/* ============================================================================
   CONTACT  -  /en/contact  and  /ar/contact
   ----------------------------------------------------------------------------
   Section 9 of docs/SHARPER_Website_Draft_Section_EN_AR.docx.

   The form is a real one: it posts to this route's `action`, which validates
   every field on the SERVER (so validation cannot be skipped by disabling
   JavaScript or by posting directly) and writes an
   api::contact-submission.contact-submission entry in Strapi.

   Client-side JS is an enhancement only - the page works as a plain HTML form
   post, and `useNavigation()` merely swaps the button into its loading state.
   The one exception is the Cloudflare Turnstile check, which needs scripting
   whenever it is configured (see ~/components/ui/Turnstile).

   Every message the reader can see is localised: field labels and the generic
   errors come from the i18n catalogue, the page prose from the approved draft.

   THE REDESIGN
   ------------
   The Claude Design draft ("Contact") lays the page out as two columns on the
   sunken surface: the form in a raised panel, and beside it the channels, the
   consortium disclosure list and the EU funding note. Motion is the classes in
   _page-kit/motion.css - the hero entrance and washes, the band reveals, the
   panel that rises when the message is sent, and the answer that opens under a
   question. The draft's coloured hover glow is deliberately dropped.

   WHAT THE DRAFT SHIPS THAT THIS PAGE DOES NOT
     * "The project team replies within five working days." No approved
       document makes that commitment, so it is not published (CLAUDE.md 5).
     * "info@sharper.ly" and "Facebook - SHARP-ER Libya". The approved draft
       writes both as placeholders ("[project email - e.g. ...]", "[Facebook
       page link placeholder]"), so the address and the social links come from
       the CMS and the page says plainly that they are still to be published.
     * The three consortium addresses, which the draft fills with "Contact
       details TBD" - the disclosure list renders only what the CMS holds.
   ========================================================================= */

import { useEffect, useRef, type ReactNode } from "react";
import { SITE_FACEBOOK_URL } from "~/lib/site-links";
import { data, Form, Link, useLocation, useNavigation, useRouteLoaderData } from "react-router";

import { ArrowIcon, Button } from "~/components/ui/Button";
import { EuBadge } from "~/components/ui/EuBadge";
import { Input, Textarea } from "~/components/ui/Input";
import { Turnstile } from "~/components/ui/Turnstile";
import { createTranslator, sectionPath, type Locale } from "~/i18n";
import { getServerEnv } from "~/lib/env.server";
import { buildBreadcrumbJsonLd, buildMeta } from "~/lib/seo";
import { verifyTurnstile } from "~/lib/turnstile.server";

import type { Route } from "./+types/contact";
import type { CmsContactPage } from "./_page-kit/cms-types";
import { list, loadSingle, toImage } from "./_page-kit/cms.server";
import { pageCopy } from "./_page-kit/copy";
import { routeLocale } from "./_page-kit/locale";
import { RichText } from "./_page-kit/rich-text";
import {
  PageHero,
  PageSection,
  Prose,
} from "./_page-kit/sections";

import "./_page-kit/motion.css";
import { DEFAULT_THEME, type AppTheme } from "~/lib/theme";

/* ---------------------------------------------------------------------------
   LOADER
   ------------------------------------------------------------------------ */

export async function loader({ params }: Route.LoaderArgs) {
  const locale = routeLocale(params);

  const page = await loadSingle<CmsContactPage>("contact-page", {
    locale,
    populate: {
      hero: { populate: { media: true, ctas: true } },
      socialLinks: true,
      seo: { populate: { ogImage: true } },
    },
  });

  return {
    locale,
    hero: {
      eyebrow: page?.hero?.eyebrow ?? null,
      headline: page?.hero?.headline ?? null,
      subheading: page?.hero?.subheading ?? null,
      media: toImage(page?.hero?.media, "large") ?? null,
    },
    intro: page?.intro ?? null,
    generalEmail: page?.generalEmail ?? null,
    websiteLabel: page?.websiteLabel ?? null,
    socialLinks: list(page?.socialLinks).map((link) => ({
      label: link.label,
      href: link.href,
      isExternal: link.isExternal ?? true,
    })),
    seo: {
      title: page?.seo?.metaTitle ?? null,
      description: page?.seo?.metaDescription ?? null,
      image: toImage(page?.seo?.ogImage, "large") ?? null,
      noIndex: page?.seo?.noIndex ?? false,
    },
  };
}

export function meta({ loaderData, matches }: Route.MetaArgs) {
  const root = matches[0].loaderData;
  const locale = loaderData?.locale ?? root.locale;
  const t = createTranslator(locale);
  const copy = pageCopy(locale).contact;

  return buildMeta({
    locale,
    pathname: root.pathname,
    siteUrl: root.siteUrl,
    title: loaderData?.seo.title ?? t("nav.sections.contact"),
    description: loaderData?.seo.description ?? copy.lead,
    ...(loaderData?.seo.image
      ? { image: { url: loaderData.seo.image.src, alt: loaderData.seo.image.alt } }
      : {}),
    noIndex: loaderData?.seo.noIndex ?? false,
    jsonLd: buildBreadcrumbJsonLd(root.siteUrl, [
      { name: t("nav.sections.home"), pathname: sectionPath("home", locale) },
      {
        name: t("nav.sections.contact"),
        pathname: sectionPath("contact", locale),
      },
    ]),
  });
}

/* ---------------------------------------------------------------------------
   FORM CONTRACT
   ------------------------------------------------------------------------ */

const FIELD_NAMES = ["name", "organisation", "email", "subject", "message"] as const;
type ContactField = (typeof FIELD_NAMES)[number];

type ContactValues = Record<ContactField, string>;
type ContactErrors = Partial<Record<ContactField, string>>;

/**
 * A field bots fill in and people never see. Named like a real field so a
 * naive spam bot completes it; a submission that carries a value is accepted
 * with a success response and quietly dropped, which tells the bot nothing.
 */
const HONEYPOT_FIELD = "website";

/**
 * The `id` handed to each control. It has to be fixed rather than the `useId()`
 * one `Input` generates, because the error summary links at it with a fragment.
 */
function fieldDomId(field: ContactField): string {
  return `contact-${field}`;
}

/** Mirrors the maxLength constraints on the Strapi content type. */
const MAX_LENGTH: Record<ContactField, number> = {
  name: 200,
  organisation: 200,
  email: 254,
  subject: 250,
  message: 5000,
};

/** Deliberately permissive - RFC-valid addresses vary far more than any regex. */
const EMAIL_PATTERN = /^[^\s@]+@[^\s@]+\.[^\s@]{2,}$/;

const EMPTY_VALUES: ContactValues = {
  name: "",
  organisation: "",
  email: "",
  subject: "",
  message: "",
};

function readValues(form: FormData): ContactValues {
  const values = { ...EMPTY_VALUES };

  for (const field of FIELD_NAMES) {
    const raw = form.get(field);
    values[field] = typeof raw === "string" ? raw.trim() : "";
  }

  return values;
}

function validate(values: ContactValues, locale: Locale): ContactErrors {
  const t = createTranslator(locale);
  const copy = pageCopy(locale).contact;
  const errors: ContactErrors = {};

  const required: ContactField[] = ["name", "email", "subject", "message"];
  for (const field of required) {
    if (values[field] === "") errors[field] = t("form.errorRequired");
  }

  if (!errors.email && !EMAIL_PATTERN.test(values.email)) {
    errors.email = t("form.errorEmail");
  }

  for (const field of FIELD_NAMES) {
    if (!errors[field] && values[field].length > MAX_LENGTH[field]) {
      errors[field] = copy.errorTooLong;
    }
  }

  return errors;
}

/**
 * Write the message to Strapi. Server-only: `getServerEnv` lives in a
 * `.server` module, so the token cannot reach the browser bundle.
 *
 * THE PAYLOAD IS THE WHITELIST, NOTHING MORE
 * `contact-submission` has a `sanitize-submission` middleware
 * (apps/cms/src/api/contact-submission/middlewares/sanitize-submission.ts)
 * that copies out exactly `name · organisation · email · subject · message`
 * and drops the rest, then stamps `submissionStatus` and `submittedAt`
 * itself. Sending those two from here is not merely redundant - it reads as
 * though the browser decides triage state, and the value would be silently
 * discarded anyway - so the body below is the whitelist and only it.
 */
async function createContactSubmission(
  values: ContactValues,
  forwardedFor?: string,
): Promise<void> {
  const env = getServerEnv();
  const url = `${env.STRAPI_URL.replace(/\/+$/, "")}/api/contact-submissions`;

  const response = await fetch(url, {
    method: "POST",
    headers: {
      "content-type": "application/json",
      accept: "application/json",
      ...(env.STRAPI_TOKEN ? { authorization: `Bearer ${env.STRAPI_TOKEN}` } : {}),
      ...(forwardedFor ? { "x-forwarded-for": forwardedFor } : {}),
    },
    body: JSON.stringify({
      data: {
        name: values.name,
        // An empty optional field is stored as null, not as "".
        organisation: values.organisation === "" ? null : values.organisation,
        email: values.email,
        subject: values.subject,
        message: values.message,
      },
    }),
    signal: AbortSignal.timeout(10_000),
  });

  if (!response.ok) {
    throw new Error(
      `Strapi responded ${response.status} ${response.statusText} for ${url}`,
    );
  }
}

export async function action({ params, request }: Route.ActionArgs) {
  const locale = routeLocale(params);
  const form = await request.formData();

  // Honeypot: answer exactly like a success, store nothing.
  const trap = form.get(HONEYPOT_FIELD);
  if (typeof trap === "string" && trap.trim() !== "") {
    return data({ status: "success" as const, errors: {} as ContactErrors, values: EMPTY_VALUES });
  }

  const values = readValues(form);
  const errors = validate(values, locale);

  if (Object.keys(errors).length > 0) {
    return data(
      { status: "invalid" as const, errors, values },
      { status: 400 },
    );
  }

  if (!(await verifyTurnstile(form))) {
    const t = createTranslator(locale);

    return data(
      {
        status: "failed" as const,
        errors: {} as ContactErrors,
        values,
        formError: t("form.errorVerification"),
      },
      { status: 403 },
    );
  }

  try {
    await createContactSubmission(
      values,
      request.headers.get("x-forwarded-for") ?? undefined,
    );
  } catch (error) {
    console.error("[contact] submission failed", error);
    const t = createTranslator(locale);

    return data(
      {
        status: "failed" as const,
        errors: {} as ContactErrors,
        values,
        formError: t("form.errorGeneric"),
      },
      { status: 502 },
    );
  }

  return data({ status: "success" as const, errors: {} as ContactErrors, values: EMPTY_VALUES });
}

/* ---------------------------------------------------------------------------
   PAGE
   ------------------------------------------------------------------------ */

/** See the note on the same constant in about.tsx. */
const ACCENT_EDGE =
  "[border-inline-start-color:var(--border-accent)] [border-inline-start-width:4px]";

/** The tick the draft draws in a filled circle over the "message sent" panel. */
function SentMark() {
  return (
    <span
      aria-hidden="true"
      className="flex size-12 shrink-0 items-center justify-center rounded-pill bg-[var(--surface-accent)] text-[var(--text-on-accent)]"
    >
      <svg width="24" height="24" viewBox="0 0 24 24" fill="none" aria-hidden="true">
        <path
          d="M5 13l4.5 4.5L19 7"
          stroke="currentColor"
          strokeWidth="2.4"
          strokeLinecap="round"
          strokeLinejoin="round"
        />
      </svg>
    </span>
  );
}

/** One label-and-value row of the channels list. */
function Channel({
  label,
  children,
}: {
  label: string;
  children: ReactNode;
}) {
  return (
    <div className="flex flex-col gap-2xs border-b border-[var(--border-subtle)] pb-md">
      <dt className="label-md uppercase text-[var(--text-tertiary)]">{label}</dt>
      {/* The draft sets the value itself in the page's primary tone, a step
          above the label. */}
      <dd className="body-lg-bold text-[var(--text-primary)]">{children}</dd>
    </div>
  );
}

const LINK_CLASS =
  "text-[var(--text-link)] underline underline-offset-2 hover:text-[var(--text-link-hover)]";

export default function Contact({
  loaderData,
  actionData,
}: Route.ComponentProps) {
  const { locale, hero, intro, generalEmail, socialLinks } = loaderData;
  const t = createTranslator(locale);
  const copy = pageCopy(locale).contact;

  /* The CMS wins; until an editor fills the row, the project's own confirmed
     channel stands in (lib/site-links.ts). */
  const channels =
    socialLinks.length > 0
      ? socialLinks
      : [{ label: copy.facebookLabel, href: SITE_FACEBOOK_URL, isExternal: true }];

  const navigation = useNavigation();
  const { pathname } = useLocation();
  const isSubmitting = navigation.state === "submitting";

  const root = useRouteLoaderData<{ theme?: AppTheme }>("root");
  const theme: AppTheme = root?.theme ?? DEFAULT_THEME;

  const errors = actionData?.errors ?? {};
  const values = actionData?.values ?? EMPTY_VALUES;
  const formError =
    actionData && "formError" in actionData ? actionData.formError : undefined;
  const isSuccess = actionData?.status === "success";
  const errorMessages = Object.values(errors).filter(
    (message): message is string => typeof message === "string",
  );

  /* A failed submit re-renders the page with the summary at the top of the
     form. Screen-reader users are left wherever they were, and keyboard users
     below the fold, so focus is moved onto the summary itself - it is
     tabIndex={-1} for exactly this. Keyed on `actionData`, which is a fresh
     object per submission, so a repeated failure focuses again. */
  const errorSummaryRef = useRef<HTMLDivElement>(null);

  useEffect(() => {
    if (!actionData || actionData.status === "success") return;
    errorSummaryRef.current?.focus();
  }, [actionData]);

  return (
    <>
      <PageHero
        className="border-b border-[var(--border-subtle)] bg-[var(--surface-sunken)] [--layout-hero-bottom:clamp(2.5rem,5vw,3.75rem)]"
        title={hero.headline ?? copy.heroHeadline}
        eyebrow={hero.eyebrow ?? t("nav.sections.contact")}
        lead={hero.subheading ?? copy.lead}
        ambient={[{ top: -250, from: "start", offset: "6%", width: 720, height: 560, durationSeconds: 21 }]}
        reveal
        {...(hero.media ? { media: hero.media } : {})}
      />

      <PageSection className="bg-[var(--surface-sunken)]">
        {/* Two equal columns, as the draft sets them - the form beside the
            channels, each starting at the top of the band. */}
        <div className="grid grid-cols-1 items-start gap-2xl lg:grid-cols-2 lg:gap-4xl">
          {/* ---------------------------------------------------------------
              THE FORM - one raised panel on the sunken band, as the draft has
              it. The mechanism underneath is unchanged: a real HTML form post
              that the server validates.
              --------------------------------------------------------------- */}
          <div className="sh-reveal sh-reveal--in flex flex-col gap-lg rounded-card border border-[var(--border-subtle)] bg-[var(--surface-card)] p-lg md:p-xl">
            {/* The draft opens the panel straight onto the fields; the heading
                is what labels the form in the outline and for a screen
                reader. */}
            <h2 id="contact-form-heading" className="sr-only">
              {copy.formHeading}
            </h2>

            {isSuccess ? (
              /* The draft swaps the fields for this acknowledgement inside the
                 same panel - no box of its own. */
              <div
                className="sh-rise flex flex-col items-start gap-md"
                role="status"
              >
                <SentMark />

                <p className="heading-h3 text-[var(--text-primary)]">
                  {t("form.successTitle")}
                </p>
                {/* The draft promises a reply "within five working days"; no
                    approved document does, so the generic acknowledgement from
                    the message catalogue stands instead. */}
                <p className="body-md text-[var(--text-secondary)]">
                  {t("form.successBody")}
                </p>
                <Button as={Link} to={pathname} variant="secondary">
                  {copy.sendAnother}
                </Button>
              </div>
            ) : (
              <Form
                method="post"
                aria-labelledby="contact-form-heading"
                className="flex flex-col gap-lg"
                noValidate
              >
                {formError || errorMessages.length > 0 ? (
                  <div
                    ref={errorSummaryRef}
                    tabIndex={-1}
                    role="alert"
                    className="flex flex-col gap-xs rounded-card border border-[var(--border-danger)] bg-[var(--surface-danger-subtle)] p-md"
                  >
                    <p className="body-md-bold text-[var(--text-danger)]">
                      {formError ?? copy.errorSummaryTitle}
                    </p>
                    {errorMessages.length > 0 ? (
                      <ul className="flex list-disc flex-col gap-2xs ps-lg body-sm text-[var(--text-secondary)]">
                        {/* Listed in form order, not object order, and each one
                            is a link at the control it is about. The label is
                            repeated so the link text still identifies the field
                            when the messages are read out of context. */}
                        {FIELD_NAMES.filter((field) => errors[field]).map((field) => (
                          <li key={field}>
                            <a
                              href={`#${fieldDomId(field)}`}
                              className="underline underline-offset-2 hover:text-[var(--text-primary)]"
                            >
                              {t(`form.${field}`)}: {errors[field]}
                            </a>
                          </li>
                        ))}
                      </ul>
                    ) : null}
                  </div>
                ) : null}

                {/* Honeypot - off-screen, out of the tab order and out of the
                    accessibility tree, so only an automated client fills it. */}
                <div aria-hidden="true" className="sr-only">
                  <label htmlFor="contact-website">{copy.honeypotLabel}</label>
                  <input
                    id="contact-website"
                    type="text"
                    name={HONEYPOT_FIELD}
                    tabIndex={-1}
                    autoComplete="off"
                    defaultValue=""
                  />
                </div>

                {/* One column at every width - the draft stacks the four
                    fields above the message. */}
                <div className="flex flex-col gap-lg">
                  <Input
                    name="name"
                    id={fieldDomId("name")}
                    label={t("form.name")}
                    required
                    autoComplete="name"
                    maxLength={MAX_LENGTH.name}
                    defaultValue={values.name}
                    {...(errors.name ? { error: errors.name } : {})}
                  />
                  <Input
                    name="organisation"
                    id={fieldDomId("organisation")}
                    label={t("form.organisation")}
                    hint={copy.organisationHint}
                    autoComplete="organization"
                    maxLength={MAX_LENGTH.organisation}
                    defaultValue={values.organisation}
                    {...(errors.organisation ? { error: errors.organisation } : {})}
                  />
                  <Input
                    name="email"
                    id={fieldDomId("email")}
                    type="email"
                    label={t("form.email")}
                    required
                    autoComplete="email"
                    maxLength={MAX_LENGTH.email}
                    defaultValue={values.email}
                    {...(errors.email ? { error: errors.email } : {})}
                  />
                  <Input
                    name="subject"
                    id={fieldDomId("subject")}
                    label={t("form.subject")}
                    required
                    maxLength={MAX_LENGTH.subject}
                    defaultValue={values.subject}
                    {...(errors.subject ? { error: errors.subject } : {})}
                  />
                </div>

                <Textarea
                  name="message"
                  id={fieldDomId("message")}
                  label={t("form.message")}
                  required
                  rows={6}
                  maxLength={MAX_LENGTH.message}
                  defaultValue={values.message}
                  {...(errors.message ? { error: errors.message } : {})}
                />

                <Turnstile action="contact" locale={locale} resetKey={actionData} />

                <Button
                  type="submit"
                  size="lg"
                  variant="primary"
                  isLoading={isSubmitting}
                  iconEnd={<ArrowIcon />}
                  className="self-start"
                >
                  {isSubmitting ? t("form.sending") : t("form.send")}
                </Button>
              </Form>
            )}
          </div>

          {/* ---------------------------------------------------------------
              THE CHANNELS COLUMN
              --------------------------------------------------------------- */}
          <div className="flex flex-col gap-xl">
            <div className="sh-reveal flex flex-col gap-md">
              {/* The draft opens this column straight onto the channel rows;
                  the heading is here for the outline only. */}
              <h2 id="contact-details-heading" className="sr-only">
                {copy.detailsHeading}
              </h2>

              {intro ? (
                <Prose>
                  <RichText markdown={intro} />
                </Prose>
              ) : null}

              <dl className="flex flex-col gap-md">
                <Channel label={copy.generalEnquiries}>
                  {generalEmail ? (
                    <a href={`mailto:${generalEmail}`} className={LINK_CLASS}>
                      {generalEmail}
                    </a>
                  ) : (
                    /* The approved draft writes the address as a placeholder,
                       so nothing stands in for it. A sentence is not a channel
                       value, so it keeps the quieter body tone. */
                    <span className="body-md text-[var(--text-secondary)]">
                      {copy.contactPending}
                    </span>
                  )}
                </Channel>

                <Channel label={copy.websiteLabel}>
                  <a href={copy.websiteHref} className={LINK_CLASS}>
                    {loaderData.websiteLabel ?? copy.websiteText}
                  </a>
                </Channel>

                {/* The CMS owns this row; until an editor fills it, the
                    project's own confirmed Facebook page stands in. */}
                {channels.length > 0 ? (
                  <Channel label={t("site.followUs")}>
                    <ul className="flex flex-wrap gap-md">
                      {channels.map((link) => (
                        <li key={link.href}>
                          <a
                            href={link.href}
                            {...(link.isExternal
                              ? { target: "_blank", rel: "noopener noreferrer" }
                              : {})}
                            className={LINK_CLASS}
                          >
                            {link.label}
                          </a>
                        </li>
                      ))}
                    </ul>
                  </Channel>
                ) : null}
              </dl>
            </div>

            {/* EU VISIBILITY - the funding note the draft prints at the foot of
                this column. The emblem and the statement come from the shared
                badge, so the wording and the artwork stay contractual. */}
            <div
              className={`sh-reveal flex items-center gap-md rounded-card border border-[var(--border-subtle)] bg-[var(--surface-raised)] p-md ${ACCENT_EDGE}`}
            >
              <EuBadge
                size="sm"
                statement={t("site.euStatement")}
                locale={locale}
                surface={theme}
              />
            </div>
          </div>
        </div>
      </PageSection>
    </>
  );
}