"use client";

import { useCallback, useEffect, useMemo, useState } from "react";
import Link from "next/link";
import { useRouter, useSearchParams } from "next/navigation";
import { Badge, Button, Container } from "@/components/ui";
import { useAuth } from "@/hooks/useAuth";
import {
  loadAssessmentSchema,
  loadCommercialBundles,
  loadCommercialPricing,
  loadCommercialProducts,
  requestRecommendations,
} from "../adapters";
import type {
  AdapterResult,
  AssessmentQuestion,
  AssessmentSchema,
  CommercialBundle,
  CommercialPricingItem,
  CommercialProduct,
  RecommendationResult,
} from "../types";
import {
  BundleCard,
  CommercialEmptyState,
  ProductCard,
} from "../components";
import {
  loadAssessmentSession,
  saveAssessmentSession,
  type AssessmentSession,
} from "../session";

type WizardStep =
  | "assessment"
  | "recommendations"
  | "bundles"
  | "pricing"
  | "trial_summary"
  | "create_workspace";

function QuestionField({
  question,
  value,
  onChange,
}: {
  question: AssessmentQuestion;
  value: unknown;
  onChange: (v: unknown) => void;
}) {
  const inputClass =
    "mt-1 w-full rounded-xl border border-gray-200 bg-white px-4 py-2.5 text-sm focus:border-primary focus:outline-none focus:ring-1 focus:ring-primary dark:border-gray-700 dark:bg-gray-900";

  if (question.input_type === "boolean") {
    return (
      <label className="flex items-center gap-2 text-sm">
        <input
          type="checkbox"
          checked={Boolean(value)}
          onChange={(e) => onChange(e.target.checked)}
        />
        {question.prompt}
      </label>
    );
  }

  if (question.input_type === "number") {
    return (
      <label className="block text-sm font-medium text-secondary dark:text-gray-100">
        {question.prompt}
        <input
          type="number"
          className={inputClass}
          value={typeof value === "number" || typeof value === "string" ? value : ""}
          onChange={(e) => onChange(e.target.value === "" ? null : Number(e.target.value))}
        />
      </label>
    );
  }

  if ((question.input_type === "multi" || question.input_type === "single") && question.options?.length) {
    const multi = question.input_type === "multi";
    const selected = multi ? (Array.isArray(value) ? (value as string[]) : []) : null;
    return (
      <fieldset>
        <legend className="text-sm font-medium text-secondary dark:text-gray-100">
          {question.prompt}
        </legend>
        <div className="mt-3 grid gap-2 sm:grid-cols-2">
          {question.options.map((opt) => {
            const on = multi ? selected!.includes(opt.value) : value === opt.value;
            return (
              <button
                key={opt.value}
                type="button"
                className={`rounded-2xl border p-4 text-right text-sm transition ${
                  on
                    ? "border-primary bg-[var(--color-primary-soft)] shadow-sm"
                    : "border-gray-200 bg-white hover:border-gray-300 dark:border-gray-700 dark:bg-gray-900"
                }`}
                onClick={() => {
                  if (multi) {
                    onChange(
                      on ? selected!.filter((v) => v !== opt.value) : [...selected!, opt.value]
                    );
                  } else onChange(opt.value);
                }}
              >
                {opt.label}
              </button>
            );
          })}
        </div>
      </fieldset>
    );
  }

  return (
    <label className="block text-sm font-medium text-secondary dark:text-gray-100">
      {question.prompt}
      <input
        className={inputClass}
        value={typeof value === "string" ? value : ""}
        onChange={(e) => onChange(e.target.value)}
      />
    </label>
  );
}

const STEPS: { id: WizardStep; label: string }[] = [
  { id: "assessment", label: "کشف" },
  { id: "recommendations", label: "پیشنهاد" },
  { id: "bundles", label: "باندل" },
  { id: "pricing", label: "قیمت" },
  { id: "trial_summary", label: "Trial" },
];

export function CommercialDiscoverExperience() {
  const { isAuthenticated, login, loading: authLoading } = useAuth();
  const router = useRouter();
  const searchParams = useSearchParams();
  const typeParam = searchParams.get("type");

  const [step, setStep] = useState<WizardStep>("assessment");
  const [schemaRes, setSchemaRes] = useState<AdapterResult<AssessmentSchema> | null>(null);
  const [productsRes, setProductsRes] = useState<AdapterResult<CommercialProduct[]> | null>(null);
  const [bundlesRes, setBundlesRes] = useState<AdapterResult<CommercialBundle[]> | null>(null);
  const [pricingRes, setPricingRes] = useState<AdapterResult<CommercialPricingItem[]> | null>(null);
  const [recoRes, setRecoRes] = useState<AdapterResult<RecommendationResult> | null>(null);
  const [answers, setAnswers] = useState<Record<string, unknown>>({});
  const [selectedBundle, setSelectedBundle] = useState<string | null>(null);
  const [qIndex, setQIndex] = useState(0);
  const [busy, setBusy] = useState(false);
  const [booted, setBooted] = useState(false);

  useEffect(() => {
    const session = loadAssessmentSession();
    const nextAnswers = { ...session.answers };
    if (typeParam && !nextAnswers.business_type_code) {
      nextAnswers.business_type_code = typeParam;
    }
    setAnswers(nextAnswers);
    if (session.selected_bundle_code) setSelectedBundle(session.selected_bundle_code);
    void (async () => {
      setBusy(true);
      const [schema, products, bundles, pricing] = await Promise.all([
        loadAssessmentSchema(),
        loadCommercialProducts(),
        loadCommercialBundles(),
        loadCommercialPricing(),
      ]);
      setSchemaRes(schema);
      setProductsRes(products);
      setBundlesRes(bundles);
      setPricingRes(pricing);
      setBusy(false);
      setBooted(true);
    })();
  }, [typeParam]);

  const persist = useCallback((next: AssessmentSession) => {
    saveAssessmentSession(next);
  }, []);

  const questions = schemaRes?.data.questions ?? [];
  const currentQ = questions[qIndex];

  const runRecommendations = async () => {
    setBusy(true);
    persist({ answers, selected_bundle_code: selectedBundle });
    const reco = await requestRecommendations(answers);
    setRecoRes(reco);
    const top = reco.data.recommended_bundles[0]?.code;
    if (top && !selectedBundle) {
      setSelectedBundle(top);
      persist({ answers, selected_bundle_code: top });
    }
    setStep("recommendations");
    setBusy(false);
  };

  const productByCode = useMemo(() => {
    const map = new Map<string, CommercialProduct>();
    (productsRes?.data ?? []).forEach((p) => map.set(p.product_code, p));
    return map;
  }, [productsRes]);

  const bundleByCode = useMemo(() => {
    const map = new Map<string, CommercialBundle>();
    (bundlesRes?.data ?? []).forEach((b) => map.set(b.bundle_code, b));
    return map;
  }, [bundlesRes]);

  const recommendedProducts = (recoRes?.data.recommended_products ?? [])
    .map((r) => ({ ...r, product: productByCode.get(r.code) }))
    .filter((r) => r.product);

  const optionalProducts = (productsRes?.data ?? []).filter(
    (p) => !recommendedProducts.some((r) => r.code === p.product_code) && p.visibility !== "hidden"
  );

  const recommendedBundles = (recoRes?.data.recommended_bundles ?? [])
    .map((r) => ({ ...r, bundle: bundleByCode.get(r.code) }))
    .filter((r) => r.bundle);

  const displayBundles =
    recommendedBundles.length > 0
      ? recommendedBundles.map((r) => r.bundle!)
      : bundlesRes?.data ?? [];

  const selectedBundleObj = selectedBundle ? bundleByCode.get(selectedBundle) : null;
  const pricingForBundle = (pricingRes?.data ?? []).filter((p) =>
    selectedBundleObj?.pricing_refs?.includes(p.pricing_item_code)
  );

  const goWorkspace = () => {
    persist({
      answers,
      selected_bundle_code: selectedBundle,
      selected_product_codes: recoRes?.data.recommended_products.map((p) => p.code),
      activate_trial: true,
    });
    if (isAuthenticated) {
      const intent =
        typeof answers.business_type_code === "string" ? answers.business_type_code : "";
      router.push(intent ? `/onboarding?intent=${encodeURIComponent(intent)}` : "/onboarding");
    } else {
      setStep("create_workspace");
    }
  };

  const stepIndex = STEPS.findIndex((s) => s.id === step);

  if (!booted) {
    return (
      <Container className="py-24 text-center">
        <div className="mx-auto h-10 w-10 animate-pulse rounded-full bg-[var(--color-primary-muted)]" />
        <p className="mt-4 text-sm text-gray-500">آماده‌سازی مسیر کشف…</p>
      </Container>
    );
  }

  return (
    <div className="min-h-[70vh] bg-[var(--canvas)] pb-16 dark:bg-gray-950">
      <div className="border-b border-gray-100 bg-white dark:border-gray-800 dark:bg-gray-950">
        <Container className="py-6">
          <div className="flex flex-wrap items-center justify-between gap-3">
            <div>
              <Link href="/" className="text-xs text-primary">
                ← بازگشت به خانه
              </Link>
              <h1 className="mt-2 text-2xl font-bold text-secondary dark:text-gray-100">
                کشف و راه‌اندازی
              </h1>
            </div>
            <ol className="flex flex-wrap gap-2">
              {STEPS.map((s, i) => (
                <li
                  key={s.id}
                  className={`rounded-full px-3 py-1 text-xs font-medium ${
                    i <= stepIndex
                      ? "bg-primary text-white"
                      : "bg-gray-100 text-gray-500 dark:bg-gray-800"
                  }`}
                >
                  {s.label}
                </li>
              ))}
            </ol>
          </div>
        </Container>
      </div>

      {step === "assessment" ? (
        <Container className="py-10">
          <div className="mx-auto max-w-xl">
            <h2 className="text-xl font-bold text-secondary dark:text-gray-100">ارزیابی نیازها</h2>
            <p className="mt-2 text-sm text-gray-600 dark:text-gray-400">
              سؤالات از assessment schema — صنایع و نیازها بدون لیست ثابت frontend.
            </p>

            {schemaRes?.availability === "unavailable" ||
            schemaRes?.availability === "empty" ||
            !questions.length ? (
              <div className="mt-6 space-y-4">
                <CommercialEmptyState
                  title="اسکیمای ارزیابی در دسترس نیست"
                  description={schemaRes?.message}
                />
                <div className="flex flex-wrap gap-2">
                  <Button
                    loading={busy}
                    onClick={() => {
                      setRecoRes({
                        availability: "unavailable",
                        data: {
                          recommended_products: [],
                          recommended_bundles: [],
                          recommended_capabilities: [],
                          recommended_pricing: [],
                        },
                        message: schemaRes?.message,
                        source: "none",
                      });
                      setStep("recommendations");
                    }}
                  >
                    ادامه با کاتالوگ رجیستری
                  </Button>
                </div>
              </div>
            ) : currentQ ? (
              <div className="mt-6 space-y-4 rounded-3xl border border-gray-100 bg-white p-6 shadow-sm dark:border-gray-800 dark:bg-gray-900">
                <div className="h-1.5 overflow-hidden rounded-full bg-gray-100 dark:bg-gray-800">
                  <div
                    className="h-full rounded-full bg-primary transition-all"
                    style={{ width: `${((qIndex + 1) / questions.length) * 100}%` }}
                  />
                </div>
                <p className="text-xs text-gray-400">
                  سؤال {qIndex + 1} از {questions.length}
                </p>
                <QuestionField
                  question={currentQ}
                  value={answers[currentQ.question_id]}
                  onChange={(v) => {
                    const next = { ...answers, [currentQ.question_id]: v };
                    setAnswers(next);
                    persist({ answers: next, selected_bundle_code: selectedBundle });
                  }}
                />
                <div className="flex flex-wrap gap-2 pt-2">
                  <Button
                    variant="outline"
                    disabled={qIndex === 0}
                    onClick={() => setQIndex((i) => i - 1)}
                  >
                    قبلی
                  </Button>
                  {qIndex < questions.length - 1 ? (
                    <Button
                      onClick={() => setQIndex((i) => i + 1)}
                      disabled={currentQ.required && answers[currentQ.question_id] == null}
                    >
                      بعدی
                    </Button>
                  ) : (
                    <Button loading={busy} onClick={() => void runRecommendations()}>
                      دریافت پیشنهاد
                    </Button>
                  )}
                </div>
              </div>
            ) : null}
          </div>
        </Container>
      ) : null}

      {step === "recommendations" ? (
        <Container className="py-10">
          <div className="mx-auto max-w-4xl space-y-10">
            <div>
              <h2 className="text-2xl font-bold text-secondary dark:text-gray-100">
                پیشنهاد شخصی‌سازی‌شده
              </h2>
              <p className="mt-2 text-sm text-gray-600 dark:text-gray-400">
                محصولات الزامی، اختیاری و مسیر رشد از recommendation + registry.
              </p>
              {recoRes?.message ? (
                <p className="mt-3 rounded-xl bg-amber-50 px-3 py-2 text-xs text-amber-900 dark:bg-amber-950/40 dark:text-amber-200">
                  {recoRes.message}
                </p>
              ) : null}
              {recoRes?.data.rule_trace?.length ? (
                <details className="mt-4 rounded-xl border border-gray-100 bg-white p-4 dark:border-gray-800 dark:bg-gray-950">
                  <summary className="cursor-pointer text-sm font-semibold text-secondary dark:text-gray-100">
                    چرا این پیشنهاد؟
                  </summary>
                  <ol className="mt-3 list-decimal space-y-1 ps-5 text-xs text-gray-600 dark:text-gray-400">
                    {recoRes.data.rule_trace.map((step, i) => (
                      <li key={`${i}-${step}`}>{step}</li>
                    ))}
                  </ol>
                </details>
              ) : null}
            </div>

            <section>
              <h3 className="mb-3 text-sm font-semibold text-secondary dark:text-gray-100">
                محصولات پیشنهادی / الزامی
              </h3>
              {recommendedProducts.length ? (
                <div className="grid gap-3 sm:grid-cols-2">
                  {recommendedProducts.map((r) => (
                    <div key={r.code} className="space-y-1">
                      <ProductCard
                        product={r.product!}
                        recommendationScore={r.score}
                      />
                      {r.reason ? (
                        <p className="px-1 text-xs text-gray-500">{r.reason}</p>
                      ) : null}
                    </div>
                  ))}
                </div>
              ) : (
                <CommercialEmptyState
                  title="پیشنهاد محصول خالی است"
                  description={productsRes?.message || recoRes?.message}
                  hint="پاسخ‌های ارزیابی را بررسی کنید یا بعداً وقتی رجیستری پر شد دوباره امتحان کنید."
                  actionHref="/discover"
                  actionLabel="تکرار ارزیابی"
                  secondaryHref="/pricing"
                  secondaryLabel="مشاهده قیمت‌ها"
                />
              )}
            </section>

            {optionalProducts.length ? (
              <section>
                <h3 className="mb-3 text-sm font-semibold text-secondary dark:text-gray-100">
                  محصولات اختیاری / قابل گسترش
                </h3>
                <div className="grid gap-3 sm:grid-cols-2 lg:grid-cols-3">
                  {optionalProducts.slice(0, 6).map((p) => (
                    <ProductCard key={p.product_code} product={p} />
                  ))}
                </div>
              </section>
            ) : null}

            {selectedBundleObj ? (
              <div className="rounded-2xl border border-primary/30 bg-[var(--color-primary-soft)] p-4 text-sm">
                <p className="font-semibold text-secondary">باندل پیشنهادی فعلی</p>
                <p className="mt-1">{selectedBundleObj.display_name}</p>
                {selectedBundleObj.upgrade_path_code ? (
                  <p className="mt-1 text-xs text-primary">
                    مسیر رشد: {selectedBundleObj.upgrade_path_code}
                  </p>
                ) : null}
              </div>
            ) : null}

            <div className="flex flex-wrap gap-2">
              <Button variant="outline" onClick={() => setStep("assessment")}>
                بازگشت
              </Button>
              <Button onClick={() => setStep("bundles")}>مقایسه باندل</Button>
            </div>
          </div>
        </Container>
      ) : null}

      {step === "bundles" ? (
        <Container className="py-10">
          <div className="mx-auto max-w-4xl space-y-6">
            <h2 className="text-2xl font-bold text-secondary dark:text-gray-100">مقایسه باندل</h2>
            <p className="text-sm text-gray-600 dark:text-gray-400">
              Starter / Professional / Enterprise از metadata باندل — بدون پلن ثابت.
            </p>
            {displayBundles.length ? (
              <div className="grid gap-4 lg:grid-cols-2">
                {displayBundles.map((b) => (
                  <BundleCard
                    key={b.bundle_code}
                    bundle={b}
                    recommendationScore={
                      recoRes?.data.recommended_bundles.find((r) => r.code === b.bundle_code)?.score
                    }
                    selected={selectedBundle === b.bundle_code}
                    onSelect={() => {
                      setSelectedBundle(b.bundle_code);
                      persist({ answers, selected_bundle_code: b.bundle_code });
                    }}
                  />
                ))}
              </div>
            ) : (
              <CommercialEmptyState title="باندلی نیست" description={bundlesRes?.message} />
            )}
            <div className="flex flex-wrap gap-2">
              <Button variant="outline" onClick={() => setStep("recommendations")}>
                بازگشت
              </Button>
              <Button onClick={() => setStep("pricing")}>مقایسه قیمت</Button>
            </div>
          </div>
        </Container>
      ) : null}

      {step === "pricing" ? (
        <Container className="py-10">
          <div className="mx-auto max-w-3xl space-y-6">
            <h2 className="text-2xl font-bold text-secondary dark:text-gray-100">مقایسه قیمت</h2>
            <p className="text-sm text-gray-600 dark:text-gray-400">
              آیتم‌های قیمت از رجیستری؛ تخفیف و پروموشن از discount_refs / metadata.
            </p>
            {(pricingForBundle.length ? pricingForBundle : pricingRes?.data ?? []).length ? (
              <ul className="grid gap-3 sm:grid-cols-2">
                {(pricingForBundle.length ? pricingForBundle : pricingRes!.data).map((item) => (
                  <li
                    key={item.pricing_item_code}
                    className="rounded-2xl border border-gray-100 bg-white p-4 dark:border-gray-800 dark:bg-gray-900"
                  >
                    <p className="font-semibold text-secondary dark:text-gray-100">
                      {item.display_name}
                    </p>
                    <p className="mt-1 text-xs text-gray-500">
                      {item.pricing_model || "—"} ·{" "}
                      {item.amount_minor != null
                        ? `${item.amount_minor} ${item.currency || ""}`
                        : "مبلغ از بک‌اند"}
                    </p>
                    {item.trial_days != null ? (
                      <Badge variant="default" className="mt-2">
                        Trial {item.trial_days} روز
                      </Badge>
                    ) : null}
                  </li>
                ))}
              </ul>
            ) : (
              <CommercialEmptyState title="قیمت‌گذاری خالی است" description={pricingRes?.message} />
            )}
            <div className="flex flex-wrap gap-2">
              <Button variant="outline" onClick={() => setStep("bundles")}>
                بازگشت
              </Button>
              <Button onClick={() => setStep("trial_summary")}>خلاصه Trial</Button>
            </div>
          </div>
        </Container>
      ) : null}

      {step === "trial_summary" ? (
        <Container className="py-10">
          <div className="mx-auto max-w-xl space-y-4 rounded-3xl border border-gray-100 bg-white p-8 shadow-sm dark:border-gray-800 dark:bg-gray-900">
            <h2 className="text-xl font-bold text-secondary dark:text-gray-100">خلاصه Trial</h2>
            <p className="text-sm text-gray-600 dark:text-gray-400">
              پس از ثبت‌نام و ساخت workspace، trial از Billing / commercial subscriptions فعال
              می‌شود — بدون اعداد ساختگی در این صفحه.
            </p>
            {selectedBundle ? (
              <p className="text-sm">
                باندل: <span className="font-semibold">{selectedBundle}</span>
              </p>
            ) : (
              <p className="text-xs text-gray-500">باندل انتخاب نشده — می‌توانید بعداً در Billing انتخاب کنید.</p>
            )}
            <ul className="space-y-1 text-xs text-gray-500">
              <li>✓ ساخت tenant و زیردامنه</li>
              <li>✓ داشبورد تجاری و لانچر اپ‌ها</li>
              <li>✓ دامنه اختصاصی پس از entitlement</li>
            </ul>
            <Button className="w-full" size="lg" onClick={goWorkspace}>
              ساخت Workspace
            </Button>
          </div>
        </Container>
      ) : null}

      {step === "create_workspace" ? (
        <Container className="py-10">
          <div className="mx-auto max-w-md space-y-4 rounded-3xl border border-gray-100 bg-white p-8 text-center shadow-sm dark:border-gray-800 dark:bg-gray-900">
            <h2 className="text-xl font-bold text-secondary dark:text-gray-100">ثبت‌نام / ورود</h2>
            <p className="text-sm text-gray-600 dark:text-gray-400">
              انتخاب‌های ارزیابی در session می‌ماند و پس از ورود به onboarding منتقل می‌شود.
            </p>
            <Button
              className="w-full"
              loading={authLoading}
              onClick={() => {
                persist({
                  answers,
                  selected_bundle_code: selectedBundle,
                  activate_trial: true,
                });
                login();
              }}
            >
              ورود
            </Button>
            <Link href="/register?redirect=/onboarding" className="block">
              <Button variant="outline" className="w-full">
                ثبت‌نام
              </Button>
            </Link>
          </div>
        </Container>
      ) : null}
    </div>
  );
}