/**
Users that stars a repo belongs to a user.
     
- parameter repo: repo name
- parameter name: owner
- parameter page: when repo has a lot of stargazers, pagination will be applied.
     
- returns: an RpcRequest, whose response result contains `[GithubUser]`, if pagination is applicable, response result contains `nextpage`.
*/
public func getStargazersFor(repo repo: String, owner: String, page: String = "1", defaultResponseQueue: dispatch_queue_t? = nil) -> RpcCustomResponseRequest<UserArraySerializer, StringSerializer, String> {
    precondition((repo.characters.count != 0 && owner.characters.count != 0), "Invalid Input")
        
    // Custom Response Handler to extract next `page`.
    let httpResponseHandler:((NSHTTPURLResponse?)->String?)? = { (response: NSHTTPURLResponse?) in
        if let nonNilResponse = response,
                link = (nonNilResponse.allHeaderFields["Link"] as? String),
                sinceRange = link.rangeOfString("page=") {
                    var retVal = ""
                    var checkIndex = sinceRange.endIndex
                    
                    while checkIndex != link.endIndex {
                        let character = link.characters[checkIndex]
                        let characterInt = character.zeroCharacterBasedunicodeScalarCodePoint()
                        if characterInt>=0 && characterInt<=9 {
                            retVal += String(character)
                        } else {
                            break
                        }
                        checkIndex = checkIndex.successor()
                    }
                    return retVal
        }
        return nil
    }
        
    return RpcCustomResponseRequest(client: self.client, host: "api", route: "/repos/\(owner)/\(repo)/stargazers", method: .GET, params: ["page":page], postParams: nil, postData: nil,customResponseHandler:httpResponseHandler, defaultResponseQueue: defaultResponseQueue, responseSerializer: UserArraySerializer(), errorSerializer: StringSerializer())
}

client.stars.getStargazersFor(repo: "Yep", owner: "CatchChat", page: "1").response({ (nextPage, result, error) -> Void in
    if let users = result {
        print(users.count)
    }
                
    if let page = nextPage {
        print("Next page is:\(page)")
        client.stars.getStargazersFor(repo: "Yep", owner: "CatchChat", page: page).response({ (nextPage, result, error) -> Void in
        if let users = result {
            print(users.count)
        }
                        
        if let page = nextPage {
            print("Next page is:\(page)")
            client.stars.getStargazersFor(repo: "Yep", owner: "CatchChat", page: page).response({ (nextPage, result, error) -> Void in
                /*
                    . 真这么写你就输了
                    .
                    .
                */
            })
        }
        })
    }
})

var aggregatedresult:[GithubUser] = []
// 1. 初始化一个block变量，并用dummy block赋值.
var recursiveBlock: (String, String, String) -> () = {(_, _, _) in }

// 2. recursiveBlock的实现，内部调用了自己
recursiveBlock = { repo, owner, page in
    client.stars.getStargazersFor(repo: repo, owner: owner, page: page).response({(nextPage, result, error) -> Void in
        if let users = result {
            print(users.count)
            self.myTestResult.appendContentsOf(users)
        }
        if let vpage = nextPage {
            print("Next page is:\(vpage)")
                if vpage == "1" {
                    print("Finished")
                } else {
                    // 3. 调用了自己，因为 `1`有声明这个变量,compiler就可以infer它的信息，所以能调用.
                    recursiveBlock(repo, owner, vpage)
                }
        }
    })    
}

recursiveBlock("Yep", "CatchChat", "1")

/**
    Get all the stargazers belong to a owner's repo.
     
     - note: This request is time consuming if this repo is a quite popular one. but it will run on a private serial queue and will not block main queue.
     
     - parameter repo:              repo's name.
     - parameter owner:             owner's name.
     - parameter complitionHandler: callback that call on main thread.
*/
public func getAllStargazersFor(repo repo: String, owner: String, complitionHandler:([GithubUser]?, String?)-> Void) {
    var recursiveStargazers: (String, String, String) -> Void = {_, _, _ in }
    var retVal: [GithubUser] = []
    recursiveStargazers = {
        repo, owner, page in
        self.getStargazersFor(repo: repo, owner: owner, page: page).response {
            (nextPage, result, error) -> Void in
            guard let users = result, vpage = nextPage else {
                complitionHandler(nil, error?.description ?? "Error,Could not finish this request")
                return
            }

            retVal.appendContentsOf(users)
            if vpage == "1" {
                complitionHandler(retVal, nil)
            } else {
                recursiveStargazers(repo, owner, vpage)
            }
        }
    }
        
    recursiveStargazers(repo, owner, "1")
}