"use client";

import { useState } from "react";
import Link from "next/link";
import { ArrowLeft, Check, LoaderCircle, RotateCcw } from "lucide-react";
import { submitSupport, type SupportKind } from "@/lib/api/support";
import { isApiError } from "@/lib/api/client";
import { cn } from "@/lib/utils";

type SupportFormProps = {
  kind: SupportKind;
  eyebrow: string;
  title: string;
  intro: string;
  categories?: string[];
  showRating?: boolean;
  showTitleField?: boolean;
  messageLabel: string;
  messagePlaceholder: string;
};

type Phase = "idle" | "submitting" | "done" | "error";

const inputClass =
  "w-full rounded-xl border border-white/12 bg-white/[0.03] px-3.5 py-3 text-[15px] text-white placeholder:text-white/30 outline-none transition focus:border-white/40";
const labelClass = "block text-xs font-bold uppercase tracking-[0.14em] text-white/45";

export function SupportForm({
  kind,
  eyebrow,
  title,
  intro,
  categories,
  showRating = false,
  showTitleField = false,
  messageLabel,
  messagePlaceholder,
}: SupportFormProps) {
  const [category, setCategory] = useState<string>(categories?.[0] ?? "");
  const [titleValue, setTitleValue] = useState("");
  const [message, setMessage] = useState("");
  const [rating, setRating] = useState<number | null>(null);
  const [phase, setPhase] = useState<Phase>("idle");
  const [error, setError] = useState<string | null>(null);

  const canSubmit = message.trim().length > 0 && phase !== "submitting";

  async function handleSubmit() {
    if (!canSubmit) return;
    setPhase("submitting");
    setError(null);
    try {
      await submitSupport({
        kind,
        message: message.trim(),
        category: category || null,
        title: showTitleField ? titleValue.trim() || null : null,
        rating: showRating ? rating : null,
        page_url: typeof window !== "undefined" ? window.location.href : null,
      });
      setPhase("done");
    } catch (err) {
      // Never expose an internal payload — a plain, retryable message only.
      const status = isApiError(err) ? err.status : null;
      if (status === 429) {
        setError("You've sent a few messages in a short time. Please wait a minute and try again — your text is still here.");
      } else if (status === 422) {
        setError("Please add a bit more detail to your message before sending.");
      } else {
        setError("We could not send that just now. Check your connection and try again — your text is still here.");
      }
      setPhase("error");
    }
  }

  if (phase === "done") {
    return (
      <div className="mx-auto w-full max-w-xl rounded-2xl border border-white/12 bg-white/[0.03] p-8 text-center">
        <span className="mx-auto flex size-12 items-center justify-center rounded-full bg-emerald-500/15 text-emerald-300">
          <Check className="size-6" />
        </span>
        <h2 className="mt-5 text-xl font-bold text-white">Thank you — we received it</h2>
        <p className="mt-2 text-sm leading-6 text-white/55">
          {kind === "bug"
            ? "Your report is saved. The team reviews bug reports during the beta and will act on the clear ones first."
            : "Your feedback is saved. Real student feedback is what shapes what DocDoe builds next."}
        </p>
        <div className="mt-6 flex flex-wrap justify-center gap-3">
          <button
            type="button"
            onClick={() => {
              setMessage("");
              setTitleValue("");
              setRating(null);
              setPhase("idle");
            }}
            className="inline-flex h-11 items-center gap-2 rounded-xl border border-white/15 px-4 text-sm font-semibold text-white/75 transition hover:text-white"
          >
            Send another
          </button>
          <Link
            href="/home"
            className="inline-flex h-11 items-center gap-2 rounded-xl bg-white px-5 text-sm font-bold text-black transition hover:bg-white/90"
          >
            Back to DocDoe
          </Link>
        </div>
      </div>
    );
  }

  return (
    <div className="mx-auto w-full max-w-xl">
      <Link
        href="/"
        className="inline-flex items-center gap-2 text-sm font-medium text-white/45 transition hover:text-white"
      >
        <ArrowLeft className="size-4" /> DocDoe
      </Link>
      <p className="mt-6 text-[11px] font-bold uppercase tracking-[0.2em] text-white/40">{eyebrow}</p>
      <h1 className="mt-3 text-3xl font-semibold tracking-tight text-white sm:text-4xl">{title}</h1>
      <p className="mt-4 text-[15px] leading-7 text-white/60">{intro}</p>

      <form
        className="mt-8 space-y-5"
        onSubmit={(event) => {
          event.preventDefault();
          void handleSubmit();
        }}
      >
        {categories && categories.length > 0 ? (
          <div>
            <span className={labelClass}>Category</span>
            <div className="mt-2 flex flex-wrap gap-2">
              {categories.map((item) => (
                <button
                  key={item}
                  type="button"
                  onClick={() => setCategory(item)}
                  aria-pressed={category === item}
                  className={cn(
                    "rounded-lg border px-3 py-2 text-sm font-semibold transition",
                    category === item
                      ? "border-white bg-white text-black"
                      : "border-white/12 text-white/60 hover:border-white/30 hover:text-white",
                  )}
                >
                  {item}
                </button>
              ))}
            </div>
          </div>
        ) : null}

        {showTitleField ? (
          <label htmlFor="support-title" className="block">
            <span className={labelClass}>Title (optional)</span>
            <input
              id="support-title"
              value={titleValue}
              onChange={(event) => setTitleValue(event.target.value)}
              placeholder="Short summary"
              maxLength={200}
              className={cn(inputClass, "mt-2")}
            />
          </label>
        ) : null}

        {showRating ? (
          <div>
            <span className={labelClass}>Rating (optional)</span>
            <div className="mt-2 flex gap-2">
              {[1, 2, 3, 4, 5].map((value) => (
                <button
                  key={value}
                  type="button"
                  onClick={() => setRating(rating === value ? null : value)}
                  aria-label={`${value} out of 5`}
                  aria-pressed={rating === value}
                  className={cn(
                    "size-10 rounded-lg border text-sm font-bold transition",
                    rating !== null && value <= rating
                      ? "border-white bg-white text-black"
                      : "border-white/12 text-white/50 hover:border-white/30 hover:text-white",
                  )}
                >
                  {value}
                </button>
              ))}
            </div>
          </div>
        ) : null}

        <label htmlFor="support-message" className="block">
          <span className={labelClass}>{messageLabel}</span>
          <textarea
            id="support-message"
            value={message}
            onChange={(event) => setMessage(event.target.value)}
            placeholder={messagePlaceholder}
            rows={6}
            maxLength={4000}
            className={cn(inputClass, "mt-2 resize-y")}
          />
        </label>

        {error ? (
          <p className="rounded-lg border border-rose-400/25 bg-rose-400/[0.06] px-3 py-2 text-sm text-rose-200/90" role="alert">
            {error}
          </p>
        ) : null}

        <button
          type="submit"
          disabled={!canSubmit}
          className="inline-flex h-12 w-full items-center justify-center gap-2 rounded-xl bg-white px-6 text-[15px] font-bold text-black transition hover:bg-white/90 disabled:cursor-not-allowed disabled:opacity-40 sm:w-auto"
        >
          {phase === "submitting" ? (
            <>
              <LoaderCircle className="size-4 animate-spin" /> Sending…
            </>
          ) : phase === "error" ? (
            <>
              <RotateCcw className="size-4" /> Try again
            </>
          ) : (
            "Submit"
          )}
        </button>
        <p className="text-xs leading-5 text-white/35">
          We store only what you type here plus your browser type, so we can reproduce the issue.
          Nothing is shared publicly.
        </p>
      </form>
    </div>
  );
}