"use server";

import { cookies } from "next/headers";
import { redirect } from "next/navigation";
import { revalidatePath } from "next/cache";
import { checkPassword } from "@/lib/auth";
import {
  ADMIN_COOKIE,
  createSessionToken,
  SESSION_MAX_AGE,
} from "@/lib/session";
import {
  createPost,
  updatePost,
  deletePost,
  replaceAllPosts,
  type PostInput,
} from "@/lib/posts";
import {
  saveSettings,
  normalizeSettings,
  type Settings,
} from "@/lib/settings";
import { THEMES, isThemeId, type ThemeId } from "@/themes/registry";

function s(formData: FormData, key: string): string {
  const v = formData.get(key);
  return typeof v === "string" ? v : "";
}

// Refresh the whole site after a content/settings change. The layout-level
// revalidation covers branding + theme that live in the shared shell.
function revalidateSite() {
  revalidatePath("/", "layout");
}

/* ------------------------------- auth -------------------------------- */

export async function loginAction(formData: FormData) {
  const password = s(formData, "password");
  const next = s(formData, "next");
  if (!checkPassword(password)) {
    redirect(
      `/admin/login?error=1${next ? `&next=${encodeURIComponent(next)}` : ""}`
    );
  }
  const token = await createSessionToken();
  (await cookies()).set(ADMIN_COOKIE, token, {
    httpOnly: true,
    sameSite: "lax",
    secure: process.env.NODE_ENV === "production",
    path: "/",
    maxAge: SESSION_MAX_AGE,
  });
  redirect(next && next.startsWith("/admin") ? next : "/admin");
}

export async function logoutAction() {
  (await cookies()).delete(ADMIN_COOKIE);
  redirect("/admin/login");
}

/* ------------------------------- posts ------------------------------- */

function postInputFromForm(formData: FormData): PostInput {
  return {
    slug: s(formData, "slug"),
    title: s(formData, "title"),
    excerpt: s(formData, "excerpt"),
    body: s(formData, "body"),
    author: s(formData, "author"),
    tags: s(formData, "tags"),
    createdAt: s(formData, "createdAt"),
  };
}

export async function savePostAction(formData: FormData) {
  const input = postInputFromForm(formData);
  const idRaw = s(formData, "id");

  if (!input.title.trim()) {
    redirect(idRaw ? `/admin/posts/${idRaw}/edit?error=title` : "/admin/posts/new?error=title");
  }

  if (idRaw) {
    updatePost(Number(idRaw), input);
  } else {
    createPost(input);
  }
  revalidateSite();
  redirect("/admin/posts");
}

export async function deletePostAction(formData: FormData) {
  const id = Number(s(formData, "id"));
  if (Number.isFinite(id)) deletePost(id);
  revalidateSite();
  redirect("/admin/posts");
}

/* ------------------------------ settings ----------------------------- */

export async function saveSettingsAction(formData: FormData) {
  const allowed = formData
    .getAll("allowedThemes")
    .map(String)
    .filter(isThemeId) as ThemeId[];

  const defaultTheme = s(formData, "defaultTheme");

  const next: Settings = normalizeSettings({
    title: s(formData, "title"),
    subtitle: s(formData, "subtitle"),
    footer: s(formData, "footer"),
    version: s(formData, "version"),
    defaultTheme: isThemeId(defaultTheme) ? defaultTheme : undefined,
    publicThemeToggle: formData.get("publicThemeToggle") === "on",
    allowedThemes: allowed.length ? allowed : THEMES.map((t) => t.id),
  });

  saveSettings(next);
  revalidateSite();
  redirect("/admin/settings?saved=1");
}

/* ------------------------------- import ------------------------------ */

export async function importAction(formData: FormData) {
  const file = formData.get("file");
  const pasted = s(formData, "pasted");
  const wants = formData.getAll("what").map(String);
  const wantSettings = wants.includes("settings");
  const wantPosts = wants.includes("posts");
  const postMode = s(formData, "postMode") || "replace";

  let raw = pasted;
  if (file && file instanceof File && file.size > 0) {
    raw = await file.text();
  }
  if (!raw.trim()) redirect("/admin/settings?import=empty");

  let parsed: unknown;
  try {
    parsed = JSON.parse(raw);
  } catch {
    redirect("/admin/settings?import=invalid");
  }

  const obj = parsed as Record<string, unknown>;

  if (wantSettings && obj.settings) {
    saveSettings(normalizeSettings(obj.settings));
  }

  if (wantPosts && Array.isArray(obj.posts)) {
    const posts = (obj.posts as Record<string, unknown>[]).map(
      (p): PostInput => ({
        slug: typeof p.slug === "string" ? p.slug : undefined,
        title: typeof p.title === "string" ? p.title : "Untitled",
        excerpt: typeof p.excerpt === "string" ? p.excerpt : "",
        body: typeof p.body === "string" ? p.body : "",
        author: typeof p.author === "string" ? p.author : "webmaster",
        tags: Array.isArray(p.tags)
          ? (p.tags as string[]).join(",")
          : typeof p.tags === "string"
            ? p.tags
            : "",
        createdAt:
          typeof p.createdAt === "string"
            ? p.createdAt
            : typeof p.created_at === "string"
              ? (p.created_at as string)
              : undefined,
      })
    );
    if (postMode === "append") {
      for (const p of posts) createPost(p);
    } else {
      replaceAllPosts(posts);
    }
  }

  revalidateSite();
  redirect("/admin/settings?import=ok");
}