import { useQueryClient } from "@tanstack/react-query";
import { useState } from "react";
import { useNavigate } from "react-router-dom";

import { useT } from "../../i18n";
import { api, ApiError } from "../../lib/api";
import type { ServerConfig, SyncWindow } from "../../lib/types";

const PALETTE = ["#2563eb", "#16a34a", "#d4762a", "#9333ea", "#dc2626", "#0891b2"];
const EMPTY: ServerConfig = { host: "", port: 993, tls: "ssl", auth: "password" };

export function AccountWizard() {
  const t = useT();
  const navigate = useNavigate();
  const queryClient = useQueryClient();

  const [step, setStep] = useState<1 | 2 | 3>(1);
  const [email, setEmail] = useState("");
  const [displayName, setDisplayName] = useState("");
  const [password, setPassword] = useState("");
  const [color, setColor] = useState(PALETTE[0]);
  const [imap, setImap] = useState<ServerConfig>(EMPTY);
  const [smtp, setSmtp] = useState<ServerConfig>({ ...EMPTY, port: 465 });
  const [source, setSource] = useState<string>("");
  const [syncWindow, setSyncWindow] = useState<SyncWindow>("all");
  const [busy, setBusy] = useState(false);
  const [tested, setTested] = useState(false);
  const [error, setError] = useState("");

  const discover = async () => {
    setBusy(true);
    setError("");
    try {
      const res = await api.discover(email);
      const cand = res.candidates[0];
      if (cand) {
        setImap({ ...cand.imap });
        setSmtp({ ...cand.smtp });
        setSource(cand.source);
      } else {
        setSource("manual");
      }
      setStep(2);
    } catch (e) {
      setError(e instanceof ApiError ? e.message : String(e));
    } finally {
      setBusy(false);
    }
  };

  const test = async () => {
    setBusy(true);
    setError("");
    setTested(false);
    try {
      await api.testAccount({ imap, smtp, email, password });
      setTested(true);
    } catch (e) {
      setError(e instanceof ApiError ? e.message : String(e));
    } finally {
      setBusy(false);
    }
  };

  const create = async () => {
    setBusy(true);
    setError("");
    try {
      await api.createAccount({
        email,
        display_name: displayName || email,
        color,
        imap,
        smtp,
        password,
        sync_window: syncWindow,
      });
      await queryClient.invalidateQueries({ queryKey: ["accounts"] });
      setStep(3);
    } catch (e) {
      setError(e instanceof ApiError ? e.message : String(e));
    } finally {
      setBusy(false);
    }
  };

  const serverFields = (
    cfg: ServerConfig,
    set: (c: ServerConfig) => void,
    label: string,
  ) => (
    <fieldset className="rounded-lg border border-app-border p-3">
      <legend className="px-1 text-xs text-app-muted">{label}</legend>
      <div className="flex gap-2">
        <input
          className="flex-1 rounded border border-app-border bg-app-surface px-2 py-1 text-sm"
          placeholder={t("wizard.host")}
          value={cfg.host}
          onChange={(e) => set({ ...cfg, host: e.target.value })}
        />
        <input
          className="w-20 rounded border border-app-border bg-app-surface px-2 py-1 text-sm"
          type="number"
          value={cfg.port}
          onChange={(e) => set({ ...cfg, port: Number(e.target.value) })}
        />
        <select
          className="rounded border border-app-border bg-app-surface px-2 py-1 text-sm"
          value={cfg.tls}
          onChange={(e) => set({ ...cfg, tls: e.target.value })}
        >
          <option value="ssl">SSL</option>
          <option value="starttls">STARTTLS</option>
        </select>
      </div>
    </fieldset>
  );

  return (
    <div className="mx-auto mt-16 max-w-lg px-4">
      <h1 className="mb-6 text-2xl font-semibold">{t("wizard.title")}</h1>

      {step === 1 && (
        <form
          className="space-y-3"
          onSubmit={(e) => {
            e.preventDefault();
            discover();
          }}
        >
          <label className="block text-sm text-app-muted">{t("wizard.step1")}</label>
          <input
            className="w-full rounded-lg border border-app-border bg-app-surface px-3 py-2"
            type="email"
            placeholder={t("wizard.emailPlaceholder")}
            value={email}
            onChange={(e) => setEmail(e.target.value)}
            autoFocus
          />
          <button
            className="rounded bg-app-accent px-4 py-2 text-app-accent-fg disabled:opacity-50"
            disabled={busy || !email.includes("@")}
          >
            {busy ? t("wizard.discovering") : t("wizard.discover")}
          </button>
        </form>
      )}

      {step === 2 && (
        <div className="space-y-3">
          {source && source !== "manual" && (
            <p className="text-sm text-emerald-500">{t("wizard.foundVia", { source })}</p>
          )}
          {serverFields(imap, setImap, t("wizard.imapServer"))}
          {serverFields(smtp, setSmtp, t("wizard.smtpServer"))}
          <input
            className="w-full rounded-lg border border-app-border bg-app-surface px-3 py-2 text-sm"
            placeholder={t("wizard.displayName")}
            value={displayName}
            onChange={(e) => setDisplayName(e.target.value)}
          />
          <input
            className="w-full rounded-lg border border-app-border bg-app-surface px-3 py-2 text-sm"
            type="password"
            placeholder={t("wizard.accountPassword")}
            value={password}
            onChange={(e) => {
              setPassword(e.target.value);
              setTested(false);
            }}
          />
          <p className="text-xs text-app-faint">{t("wizard.appPasswordHint")}</p>
          <div className="flex items-center gap-2">
            <span className="text-xs text-app-muted">Color</span>
            {PALETTE.map((c) => (
              <button
                key={c}
                onClick={() => setColor(c)}
                className={`h-5 w-5 rounded-full ${color === c ? "ring-2 ring-offset-1" : ""}`}
                style={{ backgroundColor: c }}
                aria-label={c}
              />
            ))}
          </div>
          <fieldset className="rounded-lg border border-app-border p-3">
            <legend className="px-1 text-xs text-app-muted">{t("wizard.syncWindow")}</legend>
            <div className="space-y-1">
              {(["all", "3months", "new"] as const).map((w) => (
                <label key={w} className="flex cursor-pointer items-start gap-2 text-sm">
                  <input
                    type="radio"
                    name="sync-window"
                    className="mt-1"
                    checked={syncWindow === w}
                    onChange={() => setSyncWindow(w)}
                  />
                  <span>
                    <span className="font-medium">{t(`wizard.syncWindow.${w}`)}</span>
                    <span className="block text-xs text-app-faint">
                      {t(`wizard.syncWindow.${w}.hint`)}
                    </span>
                  </span>
                </label>
              ))}
            </div>
          </fieldset>
          {tested && <p className="text-sm text-emerald-500">{t("wizard.testOk")}</p>}
          <div className="flex gap-2">
            {!tested ? (
              <button
                className="rounded bg-app-accent px-4 py-2 text-app-accent-fg disabled:opacity-50"
                onClick={test}
                disabled={busy || !password || !imap.host}
              >
                {busy ? t("wizard.testing") : t("wizard.test")}
              </button>
            ) : (
              <button
                className="rounded bg-app-accent px-4 py-2 text-app-accent-fg disabled:opacity-50"
                onClick={create}
                disabled={busy}
              >
                {busy ? t("wizard.creating") : t("wizard.create")}
              </button>
            )}
            <button className="px-3 py-2 text-sm text-app-muted" onClick={() => setStep(1)}>
              {t("common.back")}
            </button>
          </div>
        </div>
      )}

      {step === 3 && (
        <div className="space-y-4">
          <p className="text-emerald-500">{t("wizard.created")}</p>
          <button
            className="rounded bg-app-accent px-4 py-2 text-app-accent-fg"
            onClick={() => navigate("/mail")}
          >
            {t("wizard.startReading")}
          </button>
        </div>
      )}

      {error && <p className="mt-3 text-sm text-red-500">{error}</p>}
    </div>
  );
}