import type { OperationPageQuery } from '@multi-simadmin/contracts';
import type { FastifyInstance, FastifyRequest } from 'fastify';
import { OperationCatalogService } from '../../application/operations/operation-catalog-service.js';
import type { OperationCatalogRegistry } from '../../application/operations/operation-catalog-service.js';

const capabilities = new Set(['query', 'command', 'job']);
const keys = new Set([
  'page',
  'pageSize',
  'sort',
  'direction',
  'risk',
  'capability',
  'batchable',
  'search',
]);
class CatalogValidationError extends Error {}

function scalarQuery(request: FastifyRequest): Record<string, string> {
  const raw = request.query;
  if (raw === null || typeof raw !== 'object' || Array.isArray(raw))
    throw new CatalogValidationError();
  const result: Record<string, string> = {};
  for (const [key, value] of Object.entries(raw)) {
    if (!keys.has(key) || typeof value !== 'string') throw new CatalogValidationError();
    result[key] = value;
  }
  return result;
}

function parseQuery(request: FastifyRequest): OperationPageQuery {
  const query = scalarQuery(request);
  const result: {
    page?: number;
    pageSize?: number;
    sort?: 'operationId' | 'risk' | 'capability';
    direction?: 'asc' | 'desc';
    risk?: 'R0' | 'R1' | 'R2' | 'R3';
    capability?: string;
    batchable?: boolean;
    search?: string;
  } = {};
  const integer = (key: 'page' | 'pageSize', maximum?: number): void => {
    const value = query[key];
    if (value === undefined) return;
    if (!/^[1-9]\d*$/.test(value)) throw new CatalogValidationError();
    const parsed = Number(value);
    if (!Number.isSafeInteger(parsed) || (maximum !== undefined && parsed > maximum))
      throw new CatalogValidationError();
    result[key] = parsed;
  };
  integer('page');
  integer('pageSize', 100);
  const sort = query.sort;
  if (sort !== undefined) {
    if (sort !== 'operationId' && sort !== 'risk' && sort !== 'capability')
      throw new CatalogValidationError();
    result.sort = sort;
  }
  const direction = query.direction;
  if (direction !== undefined) {
    if (direction !== 'asc' && direction !== 'desc') throw new CatalogValidationError();
    result.direction = direction;
  }
  const risk = query.risk;
  if (risk !== undefined) {
    if (risk !== 'R0' && risk !== 'R1' && risk !== 'R2' && risk !== 'R3')
      throw new CatalogValidationError();
    result.risk = risk;
  }
  const capability = query.capability;
  if (capability !== undefined) {
    if (!capabilities.has(capability)) throw new CatalogValidationError();
    result.capability = capability;
  }
  const batchable = query.batchable;
  if (batchable !== undefined) {
    if (batchable !== 'true' && batchable !== 'false') throw new CatalogValidationError();
    result.batchable = batchable === 'true';
  }
  const search = query.search;
  if (search !== undefined) {
    if (search.length > 200) throw new CatalogValidationError();
    result.search = search;
  }
  return result;
}

export function registerOperationRoutes(
  app: FastifyInstance,
  registry: OperationCatalogRegistry,
): void {
  const service = new OperationCatalogService(registry);
  app.get('/api/v1/operations', async (request, reply) => {
    try {
      return service.list(parseQuery(request));
    } catch (error) {
      if (!(error instanceof CatalogValidationError)) throw error;
      return reply.code(400).type('application/problem+json').send({
        type: 'about:blank',
        title: 'Bad Request',
        status: 400,
        code: 'VALIDATION_FAILED',
        detail: 'The request did not satisfy the endpoint schema.',
        requestId: request.id,
      });
    }
  });
}