import { resolve } from "node:path";
import { FileSystem } from "@effect/platform";
import { Context, Effect, Layer } from "effect";
import { z } from "zod";
import { claudeCodeViewerCacheDirPath } from "../../config/paths";

const saveSchema = z.array(z.tuple([z.string(), z.unknown()]));

const getCacheFilePath = (key: string) =>
  resolve(claudeCodeViewerCacheDirPath, `${key}.json`);

const load = (key: string) => {
  const cacheFilePath = getCacheFilePath(key);

  return Effect.gen(function* () {
    const fs = yield* FileSystem.FileSystem;

    if (!(yield* fs.exists(claudeCodeViewerCacheDirPath))) {
      yield* fs.makeDirectory(claudeCodeViewerCacheDirPath, {
        recursive: true,
      });
    }

    if (!(yield* fs.exists(cacheFilePath))) {
      yield* fs.writeFileString(cacheFilePath, "[]");
    } else {
      const content = yield* fs.readFileString(cacheFilePath);
      const parsed = saveSchema.safeParse(JSON.parse(content));

      if (!parsed.success) {
        yield* fs.writeFileString(cacheFilePath, "[]");
      } else {
        parsed.data;
        return parsed.data;
      }
    }

    return [];
  });
};

const save = (key: string, entries: readonly [string, unknown][]) => {
  const cacheFilePath = getCacheFilePath(key);

  return Effect.gen(function* () {
    const fs = yield* FileSystem.FileSystem;
    yield* fs.writeFileString(cacheFilePath, JSON.stringify(entries));
  });
};

export class PersistentService extends Context.Tag("PersistentService")<
  PersistentService,
  {
    readonly load: typeof load;
    readonly save: typeof save;
  }
>() {
  static Live = Layer.succeed(this, {
    load,
    save,
  });
}

export type IPersistentService = Context.Tag.Service<PersistentService>;