import type { IncomingMessage, ServerResponse } from 'node:http';

import { HarborError } from '../../../shared/errors.js';
import { sendJson } from '../response.js';

interface DeviceInventoryPort {
  snapshot(): unknown;
  refresh(): Promise<unknown>;
  update(deviceId: string, patch: Record<string, unknown>, expectedRevision: unknown): unknown;
  createTag(name: unknown, expectedRevision: unknown): unknown;
  renameTag(tagId: string, name: unknown, expectedRevision: unknown): unknown;
  deleteTag(tagId: string, expectedRevision: unknown): unknown;
  resetTraffic(expectedRevision: unknown): Promise<unknown>;
  setPolicy(deviceId: string, mode: unknown, expectedRevision: unknown): Promise<unknown>;
}

interface DeviceInventoryRouteDependencies {
  deviceInventory: DeviceInventoryPort | null;
  readBody(req: IncomingMessage): Promise<Record<string, unknown>>;
}

const DEVICE_PATH = /^\/api\/devices\/(dev_[a-f0-9]{16})$/;
const DEVICE_POLICY_PATH = /^\/api\/devices\/(dev_[a-f0-9]{16})\/policy$/;
const DEVICE_TAG_PATH = /^\/api\/device-tags\/(tag_[a-f0-9]{16})$/;

export function createDeviceInventoryRoute(dependencies: DeviceInventoryRouteDependencies) {
  return {
    async handle(req: IncomingMessage, res: ServerResponse) {
      const pathname = new URL(req.url || '/', 'http://localhost').pathname;

      if (pathname === '/api/devices') {
        if (!dependencies.deviceInventory || req.method !== 'GET') {
          throw new HarborError('ENDPOINT_NOT_FOUND');
        }
        sendJson(res, 200, dependencies.deviceInventory.snapshot());
        return true;
      }

      if (pathname === '/api/devices/refresh') {
        if (!dependencies.deviceInventory || req.method !== 'POST') {
          throw new HarborError('ENDPOINT_NOT_FOUND');
        }
        sendJson(res, 200, await dependencies.deviceInventory.refresh());
        return true;
      }

      if (pathname === '/api/devices/traffic') {
        if (!dependencies.deviceInventory || req.method !== 'DELETE') {
          throw new HarborError('ENDPOINT_NOT_FOUND');
        }
        const body = await dependencies.readBody(req);
        sendJson(res, 200, await dependencies.deviceInventory.resetTraffic(body.expectedRevision));
        return true;
      }

      if (pathname === '/api/device-tags') {
        if (!dependencies.deviceInventory || req.method !== 'POST') {
          throw new HarborError('ENDPOINT_NOT_FOUND');
        }
        const body = await dependencies.readBody(req);
        sendJson(
          res,
          200,
          dependencies.deviceInventory.createTag(body.name, body.expectedRevision),
        );
        return true;
      }

      const tagMatch = pathname.match(DEVICE_TAG_PATH);
      if (tagMatch) {
        if (!dependencies.deviceInventory || !['PUT', 'DELETE'].includes(req.method || '')) {
          throw new HarborError('ENDPOINT_NOT_FOUND');
        }
        const body = await dependencies.readBody(req);
        sendJson(
          res,
          200,
          req.method === 'PUT'
            ? dependencies.deviceInventory.renameTag(tagMatch[1], body.name, body.expectedRevision)
            : dependencies.deviceInventory.deleteTag(tagMatch[1], body.expectedRevision),
        );
        return true;
      }

      const deviceMatch = pathname.match(DEVICE_PATH);
      if (deviceMatch) {
        if (!dependencies.deviceInventory || req.method !== 'PUT') {
          throw new HarborError('ENDPOINT_NOT_FOUND');
        }
        const { expectedRevision, ...patch } = await dependencies.readBody(req);
        sendJson(
          res,
          200,
          dependencies.deviceInventory.update(deviceMatch[1], patch, expectedRevision),
        );
        return true;
      }

      const policyMatch = pathname.match(DEVICE_POLICY_PATH);
      if (policyMatch) {
        if (!dependencies.deviceInventory || req.method !== 'PUT') {
          throw new HarborError('ENDPOINT_NOT_FOUND');
        }
        const body = await dependencies.readBody(req);
        sendJson(
          res,
          200,
          await dependencies.deviceInventory.setPolicy(
            policyMatch[1],
            body.mode,
            body.expectedRevision,
          ),
        );
        return true;
      }

      return false;
    },
  };
}