import { exec } from 'child_process';
import regedit from 'regedit';

export async function setProxy(host, port) {
  if (process.platform === 'darwin') {
    const networks = await getMacAvailableNetworks();

    if (networks.length === 0) {
      throw 'no network';
    }

    return Promise.all(
      networks.map(network => {
        return new Promise((resolve, reject) => {
          exec(`networksetup -setsecurewebproxy "${network}" ${host} ${port}`, error => {
            if (error) {
              reject(null);
            } else {
              resolve(network);
            }
          });
        });
      }),
    );
  } else {
    const valuesToPut = {
      'HKCU\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings': {
        ProxyServer: {
          value: `${host}:${port}`,
          type: 'REG_SZ',
        },
        ProxyEnable: {
          value: 1,
          type: 'REG_DWORD',
        },
      },
    };
    return editWinRegPromise(valuesToPut);
  }
}

export async function closeProxy() {
  if (process.platform === 'darwin') {
    const networks = await getMacAvailableNetworks();

    if (networks.length === 0) {
      throw 'no network';
    }

    return Promise.all(
      networks.map(network => {
        return new Promise((resolve, reject) => {
          exec(`networksetup -setsecurewebproxystate "${network}" off`, error => {
            if (error) {
              reject(null);
            } else {
              resolve(network);
            }
          });
        });
      }),
    );
  } else {
    const valuesToPut = {
      'HKCU\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Internet Settings': {
        ProxyEnable: {
          value: 0,
          type: 'REG_DWORD',
        },
      },
    };
    return editWinRegPromise(valuesToPut);
  }
}

function getMacAvailableNetworks() {
  return new Promise((resolve, reject) => {
    exec('networksetup -listallnetworkservices', (error, stdout) => {
      if (error) {
        reject(error);
      } else {
        Promise.all(
          stdout
            .toString()
            .split('\n')
            .map(network => {
              return new Promise(resolve => {
                exec(
                  `networksetup getinfo "${network}" | grep "^IP address:\\s\\d"`,
                  (error, stdout) => {
                    if (error) {
                      resolve(null);
                    } else {
                      resolve(stdout ? network : null);
                    }
                  },
                );
              });
            }),
        ).then(networks => {
          resolve(networks.filter(Boolean));
        });
      }
    });
  });
}

function editWinRegPromise(valuesToPut) {
  return new Promise((resolve, reject) => {
    regedit.putValue(valuesToPut, function (err) {
      if (err) {
        reject(err);
      } else {
        resolve();
      }
    });
  });
}