import assert from "node:assert/strict";
import crypto from "node:crypto";
import fs from "node:fs";
import os from "node:os";
import path from "node:path";
import { pathToFileURL } from "node:url";
import test from "node:test";
import ts from "typescript";

const root = path.resolve(import.meta.dirname, "../../..");
const temporary = fs.mkdtempSync(path.join(os.tmpdir(), "library-linked-reload-unit-"));
const sourcePath = path.join(root, "web/protocol/library-linked-reload.ts");
const transpiled = ts.transpileModule(fs.readFileSync(sourcePath, "utf8"), {
  compilerOptions: { module: ts.ModuleKind.ES2022, target: ts.ScriptTarget.ES2022 },
  fileName: sourcePath,
  reportDiagnostics: true,
});
assert.deepEqual(transpiled.diagnostics, []);
fs.writeFileSync(path.join(temporary, "library-linked-reload.mjs"), transpiled.outputText);
const reload = await import(pathToFileURL(path.join(temporary, "library-linked-reload.mjs")));
const manifest = JSON.parse(fs.readFileSync(path.join(root, "tests/golden/M12-03H/manifest.json"), "utf8"));
const sha256 = (file) => crypto.createHash("sha256").update(fs.readFileSync(path.join(root, file))).digest("hex");
const library = (value) => `library:${String(value).repeat(64).slice(0, 64)}`;
const digest = (value) => crypto.createHash("sha256").update(String(value)).digest("hex");
const snapshot = (sourceLibraryId, generation, revision, marker) => ({
  sourceLibraryId,
  sourceGeneration: generation,
  sourceRevision: revision,
  dependencyClosureSha256: digest(marker),
  graphSha256: digest(`${marker}-graph`),
  dataBlocks: [
    { dataBlockId: `Object/${marker}`, owner: "SOURCE_LIBRARY", readOnly: true },
    { dataBlockId: `Mesh/${marker}`, owner: "SOURCE_LIBRARY", readOnly: true },
  ],
});

test("M12-03H binds the reload protocol and evidence artifacts", () => {
  assert.equal(manifest.task, "M12-03H");
  assert.equal(manifest.parentTask, "M12-03G");
  assert.equal(manifest.nextTask, "M12-03I");
  for (const artifact of Object.values(manifest.artifacts)) assert.equal(sha256(artifact.path), artifact.sha256, artifact.path);
});

test("M12-03H replaces only the matching library generation and preserves every other snapshot", () => {
  const sourceLibraryId = library("a");
  const otherLibraryId = library("b");
  const current = snapshot(sourceLibraryId, 3, 7, "old");
  const otherGeneration = snapshot(sourceLibraryId, 9, 2, "future");
  const otherLibrary = snapshot(otherLibraryId, 1, 4, "other");
  const state = { schemaVersion: 1, snapshots: [current, otherGeneration, otherLibrary] };
  const replacement = snapshot(sourceLibraryId, 4, 8, "new");
  const decision = reload.reloadMatchingLinkedSnapshot(state, {
    schemaVersion: 1,
    operation: "RELOAD",
    sourceLibraryId,
    expectedGeneration: 3,
    expectedRevision: 7,
    replacement,
  });
  assert.equal(decision.status, "REPLACED");
  assert.equal(decision.code, null);
  assert.deepEqual(decision.state.snapshots, [replacement, otherGeneration, otherLibrary]);
  assert.deepEqual(state.snapshots, [current, otherGeneration, otherLibrary]);
  assert(decision.state.snapshots.every((item) => item.dataBlocks.every((block) => block.owner === "SOURCE_LIBRARY" && block.readOnly)));
});

test("M12-03H rejects stale generations and keeps state byte-for-byte equivalent", () => {
  const sourceLibraryId = library("c");
  const state = { schemaVersion: 1, snapshots: [snapshot(sourceLibraryId, 5, 11, "stable")] };
  const request = {
    schemaVersion: 1,
    operation: "RELOAD",
    sourceLibraryId,
    expectedGeneration: 4,
    expectedRevision: 10,
    replacement: snapshot(sourceLibraryId, 5, 12, "late"),
  };
  const decision = reload.reloadMatchingLinkedSnapshot(state, request);
  assert.deepEqual(decision, {
    status: "STALE",
    code: "REVISION_CONFLICT",
    sourceLibraryId,
    replacedGeneration: 4,
    replacementGeneration: 5,
    state,
  });
});

test("M12-03H fails closed for malformed, substituted, duplicate, and non-adjacent reloads", () => {
  const sourceLibraryId = library("d");
  const current = snapshot(sourceLibraryId, 1, 1, "current");
  const baseRequest = {
    schemaVersion: 1,
    operation: "RELOAD",
    sourceLibraryId,
    expectedGeneration: 1,
    expectedRevision: 1,
    replacement: snapshot(sourceLibraryId, 2, 2, "replacement"),
  };
  assert.throws(() => reload.parseLinkedReloadRequest({ ...baseRequest, future: true }), { code: "TASK_VALIDATION_FAILED" });
  assert.throws(() => reload.parseLinkedReloadRequest({ ...baseRequest, replacement: { ...baseRequest.replacement, sourceLibraryId: library("e") } }), { code: "TASK_VALIDATION_FAILED" });
  assert.throws(() => reload.parseLinkedReloadState({ schemaVersion: 1, snapshots: [current, current] }), { code: "TASK_VALIDATION_FAILED" });
  const decision = reload.reloadMatchingLinkedSnapshot({ schemaVersion: 1, snapshots: [current] }, {
    ...baseRequest,
    replacement: snapshot(sourceLibraryId, 3, 3, "skip"),
  });
  assert.equal(decision.status, "STALE");
  assert.equal(decision.code, "REVISION_CONFLICT");
});

test.after(() => fs.rmSync(temporary, { recursive: true, force: true }));