"use server";

import { revalidatePath } from "next/cache";
import { redirect } from "next/navigation";
import { z } from "zod";
import { requireAdmin, requireUser } from "@/lib/auth/dal";
import type { FormState } from "@/lib/forms";
import { zodErrorToFormState } from "@/lib/forms";
import { isUniqueViolation } from "@/lib/services/errors";
import {
  changeOwnPassword,
  createUser,
  deleteUser,
  updateUser,
} from "@/lib/services/users";
import {
  changePasswordFormSchema,
  createUserFormSchema,
  updateUserFormSchema,
} from "@/lib/validation";

function readPermissions(formData: FormData) {
  return {
    canCreateTags: formData.get("canCreateTags"),
    canPublishPosts: formData.get("canPublishPosts"),
    canUnpublishPosts: formData.get("canUnpublishPosts"),
    canDeletePosts: formData.get("canDeletePosts"),
    canApproveComments: formData.get("canApproveComments"),
  };
}

export async function createUserAction(
  _prev: FormState,
  formData: FormData,
): Promise<FormState> {
  await requireAdmin();
  const parsed = createUserFormSchema.safeParse({
    username: formData.get("username"),
    password: formData.get("password"),
    tagIds: formData.getAll("tagIds"),
    permissions: readPermissions(formData),
  });
  if (!parsed.success) return zodErrorToFormState(parsed.error);

  try {
    await createUser(parsed.data);
  } catch (error) {
    if (isUniqueViolation(error)) {
      return { fieldErrors: { username: ["That username is already taken."] } };
    }
    console.error("createUserAction failed", error);
    return { formError: "Something went wrong while creating the account." };
  }
  redirect("/admin/users?created=1");
}

export async function updateUserAction(
  id: number,
  _prev: FormState,
  formData: FormData,
): Promise<FormState> {
  await requireAdmin();
  const userId = z.number().int().positive().parse(id);
  const parsed = updateUserFormSchema.safeParse({
    password: formData.get("password"),
    tagIds: formData.getAll("tagIds"),
    permissions: readPermissions(formData),
  });
  if (!parsed.success) return zodErrorToFormState(parsed.error);

  try {
    const user = await updateUser(userId, parsed.data);
    if (!user) return { formError: "That account no longer exists." };
  } catch (error) {
    console.error("updateUserAction failed", error);
    return { formError: "Something went wrong while saving the account." };
  }
  // Tag grants gate what authors can post — refresh admin pages.
  revalidatePath("/admin", "layout");
  return { status: "success" };
}

/** Any signed-in account may change its own password. */
export async function changeOwnPasswordAction(
  _prev: FormState,
  formData: FormData,
): Promise<FormState> {
  const user = await requireUser();
  const parsed = changePasswordFormSchema.safeParse({
    currentPassword: formData.get("currentPassword"),
    newPassword: formData.get("newPassword"),
  });
  if (!parsed.success) return zodErrorToFormState(parsed.error);

  try {
    const result = await changeOwnPassword(
      user.id,
      parsed.data.currentPassword,
      parsed.data.newPassword,
    );
    if (!result.ok) return { fieldErrors: { currentPassword: [result.error] } };
  } catch (error) {
    console.error("changeOwnPasswordAction failed", error);
    return { formError: "Something went wrong while changing your password." };
  }
  return { status: "success" };
}

export async function deleteUserAction(id: number): Promise<void> {
  const admin = await requireAdmin();
  const userId = z.number().int().positive().parse(id);
  // requireAdmin + the service's admin-role guard both protect the admin
  // account; this guards the sillier accident of deleting yourself.
  if (userId === admin.id) return;
  await deleteUser(userId);
  revalidatePath("/admin", "layout");
  redirect("/admin/users?deleted=1");
}