"use client";

import { useEffect, useState, type FormEvent } from "react";
import Link from "next/link";
import { Badge, Button, Card, Input } from "../../../components/ui/primitives";
import { OfflineBadge } from "../../../components/ui/offline-badge";
import { ArrowGlyph, LogoMark } from "../../../components/brand/logo";
import { PLATFORMS } from "../../../lib/platforms";
import { useApiResource } from "../../../lib/use-api";
import { api, errorMessage } from "../../../lib/api-client";
import type { MemberMutationResult } from "../../../lib/api-types";
import type { ConnectProvider } from "../../../lib/connections-client";
import { useAuth } from "../../../lib/auth-store";

// Step labels for the collective flow; solo accounts skip this wizard entirely.
const STEPS = ["Name your collective", "Invite team", "Connect accounts"];
const MIN_PASSWORD = 10;
const INVITE_ROLE_CHOICES = ["Owner", "Editor", "Viewer"] as const;
const DEFAULT_INVITE_ROLE = "Editor";
const NO_PROVIDERS: ConnectProvider[] = [];

function platformName(id: string): string {
  return PLATFORMS[id]?.displayName ?? id;
}

function SignInForm({ onSwitch }: { onSwitch: () => void }): React.ReactElement {
  const { login } = useAuth();
  const [username, setUsername] = useState("");
  const [password, setPassword] = useState("");
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | null>(null);

  async function submit(e: FormEvent): Promise<void> {
    e.preventDefault();
    setBusy(true);
    setError(null);
    try {
      await login(username.trim(), password);
      window.location.assign("/streams");
    } catch (err) {
      setError(errorMessage(err));
      setBusy(false);
    }
  }

  return (
    <form onSubmit={(e) => void submit(e)}>
      <h2 className="mb-1 text-base font-semibold">Sign in</h2>
      <p className="mb-4 text-xs text-text-faint">Use the username and password you registered with.</p>
      <div className="space-y-2">
        <Input type="text" value={username} onChange={(e) => setUsername(e.target.value)} placeholder="username" autoComplete="username" autoFocus />
        <Input type="password" value={password} onChange={(e) => setPassword(e.target.value)} placeholder="Password" autoComplete="current-password" />
      </div>
      {error !== null && <p className="mt-2 text-xs text-danger">{error}</p>}
      <div className="mt-6 flex items-center justify-between">
        <Button type="button" variant="ghost" onClick={onSwitch}>Create a workspace instead</Button>
        <Button type="submit" variant="primary" disabled={busy || username.trim() === "" || password === ""}>
          {busy ? "Signing in…" : "Sign in"}
        </Button>
      </div>
    </form>
  );
}

export default function OnboardingPage(): React.ReactElement {
  const { status, session, register, adoptToken, logout } = useAuth();
  const offline = status === "offline";
  // /login deep-links here in sign-in mode; the default entry is create-account.
  const [mode, setMode] = useState<"register" | "signin">(
    typeof window !== "undefined" && window.location.search.includes("mode=signin") ? "signin" : "register",
  );
  const [step, setStep] = useState(0);
  const [name, setName] = useState("");
  // Collectives opt-in (operator reorder #2): default OFF = solo account.
  const [creatingCollective, setCreatingCollective] = useState(false);
  const [displayName, setDisplayName] = useState("");
  const [username, setUsername] = useState("");
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [emails, setEmails] = useState("");
  const [inviteRole, setInviteRole] = useState<string>(DEFAULT_INVITE_ROLE);
  const { data: providers, source: providerSource } = useApiResource<ConnectProvider[], ConnectProvider[]>("/connections/providers", (p) => p, NO_PROVIDERS);
  const [busy, setBusy] = useState(false);
  const [error, setError] = useState<string | null>(null);
  const [sessionExpired, setSessionExpired] = useState(false);

  // The API client redirects here with ?reason=session on a 401: default to sign-in.
  useEffect(() => {
    if (new URLSearchParams(window.location.search).get("reason") === "session") {
      setSessionExpired(true);
      setMode("signin");
    }
  }, []);

  async function createWorkspace(): Promise<void> {
    if (offline) {
      if (!creatingCollective) window.location.assign("/streams");
      else setStep(1);
      return;
    }
    setBusy(true);
    setError(null);
    try {
      await register({
        // Solo default: omitting workspaceName registers a personal workspace.
        ...(creatingCollective ? { workspaceName: name.trim() } : {}),
        username: username.trim(),
        password,
        ...(displayName.trim() === "" ? {} : { displayName: displayName.trim() }),
        ...(email.trim() === "" ? {} : { email: email.trim() }),
      });
      // Solo accounts skip the team-invite wizard: there is no collective to
      // invite anyone into yet. They land straight in the app (which shows the
      // "no collectives" home menu until they create or join one).
      if (!creatingCollective) window.location.assign("/streams");
      else setStep(1);
    } catch (err) {
      setError(errorMessage(err));
    } finally {
      setBusy(false);
    }
  }

  async function sendInvites(): Promise<void> {
    const list = emails.split(/[\s,;]+/).map((e) => e.trim()).filter((e) => e.includes("@"));
    if (offline || list.length === 0) {
      setStep(2);
      return;
    }
    setBusy(true);
    setError(null);
    const failures: string[] = [];
    // Sequential: each invite bumps the authz epoch and returns the token the next call must use.
    for (const invitee of list) {
      try {
        const result = await api.post<MemberMutationResult>("/team/members/invite", { email: invitee, role: inviteRole });
        adoptToken(result.token);
      } catch (err) {
        failures.push(`${invitee}: ${errorMessage(err)}`);
      }
    }
    setBusy(false);
    if (failures.length > 0) setError(failures.join(" · "));
    else setStep(2);
  }

  const usernameValid = /^[a-z0-9][a-z0-9_.-]{1,31}$/.test(username.trim());
  const registerReady =
    (!creatingCollective || name.trim().length >= 2) && (offline || (usernameValid && password.length >= MIN_PASSWORD));

  // Signed-in visitors who land here (e.g. from the sidebar) get a way out rather than a second registration form.
  if (status === "authenticated" && session !== null && step === 0) {
    return (
      <div className="flex min-h-full items-center justify-center p-6">
        <Card className="w-[520px] max-w-full p-6">
          <h2 className="mb-1 text-base font-semibold">You&apos;re signed in</h2>
          <p className="mb-6 text-xs text-text-faint">
            @{session.user.username} · {session.role} of <span className="text-text">{session.workspace.name}</span>
          </p>
          <div className="flex justify-between">
            <Button variant="ghost" onClick={() => void logout()}>Sign out</Button>
            <Link href="/streams" className="rounded-md bg-accent px-3 py-1.5 text-xs font-medium text-white hover:bg-accent-hover">
              Continue to Streams
            </Link>
          </div>
        </Card>
      </div>
    );
  }

  return (
    <div className="flex h-full items-center justify-center p-6">
      <Card className="w-[520px] max-w-full p-6">
        <div className="mb-4 flex items-center justify-end">
          <Button
            size="sm"
            variant="outline"
            onClick={() => { setMode(mode === "signin" ? "register" : "signin"); setStep(0); }}
          >
            {mode === "signin" ? "Create a workspace" : "Existing account? Log in"}
          </Button>
        </div>
        {offline && (
          <div className="mb-4 flex justify-end">
            <OfflineBadge source="sample" />
          </div>
        )}
        {sessionExpired && step === 0 && (
          <p className="mb-4 rounded-md border border-warn/30 bg-warn/10 px-3 py-2 text-xs text-warn">
            Your session ended (expired, or your role changed). Sign in again.
          </p>
        )}

        {mode === "signin" && step === 0 && !offline ? (
          <SignInForm onSwitch={() => setMode("register")} />
        ) : (
          <>
            <div className="mb-6 flex items-center gap-2">
              {STEPS.map((s, i) => (
                <div key={s} className="flex flex-1 items-center gap-2">
                  <span
                    className={`flex h-6 w-6 items-center justify-center rounded-full text-2xs font-semibold ${
                      i < step ? "bg-live/20 text-live" : i === step ? "bg-accent text-white" : "bg-surface-2 text-text-faint"
                    }`}
                  >
                    {i < step ? "✓" : i + 1}
                  </span>
                  <span className={`text-xs ${i === step ? "text-text" : "text-text-faint"}`}>{s}</span>
                  {i < STEPS.length - 1 && <span className="h-px flex-1 bg-border-subtle" />}
                </div>
              ))}
            </div>

            {step === 0 && (
              <form
                onSubmit={(e) => {
                  e.preventDefault();
                  void createWorkspace();
                }}
              >
                <div className="mb-5">
                  <div className="-m-6 mb-5 overflow-hidden bg-black">
                    <div className="flex items-center gap-5 px-8 py-8">
                      <LogoMark size={96} className="shrink-0 text-white" />
                      <div className="min-w-0">
                        <div className="text-xl font-semibold leading-tight text-white">Horizontal Collaborative Broadcast System</div>
                        <div className="mt-1 text-xs uppercase tracking-wider text-[#00e5ff]">T-HUB</div>
                      </div>
                    </div>
                  </div>
                  <div className="text-center">
                    <h1 className="text-2xl font-semibold tracking-tight">T-HUB</h1>
                    <p className="mt-1 text-2xs text-text-faint">Your platform. Their feeds. No algorithm in between.</p>
                  </div>
                </div>
                {/*
                  Operator reorder #1/#2: registration makes a USER by default —
                  a solo account with no collective. Creating a collective is an
                  explicit opt-in that reveals the name field and the classic
                  workspace flow (provisioner mints rooms once a collective is
                  actually created from inside the app).
                */}
                <label className="mb-4 flex cursor-pointer items-start gap-2.5 rounded-lg border border-border bg-surface-2 p-3">
                  <input
                    type="checkbox"
                    checked={creatingCollective}
                    onChange={(e) => setCreatingCollective(e.target.checked)}
                    className="mt-0.5 h-4 w-4 accent-[#FF1610]"
                  />
                  <span>
                    <span className="block text-sm font-medium">I am creating a new collective</span>
                    <span className="block text-xs text-text-faint">Voy a crear un colectivo — with its own rooms and members.</span>
                  </span>
                </label>
                {creatingCollective ? (
                  <>
                    <h2 className="mb-1 text-base font-semibold">Name your collective</h2>
                    <p className="mb-4 text-xs text-text-faint">The tenant boundary for accounts, drafts, and audit.</p>
                    <Input value={name} onChange={(e) => setName(e.target.value)} placeholder="Your collective, your studio…" autoFocus />
                  </>
                ) : (
                  <h2 className="mb-4 text-base font-semibold">Create your account</h2>
                )}
                {!offline && (
                  <div className="mt-4 space-y-2">
                    <p className="text-xs text-text-faint">Your owner account</p>
                    <Input value={displayName} onChange={(e) => setDisplayName(e.target.value)} placeholder="Your name (optional)" autoComplete="name" />
                    <Input
                      type="text"
                      value={username}
                      onChange={(e) => setUsername(e.target.value.toLowerCase())}
                      placeholder="Username — this is how you sign in"
                      autoComplete="username"
                      pattern="[a-z0-9][a-z0-9_.-]{1,31}"
                      title="2-32 characters: lowercase letters, digits, dot, underscore or hyphen"
                    />
                    <Input
                      type="password"
                      value={password}
                      onChange={(e) => setPassword(e.target.value)}
                      placeholder={`Password (min ${MIN_PASSWORD} characters)`}
                      autoComplete="new-password"
                    />
                    <Input
                      type="email"
                      value={email}
                      onChange={(e) => setEmail(e.target.value)}
                      placeholder="Email (optional)"
                      autoComplete="email"
                    />
                  </div>
                )}
                {error !== null && <p className="mt-2 text-xs text-danger">{error}</p>}
                <div className="mt-6 flex items-center justify-between">
                  {offline ? <span /> : (
                    <Button type="button" variant="ghost" onClick={() => setMode("signin")}>I already have an account</Button>
                  )}
                  <Button type="submit" variant="primary" disabled={busy || !registerReady}>
                    {busy ? "Creating…" : "Continue"}
                  </Button>
                </div>
              </form>
            )}

            {step === 1 && (
              <div>
                <h2 className="mb-1 text-base font-semibold">Invite your team</h2>
                <p className="mb-4 text-xs text-text-faint">
                  Comma-separated emails. Invitees join at the chosen role; adjust roles on the Team page.
                </p>
                <textarea
                  value={emails}
                  onChange={(e) => setEmails(e.target.value)}
                  rows={3}
                  placeholder="priya@studio.io, yuki@studio.io"
                  className="w-full resize-none rounded-md border border-border bg-surface-2 p-2 text-sm focus:border-accent focus:outline-none"
                />
                <label className="mt-3 flex items-center gap-2 text-xs text-text-faint">
                  Invite role
                  <select
                    value={inviteRole}
                    onChange={(e) => setInviteRole(e.target.value)}
                    className="rounded-md border border-border bg-surface-2 px-2 py-1 text-xs"
                  >
                    {INVITE_ROLE_CHOICES.map((role) => (
                      <option key={role} value={role}>{role}</option>
                    ))}
                  </select>
                </label>
                {error !== null && <p className="mt-2 text-xs text-danger">{error}</p>}
                <div className="mt-6 flex justify-between">
                  {/* The workspace already exists once step 0 succeeds; going back would re-register. */}
                  <Button variant="ghost" onClick={() => setStep(2)}>Skip</Button>
                  <Button variant="primary" disabled={busy} onClick={() => void sendInvites()}>
                    {busy ? "Inviting…" : "Continue"}
                  </Button>
                </div>
              </div>
            )}

            {step === 2 && (
              <div>
                <h2 className="mb-1 text-base font-semibold">Connect your first accounts</h2>
                <p className="mb-4 text-xs text-text-faint">
                  {providerSource === "live" && providers.length > 0
                    ? `Available: ${providers.map((p) => platformName(p.id)).join(", ")}. Follow each linking flow — bot tokens where required, OAuth on your instance otherwise.`
                    : "Connect at least one account so your workspace can publish."}
                </p>
                <div className="space-y-2">
                  {providerSource === "live" && providers.length > 0 ? (
                    providers.map((p) => (
                      <div key={p.id} className="flex items-center justify-between rounded-md border border-border-subtle px-3 py-2.5">
                        <div className="flex items-center gap-3">
                          <ArrowGlyph size={11} className="text-accent" />
                          <span className="text-sm font-medium">{platformName(p.id)}</span>
                        </div>
                        <Button
                          size="sm"
                          variant="outline"
                          onClick={() => window.location.assign(`/connections?start=${p.id}`)}
                        >
                          Connect
                        </Button>
                      </div>
                    ))
                  ) : (
                    <p className={`rounded-md border px-3 py-2.5 text-xs ${providerSource === "loading" || providerSource === "live" ? "border-border-subtle text-text-faint" : "border-danger text-danger"}`}>
                      {providerSource === "loading"
                        ? "Loading connectable platforms…"
                        : providerSource === "live"
                          ? "No connectable platforms are available yet."
                          : "Could not load the platform list — check that the API is reachable, or continue and connect later from Connections."}
                    </p>
                  )}
                </div>
                <p className="mt-3 text-2xs text-text-faint">Connecting opens the account linking flow — you can also do this later from Connections.</p>
                <div className="mt-6 flex justify-between">
                  <Button variant="ghost" onClick={() => setStep(1)}>Back</Button>
                  <Button variant="primary" onClick={() => setStep(3)}>Finish setup</Button>
                </div>
              </div>
            )}

            {step === 3 && (
              <div className="py-8 text-center">
                <div className="mx-auto mb-4 flex h-12 w-12 items-center justify-center rounded-full bg-live/20 text-lg text-live">✓</div>
                <h2 className="text-base font-semibold">{session?.workspace.name ?? (name || "Workspace")} is ready</h2>
                <p className="mt-1 text-xs text-text-faint">
                  Link accounts any time from <Link href="/connections" className="text-accent hover:underline">Connections</Link> — or head to{" "}
                  <Link href="/streams" className="text-accent hover:underline">Streams</Link> or{" "}
                  <Link href="/compose" className="text-accent hover:underline">Compose</Link>
                </p>
              </div>
            )}
          </>
        )}
      </Card>
    </div>
  );
}