import fs from 'node:fs';

const MAX_SAFE_DEV_MEMORY = 4 * 1024 * 1024 * 1024;
const MAX_SAFE_DEV_CPUS = 4;
const MAX_SAFE_DEV_PIDS = 256;

const positive = (value) => typeof value === 'number' ? value > 0 : Number(value) > 0;

export const validateComposeModel = (model, mode) => {
  const errors = [];
  const runtime = model?.services?.runtime;
  if (!runtime) return ['runtime service is missing'];

  if (!positive(runtime.mem_limit)) errors.push('runtime memory limit must be positive');
  if (!positive(runtime.memswap_limit)) errors.push('runtime memory+swap limit must be positive');
  if (Number(runtime.memswap_limit) !== Number(runtime.mem_limit)) {
    errors.push('runtime memory+swap limit must equal its memory limit');
  }
  if (!positive(runtime.cpus)) errors.push('runtime CPU limit must be positive');
  if (!positive(runtime.pids_limit)) errors.push('runtime PID limit must be positive');

  if (mode === 'development') {
    if (runtime.environment?.RUNTIME_MODE !== 'development') {
      errors.push('development runtime mode must be literal development');
    }
    if (runtime.environment?.CORE_SOURCE_MODE !== 'bind') {
      errors.push('development Core source mode must be bind');
    }
  } else if (runtime.environment?.CORE_SOURCE_MODE !== 'clone') {
    errors.push(`${mode} Core source mode must be clone`);
  } else if (runtime.environment?.RUNTIME_MODE === 'development') {
    errors.push(`${mode} runtime must not use development mode`);
  }

  if (mode === 'development' || mode === 'smoke') {
    for (const name of ['postgres', 'redis', 'runtime', 'caddy']) {
      if (model?.services?.[name]?.restart !== 'no') errors.push(`${name} ${mode} restart policy must be no`);
    }
    if (Number(runtime.mem_limit) > MAX_SAFE_DEV_MEMORY) errors.push(`${mode} runtime memory limit exceeds 4 GiB`);
    if (Number(runtime.cpus) > MAX_SAFE_DEV_CPUS) errors.push(`${mode} runtime CPU limit exceeds 4`);
    if (Number(runtime.pids_limit) > MAX_SAFE_DEV_PIDS) errors.push(`${mode} runtime PID limit exceeds 256`);
  }

  return errors;
};

if (process.argv[1] && process.argv[1].endsWith('validate-compose-model.mjs')) {
  const mode = process.argv[2];
  const model = JSON.parse(fs.readFileSync(0, 'utf8'));
  const errors = validateComposeModel(model, mode);
  if (errors.length) {
    console.error(`Compose ${mode} safety validation failed:`);
    for (const error of errors) console.error(`- ${error}`);
    process.exitCode = 65;
  } else {
    console.log(`Compose ${mode} safety validation passed.`);
  }
}