//
//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
//

import Foundation

@objc
class ConversationSearchViewController: UITableViewController {

    var searchResults: ConversationSearchResults = ConversationSearchResults.empty

    var uiDatabaseConnection: YapDatabaseConnection {
        // TODO do we want to respond to YapDBModified? Might be hard when there's lots of search results, for only marginal value
        return OWSPrimaryStorage.shared().uiDatabaseConnection
    }

    var searcher: ConversationSearcher {
        return ConversationSearcher.shared
    }

    enum SearchSection: Int {
        case conversations = 0
        case contacts = 1
        case messages = 2
    }

    // MARK: View Lifecyle

    override func viewDidLoad() {
        super.viewDidLoad()

        self.view.isHidden = true

        self.tableView.register(ChatSearchResultCell.self, forCellReuseIdentifier: ChatSearchResultCell.reuseIdentifier)
    }

    // MARK: UITableViewDelegate

    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        guard let searchSection = SearchSection(rawValue: section) else {
            owsFail("unknown section: \(section)")
            return 0
        }

        switch searchSection {
        case .conversations:
            return searchResults.conversations.count
        case .contacts:
            return searchResults.contacts.count
        case .messages:
            return searchResults.messages.count
        }
    }

    class ChatSearchResultCell: UITableViewCell {
        static let reuseIdentifier = "ChatSearchResultCell"

        func configure(searchResult: ConversationSearchItem) {
            self.textLabel!.text = searchResult.thread.name
        }
    }

    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

        guard let searchSection = SearchSection(rawValue: indexPath.section) else {
            return UITableViewCell()
        }

        switch searchSection {
        case .conversations:
            guard let cell = tableView.dequeueReusableCell(withIdentifier: ChatSearchResultCell.reuseIdentifier) as? ChatSearchResultCell else {
                return UITableViewCell()
            }

            guard let searchResult = self.searchResults.conversations[safe: indexPath.row] else {
                return UITableViewCell()
            }
            cell.configure(searchResult: searchResult)
            return cell
        case .contacts:
            // TODO
                return UITableViewCell()
        case .messages:
            // TODO
                return UITableViewCell()
        }
    }

    override func numberOfSections(in tableView: UITableView) -> Int {
        return 3
    }

    override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        guard let searchSection = SearchSection(rawValue: section) else {
            owsFail("unknown section: \(section)")
            return nil
        }

        switch searchSection {
        case .conversations:
            if searchResults.conversations.count > 0 {
                return NSLocalizedString("SEARCH_SECTION_CONVERSATIONS", comment: "section header for search results that match existing conversations (either group or contact conversations)")
            } else {
                return nil
            }
        case .contacts:
            if searchResults.contacts.count > 0 {
                return NSLocalizedString("SEARCH_SECTION_CONTACTS", comment: "section header for search results that match a contact who doesn't have an existing conversation")
            } else {
                return nil
            }
        case .messages:
            if searchResults.messages.count > 0 {
                return NSLocalizedString("SEARCH_SECTION_MESSAGES", comment: "section header for search results that match a message in a conversation")
            } else {
                return nil
            }
        }
    }

    /*
    @available(iOS 2.0, *)
    optional public func tableView(_ tableView: UITableView, titleForFooterInSection section: Int) -> String?
    
    
    // Editing
    
    // Individual rows can opt out of having the -editing property set for them. If not implemented, all rows are assumed to be editable.
    @available(iOS 2.0, *)
    optional public func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool
    
    
    // Moving/reordering
    
    // Allows the reorder accessory view to optionally be shown for a particular row. By default, the reorder control will be shown only if the datasource implements -tableView:moveRowAtIndexPath:toIndexPath:
    @available(iOS 2.0, *)
    optional public func tableView(_ tableView: UITableView, canMoveRowAt indexPath: IndexPath) -> Bool
    
    
    // Index
    
    @available(iOS 2.0, *)
    optional public func sectionIndexTitles(for tableView: UITableView) -> [String]? // return list of section titles to display in section index view (e.g. "ABCD...Z#")
    
    @available(iOS 2.0, *)
    optional public func tableView(_ tableView: UITableView, sectionForSectionIndexTitle title: String, at index: Int) -> Int // tell table which section corresponds to section title/index (e.g. "B",1))
    
    
    // Data manipulation - insert and delete support
    
    // After a row has the minus or plus button invoked (based on the UITableViewCellEditingStyle for the cell), the dataSource must commit the change
    // Not called for edit actions using UITableViewRowAction - the action's handler will be invoked instead
    @available(iOS 2.0, *)
    optional public func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath)
    
    
    // Data manipulation - reorder / moving support
    
    @available(iOS 2.0, *)
    optional public func tableView(_ tableView: UITableView, moveRowAt sourceIndexPath: IndexPath, to destinationIndexPath: IndexPath)
 
     */

}

extension ConversationSearchViewController: UISearchBarDelegate {
//    @available(iOS 2.0, *)
//    optional public func searchBarShouldBeginEditing(_ searchBar: UISearchBar) -> Bool // return NO to not become first responder
//
//    @available(iOS 2.0, *)
//    optional public func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) // called when text starts editing
//
//    @available(iOS 2.0, *)
//    optional public func searchBarShouldEndEditing(_ searchBar: UISearchBar) -> Bool // return NO to not resign first responder
//
//    @available(iOS 2.0, *)
//    optional public func searchBarTextDidEndEditing(_ searchBar: UISearchBar) // called when text ends editing
//

    public func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
        guard searchText.stripped.count > 0 else {
            self.searchResults = ConversationSearchResults.empty
            self.view.isHidden = true
            return
        }

        self.view.isHidden = false

        self.uiDatabaseConnection.read { transaction in
            self.searchResults = self.searcher.results(searchText: searchText, transaction: transaction)
        }
        // TODO: more perfomant way to do...
        self.tableView.reloadData()
    }

//
//    @available(iOS 3.0, *)
//    optional public func searchBar(_ searchBar: UISearchBar, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool // called before text changes
//
//
//    @available(iOS 2.0, *)
//    optional public func searchBarSearchButtonClicked(_ searchBar: UISearchBar) // called when keyboard search button pressed
//
//    @available(iOS 2.0, *)
//    optional public func searchBarBookmarkButtonClicked(_ searchBar: UISearchBar) // called when bookmark button pressed
//
//    @available(iOS 2.0, *)
//    optional public func searchBarCancelButtonClicked(_ searchBar: UISearchBar) // called when cancel button pressed
//
//    @available(iOS 3.2, *)
//    optional public func searchBarResultsListButtonClicked(_ searchBar: UISearchBar) // called when search results button pressed
//
//
//    @available(iOS 3.0, *)
//    optional public func searchBar(_ searchBar: UISearchBar, selectedScopeButtonIndexDidChange selectedScope: Int)
}