/**
 * Tae Won Ha - http://taewon.de - @hataewon
 * See LICENSE
 */

#import "NeoVimServer.h"
#import "server_globals.h"
#import "Logging.h"
#import "CocoaCategories.h"


// When #define'd you can execute the NeoVimServer binary and neovim will be started:
// $ ./NeoVimServer local remote
#undef DEBUG_NEOVIM_SERVER_STANDALONE
//#define DEBUG_NEOVIM_SERVER_STANDALONE


static const double qTimeout = 10;

#define data_to_array(type)                                               \
static type *data_to_ ## type ## _array(NSData *data, NSUInteger count) { \
  NSUInteger length = count * sizeof( type );                             \
  if (data.length != length) {                                            \
    return NULL;                                                          \
  }                                                                       \
  return ( type *) data.bytes;                                            \
}

data_to_array(int)
data_to_array(NSInteger)

static inline NSUInteger response_id_from_data(NSData *data) {
  NSUInteger *values = (NSUInteger *) data.bytes;
  return values[0];
}

static inline NSData *data_without_response_id(NSData *data) {
  NSUInteger *values = (NSUInteger *) data.bytes;
  NSUInteger length = data.length - sizeof(NSUInteger);
  return length == 0 ? NSData.new : [NSData dataWithBytes:(values + 1) length:length];
}

@interface NeoVimServer ()

- (NSData *)handleMessageWithId:(SInt32)msgid data:(NSData *)data;

@end

static CFDataRef local_server_callback(CFMessagePortRef local, SInt32 msgid, CFDataRef data, void *info) {
  @autoreleasepool {
    NeoVimServer *neoVimServer = (__bridge NeoVimServer *) info;
    NSData *responseData = [neoVimServer handleMessageWithId:msgid data:(__bridge NSData *) data];

    if (responseData == nil) {
      return NULL;
    }

    return CFDataCreateCopy(kCFAllocatorDefault, (__bridge CFDataRef) responseData);
  }
}


@implementation NeoVimServer {
  NSString *_localServerName;
  NSString *_remoteServerName;

  CFMessagePortRef _remoteServerPort;

  NSThread *_localServerThread;
  CFMessagePortRef _localServerPort;
  CFRunLoopRef _localServerRunLoop;
}

- (instancetype)initWithLocalServerName:(NSString *)localServerName remoteServerName:(NSString *)remoteServerName {
  self = [super init];
  if (self == nil) {
    return nil;
  }

  _localServerName = localServerName;
  _remoteServerName = remoteServerName;

  _localServerThread = [[NSThread alloc] initWithTarget:self selector:@selector(runLocalServer) object:nil];
  _localServerThread.name = localServerName;
  [_localServerThread start];

#ifndef DEBUG_NEOVIM_SERVER_STANDALONE
  _remoteServerPort = CFMessagePortCreateRemote(kCFAllocatorDefault, (__bridge CFStringRef) _remoteServerName);
#endif

  return self;
}

- (void)dealloc {
  if (CFMessagePortIsValid(_remoteServerPort)) {
    CFMessagePortInvalidate(_remoteServerPort);
  }
  CFRelease(_remoteServerPort);

  if (CFMessagePortIsValid(_localServerPort)) {
    CFMessagePortInvalidate(_localServerPort);
  }
  CFRelease(_localServerPort);

  CFRunLoopStop(_localServerRunLoop);
  [_localServerThread cancel];
}

- (void)runLocalServer {
  @autoreleasepool {
    unsigned char shouldFree = false;
    CFMessagePortContext localContext = {
        .version = 0,
        .info = (__bridge void *) self,
        .retain = NULL,
        .release = NULL,
        .copyDescription = NULL
    };

    _localServerPort = CFMessagePortCreateLocal(
        kCFAllocatorDefault,
        (__bridge CFStringRef) _localServerName,
        local_server_callback,
        &localContext,
        &shouldFree
    );

    // FIXME: handle shouldFree == true
  }

  _localServerRunLoop = CFRunLoopGetCurrent();
  CFRunLoopSourceRef runLoopSrc = CFMessagePortCreateRunLoopSource(kCFAllocatorDefault, _localServerPort, 0);
  CFRunLoopAddSource(_localServerRunLoop, runLoopSrc, kCFRunLoopCommonModes);
  CFRelease(runLoopSrc);

#ifdef DEBUG_NEOVIM_SERVER_STANDALONE
  server_start_neovim();
#endif

  CFRunLoopRun();
}

- (void)sendMessageWithId:(NeoVimServerMsgId)msgid {
  [self sendMessageWithId:msgid data:nil];
}

- (void)sendMessageWithId:(NeoVimServerMsgId)msgid data:(NSData *)data {
#ifdef DEBUG_NEOVIM_SERVER_STANDALONE
  return;
#endif

  if (_remoteServerPort == NULL) {
    WLOG("Remote server is null: The msg (%lu:%s) could not be sent.", (unsigned long) msgid, data.cdesc);
    return;
  }

  SInt32 responseCode = CFMessagePortSendRequest(
      _remoteServerPort, msgid, (__bridge CFDataRef) data, qTimeout, qTimeout, NULL, NULL
  );

  if (responseCode == kCFMessagePortSuccess) {
    return;
  }

  WLOG("The msg (%lu:%s) could not be sent: %d", (unsigned long) msgid, data.cdesc, responseCode);
}

- (void)notifyReadiness {
#ifndef DEBUG_NEOVIM_SERVER_STANDALONE
  [self sendMessageWithId:NeoVimServerMsgIdServerReady data:nil];
#endif
}

- (void)quit {
  server_quit();
}

- (NSData *)handleMessageWithId:(SInt32)msgid data:(NSData *)data {
  switch (msgid) {

    case NeoVimAgentMsgIdAgentReady:
      server_start_neovim();
      return nil;

    case NeoVimAgentMsgIdCommand: {
      NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
      server_vim_command(string);

      return nil;
    }

    case NeoVimAgentMsgIdCommandOutput: {
      NSUInteger responseId = response_id_from_data(data);
      NSString *command = [[NSString alloc] initWithData:data_without_response_id(data) encoding:NSUTF8StringEncoding];

      server_vim_command_output(responseId, command);
      return nil;
    }

    case NeoVimAgentMsgIdInput: {
      NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
      server_vim_input(string);

      return nil;
    }

    case NeoVimAgentMsgIdInputMarked: {
      NSString *string = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
      server_vim_input_marked_text(string);

      return nil;
    }

    case NeoVimAgentMsgIdDelete: {
      NSInteger *values = data_to_NSInteger_array(data, 1);
      server_delete(values[0]);
      return nil;
    }

    case NeoVimAgentMsgIdResize: {
      int *values = data_to_int_array(data, 2);
      server_resize(values[0], values[1]);
      return nil;
    }

    case NeoVimAgentMsgIdSelectWindow: {
      int *values = data_to_int_array(data, 1);
      server_select_win(values[0]);
      return nil;
    }

    case NeoVimAgentMsgIdQuit:
      // exit() after returning the response such that the agent can get the response and so does not log a warning.
      [self performSelector:@selector(quit) onThread:_localServerThread withObject:nil waitUntilDone:NO];
      return nil;

    case NeoVimAgentMsgIdGetDirtyDocs: {
      bool dirty = server_has_dirty_docs();
      return [NSData dataWithBytes:&dirty length:sizeof(bool)];
    }

    case NeoVimAgentMsgIdGetEscapeFileNames: {
      NSArray <NSString *> *fileNames = [NSKeyedUnarchiver unarchiveObjectWithData:data];
      NSMutableArray <NSString *> *result = [NSMutableArray new];

      [fileNames enumerateObjectsUsingBlock:^(NSString* fileName, NSUInteger idx, BOOL *stop) {
        [result addObject:server_escaped_filename(fileName)];
      }];

      return [NSKeyedArchiver archivedDataWithRootObject:result];
    }

    case NeoVimAgentMsgIdGetBuffers: {
      return [NSKeyedArchiver archivedDataWithRootObject:server_buffers()];
    }

    case NeoVimAgentMsgIdGetTabs: {
      return [NSKeyedArchiver archivedDataWithRootObject:server_tabs()];
    }

    case NeoVimAgentMsgIdGetBoolOption: {
      NSUInteger responseId = response_id_from_data(data);
      NSString *optionName = [[NSString alloc] initWithData:data_without_response_id(data)
                                                  encoding:NSUTF8StringEncoding];

      server_get_bool_option(responseId, optionName);
      return nil;
    }

    case NeoVimAgentMsgIdSetBoolOption: {
      NSUInteger responseId = response_id_from_data(data);

      NSData *paramData = data_without_response_id(data);
      bool *optionValues = (bool *) paramData.bytes;
      bool optionValue = optionValues[0];

      const char *string = (const char *)(optionValues + 1);
      NSString *optionName = [[NSString alloc] initWithCString:string encoding:NSUTF8StringEncoding];

      server_set_bool_option(responseId, optionName, optionValue);
      return nil;
    }

    default:
      return nil;
  }
}

@end