const {query} = require("../client")

let eventNames = []

class LogHeader {
  /**
   * Construct a log header. You should probably use the logHeaderApi instead of doing
   * this manually, even for mutations.
   * 
   * @param {string} id 
   * @param {Date|string} date 
   * @param {string} channelName 
   * @param {string} title 
   * @param {string} description 
   * @param {string} event 
   * @param {boolean} open 
   * @param {{id:string,name:string,shortName:string,author:string}[]} characters 
   */
  constructor(id, shortId, date, channelName, title, description, eventName, open, characters) {
    this.id = id
    this.shortId = shortId
    this.date = new Date(date)
    this.channelName = channelName
    this.title = title || null
    this.description = description || null
    this.eventName = eventName || null
    this.open = open
    this.characters = characters.map(ch => new LogHeaderCharacter(ch.id, ch.name, ch.shortName, ch.author))
  }
}

class LogHeaderCharacter {
  /**
   * Construct a log header character list entry.
   * 
   * @param {string} id 
   * @param {string} name 
   * @param {string} shortName 
   * @param {string} author 
   */
  constructor(id, name, shortName, author) {
    this.id = id
    this.name = name
    this.shortName = shortName
    this.author = author
  }
}

/**
 * logHeaderApi contains the API queries for the LogHeader frontend model, which is a subset of the
 * logs model.
 */
const logHeaderApi = {
  /**
   * Call `logs` query, returns event name
   * 
   * @returns {Promise<string[]>}
   */
  eventNames() {
    return query(`
      query LogHeadersEventNames() {
        headers: logs(filter:{limit:0}) {
          eventName
        }
      }
    `, {}).then(({headers}) => {
      const eventNames = []
      const seen = {}

      for (const header of headers) {
        if (!header.eventName) {
          continue
        }

        if (!seen[header.eventName]) {
          eventNames.push(header.eventName)
          seen[header.eventName] = true
        }
      }

      return eventNames
    })
  },

  /**
   * Call `logs(filter)` query
   * 
   * @param {{search:string, channels:string|string[], events:string|string[], open:boolean, characters:string|string[], limit:number}} filter 
   * @returns {Promise<LogHeader[]>}
   */
  list(filter = {}) {
    filter = Object.assign({}, filter)
    if (filter.limit != null && filter.limit <= 0) {
      delete filter.limit
    }

    return query(`
      query LogHeaders($filter: LogsFilter) {
        headers: logs(filter:$filter) {
          id
          shortId
          date
          channelName
          title
          description
          eventName
          open
          characters {
            id
            name
            shortName
            author
          }
        }
      }
    `, {filter}).then(({headers}) => {
      return headers.map(h => new LogHeader(h.id, h.shortId, h.date, h.channelName, h.title, h.description, h.eventName, h.open, h.characters))
    })
  },
}

module.exports = {LogHeader, LogHeaderCharacter, logHeaderApi, eventNames}