import {
  Plugin,
  EventListener,
  Configurable,
} from '@squeebot/core/lib/plugin';

import { logger } from '@squeebot/core/lib/core';
import { IMessage } from '@squeebot/core/lib/types';
import { fullIDMatcher } from '@squeebot/core/lib/common';

/*
  users: {
    'service/instance/name': [
      'one',
      'two',
      '*'
    ]
  },
  rooms: {
    'service/instance/room': {
      'service/instance/name': [
        'three',
        'four',
      ]
    }
  }
*/

declare type RoleReceiver = (msg: IMessage) => string[];

@Configurable({users: {}, rooms: {}})
class PermissionsPlugin extends Plugin {
  public roleReceivers: Map<string, RoleReceiver> = new Map<string, RoleReceiver>();

  registerRoleReceiver(plugin: string, fn: RoleReceiver): void {
    if (this.roleReceivers.has(plugin)) {
      return;
    }

    this.roleReceivers.set(plugin, fn);
  }

  userPermitted(msg: IMessage, required: string[]): boolean {
    // Boot all guests instantly
    if (msg.guest === true) {
      return false;
    }

    // Receive permissions from a role fetching function registered by
    // a service or service adapter
    const rr = this.roleReceivers.get(msg.source.plugin.manifest.name);
    const userRoles = [];
    if (rr) {
      userRoles.push(...rr(msg));
    }

    const userFull = msg.fullSenderID;
    const roomFull = msg.fullRoomID;
    if (!userFull || !roomFull) {
      return false;
    }

    // Check for room access
    for (const ch in this.config.config.rooms) {
      if (fullIDMatcher(roomFull, ch)) {
        const users = this.config.config.rooms[ch];
        for (const user in users) {
          if (fullIDMatcher(userFull, user)) {
            const perms = [...users[user], ...userRoles];

            let has = false;
            for (const perm of required) {
              if (perms.indexOf(perm) !== -1) {
                has = true;
                break;
              }
            }

            if (has) {
              return true;
            }
          }
        }
      }
    }

    // Check for per-user-basis permissions
    for (const user in this.config.config.users) {
      if (fullIDMatcher(userFull, user)) {
        const perms = this.config.config.users[user];
        if (perms.indexOf('*') !== -1) {
          return true;
        }

        let has = false;
        for (const perm of required) {
          if (perms.indexOf(perm) !== -1) {
            has = true;
            break;
          }
        }

        if (has) {
          return true;
        }
      }
    }

    return false;
  }

  @EventListener('pluginUnload')
  unloadEventHandler(plugin: string | Plugin): void {
    if (plugin === this.name || plugin === this) {
      logger.debug('[%s]', this.name, 'shutting down..');
      this.emit('pluginUnloaded', this);
    }
  }

  @EventListener('pluginUnloaded')
  unloadedEventHandler(plugin: string | Plugin): void {
    const str = (typeof plugin === 'string' ? plugin : plugin.manifest.name);
    if (this.roleReceivers.has(str)) {
      this.roleReceivers.delete(str);
    }
  }
}

module.exports = PermissionsPlugin;