import crypto from "node:crypto";
import fs from "node:fs";
import path from "node:path";
import { fileURLToPath } from "node:url";

import tailwindcss from "@tailwindcss/vite";
import type { StorybookConfig } from "@storybook/react-vite";
import { mergeConfig } from "vite";

const storybookConfigDir = path.dirname(fileURLToPath(import.meta.url));
const repoRoot = path.resolve(storybookConfigDir, "../../..");
const docsSourceDir = path.resolve(storybookConfigDir, "../src");
const storybookRootCacheDir = path.resolve(
  storybookConfigDir,
  "../../../.artifacts/cache/storybook"
);
const storyFilePattern = /\.stories\.(ts|tsx)$/;

function collectStoryPaths(directory: string): string[] {
  const entries = fs.readdirSync(directory, { withFileTypes: true });
  const storyPaths: string[] = [];

  for (const entry of entries) {
    const entryPath = path.join(directory, entry.name);

    if (entry.isDirectory()) {
      storyPaths.push(...collectStoryPaths(entryPath));
      continue;
    }

    if (storyFilePattern.test(entry.name)) {
      storyPaths.push(path.relative(docsSourceDir, entryPath).split(path.sep).join("/"));
    }
  }

  return storyPaths;
}

function createStorybookCacheKey() {
  const storyPaths = collectStoryPaths(docsSourceDir).sort();

  return crypto
    .createHash("sha1")
    .update(JSON.stringify(storyPaths))
    .digest("hex")
    .slice(0, 8);
}

const storybookCacheDir = path.resolve(
  storybookRootCacheDir,
  `vite-${createStorybookCacheKey()}`
);
const uiSourceEntry = path.resolve(storybookConfigDir, "../../../packages/ui/src/index.ts");
const tokensSourceEntry = path.resolve(
  storybookConfigDir,
  "../../../packages/tokens/src/index.ts"
);

const config: StorybookConfig = {
  stories: ["../src/**/*.stories.@(ts|tsx)"],
  addons: [
    "@storybook/addon-a11y",
    "@storybook/addon-essentials",
    "@storybook/addon-interactions"
  ],
  framework: {
    name: "@storybook/react-vite",
    options: {}
  },
  async viteFinal(config) {
    return mergeConfig(config, {
      cacheDir: storybookCacheDir,
      plugins: [tailwindcss()],
      optimizeDeps: {
        exclude: ["@ai-ui/ui", "@ai-ui/tokens"]
      },
      resolve: {
        alias: [
          {
            find: /^@ai-ui\/ui$/,
            replacement: uiSourceEntry
          },
          {
            find: /^@ai-ui\/tokens$/,
            replacement: tokensSourceEntry
          }
        ]
      },
      server: {
        fs: {
          allow: [repoRoot]
        },
        watch: {
          usePolling: true,
          interval: 120,
          awaitWriteFinish: {
            stabilityThreshold: 80,
            pollInterval: 40
          }
        }
      }
    });
  }
};

export default config;