/**
 * @fileoverview Tenant and API key persistence.
 * @module store/tenants
 */

import { getStore, persist } from './db.js';
import { generateApiKey } from '../lib/tokens.js';
import { PLAN_LIMITS } from '../config.js';
import { createDebugger } from '../debug/logger.js';

const log = createDebugger('billing');

/**
 * @typedef {Object} Tenant
 * @property {string} id
 * @property {string} name
 * @property {string} plan
 * @property {string} veraeUsername
 * @property {string} veraePassword
 * @property {object|null} contract
 * @property {object} [metadata]
 * @property {string} createdAt
 */

/**
 * @param {string} tenantId
 * @returns {Tenant|null}
 */
export function getTenant(tenantId) {
  return getStore().tenants[tenantId] ?? null;
}

/**
 * @param {string} apiKey
 * @returns {Tenant|null}
 */
export function getTenantByApiKey(apiKey) {
  const store = getStore();
  const tenantId = store.apiKeys[apiKey];
  return tenantId ? store.tenants[tenantId] ?? null : null;
}

/**
 * @returns {Tenant[]}
 */
export function listTenants() {
  return Object.values(getStore().tenants);
}

/**
 * @param {Tenant} tenant
 * @returns {Tenant}
 */
export function upsertTenant(tenant) {
  const store = getStore();
  store.tenants[tenant.id] = tenant;
  persist();
  log.debug('tenant upserted', { tenantId: tenant.id, plan: tenant.plan });
  return tenant;
}

/**
 * Create a tenant and bind a new API key.
 *
 * @param {object} params
 * @param {string} params.id
 * @param {string} params.name
 * @param {string} [params.plan='free']
 * @param {string} params.veraeUsername
 * @param {string} params.veraePassword
 * @param {object|null} [params.contract=null]
 * @param {string} [params.apiKey]
 * @param {object} [params.metadata]
 * @returns {{ tenant: Tenant, apiKey: string }}
 */
export function createTenant({
  id,
  name,
  plan = 'free',
  veraeUsername,
  veraePassword,
  contract = null,
  apiKey = generateApiKey(),
  metadata = {},
}) {
  const store = getStore();
  /** @type {Tenant} */
  const tenant = {
    id,
    name,
    plan,
    veraeUsername,
    veraePassword,
    contract,
    metadata,
    createdAt: new Date().toISOString(),
  };

  store.tenants[id] = tenant;
  store.apiKeys[apiKey] = id;
  persist();

  log.info('tenant created', { tenantId: id, plan, audience: metadata.audience });
  return { tenant, apiKey };
}

/**
 * Resolve effective limits for a tenant (plan defaults or enterprise contract).
 *
 * @param {Tenant} tenant
 * @returns {{
 *   timestamps: number|null,
 *   verifications: number|null,
 *   batch: boolean,
 *   batchMaxItems: number|null,
 *   requestsPerMinute: number,
 *   allowOverage: boolean,
 *   overageRates: object
 * }}
 */
export function resolveLimits(tenant) {
  if (tenant.plan === 'enterprise' && tenant.contract) {
    return {
      timestamps: tenant.contract.includedTimestamps ?? null,
      verifications: tenant.contract.includedVerifications ?? null,
      batch: tenant.contract.batch !== false,
      batchMaxItems: tenant.contract.batchMaxItems ?? null,
      requestsPerMinute:
        tenant.contract.requestsPerMinute ?? PLAN_LIMITS.enterprise.requestsPerMinute,
      allowOverage: tenant.contract.allowOverage ?? false,
      overageRates: tenant.contract.overageRates ?? {},
    };
  }

  const base = PLAN_LIMITS[tenant.plan] ?? PLAN_LIMITS.free;
  return { ...base, allowOverage: false, overageRates: {} };
}