import { cpSync, existsSync, mkdirSync, readFileSync, readdirSync, writeFileSync } from "node:fs";
import { basename, dirname, join, relative } from "node:path";
import type { NativeTargetSpec } from "../packages/compiler/src/backend/targets.js";
import type { NativeToolchainManifest } from "../packages/compiler/src/native/toolchain.js";

/** Copy release payloads explicitly; development caches and build trees never ship. */
function copyPackage(source: string, destination: string, members: readonly string[]): void {
  mkdirSync(destination, { recursive: true });
  for (const member of ["package.json", ...members]) {
    cpSync(join(source, member), join(destination, member), {
      recursive: true,
      filter: (path) => ![".cache", "node_modules", ".DS_Store"].includes(basename(path)),
    });
  }
  for (const name of readdirSync(source)) {
    if (/^(?:LICENSE|COPYING|NOTICE|SCRIPTC_LICENSE|THIRD_PARTY_NOTICES)(?:\..*)?$/.test(name)) {
      cpSync(join(source, name), join(destination, name));
    }
  }
}

export function stageNativeCliAssets(options: {
  repository: string;
  output: string;
  target: NativeTargetSpec;
  ts7: string;
  compilerVersion: string;
}): Pick<NativeToolchainManifest, "ts7" | "llvm_package" | "runtime_pack" | "runtime_packs" | "runtime_sources" | "declarations" | "wasi_node_runner"> {
  const { repository, output, target } = options;
  const bin = join(output, "bin");
  const lib = join(output, "lib");
  mkdirSync(lib, { recursive: true });
  cpSync(join(repository, "LICENSE"), join(output, "LICENSE"));
  const helper = join(lib, "llvm");
  const runtime = join(lib, target.runtimePackPackage.replace("@scriptc/", ""));
  copyPackage(join(repository, "packages", target.helper.packageName.replace("@scriptc/", "")), helper, ["bin"]);
  copyPackage(join(repository, "packages", target.runtimePackPackage.replace("@scriptc/", "")), runtime, ["artifacts", "runtime-pack.json"]);
  const typescript = join(lib, "typescript");
  copyPackage(dirname(dirname(options.ts7)), typescript, ["lib"]);
  const sources = join(lib, "runtime-sources");
  copyPackage(join(repository, "packages/runtime"), sources, ["src", "vendor"]);
  const declarations = join(lib, "declarations");
  mkdirSync(declarations, { recursive: true });
  for (const name of ["scriptc.d.ts", "scriptc-overrides.d.ts", "scriptc-node-fallback.d.ts"]) {
    cpSync(join(repository, "packages/compiler/ambient", name), join(declarations, name));
  }
  // This optional Node host runs the built WASI module, never the compiler.
  const wasi = join(lib, "wasi");
  mkdirSync(join(wasi, "cli"), { recursive: true });
  writeFileSync(join(wasi, "package.json"), '{"type":"module"}\n');
  for (const name of ["wasi-paths.js", "cli/wasi-paths.js", "cli/wasi-runner.js"]) {
    const source = join(repository, "packages/compiler/dist", name);
    if (!existsSync(source)) throw new Error("build the compiler workspace before packaging its WASI runner");
    cpSync(source, join(wasi, name));
  }
  const identity = JSON.parse(readFileSync(join(typescript, "package.json"), "utf8")) as { version: string };
  writeFileSync(join(output, "THIRD_PARTY_NOTICES"), [
    `scriptc ${options.compilerVersion} includes the existing TypeScript ${identity.version}, LLVM, and C runtime dependencies.`,
    "TypeScript licensing: lib/typescript/LICENSE and lib/typescript/NOTICE.txt.",
    "LLVM licensing and notices: lib/llvm/LICENSE and lib/llvm/THIRD_PARTY_NOTICES.",
    "Runtime dependency licenses: lib/runtime-sources/vendor/*/LICENSE*.",
    "",
  ].join("\n"));
  return {
    ts7: relative(bin, join(typescript, "lib", basename(options.ts7))),
    llvm_package: relative(bin, helper),
    runtime_pack: relative(bin, runtime),
    runtime_packs: [{ target: target.name, path: relative(bin, runtime) }],
    runtime_sources: relative(bin, sources),
    declarations: relative(bin, declarations),
    wasi_node_runner: relative(bin, join(wasi, "cli/wasi-runner.js")),
  };
}