//
//  SPConnectionHandler.m
//  sequel-pro
//
//  Created by Stuart Connolly (stuconnolly.com) on November 15, 2010.
//  Copyright (c) 2010 Stuart Connolly. All rights reserved.
//
//  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.
//
//  More info at <https://github.com/sequelpro/sequelpro>

#import "SPConnectionHandler.h"
#import "SPDatabaseDocument.h"
#import "SPAlertSheets.h"
#import "SPSSHTunnel.h"
#import "SPKeychain.h"
#import "RegexKitLite.h"
#import "SPCategoryAdditions.h"
#import "SPThreadAdditions.h"

#import <SPMySQL/SPMySQL.h>

static NSString *SPLocalhostAddress = @"127.0.0.1"; 

@interface SPConnectionController ()

- (void)_restoreConnectionInterface;

@end

@interface SPConnectionController (SPConnectionHandlerPrivateAPI)

- (void)_showConnectionTestResult:(NSString *)resultString;

@end

#pragma mark -

@implementation SPConnectionController (SPConnectionHandler)

/**
 * Set up the MySQL connection, either through a successful tunnel or directly in the background.
 */
- (void)initiateMySQLConnection
{	
#ifndef SP_CODA
	if (isTestingConnection) {
		if (sshTunnel) {
			[progressIndicatorText setStringValue:NSLocalizedString(@"Testing MySQL...", @"MySQL connection test very short status message")];
		} 
		else {
			[progressIndicatorText setStringValue:NSLocalizedString(@"Testing connection...", @"Connection test very short status message")];
		}
	} 
	else if (sshTunnel) {
		[progressIndicatorText setStringValue:NSLocalizedString(@"MySQL connecting...", @"MySQL connecting very short status message")];
	} 
	else {
		[progressIndicatorText setStringValue:NSLocalizedString(@"Connecting...", @"Generic connecting very short status message")];
	}
	
	[progressIndicatorText display];
	
	[connectButton setTitle:NSLocalizedString(@"Cancel", @"cancel button")];
	[connectButton setAction:@selector(cancelConnection:)];
	[connectButton setEnabled:YES];
	[connectButton display];
#endif
	
	[NSThread detachNewThreadWithName:SPCtxt(@"SPConnectionHandler MySQL connection task", dbDocument) target:self selector:@selector(initiateMySQLConnectionInBackground) object:nil];
}

/**
 * Initiates the core of the MySQL connection process on a background thread.
 */
- (void)initiateMySQLConnectionInBackground
{
	NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
	
	mySQLConnection = [[SPMySQLConnection alloc] init];
	
	// Set up shared details
	[mySQLConnection setUsername:[self user]];
	
	// Initialise to socket if appropriate.
	if ([self type] == SPSocketConnection) {
		[mySQLConnection setUseSocket:YES];
		[mySQLConnection setSocketPath:[self socket]];
		
		// Otherwise, initialise to host, using tunnel if appropriate
	} 
	else {
		[mySQLConnection setUseSocket:NO];
		
		if ([self type] == SPSSHTunnelConnection) {
			[mySQLConnection setHost:@"127.0.0.1"];
			
			[mySQLConnection setPort:[sshTunnel localPort]];
			[mySQLConnection setProxy:sshTunnel];
		} 
		else {
			[mySQLConnection setHost:[self host]];
			
			if ([[self port] length]) [mySQLConnection setPort:[[self port] integerValue]];
		}
	}
	
	// Only set the password if there is no Keychain item set and the connection is not being tested.
	// The connection will otherwise ask the delegate for passwords in the Keychain.	
	if ((!connectionKeychainItemName || isTestingConnection) && [self password]) {
		[mySQLConnection setPassword:[self password]];
	}
	
	// Enable SSL if set
	if ([self useSSL]) {
		[mySQLConnection setUseSSL:YES];
		
		if ([self sslKeyFileLocationEnabled]) {
			[mySQLConnection setSslKeyFilePath:[self sslKeyFileLocation]];
		}
		
		if ([self sslCertificateFileLocationEnabled]) {
			[mySQLConnection setSslCertificatePath:[self sslCertificateFileLocation]];
		}
		
		if ([self sslCACertFileLocationEnabled]) {
			[mySQLConnection setSslCACertificatePath:[self sslCACertFileLocation]];
		}
		
		NSString *userSSLCipherList = [prefs stringForKey:SPSSLCipherListKey];
		if(userSSLCipherList) {
			//strip out disabled ciphers (e.g. in "foo:bar:--:baz")
			NSRange markerPos = [userSSLCipherList rangeOfRegex:@":?--"];
			if(markerPos.location != NSNotFound) {
				userSSLCipherList = [userSSLCipherList substringToIndex:markerPos.location];
			}
			[mySQLConnection setSslCipherList:userSSLCipherList];
		}
	}
	
	if(![self useCompression])
		[mySQLConnection removeClientFlags:SPMySQLClientFlagCompression];
	
	// Connection delegate must be set before actual connection attempt is made
	[mySQLConnection setDelegate:dbDocument];
	
	// Set whether or not we should enable delegate logging according to the prefs
	[mySQLConnection setDelegateQueryLogging:[prefs boolForKey:SPConsoleEnableLogging]];
	
	// Set options from preferences
	[mySQLConnection setTimeout:[[prefs objectForKey:SPConnectionTimeoutValue] integerValue]];
	[mySQLConnection setUseKeepAlive:[[prefs objectForKey:SPUseKeepAlive] boolValue]];
	[mySQLConnection setKeepAliveInterval:[[prefs objectForKey:SPKeepAliveInterval] floatValue]];
	
	// Connect
	[mySQLConnection connect];
	
	if (![mySQLConnection isConnected]) {
		if (sshTunnel && !cancellingConnection) {
			
			// This is a race condition we cannot fix "properly":
			// For meaningful error handling we need to also consider the debug output from the SSH connection.
			// The SSH debug output might be sligthly delayed though (flush, delegates, ...) or
			// there might not even by any output at all (when it is purely a libmysql issue).
			// TL;DR: No guaranteed events we could wait for, just trying our luck.
			[NSThread sleepForTimeInterval:0.1]; // 100ms
			
			// If the state is connection refused, attempt the MySQL connection again with the host using the hostfield value.
			if ([sshTunnel state] == SPMySQLProxyForwardingFailed) {
				if ([sshTunnel localPortFallback]) {
					[mySQLConnection setPort:[sshTunnel localPortFallback]];
					[mySQLConnection connect];
					
					if (![mySQLConnection isConnected]) {
						[NSThread sleepForTimeInterval:0.1]; //100ms
					}
				}
			}
		}
		
		if (![mySQLConnection isConnected]) {
			if (!cancellingConnection) {
				NSString *errorMessage = @"";
				if (sshTunnel && [sshTunnel state] == SPMySQLProxyForwardingFailed) {
					errorMessage = [NSString stringWithFormat:NSLocalizedString(@"Unable to connect to host %@ because the port connection via SSH was refused.\n\nPlease ensure that your MySQL host is set up to allow TCP/IP connections (no --skip-networking) and is configured to allow connections from the host you are tunnelling via.\n\nYou may also want to check the port is correct and that you have the necessary privileges.\n\nChecking the error detail will show the SSH debug log which may provide more details.\n\nMySQL said: %@", @"message of panel when SSH port forwarding failed"), [self host], [mySQLConnection lastErrorMessage]];
					[[self onMainThread] failConnectionWithTitle:NSLocalizedString(@"SSH port forwarding failed", @"title when ssh tunnel port forwarding failed") errorMessage:errorMessage detail:[sshTunnel debugMessages] rawErrorText:[mySQLConnection lastErrorMessage]];
				} 
				else if ([mySQLConnection lastErrorID] == 1045) { // "Access denied" error
					errorMessage = [NSString stringWithFormat:NSLocalizedString(@"Unable to connect to host %@ because access was denied.\n\nDouble-check your username and password and ensure that access from your current location is permitted.\n\nMySQL said: %@", @"message of panel when connection to host failed due to access denied error"), [self host], [mySQLConnection lastErrorMessage]];
					[[self onMainThread] failConnectionWithTitle:NSLocalizedString(@"Access denied!", @"connection failed due to access denied title") errorMessage:errorMessage detail:nil rawErrorText:[mySQLConnection lastErrorMessage]];
				} 
				else if ([self type] == SPSocketConnection && (![self socket] || ![[self socket] length]) && ![mySQLConnection socketPath]) {
					errorMessage = [NSString stringWithFormat:NSLocalizedString(@"The socket file could not be found in any common location. Please supply the correct socket location.\n\nMySQL said: %@", @"message of panel when connection to socket failed because optional socket could not be found"), [mySQLConnection lastErrorMessage]];
					[[self onMainThread] failConnectionWithTitle:NSLocalizedString(@"Socket not found!", @"socket not found title") errorMessage:errorMessage detail:nil rawErrorText:[mySQLConnection lastErrorMessage]];
				} 
				else if ([self type] == SPSocketConnection) {
					errorMessage = [NSString stringWithFormat:NSLocalizedString(@"Unable to connect via the socket, or the request timed out.\n\nDouble-check that the socket path is correct and that you have the necessary privileges, and that the server is running.\n\nMySQL said: %@", @"message of panel when connection to host failed"), [mySQLConnection lastErrorMessage]];
					[[self onMainThread] failConnectionWithTitle:NSLocalizedString(@"Socket connection failed!", @"socket connection failed title") errorMessage:errorMessage detail:nil rawErrorText:[mySQLConnection lastErrorMessage]];
				} 
				else {
					errorMessage = [NSString stringWithFormat:NSLocalizedString(@"Unable to connect to host %@, or the request timed out.\n\nBe sure that the address is correct and that you have the necessary privileges, or try increasing the connection timeout (currently %ld seconds).\n\nMySQL said: %@", @"message of panel when connection to host failed"), [self host], (long)[[prefs objectForKey:SPConnectionTimeoutValue] integerValue], [mySQLConnection lastErrorMessage]];
					[[self onMainThread] failConnectionWithTitle:NSLocalizedString(@"Connection failed!", @"connection failed title") errorMessage:errorMessage detail:nil rawErrorText:[mySQLConnection lastErrorMessage]];
				}
			}
			
			// Tidy up
			isConnecting = NO;
			
			if (sshTunnel) [sshTunnel disconnect], SPClear(sshTunnel);
			
			SPClear(mySQLConnection);
#ifndef SP_CODA
			if (!cancellingConnection) [self _restoreConnectionInterface];
#endif
			[pool release];
			
			return;
		}
	}
	
	if ([self database] && ![[self database] isEqualToString:@""]) {
		if (![mySQLConnection selectDatabase:[self database]]) {
			if (!isTestingConnection) {
			[[self onMainThread] failConnectionWithTitle:NSLocalizedString(@"Could not select database", @"message when database selection failed") errorMessage:[NSString stringWithFormat:NSLocalizedString(@"Connected to host, but unable to connect to database %@.\n\nBe sure that the database exists and that you have the necessary privileges.\n\nMySQL said: %@", @"message of panel when connection to db failed"), [self database], [mySQLConnection lastErrorMessage]] detail:nil rawErrorText:[mySQLConnection lastErrorMessage]];
			}
			
			// Tidy up
			isConnecting = NO;
			
			if (sshTunnel) SPClear(sshTunnel);
			
			SPClear(mySQLConnection);
			[self _restoreConnectionInterface];
			if (isTestingConnection) {
				[self _showConnectionTestResult:NSLocalizedString(@"Invalid database", @"Invalid database very short status message")];
			}

			[pool release];
			
			return;
		}
	}
	
	// Connection established
	[self performSelectorOnMainThread:@selector(mySQLConnectionEstablished) withObject:nil waitUntilDone:NO];
	
	[pool release];
}

/**
 * Initiate the SSH connection process.
 * This should only be called as part of initiateConnection:, and will indirectly
 * call initiateMySQLConnection if it's successful.
 */
- (void)initiateSSHTunnelConnection
{
	if (isTestingConnection) {
		[progressIndicatorText setStringValue:NSLocalizedString(@"Testing SSH...", @"SSH testing very short status message")];
	} else {
	[progressIndicatorText setStringValue:NSLocalizedString(@"SSH connecting...", @"SSH connecting very short status message")];
	}
	[progressIndicatorText display];
	
	[connectButton setTitle:NSLocalizedString(@"Cancel", @"cancel button")];
	[connectButton setAction:@selector(cancelConnection:)];
	[connectButton setEnabled:YES];
	[connectButton display];

	// Trim whitespace and newlines from the SSH host field before attempting to connect
	[self setSshHost:[[self sshHost] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]]];
	
	// Set up the tunnel details
	sshTunnel = [[SPSSHTunnel alloc] initToHost:[self sshHost] port:[[self sshPort] integerValue] login:[self sshUser] tunnellingToPort:([[self port] length]?[[self port] integerValue]:3306) onHost:[self host]];
	[sshTunnel setParentWindow:[dbDocument parentWindow]];
	
	// Add keychain or plaintext password as appropriate - note the checks in initiateConnection.
	if (connectionSSHKeychainItemName && !isTestingConnection) {
		[sshTunnel setPasswordKeychainName:connectionSSHKeychainItemName account:connectionSSHKeychainItemAccount];
	} else if (sshPassword) {
		[sshTunnel setPassword:[self sshPassword]];
	}
	
	// Set the public key path if appropriate
	if (sshKeyLocationEnabled && sshKeyLocation) {
		[sshTunnel setKeyFilePath:sshKeyLocation];
	}
	
	// Set the callback function on the tunnel
	[sshTunnel setConnectionStateChangeSelector:@selector(sshTunnelCallback:) delegate:self];
	
	// Ask the tunnel to connect.  This will call the callback below on success or failure, passing
	// itself as an argument - retain count should be one at this point.
	[sshTunnel connect];
}

/**
 * Called on the main thread once the MySQL connection is established on the background thread. Either the
 * connection was cancelled or it was successful. 
 */
- (void)mySQLConnectionEstablished
{	
	isConnecting = NO;
	
	// If the user is only testing the connection, kill the connection
	// once established and reset the UI.  Also catch connection cancels.
	if (isTestingConnection || cancellingConnection) {
		
		// Clean up any connections remaining, and reset the UI
		[self cancelConnection:self];
		
		if (isTestingConnection) {
			[self _showConnectionTestResult:NSLocalizedString(@"Connection succeeded", @"Connection success very short status message")];
		}
		
		return;
	}
	
#ifndef SP_CODA
	[progressIndicatorText setStringValue:NSLocalizedString(@"Connected", @"connection established message")];
	[progressIndicatorText display];
#endif
	
	// Stop the current tab's progress indicator
	[dbDocument setIsProcessing:NO];
	
	// Successful connection!
#ifndef SP_CODA
	[connectButton setEnabled:NO];
	[connectButton display];
	[progressIndicator stopAnimation:self];
	[progressIndicatorText setHidden:YES];
#endif
	
	// If SSL was enabled, check it was established correctly
	if (useSSL && ([self type] == SPTCPIPConnection || [self type] == SPSocketConnection)) {
		if (![mySQLConnection isConnectedViaSSL]) {
			SPBeginAlertSheet(NSLocalizedString(@"SSL connection not established", @"SSL requested but not used title"), NSLocalizedString(@"OK", @"OK button"), nil, nil, [dbDocument parentWindow], nil, nil, nil, NSLocalizedString(@"You requested that the connection should be established using SSL, but MySQL made the connection without SSL.\n\nThis may be because the server does not support SSL connections, or has SSL disabled; or insufficient details were supplied to establish an SSL connection.\n\nThis connection is not encrypted.", @"SSL connection requested but not established error detail"));
		} 
		else {
#ifndef SP_CODA
			[dbDocument setStatusIconToImageWithName:@"titlebarlock"]; 
#endif
		}
	}
	
#ifndef SP_CODA
	// Re-enable favorites table view
	[favoritesOutlineView setEnabled:YES];
	[(NSView *)favoritesOutlineView display];
#endif
	
	// Release the tunnel if set - will now be retained by the connection
	if (sshTunnel) SPClear(sshTunnel);
	
	// Pass the connection to the document and clean up the interface
	[self addConnectionToDocument];
}

/**
 * A callback function for the SSH Tunnel setup process - will be called on a connection
 * state change, allowing connection to fail or proceed as appropriate.  If successful,
 * will call initiateMySQLConnection.
 */
- (void)sshTunnelCallback:(SPSSHTunnel *)theTunnel
{
	if (cancellingConnection) return;
	
	NSInteger newState = [theTunnel state];
	
	// If the user cancelled the password prompt dialog, continue with no further action.
	if ([theTunnel passwordPromptCancelled]) {
		[self _restoreConnectionInterface];
		
		return;
	}
	
	if (newState == SPMySQLProxyIdle) {

#ifndef SP_CODA
		[dbDocument setTitlebarStatus:NSLocalizedString(@"SSH Disconnected", @"SSH disconnected titlebar marker")];
#endif
		
		[[self onMainThread] failConnectionWithTitle:NSLocalizedString(@"SSH connection failed!", @"SSH connection failed title") errorMessage:[theTunnel lastError] detail:[sshTunnel debugMessages] rawErrorText:[theTunnel lastError]];
	}
	else if (newState == SPMySQLProxyConnected) {
#ifndef SP_CODA
		[dbDocument setTitlebarStatus:NSLocalizedString(@"SSH Connected", @"SSH connected titlebar marker")];
#endif
		
		[self initiateMySQLConnection];
	} 
	else {
#ifndef SP_CODA
		[dbDocument setTitlebarStatus:NSLocalizedString(@"SSH Connecting…", @"SSH connecting titlebar marker")];
#endif
	}
}

/**
 * Add the connection to the parent document and restore the
 * interface, allowing the application to run as normal.
 */
- (void)addConnectionToDocument
{					
#ifndef SP_CODA
	// Hide the connection view and restore the main view
	[connectionView removeFromSuperviewWithoutNeedingDisplay];
	[databaseConnectionView setHidden:NO];
	
	// Restore the toolbar icons
	NSArray *toolbarItems = [[[dbDocument parentWindow] toolbar] items];
	
	for (NSUInteger i = 0; i < [toolbarItems count]; i++) [[toolbarItems objectAtIndex:i] setEnabled:YES];
#endif
	
	if (connectionKeychainID) [dbDocument setKeychainID:connectionKeychainID];
	
	// Pass the connection to the table document, allowing it to set
	// up the other classes and the rest of the interface.
	[dbDocument setConnection:mySQLConnection];
}

/**
 * Ends a connection attempt by stopping the connection animation and
 * displaying a specified error message.
 */
- (void)failConnectionWithTitle:(NSString *)theTitle errorMessage:(NSString *)theErrorMessage detail:(NSString *)errorDetail rawErrorText:(NSString *)rawErrorText
{
	BOOL isSSHTunnelBindError = NO;
	
#ifndef SP_CODA
	[self _restoreConnectionInterface];
#endif
	
	// Release as appropriate
	if (sshTunnel) {
		[sshTunnel disconnect], SPClear(sshTunnel);
		
		// If the SSH tunnel connection failed because the port it was trying to bind to was already in use take note
		// of it so we can give the user the option of connecting via standard connection and use the existing tunnel. 
		if ([rawErrorText rangeOfString:@"bind"].location != NSNotFound) {
			isSSHTunnelBindError = YES;
		}
	}
	
	if (errorDetail) [errorDetailText setString:errorDetail];
	
	// Inform the delegate that the connection attempt failed
	if (delegate && [delegate respondsToSelector:@selector(connectionControllerConnectAttemptFailed:)]) {
		[[(NSObject *)delegate onMainThread] connectionControllerConnectAttemptFailed:self];
	}
	
	// Only display the connection error message if there is a window visible
	if ([[dbDocument parentWindow] isVisible]) {
		SPBeginAlertSheet(theTitle, NSLocalizedString(@"OK", @"OK button"), (errorDetail) ? NSLocalizedString(@"Show Detail", @"Show detail button") : nil, (isSSHTunnelBindError) ? NSLocalizedString(@"Use Standard Connection", @"use standard connection button") : nil, [dbDocument parentWindow], self, @selector(connectionFailureSheetDidEnd:returnCode:contextInfo:), @"connect", theErrorMessage);
	}
}

/**
 * Alert sheet callback method - invoked when an error sheet is closed.
 */
- (void)connectionFailureSheetDidEnd:(NSAlert *)alert returnCode:(NSInteger)returnCode contextInfo:(void *)contextInfo
{
	if (returnCode == NSAlertAlternateReturn) {
		[errorDetailText setFont:[NSFont userFontOfSize:12]];
		[errorDetailText setAlignment:NSLeftTextAlignment];
		[errorDetailWindow makeKeyAndOrderFront:self];
	}

	// Currently only SSH port bind errors offer a 3rd option in the error dialog, but if this ever changes
	// this will definitely need to be updated.
	else if (returnCode == NSAlertOtherReturn) {
		
		// Extract the local port number that SSH attempted to bind to from the debug output
		NSString *tunnelPort = [[[errorDetailText string] componentsMatchedByRegex:@"LOCALHOST:([0-9]+)" capture:1L] lastObject];
		
		// Change the connection type to standard TCP/IP
		[self setType:SPTCPIPConnection];
		
		// Change connection details
		[self setPort:tunnelPort];
		[self setHost:SPLocalhostAddress];
		
#ifndef SP_CODA
		// Change to standard TCP/IP connection view
		[self resizeTabViewToConnectionType:SPTCPIPConnection animating:YES];
#endif
		
		// Initiate the connection after a half second delay to give the connection view a chance to resize
		[self performSelector:@selector(initiateConnection:) withObject:self afterDelay:0.5];				
	}
}

@end

#pragma mark -

@implementation SPConnectionController (SPConnectionHandlerPrivateAPI)

/**
 * Display a connection test error or success message
 */
- (void)_showConnectionTestResult:(NSString *)resultString
{
	if (![NSThread isMainThread]) {
		[[self onMainThread] _showConnectionTestResult:resultString];
	}

	[helpButton setHidden:NO];
	[progressIndicator stopAnimation:self];
	[progressIndicatorText setStringValue:resultString];
	[progressIndicatorText setHidden:NO];
}

@end