError(message);
      toast(message, "error");
      return;
    }
    toast("FAQ deleted successfully.", "success");
    router.refresh();
  }

  return (
    <div>
      {dialog}
      {error && <p className="mb-3 text-sm text-red-600">{error}</p>}

      <div className={cn("flex flex-col divide-y divide-kolabora-neutral-dark/10", cardClasses())}>
        {faqs.length === 0 && (
          <p className="px-4 py-6 text-center text-sm text-kolabora-neutral-dark/70">No FAQs yet.</p>
        )}
        {faqs.map((faq) =>
          editingId === faq.id ? (
            <form
              key={faq.id}
              onSubmit={(e) => handleUpdate(e, faq.id)}
              className="flex flex-col gap-2 px-4 py-3"
            >
              <Input
                size="sm"
                required
                value={editForm.question}
                onChange={(e) => setEditForm({ ...editForm, question: e.target.value })}
                placeholder="Question"
              />
              <Textarea
                size="sm"
                required
                rows={3}
                value={editForm.answer}
                onChange={(e) => setEditForm({ ...editForm, answer: e.target.value })}
                placeholder="Answer"
              />
              <div className="flex items-center gap-3">
                <Input
                  size="sm"
                  type="number"
                  value={editForm.display_order}
                  onChange={(e) => setEditForm({ ...editForm, display_order: e.target.value })}
                  placeholder="Order"
                  className="w-24"
                />
                <label className="flex items-center gap-1.5 text-sm">
                  <input
                    type="checkbox"
                    checked={editForm.is_active}
                    onChange={(e) => setEditForm({ ...editForm, is_active: e.target.checked })}
                  />
                  Active
                </label>
                <Button type="submit" size="sm" loading={isSubmitting} className="ml-auto">
                  Save
                </Button>
                <Button
                  type="button"
                  variant="secondary"
                  size="sm"
                  onClick={() => setEditingId(null)}
                  disabled={isSubmitting}
                >
                  Cancel
                </Button>
              </div>
            </form>
          ) : (
            <div key={faq.id} className="flex items-start justify-between gap-3 px-4 py-3">
              <div>
                <p className="font-medium">{faq.question}</p>
                <p className="mt-1 text-sm text-kolabora-neutral-dark/70">{faq.answer}</p>
                {!faq.is_active && (
                  <span className="mt-1 inline-block rounded-full bg-kolabora-neutral-dark/10 px-2 py-0.5 text-xs">
                    Inactive
                  </span>
                )}
              </div>
              <div className="flex shrink-0 gap-2">
                <Button
                  type="button"
                  variant="secondary"
                  size="sm"
                  onClick={() => {
                    setEditingId(faq.id);
                    setEditForm({
                      question: faq.question,
                      answer: faq.answer,
                      display_order: String(faq.display_order),
                      is_active: faq.is_active,
                    });
                  }}
                >
                  Edit
                </Button>
                <Button
                  type="button"
                  variant="danger"
                  size="sm"
                  onClick={() => handleDelete(faq.id)}
                  loading={deletingId === faq.id}
                >
                  Delete
                </Button>
              </div>
            </div>
          ),
        )}
      </div>

      {showCreate ? (
        <form onSubmit={handleCreate} className={cn("mt-4 flex flex-col gap-2", cardClasses("p-4"))}>
          <Input
            required
            value={createForm.question}
            onChange={(e) => setCreateForm({ ...createForm, question: e.target.value })}
            placeholder="Question"
          />
          <Textarea
            required
            rows={3}
            value={createForm.answer}
            onChange={(e) => setCreateForm({ ...createForm, answer: e.target.value })}
            placeholder="Answer"
          />
          <div className="flex items-center gap-3">
            <Input
              type="number"
              value={createForm.display_order}
              onChange={(e) => setCreateForm({ ...createForm, display_order: e.target.value })}
              placeholder="Order"
              className="w-24"
            />
            <label className="flex items-center gap-1.5 text-sm">
              <input
                type="checkbox"
                checked={createForm.is_active}
                onChange={(e) => setCreateForm({ ...createForm, is_active: e.target.checked })}
              />
              Active
            </label>
            <Button type="submit" loading={isSubmitting} className="ml-auto">
              Save
            </Button>
            <Button type="button" variant="secondary" onClick={() => setShowCreate(false)} disabled={isSubmitting}>
              Cancel
            </Button>
          </div>
        </form>
      ) : (
        <Button type="button" onClick={() => setShowCreate(true)} className="mt-4">
          + Add FAQ
        </Button>
      )}
    </div>
  );
}