#!/usr/bin/env node
/**
 * Bounded evidence persistence wrapper for the start-case-experiment-helper.
 *
 * Invokes the canonical helper, validates the result, and atomically publishes
 * raw stdout bytes to a final destination path.
 */

const { execFile } = require("child_process");
const fsMod = require("fs");
const os = require("os");
const path = require("path");

// ── Argument parsing ──────────────────────────────────────────────

function parseArgs(argv) {
  const args = {};
  for (let i = 2; i < argv.length; i++) {
    switch (argv[i]) {
      case "--condition": args.condition = argv[++i]; break;
      case "--treatment": args.treatment = argv[++i]; break;
      case "--file": args.file = argv[++i]; break;
      case "--output": args.output = argv[++i]; break;
    }
  }
  return args;
}

const args = parseArgs(process.argv);

// ── Validate required arguments ───────────────────────────────────

if (!args.condition || !args.file || !args.output) {
  console.error("Usage: evidence-persist.cjs --condition D|E --treatment <val for E> --file <fixture> --output <dest>");
  process.exit(1);
}

const validConditions = ["D", "E"];
if (!validConditions.includes(args.condition)) {
  console.error("--condition must be D or E");
  process.exit(1);
}

if (args.condition === "E" && args.treatment !== "e-investigability-first") {
  console.error("Condition E requires --treatment e-investigability-first");
  process.exit(1);
}

// ── Persistence contract: require existing input fixture ──────────

if (!fsMod.existsSync(args.file)) {
  console.error("Input fixture does not exist: " + args.file);
  process.exit(1);
}

// ── Persistence contract: compute output directory for temp placement ──

const outputDir = path.dirname(path.resolve(args.output));

// ── Create unique temp path in final destination directory ────────

const tmpFile = path.join(outputDir, ".evidence-persist-tmp-" + process.pid + "-" + Date.now() + ".json");

async function main() {
  const helperPath = path.join(__dirname, "start-case-experiment-helper.cjs");
  const tsxPath = path.join(__dirname, "..", "node_modules", ".bin", "tsx");

  const helperArgs = ["--file", args.file, "--reconstruction-only"];
  if (args.condition) helperArgs.push("--condition", args.condition);
  if (args.treatment) helperArgs.push("--treatment", args.treatment);

  const stdoutChunks = [];
  const stderrChunks = [];

  var child;
  var exitCodeResult;

  await new Promise(function(resolve, reject) {
    child = require("child_process").spawn(process.execPath, [tsxPath, helperPath].concat(helperArgs), {
      cwd: path.join(__dirname, ".."),
      timeout: 120000,
      env: Object.assign(Object.create(null), process.env, {
        START_CASE_EXPERIMENT_HELPER_MOCK: "1",
      }),
      stdio: ["pipe", "pipe", "pipe"],
    });

    child.stdout.on("data", function(chunk) { stdoutChunks.push(chunk); });
    child.stderr.on("data", function(chunk) { stderrChunks.push(chunk); });

    child.on("close", function(code) { exitCodeResult = code; resolve(code); });
    child.on("error", function(err) { reject(err); });
  }).then(function(code) {
    return code;
  });

  // ── Persistence contract: require exit code zero ────────────────

  if (child.exitCode !== 0) {
    var stderr = Buffer.concat(stderrChunks).toString().trim();
    console.error("Helper exited with code " + child.exitCode);
    if (stderr) console.error("stderr:", stderr.substring(0, 500));
    throw new Error("Helper did not exit cleanly (code " + child.exitCode + ")");
  }

  // ── Capture stdout as raw bytes without reformatting ────────────

  var rawStdout = Buffer.concat(stdoutChunks);
  if (rawStdout.length === 0) {
    throw new Error("Helper produced empty output");
  }

  // ── Persistence contract: require complete, parseable JSON output ─

  var result;
  try {
    result = JSON.parse(rawStdout.toString());
  } catch (e) {
    throw new Error("Output is not valid JSON: " + e.message);
  }

  // ── Require success === true and statusCode === 200 ─────────────

  if (result.success !== true || result.statusCode !== 200) {
    console.error("Helper validation failed: not successful or status != 200");
    throw new Error("Result is not successful or status code is not 200");
  }

  // ── Require condition match ─────────────────────────────────────

  var expectedConditionType = args.condition === "D" ? "deconstruct" : "investigability-first";
  if (result.conditionType !== expectedConditionType && result.condition !== args.condition) {
    throw new Error("Result condition mismatch: expected " + args.condition);
  }

  // ── Require nonempty freeformText ───────────────────────────────

  if (!result.freeformText || typeof result.freeformText !== "string" || result.freeformText.length === 0) {
    throw new Error("Result does not contain non-empty freeformText");
  }

  // ── Require reconstruction-only execution metadata present and consistent ─

  if (result.execution) {
    var exec = result.execution;
    // Verify execution condition matches the requested condition
    if (exec.condition !== args.condition && exec.condition !== "A") {
      throw new Error("execution.condition mismatch: " + exec.condition);
    }
    // execution proves reconstruction-only path was taken
  } else {
    throw new Error("Missing execution metadata in result");
  }

  // Also verify diagnostics.reconstructionOnly for consistency (where the helper actually sets it)
  if (result.diagnostics && result.diagnostics.reconstructionOnly !== true) {
    throw new Error("diagnostics.reconstructionOnly is not set to true");
  }

  // ── Persistence contract: write raw stdout bytes to temp file ───

  fsMod.writeFileSync(tmpFile, rawStdout, { mode: 0o644 });

  // ── Persistence contract: publish using atomic hard-link (no-overwrite) ─

  try {
    fsMod.linkSync(tmpFile, args.output);
    try { fsMod.unlinkSync(tmpFile); } catch(e2) {}
    console.log("Evidence published: " + args.output);
  } catch(err) {
    if (err && err.code === "EEXIST") {
      try { fsMod.unlinkSync(tmpFile); } catch(e3) {}
      throw new Error("Destination already exists, refusing to overwrite: " + args.output);
    }
    throw err;
  }
}

main().catch(function(err) {
  if (tmpFile && fsMod.existsSync(tmpFile)) {
    try { fsMod.unlinkSync(tmpFile); } catch(e2) {}
  }
  console.error("Evidence persistence failed:", err.message);
  process.exit(1);
});