import { defineConfig, defineDocs } from "fumadocs-mdx/config";
import { remarkMdxMermaid } from "fumadocs-core/mdx-plugins/remark-mdx-mermaid";
import lastModified from "fumadocs-mdx/plugins/last-modified";
import { metaSchema, pageSchema } from "fumadocs-core/source/schema";
import { z } from "zod";
import remarkMath from "remark-math";
import remarkDirective from "remark-directive";
import rehypeKatex from "rehype-katex";
import { remarkAdmonitions } from "./lib/remark-admonitions";
import { AUTHOR_IDS } from "./lib/authors";
import { BLOG_CATEGORY_IDS } from "./lib/blog-categories";

/**
 * Extend Fumadocs' default page frontmatter with a Docusaurus-style
 * `sidebar_label`. When set, the page's sidebar label is overridden
 * (see the tree transformer in `lib/source.ts`); the page's H1 still
 * uses the regular `title` field.
 *
 * Note: fumadocs-mdx only allows collection/config exports from this
 * file, so this schema stays internal (non-exported).
 */
const extendedPageSchema = pageSchema.extend({
  sidebar_label: z.string().optional(),
});

const commonOptions = {
  docs: {
    schema: extendedPageSchema,
    postprocess: {
      includeProcessedMarkdown: true,
    },
  },
  meta: {
    schema: metaSchema,
  },
} as const;

/**
 * Blog-specific frontmatter. Kept separate from `commonOptions` so
 * docs/guides/etc don't silently accept `authors`/`date` fields they
 * would ignore. `z.enum(AUTHOR_IDS)` locks `authors` to known IDs
 * from `lib/authors.ts` — a typo fails the build with a clear path.
 */
const blogPageSchema = extendedPageSchema.extend({
  authors: z.array(z.enum(AUTHOR_IDS)).min(1).optional(),
  date: z.coerce.date().optional(),
  image: z.string().url().optional(),
  // Optional — pins a post to one of the known categories in
  // `lib/blog-categories.ts`. Kept as a single value (not an array)
  // because the sidebar groupings are also single-section.
  category: z.enum(BLOG_CATEGORY_IDS).optional(),
});

const blogOptions = {
  docs: {
    schema: blogPageSchema,
    postprocess: {
      includeProcessedMarkdown: true,
    },
  },
  meta: {
    schema: metaSchema,
  },
} as const;

export const docs = defineDocs({ dir: "content/docs", ...commonOptions });
export const guides = defineDocs({ dir: "content/guides", ...commonOptions });
export const tutorials = defineDocs({
  dir: "content/tutorials",
  ...commonOptions,
});
export const integrations = defineDocs({
  dir: "content/integrations",
  ...commonOptions,
});
export const changelog = defineDocs({
  dir: "content/changelog",
  ...commonOptions,
});
export const blog = defineDocs({ dir: "content/blog", ...blogOptions });

export default defineConfig({
  // `lastModified` reads each file's latest git commit timestamp at build
  // time and injects it as `page.data.lastModified`. Outside a git tree
  // (e.g. fresh checkouts before first commit) the value is `null`, which
  // `<PageLastUpdate>` silently no-ops on — safe to always enable.
  plugins: [lastModified()],
  mdxOptions: {
    // remarkDirective parses `:::type[title]` container directives;
    // remarkAdmonitions rewrites the recognized ones into <Callout>.
    remarkPlugins: [
      remarkMath,
      remarkDirective,
      remarkAdmonitions,
      remarkMdxMermaid,
    ],
    // rehypeKatex must run before the syntax highlighter
    rehypePlugins: (v) => [rehypeKatex, ...v],
    // Fumadocs' default `remark-image` plugin tries to fetch every
    // remote image at build time to precompute `width`/`height` for
    // `next/image`. Our blog + tutorial content references dozens of
    // images on `deepeval-docs.s3.us-east-1.amazonaws.com` — those
    // fetches intermittently time out (see the "Failed obtain image
    // size" build error), which hard-fails the entire build.
    //
    // Setting `external: false` keeps the plugin running for LOCAL
    // images (under `public/` — still get proper dimensions + blur
    // placeholders) but skips remote URLs: they pass through as plain
    // `<img src="https://…">` tags. Runtime rendering still works
    // because `next.config.mjs` whitelists the S3 hostname for
    // `next/image`, and Next's lowering of `![]()` to `<Image>` at
    // the MDX layer is happy without precomputed dimensions as long
    // as an `<img>` fallback is acceptable in the HTML output.
    remarkImageOptions: { external: false },
  },
});