import { openSync, closeSync, fstatSync, readFileSync, lstatSync, realpathSync, constants } from 'node:fs';
import { isAbsolute, relative, resolve } from 'node:path';
import { BusError } from './broker.mjs';
const deny = (code) => {
  throw new BusError(code);
};
const inside = (root, path) => {
  const r = relative(root, path);
  return r === '' || (!r.startsWith('..') && !isAbsolute(r));
};
const day = (value) =>
  typeof value === 'string' &&
  /^\d{4}-\d{2}-\d{2}$/.test(value) &&
  !Number.isNaN(Date.parse(value)) &&
  new Date(value).toISOString().slice(0, 10) === value;
export class Credentials {
  #tokens = new Map();
  constructor({ references = {}, repoRoots = [], dataRoot, env = process.env }) {
    try {
      for (const [instance, services] of Object.entries(references))
        for (const [service, ref] of Object.entries(services)) {
          if (!['gitea', 'vikunja'].includes(service) || !ref || typeof ref !== 'object')
            deny('credential-reference');
          const date = service === 'vikunja' ? ref.expires : ref.rotateBy;
          if (!day(date)) deny('credential-date');
          if (
            (ref.service !== undefined && ref.service !== service) ||
            Object.keys(ref).some(
              (k) => !['service', 'file', 'env', service === 'vikunja' ? 'expires' : 'rotateBy'].includes(k),
            ) ||
            Boolean(ref.file) === Boolean(ref.env)
          )
            deny('credential-reference');
          let token;
          if (ref.file) {
            if (!isAbsolute(ref.file)) deny('credential-location');
            let resolved, original;
            try {
              original = lstatSync(ref.file);
              resolved = realpathSync(ref.file);
            } catch {
              deny('credential-file');
            }
            if (original.isSymbolicLink() || !original.isFile()) deny('credential-file');
            if (
              [...repoRoots, dataRoot].filter(Boolean).some((root) =>
                inside(
                  (() => {
                    try {
                      return realpathSync(root);
                    } catch {
                      return resolve(root);
                    }
                  })(),
                  resolved,
                ),
              )
            )
              deny('credential-location');
            let fd;
            try {
              fd = openSync(ref.file, constants.O_RDONLY | constants.O_NOFOLLOW);
              const s = fstatSync(fd);
              if (
                !s.isFile() ||
                s.uid !== process.getuid() ||
                (s.mode & 0o777) !== 0o600 ||
                s.size > 16384 ||
                s.ino !== original.ino ||
                s.dev !== original.dev
              )
                deny('credential-file');
              token = readFileSync(fd, 'utf8');
            } catch (e) {
              if (e instanceof BusError) throw e;
              deny('credential-file');
            } finally {
              if (fd !== undefined) closeSync(fd);
            }
          } else {
            if (!/^[A-Z_][A-Z0-9_]*$/.test(ref.env)) deny('credential-reference');
            token = env[ref.env];
          }
          if (typeof token !== 'string' || token.length > 16384 || !/^[-A-Za-z0-9._~]+\n?$/.test(token))
            deny('credential-format');
          token = token.replace(/\n$/, '');
          if (token.length < 16) deny('credential-format');
          this.#tokens.set(instance + ':' + service, { token, date });
        }
    } catch (e) {
      this.close();
      throw e;
    }
  }
  assertClean(value) {
    let encoded;
    try {
      encoded = JSON.stringify(value);
    } catch {
      deny('invalid-request');
    }
    for (const { token } of this.#tokens.values()) if (encoded?.includes(token)) deny('credential-leak');
  }
  async use(instance, service, operation) {
    const entry = this.#tokens.get(instance + ':' + service);
    if (!entry) deny('credential-unavailable');
    if (service === 'vikunja' && Date.now() >= Date.parse(entry.date + 'T00:00:00Z'))
      deny('credential-expired');
    let result;
    try {
      result = await operation(entry.token);
    } catch {
      deny('service-failed');
    }
    this.assertClean(result);
    return result;
  }
  status() {
    return [...this.#tokens.entries()].map(([key, { date }]) => {
      const i = key.lastIndexOf(':'),
        service = key.slice(i + 1),
        left = Date.parse(date + 'T00:00:00Z') - Date.now();
      return {
        instance: key.slice(0, i),
        service,
        date,
        state:
          service === 'gitea'
            ? left <= 0
              ? 'rotation-due'
              : 'valid'
            : left <= 0
              ? 'expired'
              : left < 7 * 86400000
                ? 'expiring'
                : 'valid',
      };
    });
  }
  close() {
    this.#tokens.clear();
  }
}