import { createHash } from "node:crypto";
import { mkdtemp, readdir, readFile, rm } from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { afterEach, describe, expect, it } from "vitest";
import { discoverRepositoryMigrations } from "../src/cli/migration-command-support.js";
import { resolveCommandModulesDirectory } from "../src/cli/modules-directory-environment.js";
import { discoverCoreMigrations } from "../src/migrations/index.js";
import { ModuleDiscoveryError } from "../src/modules/index.js";
import { createMigrationModule } from "./support/migration-module-fixture.js";

const repositoryRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..", "..");
const temporaryDirectories: string[] = [];

afterEach(async () => {
  await Promise.all(
    temporaryDirectories.splice(0).map((directory) => rm(directory, { recursive: true })),
  );
});

async function externalModulesDirectory(): Promise<string> {
  const directory = await mkdtemp(path.join(tmpdir(), "ekklesia-installed-modules-"));
  temporaryDirectories.push(directory);
  return directory;
}

describe("operator commands select the modules directory through host configuration", () => {
  it("defaults to the repository's own modules directory", () => {
    expect(resolveCommandModulesDirectory({}, "/opt/ekklesia")).toEqual({
      modulesDirectory: "/opt/ekklesia/modules",
      modulesDirectoryRequired: false,
    });
  });

  it("honours EKKLESIA_MODULES_DIR", () => {
    expect(
      resolveCommandModulesDirectory(
        { EKKLESIA_MODULES_DIR: "/var/lib/ekklesia/modules" },
        "/opt/ekklesia",
      ),
    ).toEqual({ modulesDirectory: "/var/lib/ekklesia/modules", modulesDirectoryRequired: true });
  });

  it("refuses a relative EKKLESIA_MODULES_DIR without echoing it", () => {
    expect(() =>
      resolveCommandModulesDirectory({ EKKLESIA_MODULES_DIR: "modules-9e1f" }, "/opt/ekklesia"),
    ).toThrow(ModuleDiscoveryError);
    try {
      resolveCommandModulesDirectory({ EKKLESIA_MODULES_DIR: "modules-9e1f" }, "/opt/ekklesia");
    } catch (error) {
      expect(JSON.stringify((error as ModuleDiscoveryError).issues)).not.toContain("9e1f");
    }
  });

  it("plans migrations for modules installed outside the repository, with Core's from the platform", async () => {
    // A minimal installed module generated from nothing in the repository, so this test never
    // depends on build output or ignored files: a clean checkout runs it before anything is built.
    const modulesDirectory = await externalModulesDirectory();
    const installed = await createMigrationModule(modulesDirectory, "example");
    expect(path.relative(repositoryRoot, modulesDirectory).startsWith("..")).toBe(true);

    const aggregate = await discoverRepositoryMigrations(repositoryRoot, {
      EKKLESIA_MODULES_DIR: modulesDirectory,
    });

    expect(aggregate.modules.map((module) => module.moduleId)).toEqual(["core", "example"]);

    // Core's migrations are exactly the platform's own, byte for byte, from `core/drizzle`.
    const platformCore = await discoverCoreMigrations({
      coreMigrationsDirectory: path.join(repositoryRoot, "core", "drizzle"),
    });
    const fingerprint = (migrations: readonly { identity: string; checksum: string }[]) =>
      migrations.map((migration) => `${migration.identity} ${migration.checksum}`);
    expect(platformCore.length).toBeGreaterThan(0);
    expect(fingerprint(aggregate.modules[0]?.migrations ?? [])).toEqual(fingerprint(platformCore));

    // The module's migration is the one installed outside the repository, byte for byte.
    const installedSql = await readFile(
      path.join(installed.migrationDirectory ?? "", "0000_initial.sql"),
    );
    expect(fingerprint(aggregate.modules[1]?.migrations ?? [])).toEqual([
      `example:0000_initial ${createHash("sha256").update(installedSql).digest("hex")}`,
    ]);
  });

  it("fails closed when the configured directory does not exist", async () => {
    const parent = await externalModulesDirectory();
    await expect(
      discoverRepositoryMigrations(repositoryRoot, {
        EKKLESIA_MODULES_DIR: path.join(parent, "absent"),
      }),
    ).rejects.toBeInstanceOf(ModuleDiscoveryError);
  });
});

describe("no source chooses a modules directory except the resolver", () => {
  async function sourceFiles(directory: string): Promise<readonly string[]> {
    const entries = await readdir(directory, { recursive: true, withFileTypes: true });
    return entries
      .filter((entry) => entry.isFile() && entry.name.endsWith(".ts"))
      .map((entry) => path.join(entry.parentPath, entry.name));
  }

  it("never joins `modules` onto a root anywhere else in Core or the API", async () => {
    const files = [
      ...(await sourceFiles(path.join(repositoryRoot, "core", "src"))),
      ...(await sourceFiles(path.join(repositoryRoot, "apps", "api", "src"))),
    ];
    const resolver = path.join(repositoryRoot, "core", "src", "modules", "modules-directory.ts");
    for (const file of files) {
      if (file === resolver) {
        continue;
      }
      const text = await readFile(file, "utf8");
      expect(text, path.relative(repositoryRoot, file)).not.toMatch(/,\s*"modules"\s*\)/u);
    }
  });
});