import path from "node:path";

import {
  getChangedFiles,
  selectSuitesForChangedFiles,
  writeHarnessArtifact,
  repoRoot
} from "./core.mjs";

function parseArgs(argv) {
  const options = {
    changedFiles: [],
    from: null,
    json: false,
    to: null
  };

  for (let index = 0; index < argv.length; index += 1) {
    const current = argv[index];

    if (current === "--") {
      continue;
    }

    if (current === "--json") {
      options.json = true;
      continue;
    }

    if (current === "--changed-file" || current === "--from" || current === "--to") {
      const next = argv[index + 1];

      if (!next) {
        throw new Error(`Expected a value after ${current}.`);
      }

      if (current === "--changed-file") {
        options.changedFiles.push(next);
      } else if (current === "--from") {
        options.from = next;
      } else {
        options.to = next;
      }

      index += 1;
      continue;
    }

    throw new Error(`Unknown argument: ${current}`);
  }

  return options;
}

const options = parseArgs(process.argv.slice(2));
const changedFiles = getChangedFiles(options);
const selection = selectSuitesForChangedFiles(changedFiles);
const reportPath = writeHarnessArtifact("selection", {
  ...selection,
  selectedAt: new Date().toISOString()
});

if (options.json) {
  process.stdout.write(
    `${JSON.stringify({ ...selection, reportPath: path.relative(repoRoot, reportPath) }, null, 2)}\n`
  );
  process.exit(0);
}

process.stdout.write(`Harness selection report written to ${path.relative(repoRoot, reportPath)}\n`);

if (selection.suites.length === 0) {
  process.stdout.write("No harness suites selected for the current diff.\n");
} else {
  process.stdout.write("Selected harness suites:\n");

  for (const suiteName of selection.suites) {
    process.stdout.write(`- ${suiteName}\n`);

    for (const reason of selection.reasons[suiteName] ?? []) {
      process.stdout.write(`  - ${reason.file}: ${reason.reason}\n`);
    }
  }
}

if (selection.unmatchedFiles.length > 0) {
  process.stdout.write("Unmatched files:\n");

  for (const filePath of selection.unmatchedFiles) {
    process.stdout.write(`- ${filePath}\n`);
  }
}