import { hasPermission } from "@cms/content/rbac"
import { createPost, deletePost, listPosts, updatePost } from "@cms/db"
import { Button } from "@cms/ui/button"
import { revalidatePath } from "next/cache"
import Link from "next/link"
import { redirect } from "next/navigation"

import { AdminShell } from "@/components/admin-shell"
import { translateMessage } from "@/i18n/messages"
import { getAdminMessages, resolveAdminLocale } from "@/i18n/server"
import { requirePermissionForRoute } from "@/lib/route-guards"

export const dynamic = "force-dynamic"

type SearchParamsInput = Record<string, string | string[] | undefined>

function readFirstValue(value: string | string[] | undefined): string | null {
  if (Array.isArray(value)) {
    return value[0] ?? null
  }

  return value ?? null
}

function readRequiredField(formData: FormData, field: string): string {
  const value = formData.get(field)

  if (typeof value !== "string") {
    return ""
  }

  return value.trim()
}

function readOptionalField(formData: FormData, field: string): string | undefined {
  const value = readRequiredField(formData, field)
  return value.length > 0 ? value : undefined
}

async function requireNewsWritePermission() {
  await requirePermissionForRoute({
    nextPath: "/",
    permission: "news:write",
    scope: "team",
  })
}

function redirectWithState(params: { notice?: string; error?: string }) {
  const query = new URLSearchParams()

  if (params.notice) {
    query.set("notice", params.notice)
  }

  if (params.error) {
    query.set("error", params.error)
  }

  const value = query.toString()
  redirect(value ? `/?${value}` : "/")
}

async function getDashboardTranslator() {
  const locale = await resolveAdminLocale()
  const messages = await getAdminMessages(locale)

  return (key: string, fallback: string) => translateMessage(messages, key, fallback)
}

async function createPostAction(formData: FormData) {
  "use server"

  await requireNewsWritePermission()
  const t = await getDashboardTranslator()

  const status = readRequiredField(formData, "status")

  try {
    await createPost({
      title: readRequiredField(formData, "title"),
      slug: readRequiredField(formData, "slug"),
      excerpt: readOptionalField(formData, "excerpt"),
      body: readRequiredField(formData, "body"),
      status: status === "published" ? "published" : "draft",
    })
  } catch {
    redirectWithState({
      error: t("dashboard.posts.errors.createFailed", "Create failed. Please check your input."),
    })
  }

  revalidatePath("/")
  redirectWithState({ notice: t("dashboard.posts.success.created", "Post created.") })
}

async function updatePostAction(formData: FormData) {
  "use server"

  await requireNewsWritePermission()
  const t = await getDashboardTranslator()

  const id = readRequiredField(formData, "id")
  const status = readRequiredField(formData, "status")

  if (!id) {
    redirectWithState({
      error: t("dashboard.posts.errors.updateMissingId", "Update failed. Missing post id."),
    })
  }

  try {
    await updatePost(id, {
      title: readRequiredField(formData, "title"),
      slug: readRequiredField(formData, "slug"),
      excerpt: readOptionalField(formData, "excerpt"),
      body: readRequiredField(formData, "body"),
      status: status === "published" ? "published" : "draft",
    })
  } catch {
    redirectWithState({
      error: t("dashboard.posts.errors.updateFailed", "Update failed. Please check your input."),
    })
  }

  revalidatePath("/")
  redirectWithState({ notice: t("dashboard.posts.success.updated", "Post updated.") })
}

async function deletePostAction(formData: FormData) {
  "use server"

  await requireNewsWritePermission()
  const t = await getDashboardTranslator()

  const id = readRequiredField(formData, "id")

  if (!id) {
    redirectWithState({
      error: t("dashboard.posts.errors.deleteMissingId", "Delete failed. Missing post id."),
    })
  }

  try {
    await deletePost(id)
  } catch {
    redirectWithState({ error: t("dashboard.posts.errors.deleteFailed", "Delete failed.") })
  }

  revalidatePath("/")
  redirectWithState({ notice: t("dashboard.posts.success.deleted", "Post deleted.") })
}

export default async function AdminHomePage({
  searchParams,
}: {
  searchParams: Promise<SearchParamsInput>
}) {
  const role = await requirePermissionForRoute({
    nextPath: "/",
    permission: "news:read",
    scope: "team",
  })

  const [resolvedSearchParams, locale, posts] = await Promise.all([
    searchParams,
    resolveAdminLocale(),
    listPosts(),
  ])
  const messages = await getAdminMessages(locale)
  const t = (key: string, fallback: string) => translateMessage(messages, key, fallback)

  const notice = readFirstValue(resolvedSearchParams.notice)
  const error = readFirstValue(resolvedSearchParams.error)
  const canCreatePost = hasPermission(role, "news:write", "team")

  return (
    <AdminShell
      role={role}
      activePath="/"
      badge={t("dashboard.badge", "Admin App")}
      title={t("dashboard.title", "Content Dashboard")}
      description={t("dashboard.description", "Manage posts from a dedicated admin surface.")}
      actions={
        <>
          <Link
            href="/todo"
            className="inline-flex rounded-md border border-neutral-300 px-4 py-2 text-sm font-medium hover:bg-neutral-100"
          >
            {t("dashboard.actions.openRoadmap", "Open roadmap and progress")}
          </Link>
          <Link
            href="/settings"
            className="inline-flex rounded-md border border-neutral-300 px-4 py-2 text-sm font-medium hover:bg-neutral-100"
          >
            {t("settings.title", "Settings")}
          </Link>
        </>
      }
    >
      {notice ? (
        <section className="rounded-xl border border-emerald-300 bg-emerald-50 px-4 py-3 text-sm text-emerald-800">
          {notice}
        </section>
      ) : null}

      {error ? (
        <section className="rounded-xl border border-red-300 bg-red-50 px-4 py-3 text-sm text-red-800">
          {error}
        </section>
      ) : null}

      <section className="rounded-xl border border-neutral-200 p-6">
        <div className="space-y-4">
          <div className="flex items-center justify-between">
            <h2 className="text-xl font-medium">
              {t("dashboard.posts.title", "Posts CRUD Sandbox")}
            </h2>
            <p className="text-xs uppercase tracking-wide text-neutral-500">
              {t("dashboard.notices.crudSandboxTag", "MVP0 functional test")}
            </p>
          </div>

          {canCreatePost ? (
            <form
              action={createPostAction}
              className="space-y-3 rounded-lg border border-neutral-200 p-4"
            >
              <h3 className="text-sm font-semibold">
                {t("dashboard.posts.createTitle", "Create post")}
              </h3>
              <div className="grid gap-3 md:grid-cols-2">
                <label className="space-y-1">
                  <span className="text-xs text-neutral-600">
                    {t("dashboard.posts.fields.title", "Title")}
                  </span>
                  <input
                    name="title"
                    required
                    minLength={3}
                    className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                  />
                </label>
                <label className="space-y-1">
                  <span className="text-xs text-neutral-600">
                    {t("dashboard.posts.fields.slug", "Slug")}
                  </span>
                  <input
                    name="slug"
                    required
                    minLength={3}
                    className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                  />
                </label>
              </div>
              <label className="space-y-1">
                <span className="text-xs text-neutral-600">
                  {t("dashboard.posts.fields.excerpt", "Excerpt")}
                </span>
                <input
                  name="excerpt"
                  className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                />
              </label>
              <label className="space-y-1">
                <span className="text-xs text-neutral-600">
                  {t("dashboard.posts.fields.body", "Body")}
                </span>
                <textarea
                  name="body"
                  required
                  minLength={1}
                  rows={4}
                  className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                />
              </label>
              <label className="space-y-1">
                <span className="text-xs text-neutral-600">
                  {t("dashboard.posts.fields.status", "Status")}
                </span>
                <select
                  name="status"
                  defaultValue="draft"
                  className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                >
                  <option value="draft">{t("dashboard.posts.status.draft", "Draft")}</option>
                  <option value="published">
                    {t("dashboard.posts.status.published", "Published")}
                  </option>
                </select>
              </label>
              <Button type="submit">{t("dashboard.posts.actions.create", "Create post")}</Button>
            </form>
          ) : (
            <div className="rounded-lg border border-amber-300 bg-amber-50 px-4 py-3 text-sm text-amber-800">
              {t(
                "dashboard.notices.noCrudPermission",
                "You can read posts, but your role cannot create/update/delete posts.",
              )}
            </div>
          )}
        </div>

        <div className="space-y-3">
          {posts.map((post) => (
            <article key={post.id} className="rounded-lg border border-neutral-200 p-4">
              {canCreatePost ? (
                <>
                  <form action={updatePostAction} className="space-y-3">
                    <input type="hidden" name="id" value={post.id} />
                    <div className="grid gap-3 md:grid-cols-2">
                      <label className="space-y-1">
                        <span className="text-xs text-neutral-600">
                          {t("dashboard.posts.fields.title", "Title")}
                        </span>
                        <input
                          name="title"
                          required
                          minLength={3}
                          defaultValue={post.title}
                          className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                        />
                      </label>
                      <label className="space-y-1">
                        <span className="text-xs text-neutral-600">
                          {t("dashboard.posts.fields.slug", "Slug")}
                        </span>
                        <input
                          name="slug"
                          required
                          minLength={3}
                          defaultValue={post.slug}
                          className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                        />
                      </label>
                    </div>
                    <label className="space-y-1">
                      <span className="text-xs text-neutral-600">
                        {t("dashboard.posts.fields.excerpt", "Excerpt")}
                      </span>
                      <input
                        name="excerpt"
                        defaultValue={post.excerpt ?? ""}
                        className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                      />
                    </label>
                    <label className="space-y-1">
                      <span className="text-xs text-neutral-600">
                        {t("dashboard.posts.fields.body", "Body")}
                      </span>
                      <textarea
                        name="body"
                        required
                        minLength={1}
                        rows={4}
                        defaultValue={post.body}
                        className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                      />
                    </label>
                    <label className="space-y-1">
                      <span className="text-xs text-neutral-600">
                        {t("dashboard.posts.fields.status", "Status")}
                      </span>
                      <select
                        name="status"
                        defaultValue={post.status}
                        className="w-full rounded border border-neutral-300 px-3 py-2 text-sm"
                      >
                        <option value="draft">{t("dashboard.posts.status.draft", "Draft")}</option>
                        <option value="published">
                          {t("dashboard.posts.status.published", "Published")}
                        </option>
                      </select>
                    </label>
                    <Button type="submit">
                      {t("dashboard.posts.actions.save", "Save changes")}
                    </Button>
                  </form>
                  <form action={deletePostAction} className="mt-3">
                    <input type="hidden" name="id" value={post.id} />
                    <Button type="submit" variant="secondary">
                      {t("dashboard.posts.actions.delete", "Delete")}
                    </Button>
                  </form>
                </>
              ) : (
                <>
                  <div className="flex items-center justify-between gap-3">
                    <h3 className="text-lg font-medium">{post.title}</h3>
                    <span className="rounded-full bg-neutral-100 px-3 py-1 text-xs uppercase tracking-wide">
                      {post.status}
                    </span>
                  </div>
                  <p className="mt-2 text-sm text-neutral-600">{post.slug}</p>
                  <p className="mt-2 text-sm text-neutral-600">
                    {post.excerpt ?? t("dashboard.posts.fallback.noExcerpt", "No excerpt")}
                  </p>
                </>
              )}
            </article>
          ))}
        </div>
      </section>
    </AdminShell>
  )
}