#include <ctype.h>
#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <errno.h>

#include <flash.h>
#include <macros.h>
#include <shell.h>

static void do_flash_probe(const char *s);
static void do_flash_info(const char *s);
static void do_flash_read(const char *s);
static void do_flash_write(const char *s);
static void do_flash_erase(const char *s);

static struct cmd flash_cmds[] = {
	{ "probe", do_flash_probe },
	{ "info", do_flash_info },
	{ "read", do_flash_read },
	{ "write", do_flash_write },
	{ "erase", do_flash_erase },
	{ NULL, NULL },
};

struct flash_dev *flash = NULL;

/* TODO: implement a parser for hex arrays that is more user-friendly.
 * Also implement dry runs for programmers. */
static void parse_hex(FILE *fp, char *buf, size_t len)
{
	size_t i;
	char s[3];

	for (i = 0; i < len; ++i) {
		memset(s, '\0', 3);

		while ((s[0] = getc(fp)) && !isxdigit(s[0]))
			putchar(s[0]);

		putchar(s[0]);

		while ((s[1] = getc(fp)) && !isxdigit(s[1]))
			putchar(s[1]);

		putchar(s[1]);

		*buf++ = strtoul(s, NULL, 16);
	}
}

static void print_hex_ascii(const char *buf, size_t len)
{
	size_t n, i;
	uint8_t c;

	for (; len; buf += n, len -= n) {
		n = min(len, 16);
		
		for (i = 0; i < 16; ++i) {
			c = (i < n) ? buf[i] : 0;
			printf("%x", c);
		}

		printf(" ");

		for (i = 0; i < 16; ++i) {
			c = (i < n) ? buf[i] : 0;
			printf("%c", isalnum(c) ? c : '.');
		}

		printf("\n");
	}
}

static void print_size(size_t size)
{
	if (size == 0) {
		printf("0");
#if defined(TIB)
	} else if (size % TIB == 0) {
		printf("%" PRSZu " TiB", size / TIB);
#endif
	} else if (size % GIB == 0) {
		printf("%" PRSZu " GiB", size / GIB);
	} else if (size % MIB == 0) {
		printf("%" PRSZu " MiB", size / MIB);
	} else if (size % KIB == 0) {
		printf("%" PRSZu " KiB", size / KIB);
	} else {
		printf("%" PRSZu " B", size);
	}
}

static void do_flash_probe(const char *s)
{
	(void)s;

	if (flash) {
		flash_release(flash);
		flash = NULL;
	}

	if (!(flash = flash_probe())) {
		fprintf(stderr, "error: unable to probe flash device.\n");
	}
}

static void do_flash_info(const char *s)
{
	size_t size;

	(void)s;

	if (!flash) {
		fprintf(stderr, "error: no flash device probed.\n");
		return;
	}

	size = flash_get_size(flash);

	printf("Capacity: %" PRSZu " blocks (", size / (4 * KIB));
	print_size(size);
	printf(")\n");
}

static void do_flash_read(const char *s)
{
	char buf[256], *end = NULL;
	size_t addr, len, nbytes;

	if (!flash) {
		fprintf(stderr, "error: no flash device probed.\n");
		return;
	}

	if (strncmp(s, "0x", 2) == 0)
		s += 2;

	addr = strtoull(s, &end, 16);
	s = end;

	if (errno == EINVAL || errno == ERANGE)
		return;

	s += strspn(s, " \n");

	if (strncmp(s, "0x", 2) == 0)
		s += 2;

	len = strtoull(s, &end, 16);
	s = end;

	if (errno == EINVAL || errno == ERANGE)
		return;

	if (!len)
		return;

	while (len) {
		nbytes = min(len, 256);
		flash_read(flash, addr, buf, nbytes);
		print_hex_ascii(buf, nbytes);

		addr += nbytes;
		len -= nbytes;
	}
}

static void do_flash_write(const char *s)
{
	char buf[256], *end = NULL;
	size_t addr, len, nbytes;

	if (!flash) {
		fprintf(stderr, "error: no flash device probed.\n");
		return;
	}

	if (strncmp(s, "0x", 2) == 0)
		s += 2;

	addr = strtoull(s, &end, 16);
	s = end;

	if (errno == EINVAL || errno == ERANGE)
		return;

	s += strspn(s, " \n");

	if (strncmp(s, "0x", 2) == 0)
		s += 2;

	len = strtoull(s, &end, 16);
	s = end;

	if (errno == EINVAL || errno == ERANGE)
		return;

	if (!len)
		return;

	while (len) {
		nbytes = min(len, 256);
		parse_hex(stdin, buf, nbytes);
		printf("\n");
		print_hex_ascii(buf, nbytes);
		flash_write(flash, addr, buf, nbytes);

		addr += nbytes;
		len -= nbytes;
	}
}

static void do_flash_erase(const char *s)
{
	char *end = NULL;
	size_t addr, len;

	if (!flash) {
		fprintf(stderr, "error: no flash device probed.\n");
		return;
	}

	if (strncmp(s, "0x", 2) == 0)
		s += 2;

	addr = strtoull(s, &end, 16);
	s = end;

	if (errno == EINVAL || errno == ERANGE)
		return;

	s += strspn(s, " \n");

	if (strncmp(s, "0x", 2) == 0)
		s += 2;

	len = strtoull(s, &end, 16);
	s = end;

	if (errno == EINVAL || errno == ERANGE)
		return;

	if (!len)
		return;

	flash_erase(flash, addr, len);
}

void do_flash_cmd(const char *line)
{
	cmd_exec(flash_cmds, line);
}