import { Alepha } from "alepha";
import { FileSystemProvider, MemoryFileSystemProvider } from "alepha/system";
import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { BuildCloudflareTask } from "../tasks/BuildCloudflareTask.ts";

/**
 * Exposes the protected binding enhancers so the wrangler.jsonc shape can be
 * asserted directly without driving a full build.
 */
class TestBuildCloudflareTask extends BuildCloudflareTask {
  public testEnhanceD1 = this.enhanceD1.bind(this);
  public testEnhanceR2 = this.enhanceR2.bind(this);
  public testEnhanceQueue = this.enhanceQueue.bind(this);
  public testWriteWorkerEntryPoint = this.writeWorkerEntryPoint.bind(this);
}

describe("BuildCloudflareTask", () => {
  const createTask = () => {
    const alepha = Alepha.create().with({
      provide: FileSystemProvider,
      use: MemoryFileSystemProvider,
    });
    return alepha.inject(TestBuildCloudflareTask);
  };

  const createTaskWithFs = () => {
    const alepha = Alepha.create().with({
      provide: FileSystemProvider,
      use: MemoryFileSystemProvider,
    });
    return {
      task: alepha.inject(TestBuildCloudflareTask),
      fs: alepha.inject(MemoryFileSystemProvider),
    };
  };

  // Snapshot + restore the env vars these enhancers read so tests don't leak.
  const ENV_KEYS = [
    "DATABASE_URL",
    "R2_BUCKET_NAME",
    "CLOUDFLARE_JURISDICTION",
    "CLOUDFLARE_QUEUE_NAME",
    "CLOUDFLARE_QUEUE_DLQ_NAME",
    "CLOUDFLARE_QUEUE_MAX_RETRIES",
  ] as const;
  const saved: Record<string, string | undefined> = {};
  beforeEach(() => {
    for (const k of ENV_KEYS) saved[k] = process.env[k];
  });
  afterEach(() => {
    for (const k of ENV_KEYS) {
      if (saved[k] === undefined) delete process.env[k];
      else process.env[k] = saved[k];
    }
  });

  describe("enhanceD1", () => {
    it("does not emit `jurisdiction` on the D1 binding (wrangler rejects it)", () => {
      // D1 jurisdiction is applied at database-creation time, not on the
      // binding — wrangler warns on the unexpected field. See CloudflareApi.
      process.env.DATABASE_URL = "d1://my-db:db-id-123";
      process.env.CLOUDFLARE_JURISDICTION = "eu";

      const wrangler: Record<string, any> = {};
      createTask().testEnhanceD1(wrangler);

      expect(wrangler.d1_databases).toEqual([
        { binding: "DB", database_name: "my-db", database_id: "db-id-123" },
      ]);
      expect(wrangler.d1_databases[0]).not.toHaveProperty("jurisdiction");
      expect(wrangler.vars.DATABASE_URL).toBe("d1://DB");
    });

    it("ignores non-d1 DATABASE_URL", () => {
      process.env.DATABASE_URL = "postgres://localhost/db";
      const wrangler: Record<string, any> = {};
      createTask().testEnhanceD1(wrangler);
      expect(wrangler.d1_databases).toBeUndefined();
    });
  });

  describe("enhanceR2", () => {
    it("keeps `jurisdiction` on the R2 binding (wrangler accepts it)", () => {
      process.env.R2_BUCKET_NAME = "my-bucket";
      process.env.CLOUDFLARE_JURISDICTION = "eu";

      const wrangler: Record<string, any> = {};
      createTask().testEnhanceR2(wrangler);

      expect(wrangler.r2_buckets).toEqual([
        { binding: "my-bucket", bucket_name: "my-bucket", jurisdiction: "eu" },
      ]);
    });
  });

  describe("enhanceQueue", () => {
    /**
     * The worker's queue handler calls `msg.retry()` on any throw. Without a
     * `dead_letter_queue`, CF burns its retries and then DISCARDS the message —
     * a poison job disappears with no record and no signal.
     */
    it("gives the consumer a dead-letter queue and a retry ceiling", () => {
      process.env.CLOUDFLARE_QUEUE_NAME = "my-queue";

      const wrangler: Record<string, any> = {};
      createTask().testEnhanceQueue(wrangler);

      expect(wrangler.queues.consumers).toEqual([
        {
          queue: "my-queue",
          dead_letter_queue: "my-queue-dlq",
          max_retries: 3,
        },
      ]);
    });

    it("honours an explicit dead-letter queue and retry ceiling", () => {
      process.env.CLOUDFLARE_QUEUE_NAME = "my-queue";
      process.env.CLOUDFLARE_QUEUE_DLQ_NAME = "shared-dlq";
      process.env.CLOUDFLARE_QUEUE_MAX_RETRIES = "5";

      const wrangler: Record<string, any> = {};
      createTask().testEnhanceQueue(wrangler);

      expect(wrangler.queues.consumers[0]).toEqual({
        queue: "my-queue",
        dead_letter_queue: "shared-dlq",
        max_retries: 5,
      });
    });

    it("ignores a non-numeric retry ceiling rather than emitting NaN", () => {
      process.env.CLOUDFLARE_QUEUE_NAME = "my-queue";
      process.env.CLOUDFLARE_QUEUE_MAX_RETRIES = "not-a-number";

      const wrangler: Record<string, any> = {};
      createTask().testEnhanceQueue(wrangler);

      expect(wrangler.queues.consumers[0].max_retries).toBe(3);
    });
  });

  describe("writeWorkerEntryPoint", () => {
    const ENTRY = "/root/dist/main.cloudflare.js";

    /**
     * A single CF isolate serves concurrent invocations. Stashing the
     * per-invocation `executionCtx.waitUntil` on the shared Alepha store means
     * request B overwrites request A's, and A's background work then calls B's
     * (already-returned) context — "waitUntil after response" — silently
     * killing it. The handle must ride the per-invocation async context.
     */
    it("does not stash waitUntil on the shared global store", async () => {
      const { task, fs } = createTaskWithFs();

      await task.testWriteWorkerEntryPoint("/root", "dist");

      expect(
        fs.wasWrittenMatching(
          ENTRY,
          /__alepha\.set\(\s*["']cloudflare\.waitUntil["']/,
        ),
      ).toBe(false);
    });

    it("scopes waitUntil to each invocation's async context", async () => {
      const { task, fs } = createTaskWithFs();

      await task.testWriteWorkerEntryPoint("/root", "dist");

      // Every entry point (fetch / scheduled / queue) must run its body inside
      // an Alepha fork seeded with that invocation's waitUntil.
      expect(fs.wasWrittenMatching(ENTRY, /__alepha\.context\.run\(/)).toBe(
        true,
      );
    });
  });
});