/*
 * File:        printk.c
 * Purpose:     The standard C library routine printf(), but without
 *              all the baggage.
 */

#include "common.h"
#include <stdarg.h>

/********************************************************************/

typedef struct
{
    int dest;
    void (*func)(char);
    char *loc;
} PRINTK_INFO;

int
printk (PRINTK_INFO *, const char *, va_list);

/********************************************************************/

#define DEST_CONSOLE    (1)
#define DEST_STRING     (2)

#define FLAGS_MINUS     (0x01)
#define FLAGS_PLUS      (0x02)
#define FLAGS_SPACE     (0x04)
#define FLAGS_ZERO      (0x08)
#define FLAGS_POUND     (0x10)

#define IS_FLAG_MINUS(a)    (a & FLAGS_MINUS)
#define IS_FLAG_PLUS(a)     (a & FLAGS_PLUS)
#define IS_FLAG_SPACE(a)    (a & FLAGS_SPACE)
#define IS_FLAG_ZERO(a)     (a & FLAGS_ZERO)
#define IS_FLAG_POUND(a)    (a & FLAGS_POUND)

#define LENMOD_h        (0x01)
#define LENMOD_l        (0x02)
#define LENMOD_L        (0x04)

#define IS_LENMOD_h(a)  (a & LENMOD_h)
#define IS_LENMOD_l(a)  (a & LENMOD_l)
#define IS_LENMOD_L(a)  (a & LENMOD_L)

#define FMT_d   (0x0001)
#define FMT_o   (0x0002)
#define FMT_x   (0x0004)
#define FMT_X   (0x0008)
#define FMT_u   (0x0010)
#define FMT_c   (0x0020)
#define FMT_s   (0x0040)
#define FMT_p   (0x0080)
#define FMT_n   (0x0100)

#define IS_FMT_d(a)     (a & FMT_d)
#define IS_FMT_o(a)     (a & FMT_o)
#define IS_FMT_x(a)     (a & FMT_x)
#define IS_FMT_X(a)     (a & FMT_X)
#define IS_FMT_u(a)     (a & FMT_u)
#define IS_FMT_c(a)     (a & FMT_c)
#define IS_FMT_s(a)     (a & FMT_s)
#define IS_FMT_p(a)     (a & FMT_p)
#define IS_FMT_n(a)     (a & FMT_n)

/********************************************************************/
static void
printk_putc (int c, int *count, PRINTK_INFO *info)
{
    switch (info->dest)
    {
    case DEST_CONSOLE:
        info->func((char)c);
        break;
    case DEST_STRING:
        *(info->loc) = (unsigned char)c;
        ++(info->loc);
        break;
    default:
        break;
    }
    *count += 1;
}

/********************************************************************/
static int
printk_mknumstr (char *numstr, void *nump, int neg, int radix)
{
    int a, b, c;
    unsigned int ua, ub, uc;

    int nlen;
    char *nstrp;

    nlen = 0;
    nstrp = numstr;
    *nstrp++ = '\0';

    if (neg)
    {
        a = *(int *)nump;
        if (a == 0)
        {
            *nstrp = '0';
            ++nlen;
            goto done;
        }
        while (a != 0)
        {
            b = (int)a / (int)radix;
            c = (int)a - ((int)b * (int)radix);
            if (c < 0)
            {
                c = ~c + 1 + '0';
            }
            else
            {
                c = c + '0';
            }
            a = b;
            *nstrp++ = (char)c;
            ++nlen;
        }
    }
    else
    {
        ua = *(unsigned int *)nump;
        if (ua == 0)
        {
            *nstrp = '0';
            ++nlen;
            goto done;
        }
        while (ua != 0)
        {
            ub = (unsigned int)ua / (unsigned int)radix;
            uc = (unsigned int)ua - ((unsigned int)ub * (unsigned int)radix);
            if (uc < 10)
            {
                uc = uc + '0';
            }
            else
            {
                uc = uc - 10 + 'A';
            }
            ua = ub;
            *nstrp++ = (char)uc;
            ++nlen;
        }
    }
done:
    return nlen;
}

/********************************************************************/
static void
printk_pad_zero (int curlen, int field_width, int *count, PRINTK_INFO *info)
{
    int i;

    for (i = curlen; i < field_width; i++)
    {
        printk_putc('0', count, info);
    }
}

/********************************************************************/
static void
printk_pad_space (int curlen, int field_width, int *count, PRINTK_INFO *info)
{
    int i;

    for (i = curlen; i < field_width; i++)
    {
        printk_putc(' ', count, info);
    }
}

/********************************************************************/
int
printk (PRINTK_INFO *info, const char *fmt, va_list ap)
{
    /* va_list ap; */
    char *p;
    int c;

    char vstr[33];
    char *vstrp;
    int vlen;

    int done;
    int count = 0;

    int flags_used;
    int field_width;
#if 0
    int precision_used;
    int precision_width;
    int length_modifier;
#endif

    int ival;
    int schar, dschar;
    int *ivalp;
    char *sval;
    int cval;
    unsigned int uval;

    /*
     * Start parsing apart the format string and display appropriate
     * formats and data.
     */
    for (p = (char *)fmt; (c = *p) != 0; p++)
    {
        /*
         * All formats begin with a '%' marker.  Special chars like
         * '\n' or '\t' are normally converted to the appropriate
         * character by the __compiler__.  Thus, no need for this
         * routine to account for the '\' character.
         */
        if (c != '%')
        {
            /*
             * This needs to be replaced with something like
             * 'out_char()' or call an OS routine.
             */
#ifndef UNIX_DEBUG
            if (c != '\n')
            {
                printk_putc(c, &count, info);
            }
            else
            {
                printk_putc(0x0D /* CR */, &count, info);
                printk_putc(0x0A /* LF */, &count, info);
            }
#else
            printk_putc(c, &count, info);
#endif

            /*
             * By using 'continue', the next iteration of the loop
             * is used, skipping the code that follows.
             */
            continue;
        }

        /*
         * First check for specification modifier flags.
         */
        flags_used = 0;
        done = FALSE;
        while (!done)
        {
            switch (/* c = */ *++p)
            {
            case '-':
                flags_used |= FLAGS_MINUS;
                break;
            case '+':
                flags_used |= FLAGS_PLUS;
                break;
            case ' ':
                flags_used |= FLAGS_SPACE;
                break;
            case '0':
                flags_used |= FLAGS_ZERO;
                break;
            case '#':
                flags_used |= FLAGS_POUND;
                break;
            default:
                /* we've gone one char too far */
                --p;
                done = TRUE;
                break;
            }
        }

        /*
         * Next check for minimum field width.
         */
        field_width = 0;
        done = FALSE;
        while (!done)
        {
            switch (c = *++p)
            {
            case '0':
            case '1':
            case '2':
            case '3':
            case '4':
            case '5':
            case '6':
            case '7':
            case '8':
            case '9':
                field_width = (field_width * 10) + (c - '0');
                break;
            default:
                /* we've gone one char too far */
                --p;
                done = TRUE;
                break;
            }
        }

        /*
         * Next check for the width and precision field separator.
         */
        if (/* (c = *++p) */ *++p == '.')
        {
            /* precision_used = TRUE; */

            /*
             * Must get precision field width, if present.
             */
            /* precision_width = 0; */
            done = FALSE;
            while (!done)
            {
                switch (/* c = uncomment if used below */ *++p)
                {
                case '0':
                case '1':
                case '2':
                case '3':
                case '4':
                case '5':
                case '6':
                case '7':
                case '8':
                case '9':
#if 0
                    precision_width = (precision_width * 10) +
                                      (c - '0');
#endif
                    break;
                default:
                    /* we've gone one char too far */
                    --p;
                    done = TRUE;
                    break;
                }
            }
        }
        else
        {
            /* we've gone one char too far */
            --p;
#if 0
            precision_used = FALSE;
            precision_width = 0;
#endif
        }

        /*
         * Check for the length modifier.
         */
        /* length_modifier = 0; */
        switch (/* c = */ *++p)
        {
        case 'h':
            /* length_modifier |= LENMOD_h; */
            break;
        case 'l':
            /* length_modifier |= LENMOD_l; */
            break;
        case 'L':
            /* length_modifier |= LENMOD_L; */
            break;
        default:
            /* we've gone one char too far */
            --p;
            break;
        }

        /*
         * Now we're ready to examine the format.
         */
        switch (c = *++p)
        {
        case 'd':
        case 'i':
            ival = (int)va_arg(ap, int);
            vlen = printk_mknumstr(vstr, &ival, TRUE, 10);
            vstrp = &vstr[vlen];

            if (ival < 0)
            {
                schar = '-';
                ++vlen;
            }
            else
            {
                if (IS_FLAG_PLUS(flags_used))
                {
                    schar = '+';
                    ++vlen;
                }
                else
                {
                    if (IS_FLAG_SPACE(flags_used))
                    {
                        schar = ' ';
                        ++vlen;
                    }
                    else
                    {
                        schar = 0;
                    }
                }
            }
            dschar = FALSE;

            /*
             * do the ZERO pad.
             */
            if (IS_FLAG_ZERO(flags_used))
            {
                if (schar)
                    printk_putc(schar, &count, info);
                dschar = TRUE;

                printk_pad_zero (vlen, field_width, &count, info);
                vlen = field_width;
            }
            else
            {
                if (!IS_FLAG_MINUS(flags_used))
                {
                    printk_pad_space (vlen, field_width, &count, info);

                    if (schar)
                        printk_putc(schar, &count, info);
                    dschar = TRUE;
                }
            }

            /* the string was built in reverse order, now display in */
            /* correct order */
            if (!dschar && schar)
            {
                printk_putc(schar, &count, info);
            }
            goto cont_xd;

        case 'x':
        case 'X':
            uval = (unsigned int)va_arg(ap, unsigned int);
            vlen = printk_mknumstr(vstr, &uval, FALSE, 16);
            vstrp = &vstr[vlen];

            dschar = FALSE;
            if (IS_FLAG_ZERO(flags_used))
            {
                if (IS_FLAG_POUND(flags_used))
                {
                    printk_putc('0', &count, info);
                    printk_putc('x', &count, info);
                    /*vlen += 2;*/
                    dschar = TRUE;
                }
                printk_pad_zero (vlen, field_width, &count, info);
                vlen = field_width;
            }
            else
            {
                if (!IS_FLAG_MINUS(flags_used))
                {
                    if (IS_FLAG_POUND(flags_used))
                    {
                        vlen += 2;
                    }
                    printk_pad_space (vlen, field_width, &count, info);
                    if (IS_FLAG_POUND(flags_used))
                    {
                        printk_putc('0', &count, info);
                        printk_putc('x', &count, info);
                        dschar = TRUE;
                    }
                }
            }

            if ((IS_FLAG_POUND(flags_used)) && !dschar)
            {
                printk_putc('0', &count, info);
                printk_putc('x', &count, info);
                vlen += 2;
            }
            goto cont_xd;

        case 'o':
            uval = (unsigned int)va_arg(ap, unsigned int);
            vlen = printk_mknumstr(vstr, &uval, FALSE, 8);
            goto cont_u;
        case 'b':
            uval = (unsigned int)va_arg(ap, unsigned int);
            vlen = printk_mknumstr(vstr, &uval, FALSE, 2);
            goto cont_u;
        case 'p':
            uval = (unsigned int)va_arg(ap, void *);
            vlen = printk_mknumstr(vstr, &uval, FALSE, 16);
            goto cont_u;
        case 'u':
            uval = (unsigned int)va_arg(ap, unsigned int);
            vlen = printk_mknumstr(vstr, &uval, FALSE, 10);

cont_u:
            vstrp = &vstr[vlen];

            if (IS_FLAG_ZERO(flags_used))
            {
                printk_pad_zero (vlen, field_width, &count, info);
                vlen = field_width;
            }
            else
            {
                if (!IS_FLAG_MINUS(flags_used))
                {
                    printk_pad_space (vlen, field_width, &count, info);
                }
            }

cont_xd:
            while (*vstrp)
                printk_putc(*vstrp--, &count, info);

            if (IS_FLAG_MINUS(flags_used))
            {
                printk_pad_space (vlen, field_width, &count, info);
            }
            break;

        case 'c':
            cval = (char)va_arg(ap, unsigned int);
            printk_putc(cval, &count, info);
            break;
        case 's':
            sval = (char *)va_arg(ap, char *);
            if (sval)
            {
                vlen = strlen(sval);
                if (!IS_FLAG_MINUS(flags_used))
                {
                    printk_pad_space (vlen, field_width, &count, info);
                }
                while (*sval)
                    printk_putc(*sval++, &count, info);
                if (IS_FLAG_MINUS(flags_used))
                {
                    printk_pad_space (vlen, field_width, &count, info);
                }
            }
            break;
        case 'n':
            ivalp = (int *)va_arg(ap, int *);
            *ivalp = count;
            break;
        default:
            printk_putc(c, &count, info);
            break;
        }
    }
    return count;
}

/********************************************************************/
#ifdef  NPRINTF     //禁用printf
int
printf (const char *fmt, ...)
{
    return 1;     //报告发送成功
}
#else
int
printf (const char *fmt, ...)
{
    va_list ap;
    int rvalue;
    PRINTK_INFO info;


    info.dest = DEST_CONSOLE;
    info.func = &out_char;
    /*
     * Initialize the pointer to the variable length argument list.
     */
    va_start(ap, fmt);
    rvalue = printk(&info, fmt, ap);
    /*
     * Cleanup the variable length argument list.
     */
    va_end(ap);
    return rvalue;
}
#endif

/********************************************************************/
int
sprintf (char *s, const char *fmt, ...)
{
    va_list ap;
    int rvalue = 0;
    PRINTK_INFO info;

    /*
     * Initialize the pointer to the variable length argument list.
     */
    if (s != 0)
    {
        info.dest = DEST_STRING;
        info.loc = s;
        va_start(ap, fmt);
        rvalue = printk(&info, fmt, ap);
        *info.loc = '\0';
        va_end(ap);
    }
    return rvalue;
}

/********************************************************************/
