import { beforeEach, describe, expect, mock, test } from "bun:test";
import { fakeD1 } from "../metering/fake-d1.test-helper";
import { scopedTestState } from "./scoped.test-helper";

let d1 = fakeD1();
const scoped = scopedTestState();
scoped.install();
const kv = new Map<string, string>();
const fakeEnv = {
  get DB() {
    return d1.binding;
  },
  KV: {
    get: async (key: string, type?: string) => {
      const value = kv.get(key) ?? null;
      return value !== null && type === "json" ? JSON.parse(value) : value;
    },
    put: async (key: string, value: string) => void kv.set(key, value),
    delete: async (key: string) => void kv.delete(key),
  },
};
mock.module("cloudflare:workers", () => ({ env: fakeEnv, waitUntil: () => undefined }));

const { dropAliasesForPreview, dropPullAliasesForIssue, syncPullAliases, sweepClosedPullAliasesForScope } =
  await import("./pr-aliases");

function addPull(id: string, number: number, headRepo: string): void {
  scoped.insert("r1", "issues", { id, number });
  scoped.insert("r1", "pull_requests", { issue_id: id, head_repo_id: headRepo, head_ref: "feature" });
  scoped.register("issue", id, "r1");
}

function setup(): void {
  d1 = fakeD1();
  kv.clear();
  scoped.reset();
  scoped.site({ id: "s1", owner_id: "u1", repo_id: "r1", label: "blog--alice" });
  addPull("i7", 7, "r1");
  addPull("i8", 8, "fork");
}

const site = (commitPreviews: number) => ({
  id: "s1",
  repo_id: "r1",
  label: "blog--alice",
  commit_previews: commitPreviews,
});

const deployment = (id: string, sha: string) => ({ id, environment: "preview" as const, branch: "feature", sha });

const COMMITS = 7;
const pointer = (label: string) => JSON.parse(kv.get(`sites:slot:${label}`) ?? "null");

describe("pull request aliases", () => {
  beforeEach(setup);

  test("points pr-N at the latest preview of a same-repo pull request only", async () => {
    await syncPullAliases(site(0), deployment("d1", "abcdef1234"));
    await syncPullAliases(site(0), deployment("d2", "1234567890"));
    expect(pointer("pr-7--blog--alice")).toEqual({ siteId: "s1", deploymentId: "d2" });
    expect(pointer("pr-8--blog--alice")).toBeNull();
    expect(pointer("abcdef1--blog--alice")).toBeNull();
  });

  test("commit previews are immutable and keep the last five", async () => {
    for (let index = 0; index < COMMITS; index += 1) {
      await syncPullAliases(site(1), deployment(`d${index}`, `${index}000000aaaa`));
    }
    expect(pointer("0000000--blog--alice")).toBeNull();
    expect(pointer("1000000--blog--alice")).toBeNull();
    expect(pointer("2000000--blog--alice")).toEqual({ siteId: "s1", deploymentId: "d2" });
    expect(pointer("6000000--blog--alice")).toEqual({ siteId: "s1", deploymentId: "d6" });
  });

  test("closing the pull request drops its hosts", async () => {
    await syncPullAliases(site(1), deployment("d1", "abcdef1234"));
    await dropPullAliasesForIssue("i7");
    expect(pointer("pr-7--blog--alice")).toBeNull();
    expect(pointer("abcdef1--blog--alice")).toBeNull();
  });

  test("the sweep drops aliases of pull requests closed without the hook", async () => {
    await syncPullAliases(site(0), deployment("d1", "abcdef1234"));
    scoped.repo("r1").run("UPDATE issues SET state = 'closed' WHERE id = 'i7'");
    expect(await sweepClosedPullAliasesForScope("r1")).toBe(false);
    expect(pointer("pr-7--blog--alice")).toBeNull();
  });

  test("a commit shared by two pull requests survives pruning and closing of one of them", async () => {
    addPull("i9", 9, "r1");
    await syncPullAliases(site(1), deployment("d1", "abcdef1234"));
    await dropPullAliasesForIssue("i7");
    expect(pointer("abcdef1--blog--alice")).toEqual({ siteId: "s1", deploymentId: "d1" });
    expect(pointer("pr-9--blog--alice")).toEqual({ siteId: "s1", deploymentId: "d1" });
  });

  test("removing the branch preview drops the aliases serving it", async () => {
    scoped.insert("r1", "site_deployments", { id: "d1", site_id: "s1", label: "feature--blog--alice" });
    await syncPullAliases(site(1), deployment("d1", "abcdef1234"));
    await dropAliasesForPreview("s1", "feature--blog--alice");
    expect(pointer("pr-7--blog--alice")).toBeNull();
    expect(pointer("abcdef1--blog--alice")).toBeNull();
  });

  test("never takes over another site's host", async () => {
    kv.set("sites:slot:pr-7--blog--alice", JSON.stringify({ siteId: "s1-other", deploymentId: "x" }));
    scoped.site({ id: "s1-other", owner_id: "u2", label: "other" });
    await syncPullAliases(site(0), deployment("d1", "abcdef1234"));
    expect(pointer("pr-7--blog--alice")).toEqual({ siteId: "s1-other", deploymentId: "x" });
  });
});