//
//  PostsLoader.swift
//  librx
//
//  Created by Yunlong Zheng on 15/8/17.
//  Copyright (c) 2015年 librx. All rights reserved.
//

import Foundation

class PostsLoader {

    typealias PostfixLoadCompetion = (posts:[Post], error: String?) ->()
    typealias ExplorefixLoadCompetion = (sources: [ExploreSource]) ->()
    
    enum PostSection: CustomStringConvertible {
    
        case Default
        case RecentTimeLine
        case HotTimeLine
        case MyPostTimeLine
        case UserPosts(userId: Int)
        case Liked
        case UserLiked(userId: Int)
        case BookMark
        case UserBookMark(userId: Int)
        case Search(_: String)
        
        var description: String {
            
            switch(self) {
            case .Default: return "HotForYou"
            case .RecentTimeLine: return "Recent"
            case .HotTimeLine: return "HotTimeline"
            case .Search(_): return "search"
            case .MyPostTimeLine: return "MyPost"
            case .Liked: return "MyLike"
            case .BookMark: return "Bookmar"
            case .UserPosts(let userId): return "user\(userId)posts"
            case .UserLiked(let userId): return "user\(userId)liked"
            case .UserBookMark(let userId): return "user\(userId)bookmark"
            }
            
        }
        
        var cacheKey: String {
            
            switch(self) {
            case .Default: return "defaultpostkey"
            case .RecentTimeLine: return "recenttimelinekey"
            case .HotTimeLine: return "hottimelinekey"
            case .Search(_): return "searchkey"
            case .MyPostTimeLine: return "myposttimelinekey"
            case .Liked: return "likedkey"
            case .BookMark: return "bookmarkkey"
            case .UserPosts(let userId): return "user\(userId)postskey"
            case .UserLiked(let userId): return "user\(userId)likedkey"
            case .UserBookMark(let userId): return "user\(userId)bookmarkkey"
            }
        }
        
        var tableString: String {
            
            switch(self) {
            case .Default: return "当前没有可显示的内容，请下拉刷新"
            case .RecentTimeLine: return "人人可用的信息分享平台"
            case .HotTimeLine: return "这里我们将向你展示最热的内容"
            case .Search(_): return "当前没有可显示的内容，请下拉刷新"
            case .MyPostTimeLine: return "分享，也是一种生活态度"
            case .Liked: return "喜欢，来表明你的个性"
            case .BookMark: return "收藏，的就是对你最有价值的"
            case .UserPosts(_): return "还没有分享任何内容"
            case .UserLiked(_): return "喜欢，来表明你的个性"
            case .UserBookMark(_): return "收藏，的就是对你最有价值的"
            }
        }
        
        
    }
    
    private (set) var hasMore: Bool = false
    private var page: Int = 1
    private var isLoading: Bool = false
    private let keyword: String!
    private let section: PostSection
    
    init(_ section: PostSection = .RecentTimeLine) {
        self.section = section
        switch (section){
            case let .Search(keyword):
                self.keyword = keyword
            default:
                self.keyword = nil
        }
        
    }
    
    func loadExploreSourcesFromUrl(page: Int=1, url: String, completion: ExplorefixLoadCompetion) {
    
        if isLoading {
            return
        }
        
        isLoading = true
        return exploreSourcesFromUrl(url, completion: completion)
        
    }
    
    
    
    func load(page: Int=1, completion: PostfixLoadCompetion){
    
        if isLoading {
            return
        }
        
        isLoading = true
   
        switch(section) {
            case .MyPostTimeLine: return postsByMe(page, completion:completion)
            case .Liked: return postsByMeLiked(page, completion: completion)
            case .BookMark: return postsByMeBookMark(page, completion:completion)
            case .UserPosts(let userId): return postsByUser(page, userId: userId, completion: completion)
            case .UserLiked(let userId): return postsByUserLiked(page, userId: userId, completion: completion)
            case .UserBookMark(let userId): return postsByUserBookMark(page, userId: userId, completion: completion)
            default: return postsBySection(page, completion: completion)
        }
        
    }
    
    func exploreSourcesFromUrl(url: String, completion: ExplorefixLoadCompetion){

        LibrxService.loadExploreSourcesByUrl(url) { sources in
            completion(sources: sources)
        }
    
    }
    
    func postsByUser(page: Int=1, userId: Int, completion: PostfixLoadCompetion) {

        LibrxService.postsForUser(page, userId: userId, section: section){ [weak self] (posts, error) in
            if let storongSelf = self {
                storongSelf.isLoading = false
                completion(posts: posts, error: error)
            }
        }
        
    }
    
    
    func postsByMe(page: Int=1, completion: PostfixLoadCompetion) {
        
        LibrxService.postsForMyPosts(page, section: section){ [weak self] (posts, error) in
            if let storongSelf = self {
                storongSelf.isLoading = false
                completion(posts: posts, error: error)
            }
        }
        
    }
    
    func postsByMeLiked(page: Int=1,completion: PostfixLoadCompetion) {
        
        let userId = LocalStore.accessUserId()
        LibrxService.postsForUserLiked(page, userId: userId!, section: section){ [weak self] (posts, error) in
            if let storongSelf = self {
                storongSelf.isLoading = false
                completion(posts: posts, error: error)
            }
        }
        
    }
    
    func postsByUserLiked(page: Int=1, userId: Int, completion: PostfixLoadCompetion) {
        
        LibrxService.postsForUserLiked(page, userId: userId, section: section){ [weak self] (posts, error) in
            if let storongSelf = self {
                storongSelf.isLoading = false
                completion(posts: posts, error: error)
            }
        }
        
    }
    
    func postsByMeBookMark(page: Int=1, completion: PostfixLoadCompetion) {
        
        let userId = LocalStore.accessUserId()
        LibrxService.postsForUserBookMark(page, userId: userId!, section: section){ [weak self] (posts, error) in
            if let storongSelf = self {
                storongSelf.isLoading = false
                completion(posts: posts, error: error)
            }
        }
        
    }
    
    func postsByUserBookMark(page: Int=1, userId: Int, completion: PostfixLoadCompetion) {
        
        LibrxService.postsForUserBookMark(page, userId: userId, section: section){ [weak self] (posts, error) in
            if let storongSelf = self {
                storongSelf.isLoading = false
                completion(posts: posts, error: error)
            }
        }
        
    }
    
    
    func postsBySection(page: Int=1, completion: PostfixLoadCompetion) {
        LibrxService.postsBySection(page, keyword: self.keyword, section: section) { [weak self] (posts, error) in
            if let storongSelf = self {
                storongSelf.isLoading = false
                completion(posts: posts, error: error)
            }
        }

    }

    
}