import { mkdir, mkdtemp, realpath, rm, symlink, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";
import { fileURLToPath } from "node:url";

/**
 * Generated module fixtures for the packager's tests: a built module directory in a temporary
 * location, whose `node_modules` links to the real Module SDK and Drizzle this package depends on.
 * Everything a development module directory holds is there, including what must never ship
 * (`src/`, `tests/`, declarations, source maps, `workspace:` ranges), so a test can prove the
 * packager leaves it out.
 */

const packageRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..", "..");

export interface FakePackage {
  readonly name: string;
  readonly version?: string;
  readonly packageJson?: Record<string, unknown>;
  /** Files relative to the fake package's root. */
  readonly files?: Record<string, string | Uint8Array>;
}

export interface FixtureModuleOptions {
  readonly id?: string;
  readonly version?: string;
  readonly serverSource?: string;
  readonly withModuleDatabase?: boolean;
  readonly withSchema?: boolean;
  readonly fakePackages?: readonly FakePackage[];
  readonly manifest?: (manifest: Record<string, unknown>) => Record<string, unknown>;
}

const temporaryDirectories: string[] = [];

export async function cleanupFixtures(): Promise<void> {
  await Promise.all(
    temporaryDirectories
      .splice(0)
      .map((directory) => rm(directory, { force: true, recursive: true })),
  );
}

export async function scratchDirectory(prefix = "ekklesia-pack-"): Promise<string> {
  const directory = await realpath(await mkdtemp(path.join(tmpdir(), prefix)));
  temporaryDirectories.push(directory);
  return directory;
}

async function write(file: string, contents: string | Uint8Array): Promise<void> {
  await mkdir(path.dirname(file), { recursive: true });
  await writeFile(file, contents);
}

const defaultServer = (
  id: string,
  version: string,
) => `import { defineModuleRuntime } from "@ekklesia/module-sdk";
export default defineModuleRuntime({ id: ${JSON.stringify(id)}, version: ${JSON.stringify(version)}, register() {} });
`;

const schemaSource = (
  id: string,
) => `import { createModuleTable, defineModuleSchema } from "@ekklesia/module-sdk";
import { text, uuid } from "drizzle-orm/pg-core";
export const records = createModuleTable(${JSON.stringify(id)})("records", {
  id: uuid("id").primaryKey(),
  value: text("value").notNull(),
});
export default defineModuleSchema({ moduleId: ${JSON.stringify(id)}, tables: { records } });
`;

export async function fixtureModule(options: FixtureModuleOptions = {}): Promise<string> {
  const id = options.id ?? "example";
  const version = options.version ?? "0.1.0";
  const root = await scratchDirectory("ekklesia-pack-fixture-");
  const moduleDirectory = path.join(root, id);
  const tableName = `${id.replaceAll("-", "_")}_records`;

  const baseManifest: Record<string, unknown> = {
    manifestVersion: 8,
    id,
    name: `${id} module`,
    version,
    compatibility: { platform: "^0.1.0", moduleSdk: "^0.1.0" },
    capabilities: [],
    permissions: [],
    entrypoints: {
      server: "./dist/server/index.js",
      ...(options.withSchema ? { schema: "./dist/schema/index.js" } : {}),
      migrations: "./drizzle",
    },
  };
  const manifest = options.manifest ? options.manifest(baseManifest) : baseManifest;

  await write(
    path.join(moduleDirectory, "ekklesia.module.json"),
    `${JSON.stringify(manifest, null, 2)}\n`,
  );
  await write(
    path.join(moduleDirectory, "package.json"),
    `${JSON.stringify(
      {
        name: `@test/module-${id}`,
        version,
        private: true,
        type: "module",
        scripts: { build: "tsc" },
        dependencies: {
          "@ekklesia/module-sdk": "workspace:*",
          ...(options.withModuleDatabase ? { "@ekklesia/module-database": "workspace:*" } : {}),
          "drizzle-orm": "0.45.2",
        },
        devDependencies: { typescript: "7.0.2" },
        exports: { ".": "./dist/server/index.js" },
        ekklesia: { layer: "module" },
      },
      null,
      2,
    )}\n`,
  );
  await write(
    path.join(moduleDirectory, "dist/server/index.js"),
    options.serverSource ?? defaultServer(id, version),
  );
  await write(path.join(moduleDirectory, "dist/server/index.js.map"), '{"version":3}\n');
  await write(path.join(moduleDirectory, "dist/server/index.d.ts"), "export {};\n");
  if (options.withSchema) {
    await write(path.join(moduleDirectory, "dist/schema/index.js"), schemaSource(id));
  }
  await write(path.join(moduleDirectory, "src/server/index.ts"), "export {};\n");
  await write(path.join(moduleDirectory, "tests/server.test.ts"), "export {};\n");
  await write(path.join(moduleDirectory, "README.md"), "# Development notes\n");

  await write(
    path.join(moduleDirectory, "drizzle/0000_initial.sql"),
    `CREATE TABLE "${tableName}" ("id" uuid PRIMARY KEY NOT NULL, "value" text NOT NULL);\n`,
  );
  await write(
    path.join(moduleDirectory, "drizzle/meta/_journal.json"),
    JSON.stringify({
      version: "7",
      dialect: "postgresql",
      entries: [
        { idx: 0, version: "7", when: 1_700_000_000_000, tag: "0000_initial", breakpoints: true },
      ],
    }),
  );
  await write(
    path.join(moduleDirectory, "drizzle/meta/_ekklesia.json"),
    JSON.stringify({
      version: 1,
      moduleId: id,
      entries: [{ tag: "0000_initial", destructive: { mode: "none" } }],
    }),
  );
  await write(
    path.join(moduleDirectory, "drizzle/meta/0000_snapshot.json"),
    JSON.stringify({
      version: "7",
      dialect: "postgresql",
      id: "10000000-0000-4000-8000-000000000001",
      prevId: "00000000-0000-0000-0000-000000000000",
    }),
  );

  // The module's dependencies, as a workspace links them: the real packages this package depends on.
  const modules = path.join(moduleDirectory, "node_modules");
  await mkdir(path.join(modules, "@ekklesia"), { recursive: true });
  await symlink(
    await realpath(path.join(packageRoot, "node_modules", "@ekklesia", "module-sdk")),
    path.join(modules, "@ekklesia", "module-sdk"),
  );
  if (options.withModuleDatabase) {
    await symlink(
      await realpath(path.join(packageRoot, "node_modules", "@ekklesia", "module-database")),
      path.join(modules, "@ekklesia", "module-database"),
    );
  }
  await symlink(
    await realpath(path.join(packageRoot, "node_modules", "drizzle-orm")),
    path.join(modules, "drizzle-orm"),
  );
  for (const fake of options.fakePackages ?? []) {
    const fakeRoot = path.join(modules, ...fake.name.split("/"));
    await write(
      path.join(fakeRoot, "package.json"),
      JSON.stringify({
        name: fake.name,
        version: fake.version ?? "1.0.0",
        type: "module",
        main: "index.js",
        license: "MIT",
        ...fake.packageJson,
      }),
    );
    for (const [relative, contents] of Object.entries(fake.files ?? {})) {
      await write(path.join(fakeRoot, relative), contents);
    }
  }
  return moduleDirectory;
}

export const SOURCE_REVISION = "86ae907f59458508e3277666cdd214f5bd7c1078";