/// Copyright (c) 2020 Razeware LLC
/// 
/// Permission is hereby granted, free of charge, to any person obtaining a copy
/// of this software and associated documentation files (the "Software"), to deal
/// in the Software without restriction, including without limitation the rights
/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
/// copies of the Software, and to permit persons to whom the Software is
/// furnished to do so, subject to the following conditions:
/// 
/// The above copyright notice and this permission notice shall be included in
/// all copies or substantial portions of the Software.
/// 
/// Notwithstanding the foregoing, you may not use, copy, modify, merge, publish,
/// distribute, sublicense, create a derivative work, and/or sell copies of the
/// Software in any work that is designed, intended, or marketed for pedagogical or
/// instructional purposes related to programming, coding, application development,
/// or information technology.  Permission for such use, copying, modification,
/// merger, publication, distribution, sublicensing, creation of derivative works,
/// or sale is expressly withheld.
/// 
/// This project and source code may use libraries or frameworks that are
/// released under various Open-Source licenses. Use of those libraries and
/// frameworks are governed by their own individual licenses.
///
/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
/// THE SOFTWARE.

import UIKit
import RxSwift

class MainTableViewController: UITableViewController {
  private let searchController = UISearchController(searchResultsController: nil)
  private let bag = DisposeBag()
  private var gifs = [GiphyGif]()
  private let search = BehaviorSubject(value: "")
  
  override func viewDidLoad() {
    super.viewDidLoad()
    
    title = "iGif"
    
    searchController.searchResultsUpdater = self
    searchController.dimsBackgroundDuringPresentation = false
    definesPresentationContext = true
    tableView.tableHeaderView = searchController.searchBar
    
    search.filter { $0.count >= 3 }
      .throttle(.milliseconds(300), scheduler: MainScheduler.instance)
      .distinctUntilChanged()
      .flatMapLatest { query -> Observable<[GiphyGif]> in
        return ApiController.shared.search(text: query)
          .catchErrorJustReturn([])
      }
      .observeOn(MainScheduler.instance)
      .subscribe(onNext: { result in
        self.gifs = result
        self.tableView.reloadData()
      })
      .disposed(by: bag)
  }
  
  // MARK: - Table view data source
  
  override func numberOfSections(in tableView: UITableView) -> Int {
    return 1
  }
  
  override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return gifs.count
  }

  override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "GifCell", for: indexPath) as! GifTableViewCell

    let gif = gifs[indexPath.item]
    cell.downloadAndDisplay(gif: gif.image.url)

    return cell
  }
}

extension MainTableViewController: UISearchResultsUpdating {
  
  public func updateSearchResults(for searchController: UISearchController) {
    search.onNext(searchController.searchBar.text ?? "")
  }
  
}
