0001    //
0002    //  Branch.swift
0003    //  HelloServer
0004    //
0005    //  Created by Logan Wright on 2/15/16.
0006    //  Copyright © 2016 LoganWright. All rights reserved.
0007    //
0008    
0009    /**
0010        When routing requests, different branches will be established, 
0011        in a linked list style stemming from their host and request method.  
0012        It can be represented as:
0013     
0014        | host | request.method | branch -> branch -> branch
0015     */
0016    internal final class Branch
Branch.swift:48
    private(set) var subBranches: [String : Branch] = [:]
Branch.swift:109
            let next = subBranches["*"] ?? Branch(name: substring)
Branch.swift:113
            let next = subBranches[key] ?? Branch(name: key)
BranchRouter.swift:16
    private final var tree: [Host : [Request.Method : Branch]] = [:]
BranchRouter.swift:45
        let branch = root[method] ?? Branch(name: "") {
0017        
0018        /**
0019            The name of the branch, ie if we have a path hello/:name, 
0020            the branch structure will be:
0021            Branch('hello') (connected to) Branch('name')
0022         
0023            In cases where a slug is used, ie ':name' the slug 
0024            will be used as the name and passed as a key in matching.
0025         */
0026        let name
Branch.swift:59
        self.name = name
Branch.swift:80
            request.parameters[wildcard.name] = key.stringByRemovingPercentEncoding: String
0027        
0028        /**
0029            There are two types of branches, those that support a handler, 
0030            and those that are a linker between branches, 
0031            for example /users/messages/:id will have 3 connected branches, 
0032            only one of which supports a handler.
0033         
0034            Branch('users') -> Branch('messages') -> *Branches('id')
0035         
0036            *indicates a supported branch.
0037         */
0038        private var handler
Branch.swift:60
        self.handler = handler
Branch.swift:74
            return handler
Branch.swift:99
            self.handler = handler: Request.Handler?
0039        
0040        /**
0041            key or *
0042         
0043            If it is a `key`, then it connects to an additional branch.
0044         
0045            If it is `*`, it is a slug point and the name
0046            represents a key for a dynamic value.
0047         */
0048        private(set) var subBranches
Branch.swift:77
        if let next = subBranches[key] {
Branch.swift:79
        } else if let wildcard = subBranches["*"] {
Branch.swift:109
            let next = subBranches["*"] ?? Branch(name: substring)
Branch.swift:111
            subBranches["*"] = next
Branch.swift:113
            let next = subBranches[key] ?? Branch(name: key)
Branch.swift:115
            subBranches[key] = next: [String : Branch] = [:]
0049        
0050        /**
0051            Used to create a new branch
0052         
0053            - parameter name: The name associated with the branch, or the key when dealing with a slug
0054            - parameter handler: The handler to be called if its a valid endpoint, or `nil` if this is a bridging branch
0055         
0056            - returns: an initialized request Branch
0057         */
0058        init
Branch.swift:109
            let next = subBranches["*"] ?? Branch(name: substring)
Branch.swift:113
            let next = subBranches[key] ?? Branch(name: key)
BranchRouter.swift:45
        let branch = root[method] ?? Branch(name: "")(name: String, handler: Request.Handler? = nil) {
0059            self.name = name
0060            self.handler = handler
0061        }
0062       
0063        /**
0064            This function will recursively traverse the branch 
0065            until the path is fulfilled or the branch ends
0066         
0067            - parameter request: the request to use in matching
0068            - parameter comps:   ordered pathway components generator
0069         
0070            - returns: a request handler or nil if not supported
0071         */
0072        func handle
Branch.swift:78
            return next.handle(request, comps: comps)
Branch.swift:81
            return wildcard.handle(request, comps: comps)
BranchRouter.swift:31
        return branch.handle(request, comps: generator)(request: Request, comps: CompatibilityGenerator<String>) -> Request.Handler? {
0073            guard let key = comps.next() else {
0074                return handler
0075            }
0076            
0077            if let next = subBranches[key] {
0078                return next.handle(request, comps: comps)
0079            } else if let wildcard = subBranches["*"] {
0080                request.parameters[wildcard.name] = key.stringByRemovingPercentEncoding
0081                return wildcard.handle(request, comps: comps)
0082            } else {
0083                return nil
0084            }
0085        }
0086    
0087        /**
0088            If a branch exists that is linked as:
0089         
0090             Branch('one') -> Branch('two')
0091         
0092            This branch will be extended with the given value
0093         
0094            - parameter generator: the generator that will be used to match the path components.  /users/messages/:id will return a generator that is 'users' <- 'messages' <- '*id'
0095            - parameter handler:   the handler to assign to the end path component
0096         */
0097        func extendBranch
Branch.swift:110
            next.extendBranch(generator, handler: handler)
Branch.swift:114
            next.extendBranch(generator, handler: handler)
BranchRouter.swift:48
        branch.extendBranch(generator, handler: handler)(generator: CompatibilityGenerator<String>, handler: Request.Handler) {
0098            guard let key = generator.next() else {
0099                self.handler = handler
0100                return
0101            }
0102            
0103            if key.hasPrefix(":") {
0104                let chars = key.characters
0105                let indexOne = chars.startIndex.advancedBy()
0106                let sub = key.characters.suffixFrom(indexOne)
0107                let substring = String(sub)
0108                
0109                let next = subBranches["*"] ?? Branch(name: substring)
0110                next.extendBranch(generator, handler: handler)
0111                subBranches["*"] = next
0112            } else {
0113                let next = subBranches[key] ?? Branch(name: key)
0114                next.extendBranch(generator, handler: handler)
0115                subBranches[key] = next
0116            }
0117        }
0118    }
0119