/*
 * (C) Copyright 2015 Leo C. <erbl259-lmu@yahoo.de>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include "common.h"
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#include <stdbool.h>

#include "command.h"
#include "env.h"
#include "ff.h"
#include "con-utils.h"
#include "z80-if.h"
#include "debug.h"


#define RS		128		/* CP/M record size */

/*
 *	Load Routine
 *
 *	Input:  addr = Page Address of load top
 *		 	len  = Length in pages of module to read
 *
 */
int load(FIL *File, uint16_t addr, uint8_t len)
{
	uint8_t buffer[RS];
	unsigned int br;					/* bytes read */
	int res;

	len *= 2;		/* length in records of module */
	//debug("## load: addr: 0x%.4X, records: 0x%.4X, (%u)\n", addr, len, len);

	for (; len; len--) {
		addr -= RS;
		res = f_read(File, buffer, RS, &br);
		if (res || br != RS) {
			return 1;
		}

		if (!(z80_bus_cmd(Request) & ZST_ACQUIRED)) {
			my_puts_P(PSTR("Bus timeout\n"));
			return 2;
		}
		z80_write_block(buffer, addr, RS);
		z80_bus_cmd(Release);
		//debug("## written: 0x%.4X\n", addr);
	}

	return 0;
}


command_ret_t do_loadcpm3(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
	uint16_t mem_top;
	uint8_t res_len;
	uint16_t bank_top;
	uint8_t bank_len;
	uint16_t osentry_adr = 0;
	long offset = 0;
	char *fname;
	FIL File;
	/* TODO: put CONFIG_PATH_CPM3SYS in flash */
	char default_fname[] = CONFIG_PATH_CPM3SYS;
	unsigned int br;					/* bytes read */
	uint8_t buffer[RS];
	int res;

	(void) cmdtp; (void) flag;


	if (argc > 1)
		offset = strtoul(argv[1], NULL, 16);

	fname = getenv(PSTR(ENV_PATH_CPM3SYS));

	if (argc > 2) {
		fname = argv[2];
	}

	if (fname == NULL || *fname == '\0')
		fname = default_fname;

	res = f_open(&File, fname, FA_READ );
	if (res) {
		printf_P(PSTR("Error: failed to open '%s'\n"), fname);
		return CMD_RET_FAILURE;
	}

	printf_P(PSTR("Loading: '%s'...\n"), fname);

	/* read the load record */
	res = f_read(&File, buffer, RS, &br);
	if (res || br != RS)
		goto out;

	mem_top = buffer[0] << 8;
	res_len = buffer[1];
	bank_top = buffer[2] << 8;
	bank_len = buffer[3];
	osentry_adr = buffer[4] + (buffer[5] << 8);

	/* read display info */
	res = f_read(&File, buffer, RS, &br);
	if (res || br != RS)
		goto out;

	/* print the info */
	buffer[RS-1] = '$';
	uint8_t *p = memchr(buffer, '$', RS);
	*p = '\0';
	my_puts((char *)buffer);

	/* Main System Load	*/

	/* Load Common Portion of System */
	if ((res = load(&File, mem_top, res_len)) != 0)
		goto out;

	/* Load Banked Portion of System */
	res = load(&File, bank_top, bank_len);

out:
	f_close(&File);

	if (res) {
		printf_P(PSTR("Error: failed to read '%s'\n"), fname);
		return CMD_RET_FAILURE;
	} else {
		if (res_len != 0)
			setenv_hex(PSTR(ENV_STARTADDRESS), osentry_adr);
		printf_P(PSTR("Loaded: Resident: "));
		if (res_len != 0)
			printf_P(PSTR("0x%.4X-0x%.4X, "), mem_top-res_len*256, mem_top-1);
		else
			printf_P(PSTR(" -  "));
		printf_P(PSTR("Banked: "));
		if (bank_len != 0)
			printf_P(PSTR("0x%.4X-0x%.4X\n"), bank_top-bank_len*256, bank_top-1);
		else
			printf_P(PSTR(" -  \n"));

		return CMD_RET_SUCCESS;
	}
}