import * as NodeServices from "@effect/platform-node/NodeServices";
import { assert, it, describe } from "@effect/vitest";
import * as Effect from "effect/Effect";
import * as FileSystem from "effect/FileSystem";
import * as Layer from "effect/Layer";
import * as Path from "effect/Path";

import * as ServerConfig from "../config.ts";
import * as VcsDriverRegistry from "../vcs/VcsDriverRegistry.ts";
import * as VcsProcess from "../vcs/VcsProcess.ts";
import * as WorkspaceEntries from "./WorkspaceEntries.ts";
import * as WorkspaceFileSystem from "./WorkspaceFileSystem.ts";
import * as WorkspacePaths from "./WorkspacePaths.ts";

const PROJECT_READ_FILE_MAX_BYTES = 1024 * 1024;

const ProjectLayer = WorkspaceFileSystem.layer.pipe(
  Layer.provide(WorkspacePaths.layer),
  Layer.provide(WorkspaceEntries.layer.pipe(Layer.provide(WorkspacePaths.layer))),
);

const TestLayer = Layer.empty.pipe(
  Layer.provideMerge(ProjectLayer),
  Layer.provideMerge(WorkspaceEntries.layer.pipe(Layer.provide(WorkspacePaths.layer))),
  Layer.provideMerge(WorkspacePaths.layer),
  Layer.provideMerge(VcsDriverRegistry.layer.pipe(Layer.provide(VcsProcess.layer))),
  Layer.provide(
    ServerConfig.ServerConfig.layerTest(process.cwd(), {
      prefix: "t3-workspace-files-test-",
    }),
  ),
  Layer.provideMerge(NodeServices.layer),
);

const makeTempDir = Effect.gen(function* () {
  const fileSystem = yield* FileSystem.FileSystem;
  return yield* fileSystem.makeTempDirectoryScoped({
    prefix: "t3code-workspace-files-",
  });
});

const writeTextFile = Effect.fn("writeTextFile")(function* (
  cwd: string,
  relativePath: string,
  contents = "",
) {
  const fileSystem = yield* FileSystem.FileSystem;
  const path = yield* Path.Path;
  const absolutePath = path.join(cwd, relativePath);
  yield* fileSystem
    .makeDirectory(path.dirname(absolutePath), { recursive: true })
    .pipe(Effect.orDie);
  yield* fileSystem.writeFileString(absolutePath, contents).pipe(Effect.orDie);
});

const writeBinaryFile = Effect.fn("writeBinaryFile")(function* (
  cwd: string,
  relativePath: string,
  contents: Uint8Array,
) {
  const fileSystem = yield* FileSystem.FileSystem;
  const path = yield* Path.Path;
  const absolutePath = path.join(cwd, relativePath);
  yield* fileSystem
    .makeDirectory(path.dirname(absolutePath), { recursive: true })
    .pipe(Effect.orDie);
  yield* fileSystem.writeFile(absolutePath, contents).pipe(Effect.orDie);
});

it.layer(TestLayer, { excludeTestServices: true })("WorkspaceFileSystemLive", (it) => {
  describe("readFile", () => {
    it.effect("reads UTF-8 files relative to the workspace root", () =>
      Effect.gen(function* () {
        const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
        const cwd = yield* makeTempDir;
        yield* writeTextFile(cwd, "src/index.ts", "export const answer = 42;\n");

        const result = yield* workspaceFileSystem.readFile({
          cwd,
          relativePath: "src/index.ts",
        });

        assert.deepStrictEqual(result, {
          relativePath: "src/index.ts",
          contents: "export const answer = 42;\n",
          byteLength: 26,
          truncated: false,
        });
      }),
    );

    it.effect("rejects reads outside the workspace root", () =>
      Effect.gen(function* () {
        const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
        const cwd = yield* makeTempDir;

        const error = yield* workspaceFileSystem
          .readFile({ cwd, relativePath: "../escape.md" })
          .pipe(Effect.flip);

        assert.match(
          error.message,
          /Workspace file path must be relative to the project root: \.\.\/escape\.md/,
        );
      }),
    );

    it.effect("truncates text files larger than the preview byte limit", () =>
      Effect.gen(function* () {
        const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
        const cwd = yield* makeTempDir;
        yield* writeTextFile(cwd, "large.txt", `${"a".repeat(PROJECT_READ_FILE_MAX_BYTES)}tail`);

        const result = yield* workspaceFileSystem.readFile({
          cwd,
          relativePath: "large.txt",
        });

        assert.strictEqual(result.byteLength, PROJECT_READ_FILE_MAX_BYTES + 4);
        assert.strictEqual(result.contents.length, PROJECT_READ_FILE_MAX_BYTES);
        assert.strictEqual(result.contents, "a".repeat(PROJECT_READ_FILE_MAX_BYTES));
        assert.strictEqual(result.truncated, true);
      }),
    );

    it.effect("rejects binary files before decoding them as text", () =>
      Effect.gen(function* () {
        const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
        const cwd = yield* makeTempDir;
        yield* writeBinaryFile(cwd, "image.bin", new Uint8Array([0x66, 0x6f, 0x00, 0x6f]));

        const error = yield* workspaceFileSystem
          .readFile({ cwd, relativePath: "image.bin" })
          .pipe(Effect.flip);

        assert.strictEqual(
          error.message,
          `Workspace file operation 'workspaceFileSystem.readFile' failed for 'image.bin' in '${cwd}'.`,
        );
        assert.ok(error.cause instanceof Error);
        assert.strictEqual((error.cause as Error).message, "Binary files cannot be previewed as text.");
      }),
    );

    it.effect("rejects symlinks that resolve outside the workspace root", () =>
      Effect.gen(function* () {
        const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
        const fileSystem = yield* FileSystem.FileSystem;
        const path = yield* Path.Path;
        const cwd = yield* makeTempDir;
        const outsideDir = yield* makeTempDir;
        yield* writeTextFile(outsideDir, "secret.txt", "outside\n");
        yield* fileSystem.symlink(
          path.join(outsideDir, "secret.txt"),
          path.join(cwd, "linked-secret.txt"),
        );

        const error = yield* workspaceFileSystem
          .readFile({ cwd, relativePath: "linked-secret.txt" })
          .pipe(Effect.flip);

        assert.strictEqual(
          error.message,
          `Workspace file operation 'workspaceFileSystem.readFile' failed for 'linked-secret.txt' in '${cwd}'.`,
        );
        assert.ok(error.cause instanceof Error);
        assert.strictEqual(
          (error.cause as Error).message,
          "Workspace file path resolves outside the project root.",
        );
      }),
    );
  });

  describe("writeFile", () => {
    it.effect("writes files relative to the workspace root", () =>
      Effect.gen(function* () {
        const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
        const cwd = yield* makeTempDir;
        const fileSystem = yield* FileSystem.FileSystem;
        const path = yield* Path.Path;
        const result = yield* workspaceFileSystem.writeFile({
          cwd,
          relativePath: "plans/effect-rpc.md",
          contents: "# Plan\n",
        });
        const saved = yield* fileSystem
          .readFileString(path.join(cwd, "plans/effect-rpc.md"))
          .pipe(Effect.orDie);

        assert.deepStrictEqual(result, { relativePath: "plans/effect-rpc.md" });
        assert.strictEqual(saved, "# Plan\n");
      }),
    );

    it.effect("invalidates workspace entry search cache after writes", () =>
      Effect.gen(function* () {
        const workspaceEntries = yield* WorkspaceEntries.WorkspaceEntries;
        const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
        const cwd = yield* makeTempDir;
        yield* writeTextFile(cwd, "src/existing.ts", "export {};\n");

        const beforeWrite = yield* workspaceEntries.list({ cwd });
        assert.strictEqual(
          beforeWrite.entries.some((entry) => entry.path === "plans/effect-rpc.md"),
          false,
        );

        yield* workspaceFileSystem.writeFile({
          cwd,
          relativePath: "plans/effect-rpc.md",
          contents: "# Plan\n",
        });

        const afterWrite = yield* workspaceEntries.list({ cwd });
        assert.strictEqual(
          afterWrite.entries.some((entry) => entry.path === "plans/effect-rpc.md"),
          true,
        );
        assert.strictEqual(afterWrite.truncated, false);
      }),
    );

    it.effect("rejects writes outside the workspace root", () =>
      Effect.gen(function* () {
        const workspaceFileSystem = yield* WorkspaceFileSystem.WorkspaceFileSystem;
        const cwd = yield* makeTempDir;
        const path = yield* Path.Path;
        const fileSystem = yield* FileSystem.FileSystem;

        const error = yield* workspaceFileSystem
          .writeFile({
            cwd,
            relativePath: "../escape.md",
            contents: "# nope\n",
          })
          .pipe(Effect.flip);

        assert.match(
          error.message,
          /Workspace file path must be relative to the project root: \.\.\/escape\.md/,
        );

        const escapedPath = path.resolve(cwd, "..", "escape.md");
        const escapedExists = yield* fileSystem.exists(escapedPath);
        assert.strictEqual(escapedExists, false);
      }),
    );
  });
});