import { httpGET } from '@squeebot/core/lib/common';
import { logger } from '@squeebot/core/lib/core';
import {
  Plugin,
  Configurable,
  EventListener,
  DependencyLoad
} from '@squeebot/core/lib/plugin';
import { IMessage, MessageResolver } from '@squeebot/core/lib/types';

interface IDefinition {
  partOfSpeech: string;
  text: string;
}

interface IWordCache {
  lastIndex: {
    name: string;
    index: number;
    lastTime: number;
  }[];
  definitions: IDefinition[];
  inserted: number;
}

let lastQuery = 0;
const wordCache: Record<string, IWordCache> = {};

/**
 * Find and remove words that haven't been looked up for a day
 */
function flushCache() {
  let oldestWords: string[] = [];
  Object.keys(wordCache).forEach((word) => {
    const cached = wordCache[word];
    let notOld = false;

    for (const person of cached.lastIndex) {
      if (person.lastTime > Date.now() - 24 * 60 * 60 * 1000) {
        notOld = true;
        break;
      }
    }

    if (!notOld) {
      oldestWords.push(word);
    }
  });

  if (!oldestWords.length) {
    return;
  }

  oldestWords.forEach((item) => {
    delete wordCache[item];
  });

  logger.log(`[diction] Dictionary cleared of the previous words ${oldestWords.join(', ')}.`);
}

@Configurable({
  wordnik: '',
  cooldown: 5,
  limit: 5,
})
class DictionPlugin extends Plugin {
  @EventListener('pluginUnload')
  public unloadEventHandler(plugin: string | Plugin): void {
    if (plugin === this.name || plugin === this) {
      this.emit('pluginUnloaded', this);
    }
  }

  @DependencyLoad('simplecommands')
  addCommands(cmd: any): void {
    const key = this.config.get('wordnik');
    const rate = this.config.get('cooldown', 5);
    const limit = this.config.get('limit', 5);

    if (!key) {
      logger.warn('Wordnik define command is disabled due to no credentials.');
      return;
    }

    cmd.registerCommand({
      name: 'define',
      plugin: this.name,
      execute: async (msg: IMessage, msr: MessageResolver, spec: any, prefix: string, ...simplified: any[]): Promise<boolean> => {
        const word = simplified.join(' ');

        if (!word) {
          msg.resolve('Please specifiy a word or term!');
          return true;
        }

        if (lastQuery > Date.now() - rate * 1000 && !wordCache[word]) {
          msg.resolve('You\'re doing that too fast!');
          return true;
        }

        let chosenDefinition: IDefinition;
        let definitionCount = 0;
        let definitionIndex = 0;

        // Check cached definitions
        const userTarget = msg.fullSenderID as string;
        if (wordCache[word]) {
          const cached = wordCache[word];
          const alreadyAsked = cached.lastIndex.find((item) => item.name === userTarget);
          definitionCount = cached.definitions.length;

          if (alreadyAsked) {
            let nextI = alreadyAsked.index + 1;

            if (nextI >= cached.definitions.length) {
              nextI = 0;
            }

            if (alreadyAsked.lastTime < Date.now() - 5 * 60 * 1000) {
              nextI = 0;
            }

            alreadyAsked.lastTime = Date.now();
            alreadyAsked.index = nextI;
            definitionIndex = nextI;
            chosenDefinition = cached.definitions[nextI];
          } else {
            chosenDefinition = cached.definitions[0];
            cached.lastIndex.push({
              name: userTarget,
              index: 0,
              lastTime: Date.now(),
            });
          }
        } else {
          // Request definition
          const encodedWord = encodeURIComponent(word);
          lastQuery = Date.now();

          let response;
          try {
            const s = `https://api.wordnik.com/v4/word.json/${encodedWord}/definitions?limit=${limit}&api_key=${key}`;
            response = await httpGET(s);
            response = JSON.parse(response);
          } catch (e) {
            msg.resolve('Server did not respond.');
            return true;
          }

          if (!response || !response.length) {
            msg.resolve('No definitions found.');
            return true;
          }

          const cached: IWordCache = {
            lastIndex: [
              {
                name: userTarget,
                index: 0,
                lastTime: Date.now(),
              }
            ],
            definitions: (response as Record<string, string>[])
              .filter(entry => entry.text)
              .map(({ partOfSpeech, text }) => ({
                partOfSpeech, text: text.replace(/(<([^>]+)>)/ig, '')
              })),
            inserted: Date.now(),
          }

          wordCache[word] = cached;
          chosenDefinition = cached.definitions[0];
          definitionCount = cached.definitions.length;
          logger.log(`[diction] Dictionary cached the word "${word}"`);
          flushCache();
        }

        const { partOfSpeech, text } = chosenDefinition;

        msg.resolve(`(${definitionIndex + 1}/${definitionCount}) ${word}${
          partOfSpeech ? ` - ${partOfSpeech}` : ''
        } - ${text}`);

        return true;
      },
      match: /define (\w*)/,
      aliases: ['df', 'word'],
      description: 'Find definitions for words. Call again to advance to next definition',
      usage: '<word>'
    });
  }
}

module.exports = DictionPlugin;