TableKit/Tablet/Tablet.swift

//
//    Copyright (c) 2015 Max Sokolov https://twitter.com/max_sokolov
//
//    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.
//
//    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 Foundation

internal let kActionPerformedNotificationKey = "_action"

/**
    Built in actions that Tablet provides.
*/
public enum ActionType : String {

    case click = "_click"
    case select = "_select"
    case deselect = "_deselect"
    case configure = "_configure"
    case willDisplay = "_willDisplay"
    case shouldHighlight = "_shouldHighlight"
    case height = "_height"
}

public struct ActionData<I, C> {

    public let cell: C?
    public let item: I
    public let itemIndex: Int
    public let indexPath: NSIndexPath
    
    init(cell: C?, indexPath: NSIndexPath, item: I, itemIndex: Int) {
        
        self.cell = cell
        self.indexPath = indexPath
        self.item = item
        self.itemIndex = itemIndex
    }
}

/**
    A custom action that you can trigger from your cell.
    You can eacily catch actions using a chaining manner with your row builder.
*/
public class Action {

    /// The cell that triggers an action.
    public let cell: UITableViewCell

    /// The action unique key.
    public let key: String

    /// The custom user info.
    public let userInfo: [NSObject: AnyObject]?

    public init(key: String, sender: UITableViewCell, userInfo: [NSObject: AnyObject]? = nil) {

        self.key = key
        self.cell = sender
        self.userInfo = userInfo
    }

    public func trigger() {

        NSNotificationCenter.defaultCenter().postNotificationName(kActionPerformedNotificationKey, object: self)
    }
}

/**
    If you want to delegate your cell configuration logic to cell itself (with your view model or even model) than
    just provide an implementation of this protocol for your cell. Enjoy strong typisation.
*/
public protocol ConfigurableCell {

    typealias Item

    static func reusableIdentifier() -> String
    func configureWithItem(item: Item)
}

/**
    A protocol that every row builder should follow. 
    A certain section can only works with row builders that respect this protocol.
*/
public protocol RowBuilder {

    var numberOfRows: Int { get }
    var reusableIdentifier: String { get }

    func triggerAction(key: String, cell: UITableViewCell?, indexPath: NSIndexPath, itemIndex: Int) -> AnyObject?
}

/**
    Responsible for table view's datasource and delegate.
*/
public class TableDirector: NSObject, UITableViewDataSource, UITableViewDelegate {

    private weak var tableView: UITableView!
    private var sections = [TableSectionBuilder]()

    public init(tableView: UITableView) {
        super.init()

        self.tableView = tableView
        self.tableView.delegate = self
        self.tableView.dataSource = self

        NSNotificationCenter.defaultCenter().addObserver(self, selector: "didReceiveAction:", name: kActionPerformedNotificationKey, object: nil)
    }
    
    deinit {

        NSNotificationCenter.defaultCenter().removeObserver(self)
    }

    // MARK: Public methods

    public func appendSection(section: TableSectionBuilder) {
        sections.append(section)
    }

    public func appendSections(sections: [TableSectionBuilder]) {
        self.sections.appendContentsOf(sections)
    }

    // MARK: Private methods

    /**
        Find a row builder that responsible for building a row from cell with given item type.

        - Parameters:
        - indexPath: path of cell to dequeue
    
        - Returns: A touple - (builder, builderItemIndex)
    */
    private func builderAtIndexPath(indexPath: NSIndexPath) -> (RowBuilder, Int) {

        return sections[indexPath.section].builderAtIndex(indexPath.row)!
    }
    
    private func triggerAction(action: ActionType, cell: UITableViewCell?, indexPath: NSIndexPath) -> AnyObject? {
        
        let builder = builderAtIndexPath(indexPath)
        return builder.0.triggerAction(action.rawValue, cell: cell, indexPath: indexPath, itemIndex: builder.1)
    }

    internal func didReceiveAction(notification: NSNotification) {

        if let action = notification.object as? Action, indexPath = tableView.indexPathForCell(action.cell) {

            let builder = builderAtIndexPath(indexPath)
            builder.0.triggerAction(action.key, cell: action.cell, indexPath: indexPath, itemIndex: builder.1)
        }
    }

    // MARK: UITableViewDataSource - configuration

    public func numberOfSectionsInTableView(tableView: UITableView) -> Int {

        return sections.count
    }
    
    public func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

        return sections[section].numberOfRowsInSection
    }

    public func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {

        let builder = builderAtIndexPath(indexPath)

        let cell = tableView.dequeueReusableCellWithIdentifier(builder.0.reusableIdentifier, forIndexPath: indexPath)

        builder.0.triggerAction(ActionType.configure.rawValue, cell: cell, indexPath: indexPath, itemIndex: builder.1)

        return cell
    }
    
    // MARK: UITableViewDataSource - section setup
    
    public func tableView(tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
        
        return sections[section].headerTitle
    }
    
    public func tableView(tableView: UITableView, titleForFooterInSection section: Int) -> String? {
        
        return sections[section].footerTitle
    }
    
    // MARK: UITableViewDelegate - section setup
    
    public func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {

        return sections[section].headerView
    }
    
    public func tableView(tableView: UITableView, viewForFooterInSection section: Int) -> UIView? {

        return sections[section].footerView
    }

    public func tableView(tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {

        return sections[section].headerHeight
    }

    public func tableView(tableView: UITableView, heightForFooterInSection section: Int) -> CGFloat {

        return sections[section].footerHeight
    }

    // MARK: UITableViewDelegate - actions
    
    public func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {

        let cell = tableView.cellForRowAtIndexPath(indexPath)

        if triggerAction(.click, cell: cell, indexPath: indexPath) != nil {
            tableView.deselectRowAtIndexPath(indexPath, animated: true)
        } else {
            triggerAction(.select, cell: cell, indexPath: indexPath)
        }
    }

    public func tableView(tableView: UITableView, didDeselectRowAtIndexPath indexPath: NSIndexPath) {

        triggerAction(.deselect, cell: tableView.cellForRowAtIndexPath(indexPath), indexPath: indexPath)
    }

    public func tableView(tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) {

        triggerAction(.willDisplay, cell: cell, indexPath: indexPath)
    }
    
    public func tableView(tableView: UITableView, shouldHighlightRowAtIndexPath indexPath: NSIndexPath) -> Bool {

        return triggerAction(.shouldHighlight, cell: tableView.cellForRowAtIndexPath(indexPath), indexPath: indexPath) as? Bool ?? true
    }

    public func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {

        return triggerAction(.height, cell: nil, indexPath: indexPath) as? CGFloat ?? tableView.rowHeight
    }
}