import type { AstroBuiltinAttributes } from "astro";
import type { HTMLAttributes } from "astro/types";
import { z } from "astro/zod";

import { BadgeConfigSchema } from "./badge";

/** Ensure the passed path does not start with a leading slash. */
function stripLeadingSlash(href: string) {
  if (href[0] === "/") href = href.slice(1);
  return href;
}

/** Ensure the passed path does not end with a trailing slash. */
function stripTrailingSlash(href: string) {
  if (href[href.length - 1] === "/") href = href.slice(0, -1);
  return href;
}

function stripLeadingAndTrailingSlashes(href: string): string {
  href = stripLeadingSlash(href);
  href = stripTrailingSlash(href);
  return href;
}

const SidebarBaseSchema = z.object({
  /** The visible label for this item in the sidebar. */
  label: z.string(),
  /** Translations of the `label` for each supported language. */
  translations: z.record(z.string()).default({}),
  /** Adds a badge to the link item */
  badge: BadgeConfigSchema(),
});

const SidebarGroupSchema = SidebarBaseSchema.extend({
  /** Whether this item should be collapsed by default. */
  collapsed: z.boolean().default(false),
});

// HTML attributes that can be added to an anchor element, validated as
// `Record<string, string | number | boolean | undefined>` but typed as `HTMLAttributes<'a'>`
// for user convenience.
const linkHTMLAttributesSchema = z.record(
  z.union([z.string(), z.number(), z.boolean(), z.undefined()])
) as z.Schema<
  Omit<HTMLAttributes<"a">, keyof AstroBuiltinAttributes | "children">
>;
export type LinkHTMLAttributes = z.infer<typeof linkHTMLAttributesSchema>;

export const SidebarLinkItemHTMLAttributesSchema = () =>
  linkHTMLAttributesSchema.default({});

const SidebarLinkItemSchema = SidebarBaseSchema.extend({
  /** The link to this item’s content. Can be a relative link to local files or the full URL of an external page. */
  link: z.string(),
  /** HTML attributes to add to the link item. */
  attrs: SidebarLinkItemHTMLAttributesSchema(),
});
export type SidebarLinkItem = z.infer<typeof SidebarLinkItemSchema>;

const AutoSidebarGroupSchema = SidebarGroupSchema.extend({
  /** Enable autogenerating a sidebar category from a specific docs directory. */
  autogenerate: z.object({
    /** The directory to generate sidebar items for. */
    directory: z.string().transform(stripLeadingAndTrailingSlashes),
    /**
     * Whether the autogenerated subgroups should be collapsed by default.
     * Defaults to the `AutoSidebarGroup` `collapsed` value.
     */
    collapsed: z.boolean().optional(),
    // TODO: not supported by Docusaurus but would be good to have
    /** How many directories deep to include from this directory in the sidebar. Default: `Infinity`. */
    // depth: z.number().optional(),
  }),
});
export type AutoSidebarGroup = z.infer<typeof AutoSidebarGroupSchema>;

type ManualSidebarGroupInput = z.input<typeof SidebarGroupSchema> & {
  /** Array of links and subcategories to display in this category. */
  items: Array<
    | z.input<typeof SidebarLinkItemSchema>
    | z.input<typeof AutoSidebarGroupSchema>
    | ManualSidebarGroupInput
  >;
};

type ManualSidebarGroupOutput = z.output<typeof SidebarGroupSchema> & {
  /** Array of links and subcategories to display in this category. */
  items: Array<
    | z.output<typeof SidebarLinkItemSchema>
    | z.output<typeof AutoSidebarGroupSchema>
    | ManualSidebarGroupOutput
  >;
};

const ManualSidebarGroupSchema: z.ZodType<
  ManualSidebarGroupOutput,
  z.ZodTypeDef,
  ManualSidebarGroupInput
> = SidebarGroupSchema.extend({
  /** Array of links and subcategories to display in this category. */
  items: z.lazy(() =>
    z
      .union([
        SidebarLinkItemSchema,
        ManualSidebarGroupSchema,
        AutoSidebarGroupSchema,
      ])
      .array()
  ),
});

export const SidebarItemSchema = z.union([
  SidebarLinkItemSchema,
  ManualSidebarGroupSchema,
  AutoSidebarGroupSchema,
]);
export type SidebarItem = z.infer<typeof SidebarItemSchema>;