/*
 * (C) Copyright 2003
 * Tait Electronics Limited, Christchurch, New Zealand
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

/*
 * This file provides a shell like 'test' function to return
 * true/false from an integer or string compare of two memory
 * locations or a location and a scalar/literal.
 * A few parts were lifted from bash 'test' command
 */

#include <common.h>
#include <config.h>
#include <command.h>
#include <mapmem.h>

#include <asm/io.h>

#define EQ      0
#define NE      1
#define LT      2
#define GT      3
#define LE      4
#define GE      5

struct op_tbl_s {
        char    *op;            /* operator string */
        int     opcode;         /* internal representation of opcode */
};

typedef struct op_tbl_s op_tbl_t;

static const op_tbl_t op_table [] = {
        { "-lt", LT },
        { "<"  , LT },
        { "-gt", GT },
        { ">"  , GT },
        { "-eq", EQ },
        { "==" , EQ },
        { "-ne", NE },
        { "!=" , NE },
        { "<>" , NE },
        { "-ge", GE },
        { ">=" , GE },
        { "-le", LE },
        { "<=" , LE },
};

static long evalexp(char *s, int w)
{
        long l = 0;
        unsigned long addr;
        void *buf;

        /* if the parameter starts with a * then assume is a pointer to the value we want */
        if (s[0] == '*') {
                addr = simple_strtoul(&s[1], NULL, 16);
                buf = map_physmem(addr, w, MAP_WRBACK);
                if (!buf && addr) {
                        puts("Failed to map physical memory\n");
                        return 0;
                }
                switch (w) {
                case 1:
                        l = (long)(*(u8 *)buf);
                        break;
                case 2:
                        l = (long)(*(u16 *)buf);
                        break;
                case 4:
                        l = (long)(*(u32 *)buf);
                        break;
                }
                unmap_physmem(buf, w);
                return l;
        } else {
                l = simple_strtoul(s, NULL, 16);
        }

        /* avoid overflow on mask calculus */
        return (w >= sizeof(long)) ? l : (l & ((1UL << (w * 8)) - 1));
}

static char * evalstr(char *s)
{
        /* if the parameter starts with a * then assume a string pointer else its a literal */
        if (s[0] == '*') {
                return (char *)simple_strtoul(&s[1], NULL, 16);
        } else if (s[0] == '$') {
                int i = 2;

                if (s[1] != '{')
                        return NULL;

                while (s[i] != '}') {
                        if (s[i] == 0)
                                return NULL;
                        i++;
                }
                s[i] = 0;
                return  getenv((const char *)&s[2]);
        } else {
                return s;
        }
}

static int stringcomp(char *s, char *t, int op)
{
        int p;
        char *l, *r;

        l = evalstr(s);
        r = evalstr(t);

        p = strcmp(l, r);
        switch (op) {
        case EQ: return (p == 0);
        case NE: return (p != 0);
        case LT: return (p < 0);
        case GT: return (p > 0);
        case LE: return (p <= 0);
        case GE: return (p >= 0);
        }
        return (0);
}

static int arithcomp (char *s, char *t, int op, int w)
{
        long l, r;

        l = evalexp (s, w);
        r = evalexp (t, w);

        switch (op) {
        case EQ: return (l == r);
        case NE: return (l != r);
        case LT: return (l < r);
        case GT: return (l > r);
        case LE: return (l <= r);
        case GE: return (l >= r);
        }
        return (0);
}

static int binary_test(char *op, char *arg1, char *arg2, int w)
{
        int len, i;
        const op_tbl_t *optp;

        len = strlen(op);

        for (optp = (op_tbl_t *)&op_table, i = 0;
             i < ARRAY_SIZE(op_table);
             optp++, i++) {

                if ((strncmp (op, optp->op, len) == 0) && (len == strlen (optp->op))) {
                        if (w == 0) {
                                return (stringcomp(arg1, arg2, optp->opcode));
                        } else {
                                return (arithcomp (arg1, arg2, optp->opcode, w));
                        }
                }
        }

        printf("Unknown operator '%s'\n", op);
        return 0;       /* op code not found */
}

/* command line interface to the shell test */
static int do_itest(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
{
        int     value, w;

        /* Validate arguments */
        if ((argc != 4))
                return CMD_RET_USAGE;

        /* Check for a data width specification.
         * Defaults to long (4) if no specification.
         * Uses -2 as 'width' for .s (string) so as not to upset existing code
         */
        switch (w = cmd_get_data_size(argv[0], 4)) {
        case 1:
        case 2:
        case 4:
                value = binary_test (argv[2], argv[1], argv[3], w);
                break;
        case -2:
                value = binary_test (argv[2], argv[1], argv[3], 0);
                break;
        case -1:
        default:
                puts("Invalid data width specifier\n");
                value = 0;
                break;
        }

        return !value;
}

U_BOOT_CMD(
        itest, 4, 0, do_itest,
        "return true/false on integer compare",
        "[.b, .w, .l, .s] [*]value1 <op> [*]value2"
);