#!/usr/bin/env node
import { createHash } from "node:crypto";
import { readFileSync, writeFileSync } from "node:fs";
import path from "node:path";
import { fileURLToPath, pathToFileURL } from "node:url";
import { verifyFullLocalDiscovery } from "./verify-full-local-discovery.mjs";
import { sourceSnapshot } from "./full-local-diagnostic.mjs";

const hash = value => createHash("sha256").update(value).digest("hex");
export const caseKey = entry => JSON.stringify([entry.file, entry.id, entry.title, entry.projectName ?? "", entry.repeatEachIndex ?? 0]);
const sameCandidate = (a, b) => Boolean(a && b && /^[a-f0-9]{40}$/.test(a.commit ?? "") && /^[a-f0-9]{64}$/.test(a.digest ?? "") && a.commit === b.commit && a.digest === b.digest);

export const localSpecArgs = plan => plan.localSpecs.map(file => `${file.slice(7).replace(/[.*+?^${}()|[\]\\]/gu, "\\$&")}$`);

export function coveragePlan(root, discovery, contract, candidate) {
  const full = verifyFullLocalDiscovery(root, discovery);
  const issues = [...full.issues];
  const exceptions = contract?.exceptions ?? [];
  if (contract?.schemaVersion !== 1 || !Array.isArray(contract?.exceptions) || !contract.approvalReference) issues.push("invalid_coverage_contract");
  if (!sameCandidate(candidate, candidate)) issues.push("invalid_candidate");
  const keys = full.cases.map(caseKey);
  if (new Set(keys).size !== keys.length) issues.push("duplicate_discovery_case");
  const registered = new Map();
  for (const entry of exceptions) {
    const key = caseKey(entry);
    if (registered.has(key)) issues.push("duplicate_exception");
    registered.set(key, entry);
    if (!keys.includes(key)) issues.push("exception_identity_drift");
    if (!["post-deploy", "frozen"].includes(entry.kind) || !entry.reason || !entry.entry || !entry.responsibilityRole || !entry.requiredEvidence) issues.push("invalid_exception_obligation");
    if (!full.expectedSpecs.includes(entry.file)) issues.push("exception_source_unknown");
    else if (hash(readFileSync(path.join(root, entry.file))) !== entry.sourceSha256) issues.push("exception_source_changed");
    if (entry.kind === "frozen" && !full.cases.some(row => row.file === entry.replacementFile && row.title === entry.replacementTitle && !exceptions.some(other => caseKey(other) === caseKey(row)))) issues.push("frozen_protection_missing");
  }
  const exceptionFiles = new Set(exceptions.map(entry => entry.file));
  const localCases = full.cases.filter(entry => !registered.has(caseKey(entry)));
  if (localCases.some(entry => exceptionFiles.has(entry.file))) issues.push("unregistered_case_in_exception_file");
  if (!localCases.length) issues.push("empty_local_coverage");
  const localSpecs = [...new Set(localCases.map(entry => entry.file))].sort();
  return {
    schemaVersion: 1, kind: "LAYERED_LOCAL_COVERAGE_PLAN", status: issues.length ? "FAIL" : "PASS",
    candidate: { commit: candidate?.commit, digest: candidate?.digest }, contractSha256: hash(JSON.stringify(contract)),
    discoverySha256: hash(JSON.stringify(discovery)), localSpecs, localCases,
    obligations: exceptions.map(entry => ({ ...entry, status: entry.kind === "post-deploy" ? "NOT_RUN_LOCAL" : "FROZEN_PROTECTION_REQUIRED" })),
    totalCases: full.cases.length, issues: [...new Set(issues)], normalReleaseEligible: false,
  };
}

function reportCases(report) {
  const cases = [];
  function visit(suites, inherited = "") {
    for (const suite of suites ?? []) {
      for (const spec of suite.specs ?? []) {
        let file = (spec.file ?? suite.file ?? inherited).replaceAll("\\", "/");
        if (!file.startsWith("client/tests/e2e/")) file = `client/tests/e2e/${file.replace(/^tests\/e2e\//u, "")}`;
        for (const test of spec.tests ?? []) cases.push({ file, id: spec.id, title: spec.title, projectName: test.projectName ?? "", repeatEachIndex: test.repeatEachIndex ?? 0, ...test });
      }
      visit(suite.suites, suite.file ?? inherited);
    }
  }
  visit(report?.suites);
  return cases;
}

export function verifyCaseExecution(expected, report) {
  const issues = [];
  if (!Array.isArray(report?.suites) || !Array.isArray(report?.errors)) issues.push("invalid_execution_report");
  if (report?.errors?.length) issues.push("execution_errors");
  const actual = reportCases(report);
  const byKey = new Map();
  for (const entry of actual) {
    const key = caseKey(entry);
    if (byKey.has(key)) issues.push("duplicate_execution_case");
    byKey.set(key, entry);
  }
  const cases = expected.map(entry => {
    const observed = byKey.get(caseKey(entry));
    byKey.delete(caseKey(entry));
    const passed = observed?.expectedStatus === "passed" && observed?.status === "expected" && observed?.results?.length === 1 && observed.results[0].status === "passed" && observed.results[0].retry === 0;
    if (!passed) issues.push(observed ? "case_not_clean_pass" : "missing_execution_case");
    return { ...entry, status: passed ? "PASS" : "FAIL", observedStatus: observed?.results?.at(-1)?.status ?? "NOT_RUN" };
  });
  if (byKey.size) issues.push("unexpected_execution_case");
  return { status: issues.length ? "FAIL" : "PASS", cases, issues: [...new Set(issues)] };
}

export function verifyLocalCoverage(plan, report, candidate) {
  const result = verifyCaseExecution(plan.localCases, report);
  if (plan.status !== "PASS") result.issues.push("coverage_plan_invalid");
  if (!sameCandidate(plan.candidate, candidate)) result.issues.push("candidate_changed");
  result.status = result.issues.length ? "FAIL" : "PASS";
  return { ...result, kind: "LOCAL_BROWSER_COVERAGE_ONLY", candidate: plan.candidate,
    obligations: plan.obligations.map(entry => ({ ...entry, status: entry.kind === "post-deploy" ? "NOT_RUN_LOCAL" : result.cases.some(row => row.file === entry.replacementFile && row.title === entry.replacementTitle && row.status === "PASS") ? "FROZEN_PROTECTION_PASS" : "FROZEN_PROTECTION_FAIL" })),
    deliveryStatus: "INCOMPLETE", normalReleaseEligible: false };
}

// Pure offline verifier. This does not run public tests or authorize deployment.
export function verifyPostDeployCoverage(plan, evidence) {
  const expected = plan.obligations.filter(entry => entry.kind === "post-deploy");
  const result = verifyCaseExecution(expected, evidence?.report);
  if (plan.status !== "PASS" || !expected.length) result.issues.push("coverage_plan_invalid");
  if (evidence?.profile !== "post-deploy-live" || evidence?.mode !== "live") result.issues.push("live_profile_required");
  if (!sameCandidate(plan.candidate, evidence?.candidate) || !sameCandidate(plan.candidate, evidence?.deployedCandidate)) result.issues.push("deployed_candidate_mismatch");
  result.status = result.issues.length ? "FAIL" : "PASS";
  return { ...result, normalReleaseEligible: false };
}

if (process.argv[1] && import.meta.url === pathToFileURL(path.resolve(process.argv[1])).href) {
  try {
    const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "../..");
    const [mode, directory] = process.argv.slice(2);
    const read = file => JSON.parse(readFileSync(path.join(directory, file), "utf8"));
    const contract = JSON.parse(readFileSync(path.join(root, "scripts/qa/full-local-coverage-contract.json"), "utf8"));
    const current = coveragePlan(root, read("discovery.json"), contract, sourceSnapshot(root));
    if (mode === "plan") {
      console.log(JSON.stringify(current, null, 2));
      if (current.status === "PASS") writeFileSync(path.join(directory, "local-spec-args.txt"), localSpecArgs(current).join("\n") + "\n", { flag: "wx" });
      process.exitCode = current.status === "PASS" ? 0 : 1;
    } else if (mode === "verify-local") {
      const saved = read("coverage-plan.json");
      const result = verifyLocalCoverage(saved, read("playwright-results.json"), current.candidate);
      if (JSON.stringify(saved) !== JSON.stringify(current)) result.issues.push("coverage_plan_changed");
      result.status = result.issues.length ? "FAIL" : "PASS";
      console.log(JSON.stringify(result, null, 2));
      process.exitCode = result.status === "PASS" ? 0 : 1;
    } else throw new Error("unknown_mode");
  } catch {
    console.log(JSON.stringify({ status: "FAIL", issues: ["coverage_input_invalid"], normalReleaseEligible: false }));
    process.exitCode = 1;
  }
}