#!/usr/bin/env node
import fs from 'node:fs';
import path from 'node:path';

const DEFAULT_RECEIPT_DIR = path.resolve(process.cwd(), 'state/approved-plan-continuity');

function parseArgs(argv) {
  let inputPath = null;
  let compact = false;
  let receiptDir = DEFAULT_RECEIPT_DIR;

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

    if (arg === '--input') {
      inputPath = argv[i + 1] ?? null;
      i += 1;
      continue;
    }

    if (arg.startsWith('--input=')) {
      inputPath = arg.slice('--input='.length);
      continue;
    }

    if (arg === '--receipt-dir') {
      receiptDir = argv[i + 1] ? path.resolve(argv[i + 1]) : receiptDir;
      i += 1;
      continue;
    }

    if (arg.startsWith('--receipt-dir=')) {
      receiptDir = path.resolve(arg.slice('--receipt-dir='.length));
      continue;
    }

    if (arg === '--compact') {
      compact = true;
      continue;
    }
  }

  return { inputPath, compact, receiptDir };
}

function readInput(inputPath) {
  if (!inputPath) {
    return {
      ok: false,
      error: 'missing_required_input',
    };
  }

  try {
    const raw = fs.readFileSync(inputPath, 'utf8');
    const parsed = JSON.parse(raw);
    return {
      ok: true,
      bytes: Buffer.byteLength(raw, 'utf8'),
      parsed,
    };
  } catch (error) {
    return {
      ok: false,
      error: error instanceof Error ? error.message : String(error),
    };
  }
}

function slugifySegment(value) {
  return String(value)
    .trim()
    .toLowerCase()
    .replace(/[^a-z0-9._-]+/g, '-')
    .replace(/^-+|-+$/g, '')
    .replace(/-{2,}/g, '-');
}

function buildReceipt(payload) {
  const nextAction = payload?.nextDerivedAction ?? payload?.derivedAction ?? null;
  const receipt = {
    planId: payload?.planId ?? null,
    currentTask: payload?.currentTask ?? null,
    nextTaskId: payload?.nextTaskId ?? null,
    nextDerivedAction: nextAction,
    dispatchedAt: payload?.dispatchedAt ?? null,
    dispatchRunId: payload?.dispatchRunId ?? null,
    childSessionKey: payload?.childSessionKey ?? null,
    replyClosureState: payload?.replyClosureState ?? null,
  };

  return receipt;
}

function validateReceipt(receipt) {
  const missing = [];

  for (const field of [
    'planId',
    'currentTask',
    'nextTaskId',
    'nextDerivedAction',
    'dispatchedAt',
    'dispatchRunId',
    'childSessionKey',
    'replyClosureState',
  ]) {
    if (receipt[field] == null) {
      missing.push(field);
    }
  }

  const planIdSafe = slugifySegment(receipt.planId ?? '');
  const dispatchRunIdSafe = slugifySegment(receipt.dispatchRunId ?? '');

  if (!planIdSafe) missing.push('planId_filesystem_safe');
  if (!dispatchRunIdSafe) missing.push('dispatchRunId_filesystem_safe');

  return {
    ok: missing.length === 0,
    missing,
    planIdSafe,
    dispatchRunIdSafe,
  };
}

function writeReceipt({ receipt, receiptDir, planIdSafe, dispatchRunIdSafe }) {
  fs.mkdirSync(receiptDir, { recursive: true });
  const receiptPath = path.join(receiptDir, `receipt-${planIdSafe}-${dispatchRunIdSafe}.json`);
  fs.writeFileSync(receiptPath, `${JSON.stringify(receipt, null, 2)}\n`, 'utf8');
  return receiptPath;
}

const { inputPath, compact, receiptDir } = parseArgs(process.argv.slice(2));
const input = readInput(inputPath);

let response;

if (!input.ok) {
  response = {
    ok: false,
    status: 'input_error',
    binding: 'approved_plan_dispatch',
    compact,
    inputPath,
    receipt: null,
    receiptPath: null,
    input: {
      ok: false,
      error: input.error,
    },
  };
} else {
  const receipt = buildReceipt(input.parsed);
  const validation = validateReceipt(receipt);

  if (!validation.ok) {
    response = {
      ok: false,
      status: 'missing_required_receipt_fields',
      binding: 'approved_plan_dispatch',
      compact,
      inputPath,
      receipt,
      receiptPath: null,
      missing: validation.missing,
      input: {
        ok: true,
        bytes: input.bytes,
      },
    };
  } else {
    const receiptPath = writeReceipt({
      receipt,
      receiptDir,
      planIdSafe: validation.planIdSafe,
      dispatchRunIdSafe: validation.dispatchRunIdSafe,
    });

    response = {
      ok: true,
      status: 'receipt_written',
      binding: 'approved_plan_dispatch',
      compact,
      inputPath,
      receipt,
      receiptPath,
      input: {
        ok: true,
        bytes: input.bytes,
      },
    };
  }
}

process.stdout.write(`${JSON.stringify(response)}\n`);