import { FormEvent, useEffect, useMemo, useRef, useState } from "react";
import { useNavigate } from "react-router-dom";
import { useApiKey } from "../context/ApiKeyContext";
import "./gate.css";

type Phase = "idle" | "handshake" | "cleared";

const REDUCED_MOTION_QUERY = "(prefers-reduced-motion: reduce)";

function delay(ms: number) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

function maskKey(key: string): string {
  const trimmed = key.trim();
  if (trimmed.length <= 8) return "••••";
  return `${trimmed.slice(0, 4)}••••${trimmed.slice(-4)}`;
}

function stampDate(): string {
  return new Date()
    .toLocaleDateString("en-GB", { day: "2-digit", month: "short", year: "numeric" })
    .toUpperCase();
}

export default function Gate() {
  const { apiKeys, activeKeyId, addApiKey, setActiveKeyId } = useApiKey();
  const navigate = useNavigate();

  const prefersReducedMotion = useMemo(
    () => window.matchMedia(REDUCED_MOTION_QUERY).matches,
    []
  );

  const hasStoredKeys = apiKeys.length > 0;
  const [enterMode, setEnterMode] = useState<"resume" | "fresh">(
    hasStoredKeys ? "resume" : "fresh"
  );

  const [workspaceName, setWorkspaceName] = useState("");
  const [apiKey, setApiKey] = useState("");
  const [showKey, setShowKey] = useState(false);
  const [resumeKeyId, setResumeKeyId] = useState(activeKeyId ?? apiKeys[0]?.id ?? "");
  const [error, setError] = useState<string | null>(null);
  const [phase, setPhase] = useState<Phase>("idle");

  const resumeKey = apiKeys.find((k) => k.id === resumeKeyId);

  const aliveRef = useRef(true);
  const timersRef = useRef<number[]>([]);
  useEffect(() => {
    aliveRef.current = true;
    return () => {
      aliveRef.current = false;
      timersRef.current.forEach((t) => clearTimeout(t));
    };
  }, []);

  function finish(opts: { name: string; key: string; resumeId?: string }) {
    if (!aliveRef.current) return;
    if (opts.resumeId) {
      setActiveKeyId(opts.resumeId);
    } else {
      addApiKey(opts.name, opts.key, true);
    }
    navigate("/", { replace: true });
  }

  async function runHandshake(opts: { name: string; key: string; resumeId?: string }) {
    setPhase("handshake");
    setError(null);

    if (prefersReducedMotion) {
      finish(opts);
      return;
    }

    await delay(620);
    if (!aliveRef.current) return;
    setPhase("cleared");
    const t = window.setTimeout(() => {
      finish(opts);
    }, 900);
    timersRef.current.push(t);
  }

  function handleSubmit(event: FormEvent<HTMLFormElement>) {
    event.preventDefault();
    if (phase !== "idle") return;

    if (enterMode === "resume" && resumeKey) {
      void runHandshake({
        name: resumeKey.name,
        key: resumeKey.key,
        resumeId: resumeKey.id,
      });
      return;
    }

    const name = workspaceName.trim();
    const key = apiKey.trim();
    if (!name) {
      setError("Name your workspace — anything you will recognize later.");
      return;
    }
    if (!key) {
      setError("Paste your Smartlead API key to open the module.");
      return;
    }
    void runHandshake({ name, key });
  }

  function enterDemo() {
    if (phase !== "idle") return;
    setEnterMode("fresh");
    setWorkspaceName("Demo Workspace");
    setApiKey("demo_bridge_e");
    setError(null);
    void runHandshake({ name: "Demo Workspace", key: "demo_bridge_e" });
  }

  const busy = phase !== "idle";
  const buttonLabel =
    phase === "idle"
      ? "OPEN MODULE"
      : phase === "handshake"
        ? "OPENING…"
        : "CLEARED";

  return (
    <div className="gate">
      <h1 className="gate-sr">BRIDGE Modul E — connect a Smartlead workspace</h1>

      <span className="gate-cropmark tl" aria-hidden="true" />
      <span className="gate-cropmark tr" aria-hidden="true" />
      <span className="gate-cropmark bl" aria-hidden="true" />
      <span className="gate-cropmark br" aria-hidden="true" />

      <div className="gate-formwrap">
        {phase === "cleared" && (
          <svg className="gate-stamp" viewBox="0 0 120 120" aria-hidden="true">
            <circle cx="60" cy="60" r="56" fill="none" stroke="currentColor" strokeWidth="2.5" />
            <circle cx="60" cy="60" r="47" fill="none" stroke="currentColor" strokeWidth="1.2" />
            <path id="gate-stamp-arc" d="M 24 60 A 36 36 0 0 1 96 60" fill="none" />
            <text fontSize="10.5" fontWeight="700" letterSpacing="2.5" fill="currentColor">
              <textPath href="#gate-stamp-arc" startOffset="50%" textAnchor="middle">
                CLEARED FOR DISPATCH
              </textPath>
            </text>
            <text x="60" y="63" textAnchor="middle" fontSize="15" fontWeight="800" letterSpacing="1.5" fill="currentColor">
              MODUL·E
            </text>
            <text x="60" y="78" textAnchor="middle" fontSize="8.5" fontWeight="600" letterSpacing="2" fill="currentColor">
              {stampDate()}
            </text>
          </svg>
        )}

        <div className="gate-card">
          <form onSubmit={handleSubmit} noValidate>
            {enterMode === "resume" && hasStoredKeys ? (
              <div className="gate-field">
                <label htmlFor="gate-resume">Stored workspace</label>
                <select
                  id="gate-resume"
                  value={resumeKeyId}
                  onChange={(e) => setResumeKeyId(e.target.value)}
                  disabled={busy}
                >
                  {apiKeys.map((k) => (
                    <option key={k.id} value={k.id}>
                      {k.name} — {maskKey(k.key)}
                    </option>
                  ))}
                </select>
              </div>
            ) : (
              <>
                <div className="gate-field">
                  <label htmlFor="gate-name">Workspace name</label>
                  <input
                    id="gate-name"
                    type="text"
                    value={workspaceName}
                    onChange={(e) => setWorkspaceName(e.target.value)}
                    placeholder="e.g. Acme growth pod"
                    autoComplete="off"
                    disabled={busy}
                  />
                </div>
                <div className="gate-field">
                  <label htmlFor="gate-key">Smartlead API key</label>
                  <div className="gate-key-row">
                    <input
                      id="gate-key"
                      type={showKey ? "text" : "password"}
                      value={apiKey}
                      onChange={(e) => setApiKey(e.target.value)}
                      placeholder="Paste your Smartlead key"
                      autoComplete="off"
                      spellCheck={false}
                      disabled={busy}
                      className="gate-key-input"
                    />
                    <button
                      type="button"
                      className="gate-peek"
                      onClick={() => setShowKey((v) => !v)}
                      disabled={busy || apiKey.length === 0}
                    >
                      {showKey ? "Hide" : "Show"}
                    </button>
                  </div>
                </div>
              </>
            )}

            {error && (
              <p className="gate-error" role="alert">
                {error}
              </p>
            )}

            <button
              type="submit"
              className="gate-cta"
              data-phase={phase}
              disabled={busy}
            >
              {buttonLabel}
            </button>

            {enterMode === "resume" ? (
              <button
                type="button"
                className="gate-switch"
                onClick={() => {
                  setEnterMode("fresh");
                  setError(null);
                }}
                disabled={busy}
              >
                Use a different key
              </button>
            ) : (
              <>
                <div className="gate-or">
                  <span aria-hidden="true" />
                  OR
                  <span aria-hidden="true" />
                </div>
                <button type="button" className="gate-demo" onClick={enterDemo} disabled={busy}>
                  Enter with demo data
                </button>
              </>
            )}
          </form>
        </div>
      </div>
    </div>
  );
}