#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <jsapi.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <errno.h>
#include <stdarg.h>
#include <time.h>
#include <utime.h>
#include <unistd.h>
#include <jsdate.h>
#include "js_util_functions.h"
#include "file.h"


//You must include the .0 on the constant 1000.0 so the calculation is done as a double, not as an integer.
#define SEC_TO_MSEC(sec) (sec*1000.0)




static JSBool checkForPermission(FileInformation *info, int perm);
static JSBool File_ctor(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_exists(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_create(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_touch(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_getPermissions(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_isReadable(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_isWritable(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_isExecutable(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_isLink(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_isPipe(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_isSocket(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_isDirectory(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_getLastModified(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_getLastAccess(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_getCreationTime(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_getSize(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);
static JSBool File_truncate(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval);


static JSObject *FilePrototype = NULL;
static JSClass js_File_class = {
    "File",
    JSCLASS_HAS_PRIVATE,
    JS_PropertyStub,
    JS_PropertyStub,
    JS_PropertyStub,
    JS_PropertyStub,
    JS_EnumerateStub,
    JS_ResolveStub,
    JS_ConvertStub,
    JS_FinalizeStub,
    JSCLASS_NO_OPTIONAL_MEMBERS
};

static JSFunctionSpec File_methods[] = {
    {"create", File_create, 0, 0 ,0},
    {"touch", File_touch, 0, 0, 0},
    {"exists", File_exists, 0, 0 ,0},
    {"getPermissions", File_getPermissions, 0, 0 ,0},
    {"isReadable", File_isReadable, 0, 0 ,0},
    {"isWritable", File_isWritable, 0, 0 ,0},
    {"isExecutable", File_isExecutable, 0, 0 ,0},
    {"isLink", File_isLink, 0, 0 ,0},
    {"isPipe", File_isPipe, 0, 0 ,0},
    {"isSocket", File_isSocket, 0, 0 ,0},
    {"isDirectory", File_isDirectory, 0, 0 ,0},
    {"getLastModified", File_getLastModified, 0, 0 ,0},
    {"getLastAccess", File_getLastAccess, 0, 0 ,0},
    {"getCreationTime", File_getCreationTime, 0, 0 ,0},
    {"getSize", File_getSize, 0, 0 ,0},
    {"truncate", File_truncate, 0, 0 ,0},
    {NULL}
};

static char *staterrorstr(int e){
    char *msg = NULL;
    switch (e){
		case ENOENT:
			msg = strdup("File does not exist.");
			break;
        case EACCES:
            msg = strdup("Permission denied to check file.");
            break;
        case EBADF:
            msg = strdup("Bad file descriptor");
            break;
        case ELOOP:
            msg = strdup("Symbolic link loop encountered.");
            break;
        case ENAMETOOLONG:
            msg = strdup("File name too long, not supported.");
            break;
        case ENOMEM:
            msg = strdup("Out of memory.");
            break;
        case ENOTDIR:
            msg = strdup("Path component not a directory.");
            break;
        default:
            msg = strdup("Unknown error occured.");
    }
    return msg;
}

JSBool register_class_File(JSContext *cx){
	JSObject *globalObj = JS_GetGlobalObject(cx);

    /* Define the file object. */
    FilePrototype = JS_InitClass(cx, globalObj, NULL, &js_File_class, File_ctor, 1, NULL, File_methods, NULL, NULL);
    if (!FilePrototype){
        return JS_FALSE;
    }
	return JS_TRUE;
}

JSObject *File_getPrototypeObject(){
	return FilePrototype;
}


static JSBool File_ctor(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
    if (argc < 1){
        char *str = strdup("Not enough parameters to File constructor.");
        JSString *exceptionDescription = JS_NewString(cx, str, strlen(str));
        JS_SetPendingException(cx, STRING_TO_JSVAL(exceptionDescription));
        return JS_FALSE;
    }
    else {
		char *file=NULL;
		size_t fileNameLength=0;

        FileInformation *info = malloc(sizeof(*info));
        info->fp = NULL;
        info->filename = NULL;
			
		fileNameLength = JSString_to_CString(JS_ValueToString(cx, argv[0]), &file);

        info->filename = strdup(file);
        JS_SetPrivate(cx, obj, info);
    }
    return JS_TRUE;
}


static JSBool File_create(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
    /* First see if the file already exists.  If it does, throw an exception. */
    struct stat existsCheck;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);
    
    if (stat(info->filename, &existsCheck) == 0){
		jsval exception = printf_exception(cx, "Cannot create file '%s'.  A file by that name already exists.", info->filename);
        JS_SetPendingException(cx, exception);
        return JS_FALSE;
    }
    else if (errno == ENOENT){
        FILE *fp = NULL;
        fp = fopen(info->filename, "w");
        if (fp){
            fclose(fp);            
            *rval = BOOLEAN_TO_JSVAL(JS_TRUE);
        }
        else {
            *rval = BOOLEAN_TO_JSVAL(JS_FALSE);
        }
        return JS_TRUE;
    }
    else {
        char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "Creation failed.  (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
        return JS_FALSE;
    }
	return JS_TRUE;
}

static JSBool File_touch(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat existsCheck;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);
    
	if (stat(info->filename, &existsCheck) == 0){
		struct utimbuf times;
		times.actime = time(NULL);
		times.modtime = time(NULL);

		if (utime(info->filename, &times) == 0){
			*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		}
		else {
			char *msg = staterrorstr(errno);
			jsval exception = printf_exception(cx, "touch failed.  (%d) %s", errno, msg);
			free(msg);
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}				
	}
	else if (errno == ENOENT){
		FILE *fp = fopen(info->filename, "w");
		if (fp){
			fclose(fp);
			*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		}
		else {
			char *msg = staterrorstr(errno);
			jsval exception = printf_exception(cx, "touch failed, could not create file.  (%d) %s", errno, msg);
			free(msg);
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}
	}
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "Existance check failed (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
    return JS_TRUE;
}

static JSBool File_exists(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	/* First see if the file already exists.  If it does, throw an exception. */
    struct stat existsCheck;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);
    
    if (stat(info->filename, &existsCheck) == 0){
		*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
    }
    else if (errno == ENOENT){
		*rval = BOOLEAN_TO_JSVAL(JS_FALSE);
    }
    else {
        char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "Existance check failed. (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
        return JS_FALSE;
    }
	return JS_TRUE;
}

static JSBool File_getPermissions(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
    struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);
    
    if (stat(info->filename, &fileInfo) == 0){
		*rval = INT_TO_JSVAL(fileInfo.st_mode);
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}

static JSBool File_isReadable(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);
	errno = 0;
    if (checkForPermission(info, S_IRUSR|S_IRGRP|S_IROTH)){
		*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		return JS_TRUE;
    }
	else {
		if (errno == 0){
			*rval = BOOLEAN_TO_JSVAL(JS_FALSE);
			return JS_TRUE;
		}
		else {
			char *msg = staterrorstr(errno);
			jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
			free(msg);
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}
	}
}
static JSBool File_isWritable(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);
	errno = 0;
    if (checkForPermission(info, S_IWUSR|S_IWGRP|S_IWOTH)){
		*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		return JS_TRUE;
    }
	else {
		if (errno == 0){
			*rval = BOOLEAN_TO_JSVAL(JS_FALSE);
			return JS_TRUE;
		}
		else {
			char *msg = staterrorstr(errno);
			jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
			free(msg);
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}
	}
}
static JSBool File_isExecutable(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);
	errno = 0;
    if (checkForPermission(info, S_IXUSR|S_IXGRP|S_IXOTH)){
		*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		return JS_TRUE;
    }
	else {
		if (errno == 0){
			*rval = BOOLEAN_TO_JSVAL(JS_FALSE);
			return JS_TRUE;
		}
		else {
			char *msg = staterrorstr(errno);
			jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
			free(msg);
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}
	}
}
static JSBool File_isLink(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	

    if (lstat(info->filename, &fileInfo) == 0){
		if (S_ISLNK(fileInfo.st_mode)){
			*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		}
		else {
			*rval = BOOLEAN_TO_JSVAL(JS_FALSE);
		}
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}
static JSBool File_isPipe(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	

    if (stat(info->filename, &fileInfo) == 0){
		if (S_ISFIFO(fileInfo.st_mode)){
			*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		}
		else {
			*rval = BOOLEAN_TO_JSVAL(JS_FALSE);
		}
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}
static JSBool File_isSocket(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	

    if (stat(info->filename, &fileInfo) == 0){
		if (S_ISSOCK(fileInfo.st_mode)){
			*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		}
		else {
			*rval = BOOLEAN_TO_JSVAL(JS_FALSE);
		}
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}
static JSBool File_isDirectory(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	

    if (stat(info->filename, &fileInfo) == 0){
		if (S_ISDIR(fileInfo.st_mode)){
			*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
		}
		else {
			*rval = BOOLEAN_TO_JSVAL(JS_FALSE);
		}
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}
static JSBool File_getLastModified(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	

    if (stat(info->filename, &fileInfo) == 0){
		JSObject *dateObj = js_NewDateObjectMsec(cx, SEC_TO_MSEC(fileInfo.st_mtime));
		if (!dateObj){
			jsval exception = printf_exception(cx, "Unable to construct date object to hold time.");
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}
		*rval = OBJECT_TO_JSVAL(dateObj);
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}
static JSBool File_getLastAccess(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	

    if (stat(info->filename, &fileInfo) == 0){
		JSObject *dateObj = js_NewDateObjectMsec(cx, SEC_TO_MSEC(fileInfo.st_atime));
		if (!dateObj){
			jsval exception = printf_exception(cx, "Unable to construct date object to hold time.");
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}
		*rval = OBJECT_TO_JSVAL(dateObj);
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}
static JSBool File_getCreationTime(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	

    if (stat(info->filename, &fileInfo) == 0){
		JSObject *dateObj = js_NewDateObjectMsec(cx, SEC_TO_MSEC(fileInfo.st_ctime));
		if (!dateObj){
			jsval exception = printf_exception(cx, "Unable to construct date object to hold time.");
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}
		*rval = OBJECT_TO_JSVAL(dateObj);
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}
static JSBool File_getSize(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
	struct stat fileInfo;
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	

    if (stat(info->filename, &fileInfo) == 0){
		*rval = INT_TO_JSVAL(fileInfo.st_size);
		return JS_TRUE;
    }
	else {
		char *msg = staterrorstr(errno);
		jsval exception = printf_exception(cx, "stat failed on file (%d) %s", errno, msg);
		free(msg);
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}

static JSBool File_truncate(JSContext *cx, JSObject *obj, uintN argc, jsval *argv, jsval *rval){
    FileInformation *info = (FileInformation*)JS_GetPrivate(cx, obj);	
    if (argc >= 1){
		off_t len = JSVAL_TO_INT(argv[0]);
		if (truncate(info->filename, len) == 0){
			*rval = BOOLEAN_TO_JSVAL(JS_TRUE);
			return JS_TRUE;
		}
		else {
			char *msg = staterrorstr(errno);
			jsval exception = printf_exception(cx, "Truncate failed on file. (%d) %s", errno, msg);
			free(msg);
			JS_SetPendingException(cx, exception);
			return JS_FALSE;
		}
    }
	else {
		jsval exception = printf_exception(cx, "Not enough arguments");
		JS_SetPendingException(cx, exception);
		return JS_FALSE;
	}
}

static JSBool checkForPermission(FileInformation *info, int perm){
    struct stat fileInfo;
    if (stat(info->filename, &fileInfo) == 0){
		uid_t uid=-1;
		gid_t gid=-1;

		uid = geteuid();
		gid = getegid();

		if (uid == fileInfo.st_uid){
			if (fileInfo.st_mode & (perm & S_IRWXU)){
				return JS_TRUE;
			}
			else {
				return JS_FALSE;
			}
		}
		else if (gid == fileInfo.st_gid){
			if (fileInfo.st_mode & (perm & S_IRWXG)){
				return JS_TRUE;
			}
			else {
				return JS_FALSE;
			}
		}
		else {
			if (fileInfo.st_mode & (perm & S_IRWXO)){
				return JS_TRUE;
			}
			else {
				return JS_FALSE;
			}
		}
	}
	else {
		return JS_FALSE;
	}
}