/* --provenance-sources (EXPERIMENTAL): the provenance-assisted static
 * compilation pipeline, offline — the fixture manifest
 * (SCRIPTC_PROVENANCE_MANIFEST) stands in for the live attestation +
 * source fetch, so these tests exercise everything AFTER the network:
 * source-entry mapping, the registry chokepoints (preflight edges, tsgo
 * "paths", the npm-import bypass), the @__PURE__ dead-const elision, the
 * per-package attribution, and the island fallback notes.
 *
 * The differential contract is the thesis itself: the binary compiled
 * from the ATTESTED SOURCE (static, no island) must byte-match the
 * binary island-running the PUBLISHED dist — and both must byte-match
 * Node running the published package.
 */
import { execFile } from "node:child_process";
import { mkdirSync } from "node:fs";
import { join } from "node:path";
import { promisify } from "node:util";
import { afterEach, describe, expect, test } from "vitest";
import {
  analyze,
  compile,
  resolveProvenanceSources,
  setProvenanceSources,
} from "@scriptc/compiler";

const execFileAsync = promisify(execFile);
const repoRoot = join(import.meta.dirname, "../..");
const fixtureDir = join(repoRoot, "tests/fixtures/provenance");
const entry = join(fixtureDir, "cases/greet/main.ts");
/* Suite-flavor segment: the plain and SCRIPTC_SAN=1 suites both run these
 * same (unsanitized) builds and may run concurrently — the suite lock is
 * per flavor — so they must never share a build dir. */
const flavor = process.env["SCRIPTC_SAN"] === "1" ? "san" : "plain";
const outDir = join(repoRoot, "node_modules/.cache/scriptc-tests/provenance", flavor);

const EXPECTED = "hello, world\nHELLO, COMPILER!\nhello, chain!\n";

async function buildAndRun(name: string, dynamic: boolean, program = entry): Promise<string> {
  mkdirSync(outDir, { recursive: true });
  const outPath = join(outDir, name);
  // Pinned: the provenance thesis compares a source-static binary against
  // a dist-island binary — holding both on the C lane keeps that byte
  // comparison about PROVENANCE, never about which backend each build drew.
  const result = await compile(program, { outPath, outDir, dynamic, backend: "llvm" });
  if (!result.ok) {
    throw new Error(result.diagnostics.map((d) => `${d.code}: ${d.message}`).join("\n"));
  }
  const { stdout } = await execFileAsync(outPath, [], { encoding: "utf8" });
  return stdout;
}

afterEach(() => {
  setProvenanceSources(null);
  delete process.env["SCRIPTC_PROVENANCE_MANIFEST"];
});

describe("provenance sources", () => {
  test("attested source compiles STATIC and byte-matches the island's published dist", async () => {
    // Flag off: the published dist embeds in the island (--dynamic).
    const island = await buildAndRun("greet-island", true);
    expect(island).toBe(EXPECTED);

    // Flag on: the manifest maps greeter to its source tree; the driver
    // compiles WITHOUT --dynamic — possible only because the source
    // became program modules (a bare npm import would fence a static
    // build), which IS the assertion that nothing islanded.
    process.env["SCRIPTC_PROVENANCE_MANIFEST"] = join(fixtureDir, "manifest.json");
    const sources = await resolveProvenanceSources(entry);
    expect(sources.packages).toHaveLength(1);
    const pkg = sources.packages[0]!;
    expect(pkg.name).toBe("greeter");
    expect(pkg.version).toBe("1.2.3");
    expect(pkg.entries["greeter"]).toMatch(/attested-src\/greeter\/src\/index\.ts$/);
    setProvenanceSources(sources);
    const fromSource = await buildAndRun("greet-static", false);
    expect(fromSource).toBe(island);
  });

  test("maps a published dist/esm subpath to its unmodified TypeScript source", async () => {
    const subpathEntry = join(fixtureDir, "cases/echo/main.ts");
    const node = await execFileAsync("node", [subpathEntry], { encoding: "utf8" });
    process.env["SCRIPTC_PROVENANCE_MANIFEST"] = join(fixtureDir, "manifest.json");
    const sources = await resolveProvenanceSources(subpathEntry);
    expect(sources.packages[0]?.entries["greeter/echo"]).toMatch(/attested-src\/greeter\/src\/echo\.ts$/);
    setProvenanceSources(sources);
    expect(await buildAndRun("echo-static", false, subpathEntry)).toBe(node.stdout);
  });

  test("per-package attribution counts the source static; the @__PURE__ dead const elides", async () => {
    process.env["SCRIPTC_PROVENANCE_MANIFEST"] = join(fixtureDir, "manifest.json");
    setProvenanceSources(await resolveProvenanceSources(entry));
    const { coverage } = analyze(entry);
    expect(coverage.preflightFailed).toBe(false);
    // No blockers anywhere: the dead const elided instead of fencing.
    expect(coverage.diagnostics).toHaveLength(0);
    expect(coverage.provenanceElided ?? []).toHaveLength(1);
    expect(coverage.provenanceElided![0]!.message).toContain("'Legacy'");
    // Attribution: every counted statement of the greeter source is
    // static (the elided declaration never counts — it lowers to nothing).
    const srcStats = [...(coverage.statsByFile ?? [])].filter(([f]) => f.includes("attested-src/greeter/"));
    expect(srcStats.length).toBeGreaterThan(0);
    for (const [, s] of srcStats) {
      expect(s.failed).toBe(0);
      expect(s.island).toBe(0);
    }
  });

  test("an unmappable package falls back to the island with a note, never a failure", async () => {
    process.env["SCRIPTC_PROVENANCE_MANIFEST"] = join(fixtureDir, "manifest-broken.json");
    const sources = await resolveProvenanceSources(entry);
    expect(sources.packages).toHaveLength(0);
    expect(sources.notes).toHaveLength(1);
    expect(sources.notes[0]).toContain("greeter");
    expect(sources.notes[0]).toContain("island path used");
    setProvenanceSources(sources);
    // The island path still works under the flag — the fallback contract.
    const island = await buildAndRun("greet-fallback", true);
    expect(island).toBe(EXPECTED);
  });
});