// file: menu.c
//
// Convenient framework for menu-driven programs

#include "excalibur.h"
#include "hello_plugs_menu.h"

typedef int (*r_menu_proc)(int);


void r_menu_add_title(int menu_number,char *title,r_menu_proc proc);
void r_menu_add_link(int menu_number,int link_number);
void r_menu_run(void);


#define k_menu_count 100

typedef struct
	{
	int menu_number;	// what menu a member of
	char *title;		// text of menu
	r_menu_proc proc;	// what routine to call
	int link_number;	// (context for proc) ...or what submenu to go to
	} s_menu_item;

typedef struct
	{
	s_menu_item item[k_menu_count];
	int item_count;
	r_menu_proc idle_proc;
	} s_menu_globals;

static s_menu_globals g; // {0} of course


static void r_shared_menu_add(int menu_number, char *title,r_menu_proc proc,int link_number)
	{
	s_menu_item *m;

	m = &g.item[g.item_count++];
	m->menu_number = menu_number;
	m->title = title;
	m->proc = proc;
	m->link_number = link_number;
	}

// -----------------------------
// r_menu_add_item adds an entry to menu_number.
// the first (index 0) thing added to any menu is
// assumed to be its title. The proc gets called just
// after printing the title, for header info, if any.

void r_menu_add_item(int menu_number,char *title,r_menu_proc proc,int context)
	{
	r_shared_menu_add(menu_number,title,proc,context);
	}

void r_menu_add_link(int menu_number,int link_number)
	{
	r_shared_menu_add(menu_number,0,0,link_number);
	}

static void idle_menu(void)
	{
	if(g.idle_proc)
		(g.idle_proc)(0);
	}

int r_get_char(void)
	{
	int c;

	while((c = nr_uart_rxchar(0)) < 0)
		idle_menu();
	return c;
	}

static s_menu_item *find_menu_item(int menu_number,int menu_index)
	{
	s_menu_item *m;
	int i;

	m = g.item;
	for(i = 0; i < g.item_count; i++)
		{
		if(m->menu_number == menu_number)
			{
			if(menu_index-- == 0)
				return m;
			}
		m++;
		}
	
	return 0;
	}

static char *get_menu_title(int menu_number,int menu_index)
	{
	s_menu_item *m;

	m = find_menu_item(menu_number,menu_index);
	if(m)
		return m->title;
	else
		return 0;
	}


void r_menu_run(void)
	{
	int menu_number = 0;	// current menu number
	int menu_index;
	char *s;
	int c;
	s_menu_item *m;

do_menu:
	// Print the current menu choices
	printf("\n\n\n----------------------------\n");

	m = find_menu_item(menu_number,0);
	s = m->title;
	s = s ? s : "(missing title)";

	printf("%s\n\n",s);

	if(m->proc)
		(m->proc)(0);

	menu_index = 1;
	while((m = find_menu_item(menu_number,menu_index)) != 0)
		{
		int is_link;

		is_link = 0;

		s = m->title;
		if(!s)  // submenu gets menu title...
			{
			s = get_menu_title(m->link_number,0);
			is_link = 1;
			}
		printf("   %c: %s%s\n",menu_index + 'a' - 1,s,is_link ? "..." : "");
		menu_index++;
		}
	
	printf("\n   q: Main Menu\n");

	printf("\n\n -----> ");

	// Wait for user menu choice
	c = r_get_char();

	if(c >= 'A' && c <= 'Z')
		c += 'a' - 'A';
	
	if(c >= 32 & c <= 127)
		printf("%c\n",c);
	
	if(c == 'q')
		{
		menu_number = 0;
		goto do_menu;
		}

	c = c - 'a' + 1;
	m = find_menu_item(menu_number,c);

	if(m)
		{
		if(m->proc)
			{
			(m->proc)(m->link_number);
			}
		else if(m->link_number)
			{
			menu_number = m->link_number;
			}
		}
	goto do_menu;
	}




void r_menu_set_idler(r_menu_proc idle_proc)
	{
	g.idle_proc = idle_proc;
	g.item_count = 0;
	}

//---------------------------------------------------
// User Input Routines

void r_strcpy(char *src, char *dst)
	{
	do
		{
		*dst++ = *src;
		} while (*src++);
	}

// string length max is presumed to be 64
int r_input_string(char *prompt, char *default_value, char *value_inout)
	{
	int char_position;
	int done;
	int c;
	char v[64];
	int result;

	// value blank, and default exists? use it.
	if(value_inout[0] == 0 && default_value)
		r_strcpy(default_value, value_inout);

	// print user prompt
	printf("%s: [%s] ",prompt,value_inout);

	// receive chars until return
	done = 0;
	char_position = 0;

	while(!done)
		{
		c = r_get_char();
		if(c == 27) // ESC to cancel
			return -1;
		if(c >= 0x20 && c <= 0x7e)
			{
			printf("%c",c);
			v[char_position++] = c;
			}
		else if(c == 8) // backspace
			{
			if(char_position)
				{
				printf("%c%c%c",8,' ',8);
				char_position--;
				}
			}
		else if(c == 10) // linefeed == done
			done = 1;
		}
	
	v[char_position++] = 0;

	printf("\n");

	// string not blank? replace old value with it
	if(v[0])
		r_strcpy(v,value_inout);
	
	return 0;
	}