/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1980, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "rcv.h"
#include <ctype.h>
#include "extern.h"

/*
 * Mail -- a mail program
 *
 * Message list handling.
 */

/*
 * Convert the user string of message numbers and
 * store the numbers into vector.
 *
 * Returns the count of messages picked up or -1 on error.
 */
int
getmsglist(char *buf, int *vector, int flags)
{
        int *ip;
        struct message *mp;

        if (msgCount == 0) {
                *vector = 0;
                return (0);
        }
        if (markall(buf, flags) < 0)
                return (-1);
        ip = vector;
        for (mp = &message[0]; mp < &message[msgCount]; mp++)
                if (mp->m_flag & MMARK)
                        *ip++ = mp - &message[0] + 1;
        *ip = 0;
        return (ip - vector);
}

/*
 * Mark all messages that the user wanted from the command
 * line in the message structure.  Return 0 on success, -1
 * on error.
 */

/*
 * Bit values for colon modifiers.
 */

#define CMNEW           01              /* New messages */
#define CMOLD           02              /* Old messages */
#define CMUNREAD        04              /* Unread messages */
#define CMDELETED       010             /* Deleted messages */
#define CMREAD          020             /* Read messages */

/*
 * The following table describes the letters which can follow
 * the colon and gives the corresponding modifier bit.
 */

static struct coltab {
        char    co_char;                /* What to find past : */
        int     co_bit;                 /* Associated modifier bit */
        int     co_mask;                /* m_status bits to mask */
        int     co_equal;               /* ... must equal this */
} coltab[] = {
        { 'n',          CMNEW,          MNEW,           MNEW    },
        { 'o',          CMOLD,          MNEW,           0       },
        { 'u',          CMUNREAD,       MREAD,          0       },
        { 'd',          CMDELETED,      MDELETED,       MDELETED},
        { 'r',          CMREAD,         MREAD,          MREAD   },
        { 0,            0,              0,              0       }
};

static  int     lastcolmod;

int
markall(char buf[], int f)
{
        char **np;
        int i;
        struct message *mp;
        char *namelist[NMLSIZE], *bufp;
        int tok, beg, mc, star, other, valdot, colmod, colresult;

        valdot = dot - &message[0] + 1;
        colmod = 0;
        for (i = 1; i <= msgCount; i++)
                unmark(i);
        bufp = buf;
        mc = 0;
        np = &namelist[0];
        scaninit();
        tok = scan(&bufp);
        star = 0;
        other = 0;
        beg = 0;
        while (tok != TEOL) {
                switch (tok) {
                case TNUMBER:
number:
                        if (star) {
                                printf("No numbers mixed with *\n");
                                return (-1);
                        }
                        mc++;
                        other++;
                        if (beg != 0) {
                                if (check(lexnumber, f))
                                        return (-1);
                                for (i = beg; i <= lexnumber; i++)
                                        if (f == MDELETED || (message[i - 1].m_flag & MDELETED) == 0)
                                                mark(i);
                                beg = 0;
                                break;
                        }
                        beg = lexnumber;
                        if (check(beg, f))
                                return (-1);
                        tok = scan(&bufp);
                        regret(tok);
                        if (tok != TDASH) {
                                mark(beg);
                                beg = 0;
                        }
                        break;

                case TPLUS:
                        if (beg != 0) {
                                printf("Non-numeric second argument\n");
                                return (-1);
                        }
                        i = valdot;
                        do {
                                i++;
                                if (i > msgCount) {
                                        printf("Referencing beyond EOF\n");
                                        return (-1);
                                }
                        } while ((message[i - 1].m_flag & MDELETED) != f);
                        mark(i);
                        break;

                case TDASH:
                        if (beg == 0) {
                                i = valdot;
                                do {
                                        i--;
                                        if (i <= 0) {
                                                printf("Referencing before 1\n");
                                                return (-1);
                                        }
                                } while ((message[i - 1].m_flag & MDELETED) != f);
                                mark(i);
                        }
                        break;

                case TSTRING:
                        if (beg != 0) {
                                printf("Non-numeric second argument\n");
                                return (-1);
                        }
                        other++;
                        if (lexstring[0] == ':') {
                                colresult = evalcol(lexstring[1]);
                                if (colresult == 0) {
                                        printf("Unknown colon modifier \"%s\"\n",
                                            lexstring);
                                        return (-1);
                                }
                                colmod |= colresult;
                        }
                        else
                                *np++ = savestr(lexstring);
                        break;

                case TDOLLAR:
                case TUP:
                case TDOT:
                        lexnumber = metamess(lexstring[0], f);
                        if (lexnumber == -1)
                                return (-1);
                        goto number;

                case TSTAR:
                        if (other) {
                                printf("Can't mix \"*\" with anything\n");
                                return (-1);
                        }
                        star++;
                        break;

                case TERROR:
                        return (-1);
                }
                tok = scan(&bufp);
        }
        lastcolmod = colmod;
        *np = NULL;
        mc = 0;
        if (star) {
                for (i = 0; i < msgCount; i++)
                        if ((message[i].m_flag & MDELETED) == f) {
                                mark(i+1);
                                mc++;
                        }
                if (mc == 0) {
                        printf("No applicable messages.\n");
                        return (-1);
                }
                return (0);
        }

        /*
         * If no numbers were given, mark all of the messages,
         * so that we can unmark any whose sender was not selected
         * if any user names were given.
         */

        if ((np > namelist || colmod != 0) && mc == 0)
                for (i = 1; i <= msgCount; i++)
                        if ((message[i-1].m_flag & MDELETED) == f)
                                mark(i);

        /*
         * If any names were given, go through and eliminate any
         * messages whose senders were not requested.
         */

        if (np > namelist) {
                for (i = 1; i <= msgCount; i++) {
                        for (mc = 0, np = &namelist[0]; *np != NULL; np++)
                                if (**np == '/') {
                                        if (matchfield(*np, i)) {
                                                mc++;
                                                break;
                                        }
                                }
                                else {
                                        if (matchsender(*np, i)) {
                                                mc++;
                                                break;
                                        }
                                }
                        if (mc == 0)
                                unmark(i);
                }

                /*
                 * Make sure we got some decent messages.
                 */

                mc = 0;
                for (i = 1; i <= msgCount; i++)
                        if (message[i-1].m_flag & MMARK) {
                                mc++;
                                break;
                        }
                if (mc == 0) {
                        printf("No applicable messages from {%s",
                                namelist[0]);
                        for (np = &namelist[1]; *np != NULL; np++)
                                printf(", %s", *np);
                        printf("}\n");
                        return (-1);
                }
        }

        /*
         * If any colon modifiers were given, go through and
         * unmark any messages which do not satisfy the modifiers.
         */

        if (colmod != 0) {
                for (i = 1; i <= msgCount; i++) {
                        struct coltab *colp;

                        mp = &message[i - 1];
                        for (colp = &coltab[0]; colp->co_char != '\0'; colp++)
                                if (colp->co_bit & colmod)
                                        if ((mp->m_flag & colp->co_mask)
                                            != colp->co_equal)
                                                unmark(i);

                }
                for (mp = &message[0]; mp < &message[msgCount]; mp++)
                        if (mp->m_flag & MMARK)
                                break;
                if (mp >= &message[msgCount]) {
                        struct coltab *colp;

                        printf("No messages satisfy");
                        for (colp = &coltab[0]; colp->co_char != '\0'; colp++)
                                if (colp->co_bit & colmod)
                                        printf(" :%c", colp->co_char);
                        printf("\n");
                        return (-1);
                }
        }
        return (0);
}

/*
 * Turn the character after a colon modifier into a bit
 * value.
 */
int
evalcol(int col)
{
        struct coltab *colp;

        if (col == 0)
                return (lastcolmod);
        for (colp = &coltab[0]; colp->co_char != '\0'; colp++)
                if (colp->co_char == col)
                        return (colp->co_bit);
        return (0);
}

/*
 * Check the passed message number for legality and proper flags.
 * If f is MDELETED, then either kind will do.  Otherwise, the message
 * has to be undeleted.
 */
int
check(int mesg, int f)
{
        struct message *mp;

        if (mesg < 1 || mesg > msgCount) {
                printf("%d: Invalid message number\n", mesg);
                return (-1);
        }
        mp = &message[mesg-1];
        if (f != MDELETED && (mp->m_flag & MDELETED) != 0) {
                printf("%d: Inappropriate message\n", mesg);
                return (-1);
        }
        return (0);
}

/*
 * Scan out the list of string arguments, shell style
 * for a RAWLIST.
 */
int
getrawlist(char line[], char **argv, int argc)
{
        char c, *cp, *cp2, quotec;
        int argn;
        char *linebuf;
        size_t linebufsize = BUFSIZ;

        if ((linebuf = malloc(linebufsize)) == NULL)
                err(1, "Out of memory");

        argn = 0;
        cp = line;
        for (;;) {
                for (; *cp == ' ' || *cp == '\t'; cp++)
                        ;
                if (*cp == '\0')
                        break;
                if (argn >= argc - 1) {
                        printf(
                        "Too many elements in the list; excess discarded.\n");
                        break;
                }
                cp2 = linebuf;
                quotec = '\0';
                while ((c = *cp) != '\0') {
                        /* Allocate more space if necessary */
                        if (cp2 - linebuf == linebufsize - 1) {
                                linebufsize += BUFSIZ;
                                if ((linebuf = realloc(linebuf, linebufsize)) == NULL)
                                        err(1, "Out of memory");
                                cp2 = linebuf + linebufsize - BUFSIZ - 1;
                        }
                        cp++;
                        if (quotec != '\0') {
                                if (c == quotec)
                                        quotec = '\0';
                                else if (c == '\\')
                                        switch (c = *cp++) {
                                        case '\0':
                                                *cp2++ = '\\';
                                                cp--;
                                                break;
                                        case '0': case '1': case '2': case '3':
                                        case '4': case '5': case '6': case '7':
                                                c -= '0';
                                                if (*cp >= '0' && *cp <= '7')
                                                        c = c * 8 + *cp++ - '0';
                                                if (*cp >= '0' && *cp <= '7')
                                                        c = c * 8 + *cp++ - '0';
                                                *cp2++ = c;
                                                break;
                                        case 'b':
                                                *cp2++ = '\b';
                                                break;
                                        case 'f':
                                                *cp2++ = '\f';
                                                break;
                                        case 'n':
                                                *cp2++ = '\n';
                                                break;
                                        case 'r':
                                                *cp2++ = '\r';
                                                break;
                                        case 't':
                                                *cp2++ = '\t';
                                                break;
                                        case 'v':
                                                *cp2++ = '\v';
                                                break;
                                        default:
                                                *cp2++ = c;
                                        }
                                else if (c == '^') {
                                        c = *cp++;
                                        if (c == '?')
                                                *cp2++ = '\177';
                                        /* null doesn't show up anyway */
                                        else if ((c >= 'A' && c <= '_') ||
                                            (c >= 'a' && c <= 'z'))
                                                *cp2++ = c & 037;
                                        else {
                                                *cp2++ = '^';
                                                cp--;
                                        }
                                } else
                                        *cp2++ = c;
                        } else if (c == '"' || c == '\'')
                                quotec = c;
                        else if (c == ' ' || c == '\t')
                                break;
                        else
                                *cp2++ = c;
                }
                *cp2 = '\0';
                argv[argn++] = savestr(linebuf);
        }
        argv[argn] = NULL;
        (void)free(linebuf);
        return (argn);
}

/*
 * scan out a single lexical item and return its token number,
 * updating the string pointer passed **p.  Also, store the value
 * of the number or string scanned in lexnumber or lexstring as
 * appropriate.  In any event, store the scanned `thing' in lexstring.
 */

static struct lex {
        char    l_char;
        char    l_token;
} singles[] = {
        { '$',  TDOLLAR },
        { '.',  TDOT    },
        { '^',  TUP     },
        { '*',  TSTAR   },
        { '-',  TDASH   },
        { '+',  TPLUS   },
        { '(',  TOPEN   },
        { ')',  TCLOSE  },
        { 0,    0       }
};

int
scan(char **sp)
{
        char *cp, *cp2;
        int c;
        struct lex *lp;
        int quotec;

        if (regretp >= 0) {
                strcpy(lexstring, string_stack[regretp]);
                lexnumber = numberstack[regretp];
                return (regretstack[regretp--]);
        }
        cp = *sp;
        cp2 = lexstring;
        c = *cp++;

        /*
         * strip away leading white space.
         */

        while (c == ' ' || c == '\t')
                c = *cp++;

        /*
         * If no characters remain, we are at end of line,
         * so report that.
         */

        if (c == '\0') {
                *sp = --cp;
                return (TEOL);
        }

        /*
         * If the leading character is a digit, scan
         * the number and convert it on the fly.
         * Return TNUMBER when done.
         */

        if (isdigit((unsigned char)c)) {
                lexnumber = 0;
                while (isdigit((unsigned char)c)) {
                        lexnumber = lexnumber*10 + c - '0';
                        *cp2++ = c;
                        c = *cp++;
                }
                *cp2 = '\0';
                *sp = --cp;
                return (TNUMBER);
        }

        /*
         * Check for single character tokens; return such
         * if found.
         */

        for (lp = &singles[0]; lp->l_char != '\0'; lp++)
                if (c == lp->l_char) {
                        lexstring[0] = c;
                        lexstring[1] = '\0';
                        *sp = cp;
                        return (lp->l_token);
                }

        /*
         * We've got a string!  Copy all the characters
         * of the string into lexstring, until we see
         * a null, space, or tab.
         * If the lead character is a " or ', save it
         * and scan until you get another.
         */

        quotec = 0;
        if (c == '\'' || c == '"') {
                quotec = c;
                c = *cp++;
        }
        while (c != '\0') {
                if (c == quotec) {
                        cp++;
                        break;
                }
                if (quotec == 0 && (c == ' ' || c == '\t'))
                        break;
                if (cp2 - lexstring < STRINGLEN-1)
                        *cp2++ = c;
                c = *cp++;
        }
        if (quotec && c == '\0') {
                fprintf(stderr, "Missing %c\n", quotec);
                return (TERROR);
        }
        *sp = --cp;
        *cp2 = '\0';
        return (TSTRING);
}

/*
 * Unscan the named token by pushing it onto the regret stack.
 */
void
regret(int token)
{
        if (++regretp >= REGDEP)
                errx(1, "Too many regrets");
        regretstack[regretp] = token;
        lexstring[STRINGLEN-1] = '\0';
        string_stack[regretp] = savestr(lexstring);
        numberstack[regretp] = lexnumber;
}

/*
 * Reset all the scanner global variables.
 */
void
scaninit(void)
{
        regretp = -1;
}

/*
 * Find the first message whose flags & m == f  and return
 * its message number.
 */
int
first(int f, int m)
{
        struct message *mp;

        if (msgCount == 0)
                return (0);
        f &= MDELETED;
        m &= MDELETED;
        for (mp = dot; mp < &message[msgCount]; mp++)
                if ((mp->m_flag & m) == f)
                        return (mp - message + 1);
        for (mp = dot-1; mp >= &message[0]; mp--)
                if ((mp->m_flag & m) == f)
                        return (mp - message + 1);
        return (0);
}

/*
 * See if the passed name sent the passed message number.  Return true
 * if so.
 */
int
matchsender(char *str, int mesg)
{
        char *cp;

        /* null string matches nothing instead of everything */
        if (*str == '\0')
                return (0);

        cp = nameof(&message[mesg - 1], 0);
        return (strcasestr(cp, str) != NULL);
}

/*
 * See if the passed name received the passed message number.  Return true
 * if so.
 */

static char *to_fields[] = { "to", "cc", "bcc", NULL };

static int
matchto(char *str, int mesg)
{
        struct message *mp;
        char *cp, **to;

        str++;

        /* null string matches nothing instead of everything */
        if (*str == '\0')
                return (0);

        mp = &message[mesg - 1];

        for (to = to_fields; *to != NULL; to++) {
                cp = hfield(*to, mp);
                if (cp != NULL && strcasestr(cp, str) != NULL)
                        return (1);
        }
        return (0);
}

/*
 * See if the given substring is contained within the specified field. If
 * 'searchheaders' is set, then the form '/x:y' will be accepted and matches
 * any message with the substring 'y' in field 'x'. If 'x' is omitted or
 * 'searchheaders' is not set, then the search matches any messages
 * with the substring 'y' in the 'Subject'. The search is case insensitive.
 *
 * The form '/to:y' is a special case, and will match all messages
 * containing the substring 'y' in the 'To', 'Cc', or 'Bcc' header
 * fields. The search for 'to' is case sensitive, so that '/To:y' can
 * be used to limit the search to just the 'To' field.
 */

static char lastscan[STRINGLEN];
int
matchfield(char *str, int mesg)
{
        struct message *mp;
        char *cp, *cp2;

        str++;
        if (*str == '\0')
                str = lastscan;
        else
                strlcpy(lastscan, str, sizeof(lastscan));
        mp = &message[mesg-1];

        /*
         * Now look, ignoring case, for the word in the string.
         */

        if (value("searchheaders") && (cp = strchr(str, ':')) != NULL) {
                /* Check for special case "/to:" */
                if (strncmp(str, "to:", 3) == 0)
                        return (matchto(cp, mesg));
                *cp++ = '\0';
                cp2 = hfield(*str != '\0' ? str : "subject", mp);
                cp[-1] = ':';
                str = cp;
                cp = cp2;
        } else
                cp = hfield("subject", mp);

        if (cp == NULL)
                return (0);

        return (strcasestr(cp, str) != NULL);
}

/*
 * Mark the named message by setting its mark bit.
 */
void
mark(int mesg)
{
        int i;

        i = mesg;
        if (i < 1 || i > msgCount)
                errx(1, "Bad message number to mark");
        message[i-1].m_flag |= MMARK;
}

/*
 * Unmark the named message.
 */
void
unmark(int mesg)
{
        int i;

        i = mesg;
        if (i < 1 || i > msgCount)
                errx(1, "Bad message number to unmark");
        message[i-1].m_flag &= ~MMARK;
}

/*
 * Return the message number corresponding to the passed meta character.
 */
int
metamess(int meta, int f)
{
        int c, m;
        struct message *mp;

        c = meta;
        switch (c) {
        case '^':
                /*
                 * First 'good' message left.
                 */
                for (mp = &message[0]; mp < &message[msgCount]; mp++)
                        if ((mp->m_flag & MDELETED) == f)
                                return (mp - &message[0] + 1);
                printf("No applicable messages\n");
                return (-1);

        case '$':
                /*
                 * Last 'good message left.
                 */
                for (mp = &message[msgCount-1]; mp >= &message[0]; mp--)
                        if ((mp->m_flag & MDELETED) == f)
                                return (mp - &message[0] + 1);
                printf("No applicable messages\n");
                return (-1);

        case '.':
                /*
                 * Current message.
                 */
                m = dot - &message[0] + 1;
                if ((dot->m_flag & MDELETED) != f) {
                        printf("%d: Inappropriate message\n", m);
                        return (-1);
                }
                return (m);

        default:
                printf("Unknown metachar (%c)\n", c);
                return (-1);
        }
}