#include <string.h>
#include <stdlib.h> 
#include "grubconffile.h"
#include "grubconf.m"

static CONFIG_FILE grubconf_file(
		"/boot/grub/menu.lst",
		help_nil,CONFIGF_MANAGED,
		"root","root",0600);

enum {
	VIEWITEM_TITLE = VIEWITEM_LAST
};

static const char *K_TITLE = "title";

const char *command_order[] = {
	"rootnoverify",
	"root",
	"kernel",
	"module",
	"initrd",
	"makeactive",
	"chainloader"
};

int total_commands = sizeof(command_order)/sizeof(const char *);

PUBLIC GRUB_VI_PARSER::GRUB_VI_PARSER()
	: VIEWITEMS_PARSER()
{
}

PUBLIC void GRUB_VI_PARSER::addline(const char *line)
{
	int type;
	int titlen = strlen(K_TITLE);
	if (is_comment(line)){
		type = VIEWITEM_COMMENT;
	}else if (*(str_skip(line)) == 0){
		type = VIEWITEM_EMPTY;
	}else if (strncmp(str_skip(line),K_TITLE,titlen) == 0){
		type = VIEWITEM_TITLE;
	}else{
		type = VIEWITEM_VARIABLE;
	}
	vi->add(new VIEWITEM(line,type));
}

PUBLIC GRUBCONFFILE::GRUBCONFFILE()
	: vi(gvip), haschanged(0)
{
	vi.read(grubconf_file);
	detect_ind_sep();
}

PUBLIC GRUBCONFFILE::~GRUBCONFFILE()
{
	if (haschanged) vi.write(grubconf_file,NULL);
	free(ind_globals);
	free(ind_titles);
	free(ind_scripts);
	free(sep_globals);
	free(sep_titles);
	free(sep_scripts);
}

PUBLIC int GRUBCONFFILE::count_titles()
{
	return vi.getnb(VIEWITEM_TITLE);
}

PUBLIC const char *GRUBCONFFILE::locate(int title, const char *var)
{
	VIEWITEM *it = this->locate_it(title,var);
	if (it != NULL){
		const char *p = it->line.get();
		if (*p == '\t' || *p == ' '){
			p = str_skip(p);
		}
		p += strlen(var)+1;
		if (*p == '\t' || *p == ' '){
			p = str_skip(p);
		}
		if (*p == '='){
			p = str_skip(++p);
		}
		return p;
	}
	return NULL;
}

PRIVATE VIEWITEM *GRUBCONFFILE::locate_it(int title, const char *var)
{
	int varlen = strlen(var);
	int start,end;
	if (title >= this->count_titles()){
		return NULL;
	}else if (title == -1){
		start = 0;
		end = vi.getnb(-1);
	}else{
		start = vi.realpos(title,VIEWITEM_TITLE);
		if (start == -1){
			start = 0;
			end = vi.getnb(-1);
		}else{
			end = vi.realpos(title+1,VIEWITEM_TITLE);
			if (end == -1){
				end = vi.getnb(-1);
			}
		}
	}
	for (int i = start; i < end; i++){
		VIEWITEM *it = vi.getitem(i,-1);
		if (it->type == VIEWITEM_VARIABLE
		    || it->type == VIEWITEM_TITLE){
			const char *p = str_skip(it->line.get());
			if (strncmp(p,var,varlen)==0){
				p += varlen;
				if (*p == '\t' || *p == '\0' || *p == ' ' || *p == '='){
					return it;
				}
			}
		}
	}
	return NULL;
}

PUBLIC void GRUBCONFFILE::update(int title, const char *var, const char *value)
{
	const char *ind, *sep;
	haschanged = 1;
	if (title == -1){
		ind = ind_globals;
		sep = sep_globals;
	}else if (strcmp(var,"title")==0){
		ind = ind_titles;
		sep = sep_titles;
	}else if (strcmp(var,"chainloader")==0){
		ind = ind_scripts;
		sep = " ";
	}else{
		ind = ind_scripts;
		sep = sep_scripts;
	}
	if (*value == 0){
		sep = "";
	}
	VIEWITEM *it = this->locate_it(title,var);
	if (it != NULL){
		it->line.setfromf("%s%s%s%s",ind,var,sep,value);
	}else{
		int pos = this->find_insert_position(title,var);
		if (strcmp("title",var)==0){
			it = new VIEWITEM("",VIEWITEM_TITLE);
		}else{
			it = new VIEWITEM("",VIEWITEM_VARIABLE);
		}
		it->line.setfromf("%s%s%s%s",ind,var,sep,value);
		vi.insert(pos,it,-1);
	}
}

PRIVATE int GRUBCONFFILE::find_insert_position(int title, const char *var)
{
	int nb = vi.getnb(-1);
	int last;
	if (title == -1){
		int pos = 0;
		last = pos;
		for (; pos < nb; pos++){
			VIEWITEM *it = vi.getitem(pos,-1);
			if (it->type == VIEWITEM_TITLE){
				break;
			}else if (it->type == VIEWITEM_VARIABLE){
				last = pos;
			}
		}
	}else{
		if (title >= this->count_titles()){
			return vi.getnb(-1);
		}
		int pos = vi.realpos(title,VIEWITEM_TITLE);
		last = pos;
		int total_commands = sizeof(command_order)/sizeof(const char *);
		// Find command position
		int order = -1;
		for (int j = 0; j < total_commands; j++){
			if (strcmp(var,command_order[j])==0){
				order = j;
				break;
			}
		}
		if (order == -1){
			xconf_error(MSG_U(E_INVVAR,"Invalid variable!"));
		}
		pos++; // Jump the first title
		for (; pos < nb; pos++){
			VIEWITEM *it = vi.getitem(pos,-1);
			if (it->type == VIEWITEM_TITLE){
				break;
			}else if (it->type == VIEWITEM_VARIABLE){
				bool found = true;
				int j = 0;
				const char *line = str_skip(it->line.get());
				for (; j < total_commands; j++){
					if (strncmp(line,command_order[j]
						    ,strlen(command_order[j]))==0){
						found = true;
						break;
					}
				}
				if (found == false){
					break;
				}else if (j >= order){
					break;
				}else{
					last = pos;
				}
			}
		}
	}
	return last+1;
}

PUBLIC void GRUBCONFFILE::erase(int title, const char *var)
{
	haschanged = 1;
	VIEWITEM *it = this->locate_it(title,var);
	if (it != NULL){
		vi.remove_del(it);
	}
}

PRIVATE char *GRUBCONFFILE::extract_indent(VIEWITEM *it)
{
	const char *start = it->line.get();
	const char *end = start;
	while (*end == ' ' || *end == '\t') end++;
	int len = end-start;
	char *ret = (char *) malloc(len+1);
	memcpy(ret,start,len);
	ret[len] = 0;
	return ret;
}

PRIVATE char *GRUBCONFFILE::extract_separator(VIEWITEM *it)
{
	const char *start = it->line.get();
	while (*start == ' ' || *start == '\t') start++;
	while (*start != ' ' && *start != '\t' && *start != '=') start++;
	const char *end = start;
	bool first_equal = true;
	while (*end == ' ' || *end == '\t' || (*end == '=' && first_equal)){
		if (*end == '=') first_equal = false;
		end++;
	}
	int len = end-start;
	char *ret = (char *) malloc(len+1);
	memcpy(ret,start,len);
	ret[len] = 0;
	return ret;
}

PRIVATE void GRUBCONFFILE::detect_ind_sep()
{
	const char *ind_default = "";
	const char *sep_default = " ";
	VIEWITEM *it;
	int nb = vi.getnb(-1);
	int i = 0;
	ind_globals = ind_titles = ind_scripts = NULL;
	sep_globals = sep_titles = sep_scripts = NULL;
	for (; i < nb; i++){
		it = vi.getitem(i,-1);
		if (it->type == VIEWITEM_VARIABLE){
			ind_globals = extract_indent(it);
			sep_globals = extract_separator(it);
			i++;
			break;
		}else if (it->type == VIEWITEM_TITLE){
			break;
		}
	}
	for (; i < nb; i++){
		it = vi.getitem(i,-1);
		if (it->type == VIEWITEM_TITLE){
			ind_titles = extract_indent(it);
			sep_titles = extract_separator(it);
			i++;
			break;
		}
	}
	for (; i < nb; i++){
		it = vi.getitem(i,-1);
		if (it->type == VIEWITEM_VARIABLE){
			ind_scripts = extract_indent(it);
			sep_scripts = extract_separator(it);
			break;
		}
	}
	if (ind_globals == NULL){
		ind_globals = strdup(ind_default);
		ind_titles  = strdup(ind_default);
		ind_scripts = strdup(ind_default);
		sep_globals = strdup(sep_default);
		sep_titles  = strdup(sep_default);
		sep_scripts = strdup(sep_default);
	}else if (ind_titles  == NULL){
		ind_titles  = strdup(ind_default);
		ind_scripts = strdup(ind_default);
		sep_titles  = strdup(sep_default);
		sep_scripts = strdup(sep_default);
	}else if (ind_scripts == NULL){
		ind_scripts = strdup(ind_default);
		sep_scripts = strdup(sep_default);
	}
}

PUBLIC bool GRUBCONFFILE::check_script(int pos)
{
	int cur = vi.realpos(pos,VIEWITEM_TITLE);
	if (cur == -1) return -1;
	int end = vi.realpos(pos+1,VIEWITEM_TITLE);
	if (end == -1) end = vi.getnb(-1);
	int order = -1;
	for (int i = cur+1; i < end; i++) {
		VIEWITEM *it = vi.getitem(i,-1);
		const char *line = str_skip(it->line.get());
		if (it->type == VIEWITEM_VARIABLE){
			int j = 0;
			bool found = false;
			for (; j < total_commands; j++){
				if (strncmp(line,command_order[j]
					    ,strlen(command_order[j]))==0){
					found = true;
					while (j <= order && j+1 < total_commands
					       && strncmp(line,command_order[j+1],
						          strlen(command_order[j+1]))==0){
						j++;
					}
					break;
				}
			}
			if (found == false || j <= order){
				if (found == false){
				  xconf_error(MSG_U(E_COMMINV,"Unsupported command!"));
				}else if (j == order){
				  xconf_error(MSG_U(E_COMMDUP,"Duplicated command!"));
				}else{
				  xconf_error(MSG_U(E_COMMORD,"Command out of order!"));
				}
				return false;
			}
			order = j; 
		}
		
	}
	return true;
}