/*
 * Created by Martin Carlberg on January 27, 2016.
 * Copyright 2016, Martin Carlberg All rights reserved.
 */

@import <Foundation/CPObject.j>
@import "HTTPRequest.j"
@import "HTTPResponse.j"
@import "BackendFunctionRetrievemodel.j"
@import "BackendFunctionFetch.j"
@import "BackendFunctionModify.j"

@global require
@global BackendDocumentRootPath
@global BackendOptions

var url = require('url')
var fs  = require('fs');

var _sharedInstance = nil;

@implementation WebServer : CPObject {
    CPInteger port;
}

+ (WebServer) sharedInstance {
    if (!_sharedInstance) {
        _sharedInstance = [[WebServer alloc] init];
    }
    return _sharedInstance;
}

- (id)init {
    self = [super init];

    if (self) {
        port = 1337;
    }

    return self;
}

- (void)startWebServer {
    var http = require('http');

    var databaseStore = [CPMutableDictionary dictionary];

    var server = http.createServer(function (req, res) {
        // req is an http.IncomingMessage, which is a Readable Stream
        // res is an http.ServerResponse, which is a Writable Stream

        var method = req.method;

        var body = '';
        // we want to get the data as utf8 strings
        // If you don't set an encoding, then you'll get Buffer objects
        req.setEncoding('utf8');

        // Readable streams emit 'data' events once a listener is added
        req.on('data', function (chunk) {
            body += chunk;
        });

        // the end event tells you that you have entire body
        req.on('end', function () {
            switch (method) {
                case "GET":
                    [self handleHttpGETRequest:req completionHandler:function(httpResponse) {
                        if ([httpResponse respondsToSelector:@selector(status)]) {
                            res.statusCode = [httpResponse status];
                        }
                        if ([httpResponse respondsToSelector:@selector(httpHeaders)]) {
                            [[httpResponse httpHeaders] enumerateKeysAndObjectsUsingBlock:function(headerName, headerValue) {
                            res.setHeader(headerName, headerValue);
                            }];
                        }
                        var data = [httpResponse readDataOfLength:[httpResponse contentLength]];
                        if (data != nil) {
                            // If we have a 'isa' property it is a CPData. Should be a Buffer if not and we can write a string or a Buffer
                            res.write(data.isa ? [data rawString] : data);
                        }
                        res.end();
                    }];
                    break;

                case "POST":
                    [self handleHttpPOSTRequest:req body:body completionHandler:function(httpResponse) {
                        if ([httpResponse respondsToSelector:@selector(status)]) {
                            res.statusCode = [httpResponse status];
                        }
                        if ([httpResponse respondsToSelector:@selector(httpHeaders)]) {
                            [[httpResponse httpHeaders] enumerateKeysAndObjectsUsingBlock:function(headerName, headerValue) {
                            res.setHeader(headerName, headerValue);
                            }];
                        }
                        var data = [httpResponse readDataOfLength:[httpResponse contentLength]];
                        if (data != nil) {
                            // If we have a 'isa' property it is a CPData. Should be a Buffer if not and we can write a string or a Buffer
                            res.write(data.isa ? [data rawString] : data);
                        }
                        res.end();
                    }];
                    break;

                default:
                    res.statusCode = 400;
                    res.write('error: Unsupported method ' + method);
                    res.end();
            }
        });
    });

    server.listen(port);
    console.log("Webserver started on port " + port);
}
- (void)handleHttpGETRequest:(HTTPRequest)request completionHandler:(Function/*(CPObject<HTTPResponse>)*/)completionBlock {
    var /*CPString*/ path = request.url;
    var /*CPArray*/ pathComponents = [path pathComponents];
    var /*CPMutableArray*/ unqualifiedComponents = [pathComponents mutableCopy];
    var /*CPString*/ subpath;
    var /*CPString*/ sessionKey;
    var /*CPString*/ functionName;
    var /*Class*/ functionClass = nil;
    var /*CPDictionary*/ getQuery;
    var /*CPMutableDictionary*/ parameters;
    var urlParts = url.parse(path);
    var pathname = urlParts.pathname;

    if (pathname.startsWith("/backend")) {
        try {
            while (([unqualifiedComponents count] > 0) && ([[unqualifiedComponents lastObject] rangeOfString:@"="].location != CPNotFound)) {
                [unqualifiedComponents removeLastObject];
            }

            switch ([unqualifiedComponents count]) {
                case 0:
                case 1:
                    // Path is invalid
                    return completionBlock([[UnauthorizedHTTPResponse alloc] initWithFunction:@"-"]);

                case 2:
                    // Path contains only a function name
                    functionName = [unqualifiedComponents objectAtIndex:1];
                    functionClass = [self functionClassForName:functionName];
                    sessionKey = nil;
                    subpath = @"";
                    break;

                default:
                    functionName = [unqualifiedComponents objectAtIndex:1];
                    functionClass = [self functionClassForName:functionName];
                    if (functionClass == nil) {
                        // Path contains a session key
                        sessionKey = [unqualifiedComponents objectAtIndex:1];
                        functionName = [unqualifiedComponents objectAtIndex:2];
                        functionClass = [self functionClassForName:functionName];
                        subpath = [[pathComponents subarrayWithRange:CPMakeRange(3, [pathComponents count] - 3)] componentsJoinedByString:@"/"];
    /*                    if (functionClass == nil) {
                            // Path contains a session key, and an entity name
                            functionName = @"fetch";
                            functionClass = [BackendFunctionFetch class];
                            subpath = [[pathComponents subarrayWithRange:CPMakeRange(2, [pathComponents count] - 2)] componentsJoinedByString:@"/"];
                        }*/
                    } else {
                        // Path contains a function name and a subpath
                        subpath = [[pathComponents subarrayWithRange:CPMakeRange(2, [pathComponents count] - 2)] componentsJoinedByString:@"/"];
                    }
                    break;
            }

            parameters = [[request allHeaderFields] mutableCopy];
            getQuery = [request parseGetParams];
            if (getQuery != nil) {
                parameters[@"getQuery"] = getQuery;
            }

            var /*CPObject <BackendFunction>*/ aFunction = [[functionClass alloc] initWithSubpath:subpath parameters:parameters];

            if (aFunction) {
                var parameterError = [aFunction parameterError];
                if (parameterError) {
                    console.log("parameterError: " + [parameterError userInfo]);
                }

                if (!aFunction) {
                    return completionBlock([[UnauthorizedHTTPResponse alloc] initWithFunction:functionName]);
                }

                if (/*Authority check*/true) {
                    return [aFunction responseWithCompletionHandler:function(httpResponse) {
                        return completionBlock(httpResponse);
                    }];
                } else {
                    return completionBlock([[UnauthorizedHTTPResponse alloc] initWithFunction:functionName]);
                }
            }
        } catch (exception) {
            return completionBlock([[ExceptionHTTPResponse alloc] initWithException:exception]);
        }
    } else if (BackendDocumentRootPath) {
        // Ok, here we simulate a webserver as the request is not from the LightObject framework.
        // Sometimes it is complicated to setup a webserver to make it run, this will make it very easy to start.
        fs.readFile([BackendDocumentRootPath stringByAppendingPathComponent:pathname], function(err, data) {
            if (err) {
                if (BackendOptions.verbose) console.log("Accessing: " + [BackendDocumentRootPath stringByAppendingPathComponent:pathname] + " Not Found: " + err);
                return completionBlock([[NotFoundHTTPResponse alloc] init]);
            }

            if (BackendOptions.verbose) console.log("Accessing: " + [BackendDocumentRootPath stringByAppendingPathComponent:pathname] + " with length: " + data.length);

            var pathExtension = [pathname pathExtension];
            if (pathExtension === @"html" || pathExtension === @"htm") {
                return completionBlock([[HtmlHTTPResponse alloc] initWithBytes:data]);
            }
            return completionBlock([[BufferHTTPResponse alloc] initWithBytes:data]);
        });
    }
}

- (CPObject<HTTPResponse>)handleHttpPOSTRequest:(HTTPRequest)request body:(CPString)data completionHandler:(Function/*(CPObject<HTTPResponse>)*/)completionBlock {
    var /*CPString*/ path = request.url;
    var /*CPData*/ body = request.body;
    var /*CPArray*/ pathComponents = [path pathComponents];
    var /*CPString*/ sessionKey;
    var /*CPString*/ functionName = [pathComponents count] > 0 ? [pathComponents objectAtIndex:2] : nil;
    var /*Class*/ functionClass = nil;
    var /*CPObject <BackendFunction>*/ aFunction;
//    var /*CPObject <HTTPResponse>*/ response;

    var jsonObject = [data objectFromJSON];
    var /*CPMutableDictionary*/ parameters = [CPMutableDictionary dictionaryWithJSObject:jsonObject recursively:YES];

    functionClass = [self functionClassForName:functionName];

//    if (!jsonObject) {
//        return [[ErrorHTTPResponse alloc] initWithError:postBodyJSONError session:nil];
//    }

    if ([pathComponents count] < 3) {
        aFunction = [[functionClass alloc] initWithSubpath:nil parameters:parameters];
    } else {
        aFunction = [[functionClass alloc] initWithSubpath:[CPString pathWithComponents:[pathComponents subarrayWithRange:CPMakeRange (2, [pathComponents count] - 2)]] parameters:parameters];
    }

    var parameterError = [aFunction parameterError];
    if (parameterError) {
        console.log("parameterError: " + [parameterError userInfo]);
    }

    if (/*Authority check*/true) {
        return [aFunction responseWithCompletionHandler:function(httpResponse) {
            return completionBlock(httpResponse);
        }];
    } else {
        return completionBlock([[UnauthorizedHTTPResponse alloc] initWithFunction:functionName]);
    }
}

- (Class)functionClassForName:(CPString)functionName {
    //if ([functionName rangeOfCharacterFromSet:[[CPCharacterSet letterCharacterSet] invertedSet]].location === CPNotFound)
    // As above function is missing in Cappuccino we split the string to check if string contains invalid characters
    if ([[functionName componentsSeparatedByCharactersInSet:[[CPCharacterSet letterCharacterSet] invertedSet]] count] === 1) {
        return CPClassFromString([CPString stringWithFormat:@"BackendFunction%@", [functionName capitalizedString]]);
    } else {
        return nil;
    }
}

@end