/*
Copyright (C) 2005-2008 Axel Liljencrantz

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/


/** \file fish.c
	The main loop of <tt>fish</tt>.
*/

#include "config.h"


#include <stdlib.h>
#include <stdio.h>
#include <wchar.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <unistd.h>
#include <termios.h>
#include <fcntl.h>
#include <sys/param.h>

#ifdef HAVE_GETOPT_H
#include <getopt.h>
#endif

#include <locale.h>
#include <signal.h>

#include "fallback.h"
#include "util.h"

#include "common.h"
#include "reader.h"
#include "builtin.h"
#include "function.h"
#include "complete.h"
#include "wutil.h"
#include "env.h"
#include "sanity.h"
#include "proc.h"
#include "parser.h"
#include "expand.h"
#include "intern.h"
#include "exec.h"
#include "event.h"
#include "output.h"
#include "history.h"
#include "path.h"

/* PATH_MAX may not exist */
#ifndef PATH_MAX
#define PATH_MAX 1024
#endif

/**
   The string describing the single-character options accepted by the main fish binary
*/
#define GETOPT_STRING "+hilnvc:p:d:"

static bool has_suffix(const std::string &path, const char *suffix, bool ignore_case)
{
    size_t pathlen = path.size(), suffixlen = strlen(suffix);
    return pathlen >= suffixlen && ! (ignore_case ? strcasecmp : strcmp)(path.c_str() + pathlen - suffixlen, suffix);
}

/* Modifies the given path by calling realpath. Returns true if realpath succeeded, false otherwise */
static bool get_realpath(std::string &path)
{
    char buff[PATH_MAX], *ptr;
    if ((ptr = realpath(path.c_str(), buff)))
    {
        path = ptr;
    }
    return ptr != NULL;
}

/* OS X function for getting the executable path */
extern "C" {
    int _NSGetExecutablePath(char* buf, uint32_t* bufsize);
}

/* Return the path to the current executable. This needs to be realpath'd. */
static std::string get_executable_path(const char *argv0)
{
    char buff[PATH_MAX];
#if __APPLE__
    {
        /* Returns 0 on success, -1 if the buffer is too small */
        uint32_t buffSize = sizeof buff;
        if (0 == _NSGetExecutablePath(buff, &buffSize))
            return std::string(buff);
        
        /* Loop until we're big enough */
        char *mbuff = (char *)malloc(buffSize);
        while (0 > _NSGetExecutablePath(mbuff, &buffSize))
            mbuff = (char *)realloc(mbuff, buffSize);
        
        /* Return the string */
        std::string result = mbuff;
        free(mbuff);
        return result;
    }
#endif
    {
        /* On other Unixes, try /proc directory. This might be worth breaking out into macros. */
        if (0 < readlink("/proc/self/exe", buff, sizeof buff) || // Linux
            0 < readlink("/proc/curproc/file", buff, sizeof buff) || // BSD
            0 < readlink("/proc/self/path/a.out", buff, sizeof buff)) // Solaris
        {
            return std::string(buff);
        }
    }
    
    /* Just return argv0, which probably won't work (i.e. it's not an absolute path or a path relative to the working directory, but instead something the caller found via $PATH). We'll eventually fall back to the compile time paths. */
    return std::string(argv0 ? argv0 : "");
}


static struct config_paths_t determine_config_directory_paths(const char *argv0)
{
    struct config_paths_t paths;
    bool done = false;
    std::string exec_path = get_executable_path(argv0);
    if (get_realpath(exec_path))
    {        
#if __APPLE__
        
        /* On OS X, maybe we're an app bundle, and should use the bundle's files. Since we don't link CF, use this lame approach to test it: see if the resolved path ends with /Contents/MacOS/fish, case insensitive since HFS+ usually is.
         */
        if (! done)
        {
            const char *suffix = "/Contents/MacOS/fish";
            const size_t suffixlen = strlen(suffix);
            if (has_suffix(exec_path, suffix, true))
            {
                /* Looks like we're a bundle. Cut the string at the / prefixing /Contents... and then the rest */
                wcstring wide_resolved_path = str2wcstring(exec_path);
                wide_resolved_path.resize(exec_path.size() - suffixlen);
                wide_resolved_path.append(L"/Contents/Resources/");
                
                /* Append share, etc, doc */
                paths.data = wide_resolved_path + L"share/fish";
                paths.sysconf = wide_resolved_path + L"etc/fish";
                paths.doc = wide_resolved_path + L"doc/fish";
                
                /* But the bin_dir is the resolved_path, minus fish (aka the MacOS directory) */
                paths.bin = str2wcstring(exec_path);
                paths.bin.resize(paths.bin.size() - strlen("/fish"));
                
                done = true;
            }
        }
#endif
        
        if (! done)
        {
            /* The next check is that we are in a reloctable directory tree like this:
                 bin/fish
                 etc/fish
                 share/fish
                 
                 Check it!
            */
            const char *suffix = "/bin/fish";
            if (has_suffix(exec_path, suffix, false))
            {
                wcstring base_path = str2wcstring(exec_path);
                base_path.resize(base_path.size() - strlen(suffix));
                
                paths.data = base_path + L"/share/fish";
                paths.sysconf = base_path + L"/etc/fish";
                paths.doc = base_path + L"/share/doc/fish";
                paths.bin = base_path + L"/bin";
                
                struct stat buf;
                if (0 == wstat(paths.data, &buf) && 0 == wstat(paths.sysconf, &buf))
                {
                    done = true;
                }
            }
        }
    }
    
    if (! done)
    {
        /* Fall back to what got compiled in. */
        paths.data = L"" DATADIR "/fish";
        paths.sysconf = L"" SYSCONFDIR "/fish";
        paths.doc = L"" DATADIR "/doc/fish";
        paths.bin = L"" PREFIX "/bin";
        
        done = true;
    }
    
    return paths;
}

/**
   Parse init files. exec_path is the path of fish executable as determined by argv[0].
*/
static int read_init(const struct config_paths_t &paths)
{
    parser_t &parser = parser_t::principal_parser();
    const io_chain_t empty_ios;
	parser.eval( L"builtin . " + paths.data + L"/config.fish 2>/dev/null", empty_ios, TOP );
	parser.eval( L"builtin . " + paths.sysconf + L"/config.fish 2>/dev/null", empty_ios, TOP );

	
	/*
	  We need to get the configuration directory before we can source the user configuration file
	*/
	wcstring config_dir;

	/*
	  If path_get_config returns false then we have no configuration directory
	  and no custom config to load.
	*/
    if (path_get_config(config_dir))
	{
		wcstring config_dir_escaped = escape_string( config_dir, 1 );
        wcstring eval_buff = format_string(L"builtin . %ls/config.fish 2>/dev/null", config_dir_escaped.c_str());
		parser.eval( eval_buff, empty_ios, TOP );
	}
	
	return 1;
}


/**
  Parse the argument list, return the index of the first non-switch
  arguments.
 */
static int fish_parse_opt( int argc, char **argv, const char **cmd_ptr )
{
	int my_optind;
	int force_interactive=0;
		
	while( 1 )
	{
		static struct option
			long_options[] =
			{
				{
					"command", required_argument, 0, 'c' 
				}
				,
				{
					"debug-level", required_argument, 0, 'd' 
				}
				,
				{
					"interactive", no_argument, 0, 'i' 
				}
				,
				{
					"login", no_argument, 0, 'l' 
				}
				,
				{
					"no-execute", no_argument, 0, 'n' 
				}
				,
				{
					"profile", required_argument, 0, 'p' 
				}
				,
				{
					"help", no_argument, 0, 'h' 
				}
				,
				{
					"version", no_argument, 0, 'v' 
				}
				,
				{ 
					0, 0, 0, 0 
				}
			}
		;
		
		int opt_index = 0;
		
		int opt = getopt_long( argc,
							   argv, 
							   GETOPT_STRING,
							   long_options, 
							   &opt_index );
		
		if( opt == -1 )
			break;
		
		switch( opt )
		{
			case 0:
			{
				break;
			}
			
			case 'c':		
			{
				*cmd_ptr = optarg;				
				is_interactive_session = 0;
				break;
			}
			
			case 'd':		
			{
				char *end;
				long tmp;

				errno = 0;
				tmp = strtol(optarg, &end, 10);
				
				if( tmp >= 0 && tmp <=10 && !*end && !errno )
				{
					debug_level = (int)tmp;
				}
				else
				{
					debug( 0, _(L"Invalid value '%s' for debug level switch"), optarg );
					exit_without_destructors(1);
				}
				break;
			}
			
			case 'h':
			{
				*cmd_ptr = "__fish_print_help fish";
				break;
			}
			
			case 'i':
			{
				force_interactive = 1;
				break;				
			}
			
			case 'l':
			{
				is_login=1;
				break;				
			}
			
			case 'n':
			{
				no_exec=1;
				break;				
			}
			
			case 'p':
			{
				profile = optarg;
				break;				
			}
			
			case 'v':
			{
				fwprintf( stderr, 
						  _(L"%s, version %s\n"), 
						  PACKAGE_NAME,
						  PACKAGE_VERSION );
				exit_without_destructors( 0 );				
			}
			
			case '?':
			{
				exit_without_destructors( 1 );
			}
			
		}		
	}

	my_optind = optind;
	
	is_login |= (strcmp( argv[0], "-fish") == 0);
		
	/*
	  We are an interactive session if we have not been given an
	  explicit command to execute, _and_ stdin is a tty.
	 */
	is_interactive_session &= (*cmd_ptr == 0);
	is_interactive_session &= (my_optind == argc);
	is_interactive_session &= isatty(STDIN_FILENO);	

	/*
	  We are also an interactive session if we have are forced-
	 */
	is_interactive_session |= force_interactive;

	return my_optind;
}

/**
   Calls a bunch of init functions, parses the init files and then
   parses commands from stdin or files, depending on arguments
*/

static wcstring full_escape( const wchar_t *in )
{
	wcstring out;
	for( ; *in; in++ )
	{
		if( *in < 32 )
		{
			append_format( out, L"\\x%.2x", *in );
		}
		else if( *in < 128 )
		{
			out.push_back(*in);
		}
		else if( *in < 65536 )
		{
			append_format( out, L"\\u%.4x", *in );
		}
		else
		{
			append_format( out, L"\\U%.8x", *in );
		}
	}
	return out;
}

extern int g_fork_count;
int main( int argc, char **argv )
{    
	int res=1;
	const char *cmd=0;
	int my_optind=0;

	set_main_thread();
    setup_fork_guards();
    
	wsetlocale( LC_ALL, L"" );
	is_interactive_session=1;
	program_name=L"fish";

    //struct stat tmp;
    //stat("----------FISH_HIT_MAIN----------", &tmp);

	my_optind = fish_parse_opt( argc, argv, &cmd );

	/*
	  No-exec is prohibited when in interactive mode
	*/
	if( is_interactive_session && no_exec)
	{
		debug( 1, _(L"Can not use the no-execute mode when running an interactive session") );
		no_exec = 0;
	}
    
	const struct config_paths_t paths = determine_config_directory_paths(argv[0]);
    	
	proc_init();	
	event_init();	
	wutil_init();
	//parser_init();
	builtin_init();
	function_init();
	env_init(&paths);
	reader_init();
	history_init();

    parser_t &parser = parser_t::principal_parser();

    if (g_log_forks)
        printf("%d: g_fork_count: %d\n", __LINE__, g_fork_count);

    const io_chain_t empty_ios;
	if( read_init(paths) )
	{
		if( cmd != 0 )
		{
			wchar_t *cmd_wcs = str2wcs( cmd );
			res = parser.eval( cmd_wcs, empty_ios, TOP );
			free(cmd_wcs);
			reader_exit(0, 0);
		}
		else
		{
			if( my_optind == argc )
			{
				res = reader_read( STDIN_FILENO, empty_ios );
			}
			else
			{
				char **ptr; 
				char *file = *(argv+(my_optind++));
				int i; 
				int fd;
				wchar_t *rel_filename, *abs_filename;

                
				if( ( fd = open(file, O_RDONLY) ) == -1 )
				{
					wperror( L"open" );
					return 1;
				}
                
                // OK to not do this atomically since we cannot have gone multithreaded yet
                set_cloexec(fd);
                
				if( *(argv+my_optind))
				{
                    wcstring sb;
					for( i=1,ptr = argv+my_optind; *ptr; i++, ptr++ )
					{
						if( i != 1 )
                            sb.append( ARRAY_SEP_STR );
                        sb.append( str2wcstring( *ptr ));
					}
				
					env_set( L"argv", sb.c_str(), 0 );
				}

				rel_filename = str2wcs( file );
				abs_filename = wrealpath( rel_filename, 0 );

				if( !abs_filename )
				{
					abs_filename = wcsdup(rel_filename);
				}

				reader_push_current_filename( intern( abs_filename ) );
				free( rel_filename );
				free( abs_filename );

				res = reader_read( fd, empty_ios );

				if( res )
				{
					debug( 1, 
					       _(L"Error while reading file %ls\n"), 
					       reader_current_filename()?reader_current_filename(): _(L"Standard input") );
				}				
				reader_pop_current_filename();
			}
		}
	}
	
	proc_fire_event( L"PROCESS_EXIT", EVENT_EXIT, getpid(), res );
	
	history_destroy();
	proc_destroy();
	builtin_destroy();
	reader_destroy();
	parser.destroy();
	wutil_destroy();
	event_destroy();
	
	env_destroy();
	
    if (g_log_forks)
        printf("%d: g_fork_count: %d\n", __LINE__, g_fork_count);
    
	return res?STATUS_UNKNOWN_COMMAND:proc_get_last_status();	
}