import {GroupModel} from "../Database/Models/GroupModel";
import {ConfigurationHandler, PathConfigurationFrom} from "./ConfigurationHandler";
import {GroupConfigurationProvider} from "./Groups/GroupConfigurationProvider";
import {Container} from "../Container/Container";
import {GroupConfigurationRepository} from "../Database/Repositories/GroupConfigurationRepository";
import {ServerConfigurationProvider} from "./Server/ServerConfigurationProvider";
import {Snowflake, time} from "discord.js";
import {ServerConfigurationRepository} from "../Database/Repositories/ServerConfigurationRepository";
import tzdata from 'tzdata';
import {Nullable} from "../types/Nullable";

export type Timezone = {
  zone: string, 
  gmt: string, 
  name: string, 
}

export enum TimezoneSaveTarget {
  Server,
  Group
}

export class TimezoneHandler {
  public static ALL_TIMEZONES: string[] = Object.keys(tzdata.zones)
  
  constructor(
    private readonly serverid: Snowflake,
    private readonly group: GroupModel|null = null
  ) {
  }
  
  public use<TReturn>(callback: () => TReturn): TReturn {
    const previousTZ = process.env.TZ;
    
    process.env.TZ = this.getCurrentTimezone();
    const result = callback();
    process.env.TZ = previousTZ;
    
    return result;
  }

  public getCurrentTimezone(): string {
    const configs = [
      this.getGroupConfiguration(),
      this.getServerConfiguration()
    ];

    for (const config of configs) {
      if (!config) {
        continue;
      }
      
      const timezone = config.getConfigurationByPath('timezone');
      if (timezone.from === PathConfigurationFrom.Default) {
        continue;
      }
      
      return <string>timezone.value;
    }
    
    return process.env.TZ ?? "Europe/London";
  }
  
  public save(timezone: string, target: TimezoneSaveTarget) {
    const config = target === TimezoneSaveTarget.Server ? this.getServerConfiguration() : this.getGroupConfiguration();
    if (!config) {
      return;
    }
    
    config.save('timezone', timezone);
  }
  
  private getGroupConfiguration(): Nullable<ConfigurationHandler> {
    if (!this.group) {
      return null;
    }
    
    return new ConfigurationHandler(
      new GroupConfigurationProvider(
        Container.get<GroupConfigurationRepository>(GroupConfigurationRepository.name),
        this.group
      )
    );
  }
  private getServerConfiguration(): ConfigurationHandler {
    return new ConfigurationHandler(
      new ServerConfigurationProvider(
        Container.get<ServerConfigurationRepository>(ServerConfigurationRepository.name),
        this.serverid
      )
    )
  }
}