#include <qse/types.h>
#include <locale.h>
#include <wchar.h>
#include <wctype.h>
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>

#if QSE_SIZEOF_WCHAR_T == QSE_SIZEOF_SHORT
        #define MAX_CHAR 0xFFFF
#else
        /*#define MAX_CHAR 0xE01EF*/
        #define MAX_CHAR 0x10FFFF
#endif

#define CASE_PAGE_SIZE 512
#define MAX_CASE_PAGE_COUNT ((MAX_CHAR + CASE_PAGE_SIZE) / CASE_PAGE_SIZE)

/* 
 * short is enough as the diff does not exceed
 * the maixmum value of the short type.
 */
typedef long int wcdiff_t;

typedef struct case_page_t case_page_t;
struct case_page_t
{
	size_t no;
	wcdiff_t upper[CASE_PAGE_SIZE];
	wcdiff_t lower[CASE_PAGE_SIZE]; 
	case_page_t* next;
};

size_t case_page_count = 0;
case_page_t* case_pages = NULL;

size_t case_map_count = 0;
case_page_t* case_maps[MAX_CASE_PAGE_COUNT];

void make_case_page (qse_wcint_t start, qse_wcint_t end)
{
	qse_wcint_t code, c;
	size_t i;
	wcdiff_t upper[CASE_PAGE_SIZE];
	wcdiff_t lower[CASE_PAGE_SIZE];
	case_page_t* page;

	memset (upper, 0, sizeof(upper));
	memset (lower, 0, sizeof(lower));
	for (code = start; code <= end; code++) 
	{
		c = code - start;
		upper[c] = (wcdiff_t)code - (wcdiff_t)towupper(code);
		lower[c] = (wcdiff_t)towlower(code) - (wcdiff_t)code;
	}

	for (page = case_pages; page != NULL; page = page->next) 
	{
		if (memcmp (upper, page->upper, sizeof(upper)) == 0 &&
		    memcmp (lower, page->lower, sizeof(lower)) == 0) 
		{
			case_maps[case_map_count++] = page;
			return;
		}
	}

	page = (case_page_t*)malloc (sizeof(case_page_t));
	page->no = case_page_count++;
	memcpy (page->upper, upper, sizeof(upper));
	memcpy (page->lower, lower, sizeof(lower));
	page->next = case_pages;

	case_pages = page;
	case_maps[case_map_count++] = page;
}

void emit_case_page (case_page_t* page, int page_seq)
{
	size_t i;
	wcdiff_t upper, lower; 
	int need_or;
	qse_wcint_t c;

	printf ("static case_page_t case_page_%04X[%u] =\n{\n", 
		(unsigned int)page->no, (unsigned int)CASE_PAGE_SIZE);

	for (i = 0; i < CASE_PAGE_SIZE; i++) 
	{
		need_or = 0;
		upper = page->upper[i];
		lower = page->lower[i];

		if (i != 0) printf (",\n");
		printf ("\t");

		if (upper >  SHRT_MAX || upper < SHRT_MIN ||
		    lower > SHRT_MAX || lower < SHRT_MIN) 
		{
			fprintf (stderr, "WARNING: page %u, index %u: value out of range - upper %ld lower %ld\n", 
				(unsigned int)page->no, (unsigned int)i, (long int)upper, (long int)lower);
		}

		printf ("{%ld, %ld}", (long int)upper, (long int)lower);
	}

	printf ("\n};\n");
}

void emit_case_map ()
{
	size_t i;


	printf ("static case_page_t* case_map[%u] =\n{\n", (unsigned int)case_map_count);

	for (i = 0; i < case_map_count; i++) {
		if (i != 0) printf (",\n");
		printf ("\t /* 0x%X-0x%X */ ", 
			i * CASE_PAGE_SIZE, (i + 1) * CASE_PAGE_SIZE - 1);
		printf ("case_page_%04X", case_maps[i]->no);
	}

	printf ("\n};\n");
}

static void emit_case_macros (void)
{
	printf ("/* generated by tools/uni-case.c */\n\n");
	printf ("#define CASE_MAX 0x%lX\n\n", (unsigned long)MAX_CHAR);
	printf ("typedef struct case_page_t case_page_t;\n\n");
	printf ("struct case_page_t {\n");

	/* use a 16-bit integer to use less memory.  */
	printf ("	qse_int16_t upper;\n"); 
	printf ("	qse_int16_t lower;\n");
	printf ("};\n\n");
	printf ("\n");
}

int main ()
{
	qse_wcint_t code;
	case_page_t* page;
	char* locale;
	int page_seq = 0;

	locale = setlocale (LC_ALL, "");
	if (locale == NULL ||
	    (strstr(locale, ".utf8") == NULL && strstr(locale, ".UTF8") == NULL &&
	     strstr(locale, ".utf-8") == NULL && strstr(locale, ".UTF-8") == NULL)) 
	{
		fprintf (stderr, "error: the locale should be utf-8 compatible\n");
		return -1;
	}


	for (code = 0; code < MAX_CHAR; code += CASE_PAGE_SIZE) 
	{
		make_case_page (code, code + CASE_PAGE_SIZE - 1);
	}

	emit_case_macros ();

	for (page = case_pages; page != NULL; page = page->next) 
	{
		emit_case_page (page, page_seq);	
		printf ("\n");
		page_seq++;
	}

	emit_case_map ();

	return 0;
}