/*
 * git-imap-send - drops patches into an imap Drafts folder
 *                 derived from isync/mbsync - mailbox synchronizer
 *
 * Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
 * Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net>
 * Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
 * Copyright (C) 2006 Mike McCormack
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "cache.h"

typedef struct store_conf {
        char *name;
        const char *path; /* should this be here? its interpretation is driver-specific */
        char *map_inbox;
        char *trash;
        unsigned max_size; /* off_t is overkill */
        unsigned trash_remote_new:1, trash_only_new:1;
} store_conf_t;

typedef struct string_list {
        struct string_list *next;
        char string[1];
} string_list_t;

typedef struct channel_conf {
        struct channel_conf *next;
        char *name;
        store_conf_t *master, *slave;
        char *master_name, *slave_name;
        char *sync_state;
        string_list_t *patterns;
        int mops, sops;
        unsigned max_messages; /* for slave only */
} channel_conf_t;

typedef struct group_conf {
        struct group_conf *next;
        char *name;
        string_list_t *channels;
} group_conf_t;

/* For message->status */
#define M_RECENT       (1<<0) /* unsyncable flag; maildir_* depend on this being 1<<0 */
#define M_DEAD         (1<<1) /* expunged */
#define M_FLAGS        (1<<2) /* flags fetched */

typedef struct message {
        struct message *next;
        /* string_list_t *keywords; */
        size_t size; /* zero implies "not fetched" */
        int uid;
        unsigned char flags, status;
} message_t;

typedef struct store {
        store_conf_t *conf; /* foreign */

        /* currently open mailbox */
        const char *name; /* foreign! maybe preset? */
        char *path; /* own */
        message_t *msgs; /* own */
        int uidvalidity;
        unsigned char opts; /* maybe preset? */
        /* note that the following do _not_ reflect stats from msgs, but mailbox totals */
        int count; /* # of messages */
        int recent; /* # of recent messages - don't trust this beyond the initial read */
} store_t;

typedef struct {
        char *data;
        int len;
        unsigned char flags;
        unsigned int crlf:1;
} msg_data_t;

#define DRV_OK          0
#define DRV_MSG_BAD     -1
#define DRV_BOX_BAD     -2
#define DRV_STORE_BAD   -3

static int Verbose, Quiet;

static void imap_info( const char *, ... );
static void imap_warn( const char *, ... );

static char *next_arg( char ** );

static void free_generic_messages( message_t * );

static int nfsnprintf( char *buf, int blen, const char *fmt, ... );


static void arc4_init( void );
static unsigned char arc4_getbyte( void );

typedef struct imap_server_conf {
        char *name;
        char *tunnel;
        char *host;
        int port;
        char *user;
        char *pass;
} imap_server_conf_t;

typedef struct imap_store_conf {
        store_conf_t gen;
        imap_server_conf_t *server;
        unsigned use_namespace:1;
} imap_store_conf_t;

#define NIL     (void*)0x1
#define LIST    (void*)0x2

typedef struct _list {
        struct _list *next, *child;
        char *val;
        int len;
} list_t;

typedef struct {
        int fd;
} Socket_t;

typedef struct {
        Socket_t sock;
        int bytes;
        int offset;
        char buf[1024];
} buffer_t;

struct imap_cmd;

typedef struct imap {
        int uidnext; /* from SELECT responses */
        list_t *ns_personal, *ns_other, *ns_shared; /* NAMESPACE info */
        unsigned caps, rcaps; /* CAPABILITY results */
        /* command queue */
        int nexttag, num_in_progress, literal_pending;
        struct imap_cmd *in_progress, **in_progress_append;
        buffer_t buf; /* this is BIG, so put it last */
} imap_t;

typedef struct imap_store {
        store_t gen;
        int uidvalidity;
        imap_t *imap;
        const char *prefix;
        unsigned /*currentnc:1,*/ trashnc:1;
} imap_store_t;

struct imap_cmd_cb {
        int (*cont)( imap_store_t *ctx, struct imap_cmd *cmd, const char *prompt );
        void (*done)( imap_store_t *ctx, struct imap_cmd *cmd, int response);
        void *ctx;
        char *data;
        int dlen;
        int uid;
        unsigned create:1, trycreate:1;
};

struct imap_cmd {
        struct imap_cmd *next;
        struct imap_cmd_cb cb;
        char *cmd;
        int tag;
};

#define CAP(cap) (imap->caps & (1 << (cap)))

enum CAPABILITY {
        NOLOGIN = 0,
        UIDPLUS,
        LITERALPLUS,
        NAMESPACE,
};

static const char *cap_list[] = {
        "LOGINDISABLED",
        "UIDPLUS",
        "LITERAL+",
        "NAMESPACE",
};

#define RESP_OK    0
#define RESP_NO    1
#define RESP_BAD   2

static int get_cmd_result( imap_store_t *ctx, struct imap_cmd *tcmd );


static const char *Flags[] = {
        "Draft",
        "Flagged",
        "Answered",
        "Seen",
        "Deleted",
};

static void
socket_perror( const char *func, Socket_t *sock, int ret )
{
        if (ret < 0)
                perror( func );
        else
                fprintf( stderr, "%s: unexpected EOF\n", func );
}

static int
socket_read( Socket_t *sock, char *buf, int len )
{
        ssize_t n = xread( sock->fd, buf, len );
        if (n <= 0) {
                socket_perror( "read", sock, n );
                close( sock->fd );
                sock->fd = -1;
        }
        return n;
}

static int
socket_write( Socket_t *sock, const char *buf, int len )
{
        int n = write_in_full( sock->fd, buf, len );
        if (n != len) {
                socket_perror( "write", sock, n );
                close( sock->fd );
                sock->fd = -1;
        }
        return n;
}

/* simple line buffering */
static int
buffer_gets( buffer_t * b, char **s )
{
        int n;
        int start = b->offset;

        *s = b->buf + start;

        for (;;) {
                /* make sure we have enough data to read the \r\n sequence */
                if (b->offset + 1 >= b->bytes) {
                        if (start) {
                                /* shift down used bytes */
                                *s = b->buf;

                                assert( start <= b->bytes );
                                n = b->bytes - start;

                                if (n)
                                        memmove(b->buf, b->buf + start, n);
                                b->offset -= start;
                                b->bytes = n;
                                start = 0;
                        }

                        n = socket_read( &b->sock, b->buf + b->bytes,
                                         sizeof(b->buf) - b->bytes );

                        if (n <= 0)
                                return -1;

                        b->bytes += n;
                }

                if (b->buf[b->offset] == '\r') {
                        assert( b->offset + 1 < b->bytes );
                        if (b->buf[b->offset + 1] == '\n') {
                                b->buf[b->offset] = 0;  /* terminate the string */
                                b->offset += 2; /* next line */
                                if (Verbose)
                                        puts( *s );
                                return 0;
                        }
                }

                b->offset++;
        }
        /* not reached */
}

static void
imap_info( const char *msg, ... )
{
        va_list va;

        if (!Quiet) {
                va_start( va, msg );
                vprintf( msg, va );
                va_end( va );
                fflush( stdout );
        }
}

static void
imap_warn( const char *msg, ... )
{
        va_list va;

        if (Quiet < 2) {
                va_start( va, msg );
                vfprintf( stderr, msg, va );
                va_end( va );
        }
}

static char *
next_arg( char **s )
{
        char *ret;

        if (!s || !*s)
                return NULL;
        while (isspace( (unsigned char) **s ))
                (*s)++;
        if (!**s) {
                *s = NULL;
                return NULL;
        }
        if (**s == '"') {
                ++*s;
                ret = *s;
                *s = strchr( *s, '"' );
        } else {
                ret = *s;
                while (**s && !isspace( (unsigned char) **s ))
                        (*s)++;
        }
        if (*s) {
                if (**s)
                        *(*s)++ = 0;
                if (!**s)
                        *s = NULL;
        }
        return ret;
}

static void
free_generic_messages( message_t *msgs )
{
        message_t *tmsg;

        for (; msgs; msgs = tmsg) {
                tmsg = msgs->next;
                free( msgs );
        }
}

static int
nfsnprintf( char *buf, int blen, const char *fmt, ... )
{
        int ret;
        va_list va;

        va_start( va, fmt );
        if (blen <= 0 || (unsigned)(ret = vsnprintf( buf, blen, fmt, va )) >= (unsigned)blen)
                die( "Fatal: buffer too small. Please report a bug.\n");
        va_end( va );
        return ret;
}

static struct {
        unsigned char i, j, s[256];
} rs;

static void
arc4_init( void )
{
        int i, fd;
        unsigned char j, si, dat[128];

        if ((fd = open( "/dev/urandom", O_RDONLY )) < 0 && (fd = open( "/dev/random", O_RDONLY )) < 0) {
                fprintf( stderr, "Fatal: no random number source available.\n" );
                exit( 3 );
        }
        if (read_in_full( fd, dat, 128 ) != 128) {
                fprintf( stderr, "Fatal: cannot read random number source.\n" );
                exit( 3 );
        }
        close( fd );

        for (i = 0; i < 256; i++)
                rs.s[i] = i;
        for (i = j = 0; i < 256; i++) {
                si = rs.s[i];
                j += si + dat[i & 127];
                rs.s[i] = rs.s[j];
                rs.s[j] = si;
        }
        rs.i = rs.j = 0;

        for (i = 0; i < 256; i++)
                arc4_getbyte();
}

static unsigned char
arc4_getbyte( void )
{
        unsigned char si, sj;

        rs.i++;
        si = rs.s[rs.i];
        rs.j += si;
        sj = rs.s[rs.j];
        rs.s[rs.i] = sj;
        rs.s[rs.j] = si;
        return rs.s[(si + sj) & 0xff];
}

static struct imap_cmd *
v_issue_imap_cmd( imap_store_t *ctx, struct imap_cmd_cb *cb,
                  const char *fmt, va_list ap )
{
        imap_t *imap = ctx->imap;
        struct imap_cmd *cmd;
        int n, bufl;
        char buf[1024];

        cmd = xmalloc( sizeof(struct imap_cmd) );
        nfvasprintf( &cmd->cmd, fmt, ap );
        cmd->tag = ++imap->nexttag;

        if (cb)
                cmd->cb = *cb;
        else
                memset( &cmd->cb, 0, sizeof(cmd->cb) );

        while (imap->literal_pending)
                get_cmd_result( ctx, NULL );

        bufl = nfsnprintf( buf, sizeof(buf), cmd->cb.data ? CAP(LITERALPLUS) ?
                           "%d %s{%d+}\r\n" : "%d %s{%d}\r\n" : "%d %s\r\n",
                           cmd->tag, cmd->cmd, cmd->cb.dlen );
        if (Verbose) {
                if (imap->num_in_progress)
                        printf( "(%d in progress) ", imap->num_in_progress );
                if (memcmp( cmd->cmd, "LOGIN", 5 ))
                        printf( ">>> %s", buf );
                else
                        printf( ">>> %d LOGIN <user> <pass>\n", cmd->tag );
        }
        if (socket_write( &imap->buf.sock, buf, bufl ) != bufl) {
                free( cmd->cmd );
                free( cmd );
                if (cb && cb->data)
                        free( cb->data );
                return NULL;
        }
        if (cmd->cb.data) {
                if (CAP(LITERALPLUS)) {
                        n = socket_write( &imap->buf.sock, cmd->cb.data, cmd->cb.dlen );
                        free( cmd->cb.data );
                        if (n != cmd->cb.dlen ||
                            (n = socket_write( &imap->buf.sock, "\r\n", 2 )) != 2)
                        {
                                free( cmd->cmd );
                                free( cmd );
                                return NULL;
                        }
                        cmd->cb.data = NULL;
                } else
                        imap->literal_pending = 1;
        } else if (cmd->cb.cont)
                imap->literal_pending = 1;
        cmd->next = NULL;
        *imap->in_progress_append = cmd;
        imap->in_progress_append = &cmd->next;
        imap->num_in_progress++;
        return cmd;
}

static struct imap_cmd *
issue_imap_cmd( imap_store_t *ctx, struct imap_cmd_cb *cb, const char *fmt, ... )
{
        struct imap_cmd *ret;
        va_list ap;

        va_start( ap, fmt );
        ret = v_issue_imap_cmd( ctx, cb, fmt, ap );
        va_end( ap );
        return ret;
}

static int
imap_exec( imap_store_t *ctx, struct imap_cmd_cb *cb, const char *fmt, ... )
{
        va_list ap;
        struct imap_cmd *cmdp;

        va_start( ap, fmt );
        cmdp = v_issue_imap_cmd( ctx, cb, fmt, ap );
        va_end( ap );
        if (!cmdp)
                return RESP_BAD;

        return get_cmd_result( ctx, cmdp );
}

static int
imap_exec_m( imap_store_t *ctx, struct imap_cmd_cb *cb, const char *fmt, ... )
{
        va_list ap;
        struct imap_cmd *cmdp;

        va_start( ap, fmt );
        cmdp = v_issue_imap_cmd( ctx, cb, fmt, ap );
        va_end( ap );
        if (!cmdp)
                return DRV_STORE_BAD;

        switch (get_cmd_result( ctx, cmdp )) {
        case RESP_BAD: return DRV_STORE_BAD;
        case RESP_NO: return DRV_MSG_BAD;
        default: return DRV_OK;
        }
}

static int
is_atom( list_t *list )
{
        return list && list->val && list->val != NIL && list->val != LIST;
}

static int
is_list( list_t *list )
{
        return list && list->val == LIST;
}

static void
free_list( list_t *list )
{
        list_t *tmp;

        for (; list; list = tmp) {
                tmp = list->next;
                if (is_list( list ))
                        free_list( list->child );
                else if (is_atom( list ))
                        free( list->val );
                free( list );
        }
}

static int
parse_imap_list_l( imap_t *imap, char **sp, list_t **curp, int level )
{
        list_t *cur;
        char *s = *sp, *p;
        int n, bytes;

        for (;;) {
                while (isspace( (unsigned char)*s ))
                        s++;
                if (level && *s == ')') {
                        s++;
                        break;
                }
                *curp = cur = xmalloc( sizeof(*cur) );
                curp = &cur->next;
                cur->val = NULL; /* for clean bail */
                if (*s == '(') {
                        /* sublist */
                        s++;
                        cur->val = LIST;
                        if (parse_imap_list_l( imap, &s, &cur->child, level + 1 ))
                                goto bail;
                } else if (imap && *s == '{') {
                        /* literal */
                        bytes = cur->len = strtol( s + 1, &s, 10 );
                        if (*s != '}')
                                goto bail;

                        s = cur->val = xmalloc( cur->len );

                        /* dump whats left over in the input buffer */
                        n = imap->buf.bytes - imap->buf.offset;

                        if (n > bytes)
                                /* the entire message fit in the buffer */
                                n = bytes;

                        memcpy( s, imap->buf.buf + imap->buf.offset, n );
                        s += n;
                        bytes -= n;

                        /* mark that we used part of the buffer */
                        imap->buf.offset += n;

                        /* now read the rest of the message */
                        while (bytes > 0) {
                                if ((n = socket_read (&imap->buf.sock, s, bytes)) <= 0)
                                        goto bail;
                                s += n;
                                bytes -= n;
                        }

                        if (buffer_gets( &imap->buf, &s ))
                                goto bail;
                } else if (*s == '"') {
                        /* quoted string */
                        s++;
                        p = s;
                        for (; *s != '"'; s++)
                                if (!*s)
                                        goto bail;
                        cur->len = s - p;
                        s++;
                        cur->val = xmalloc( cur->len + 1 );
                        memcpy( cur->val, p, cur->len );
                        cur->val[cur->len] = 0;
                } else {
                        /* atom */
                        p = s;
                        for (; *s && !isspace( (unsigned char)*s ); s++)
                                if (level && *s == ')')
                                        break;
                        cur->len = s - p;
                        if (cur->len == 3 && !memcmp ("NIL", p, 3))
                                cur->val = NIL;
                        else {
                                cur->val = xmalloc( cur->len + 1 );
                                memcpy( cur->val, p, cur->len );
                                cur->val[cur->len] = 0;
                        }
                }

                if (!level)
                        break;
                if (!*s)
                        goto bail;
        }
        *sp = s;
        *curp = NULL;
        return 0;

  bail:
        *curp = NULL;
        return -1;
}

static list_t *
parse_imap_list( imap_t *imap, char **sp )
{
        list_t *head;

        if (!parse_imap_list_l( imap, sp, &head, 0 ))
                return head;
        free_list( head );
        return NULL;
}

static list_t *
parse_list( char **sp )
{
        return parse_imap_list( NULL, sp );
}

static void
parse_capability( imap_t *imap, char *cmd )
{
        char *arg;
        unsigned i;

        imap->caps = 0x80000000;
        while ((arg = next_arg( &cmd )))
                for (i = 0; i < ARRAY_SIZE(cap_list); i++)
                        if (!strcmp( cap_list[i], arg ))
                                imap->caps |= 1 << i;
        imap->rcaps = imap->caps;
}

static int
parse_response_code( imap_store_t *ctx, struct imap_cmd_cb *cb, char *s )
{
        imap_t *imap = ctx->imap;
        char *arg, *p;

        if (*s != '[')
                return RESP_OK;         /* no response code */
        s++;
        if (!(p = strchr( s, ']' ))) {
                fprintf( stderr, "IMAP error: malformed response code\n" );
                return RESP_BAD;
        }
        *p++ = 0;
        arg = next_arg( &s );
        if (!strcmp( "UIDVALIDITY", arg )) {
                if (!(arg = next_arg( &s )) || !(ctx->gen.uidvalidity = atoi( arg ))) {
                        fprintf( stderr, "IMAP error: malformed UIDVALIDITY status\n" );
                        return RESP_BAD;
                }
        } else if (!strcmp( "UIDNEXT", arg )) {
                if (!(arg = next_arg( &s )) || !(imap->uidnext = atoi( arg ))) {
                        fprintf( stderr, "IMAP error: malformed NEXTUID status\n" );
                        return RESP_BAD;
                }
        } else if (!strcmp( "CAPABILITY", arg )) {
                parse_capability( imap, s );
        } else if (!strcmp( "ALERT", arg )) {
                /* RFC2060 says that these messages MUST be displayed
                 * to the user
                 */
                for (; isspace( (unsigned char)*p ); p++);
                fprintf( stderr, "*** IMAP ALERT *** %s\n", p );
        } else if (cb && cb->ctx && !strcmp( "APPENDUID", arg )) {
                if (!(arg = next_arg( &s )) || !(ctx->gen.uidvalidity = atoi( arg )) ||
                    !(arg = next_arg( &s )) || !(*(int *)cb->ctx = atoi( arg )))
                {
                        fprintf( stderr, "IMAP error: malformed APPENDUID status\n" );
                        return RESP_BAD;
                }
        }
        return RESP_OK;
}

static int
get_cmd_result( imap_store_t *ctx, struct imap_cmd *tcmd )
{
        imap_t *imap = ctx->imap;
        struct imap_cmd *cmdp, **pcmdp, *ncmdp;
        char *cmd, *arg, *arg1, *p;
        int n, resp, resp2, tag;

        for (;;) {
                if (buffer_gets( &imap->buf, &cmd ))
                        return RESP_BAD;

                arg = next_arg( &cmd );
                if (*arg == '*') {
                        arg = next_arg( &cmd );
                        if (!arg) {
                                fprintf( stderr, "IMAP error: unable to parse untagged response\n" );
                                return RESP_BAD;
                        }

                        if (!strcmp( "NAMESPACE", arg )) {
                                imap->ns_personal = parse_list( &cmd );
                                imap->ns_other = parse_list( &cmd );
                                imap->ns_shared = parse_list( &cmd );
                        } else if (!strcmp( "OK", arg ) || !strcmp( "BAD", arg ) ||
                                   !strcmp( "NO", arg ) || !strcmp( "BYE", arg )) {
                                if ((resp = parse_response_code( ctx, NULL, cmd )) != RESP_OK)
                                        return resp;
                        } else if (!strcmp( "CAPABILITY", arg ))
                                parse_capability( imap, cmd );
                        else if ((arg1 = next_arg( &cmd ))) {
                                if (!strcmp( "EXISTS", arg1 ))
                                        ctx->gen.count = atoi( arg );
                                else if (!strcmp( "RECENT", arg1 ))
                                        ctx->gen.recent = atoi( arg );
                        } else {
                                fprintf( stderr, "IMAP error: unable to parse untagged response\n" );
                                return RESP_BAD;
                        }
                } else if (!imap->in_progress) {
                        fprintf( stderr, "IMAP error: unexpected reply: %s %s\n", arg, cmd ? cmd : "" );
                        return RESP_BAD;
                } else if (*arg == '+') {
                        /* This can happen only with the last command underway, as
                           it enforces a round-trip. */
                        cmdp = (struct imap_cmd *)((char *)imap->in_progress_append -
                               offsetof(struct imap_cmd, next));
                        if (cmdp->cb.data) {
                                n = socket_write( &imap->buf.sock, cmdp->cb.data, cmdp->cb.dlen );
                                free( cmdp->cb.data );
                                cmdp->cb.data = NULL;
                                if (n != (int)cmdp->cb.dlen)
                                        return RESP_BAD;
                        } else if (cmdp->cb.cont) {
                                if (cmdp->cb.cont( ctx, cmdp, cmd ))
                                        return RESP_BAD;
                        } else {
                                fprintf( stderr, "IMAP error: unexpected command continuation request\n" );
                                return RESP_BAD;
                        }
                        if (socket_write( &imap->buf.sock, "\r\n", 2 ) != 2)
                                return RESP_BAD;
                        if (!cmdp->cb.cont)
                                imap->literal_pending = 0;
                        if (!tcmd)
                                return DRV_OK;
                } else {
                        tag = atoi( arg );
                        for (pcmdp = &imap->in_progress; (cmdp = *pcmdp); pcmdp = &cmdp->next)
                                if (cmdp->tag == tag)
                                        goto gottag;
                        fprintf( stderr, "IMAP error: unexpected tag %s\n", arg );
                        return RESP_BAD;
                  gottag:
                        if (!(*pcmdp = cmdp->next))
                                imap->in_progress_append = pcmdp;
                        imap->num_in_progress--;
                        if (cmdp->cb.cont || cmdp->cb.data)
                                imap->literal_pending = 0;
                        arg = next_arg( &cmd );
                        if (!strcmp( "OK", arg ))
                                resp = DRV_OK;
                        else {
                                if (!strcmp( "NO", arg )) {
                                        if (cmdp->cb.create && cmd && (cmdp->cb.trycreate || !memcmp( cmd, "[TRYCREATE]", 11 ))) { /* SELECT, APPEND or UID COPY */
                                                p = strchr( cmdp->cmd, '"' );
                                                if (!issue_imap_cmd( ctx, NULL, "CREATE \"%.*s\"", strchr( p + 1, '"' ) - p + 1, p )) {
                                                        resp = RESP_BAD;
                                                        goto normal;
                                                }
                                                /* not waiting here violates the spec, but a server that does not
                                                   grok this nonetheless violates it too. */
                                                cmdp->cb.create = 0;
                                                if (!(ncmdp = issue_imap_cmd( ctx, &cmdp->cb, "%s", cmdp->cmd ))) {
                                                        resp = RESP_BAD;
                                                        goto normal;
                                                }
                                                free( cmdp->cmd );
                                                free( cmdp );
                                                if (!tcmd)
                                                        return 0;       /* ignored */
                                                if (cmdp == tcmd)
                                                        tcmd = ncmdp;
                                                continue;
                                        }
                                        resp = RESP_NO;
                                } else /*if (!strcmp( "BAD", arg ))*/
                                        resp = RESP_BAD;
                                fprintf( stderr, "IMAP command '%s' returned response (%s) - %s\n",
                                         memcmp (cmdp->cmd, "LOGIN", 5) ?
                                                        cmdp->cmd : "LOGIN <user> <pass>",
                                                        arg, cmd ? cmd : "");
                        }
                        if ((resp2 = parse_response_code( ctx, &cmdp->cb, cmd )) > resp)
                                resp = resp2;
                  normal:
                        if (cmdp->cb.done)
                                cmdp->cb.done( ctx, cmdp, resp );
                        if (cmdp->cb.data)
                                free( cmdp->cb.data );
                        free( cmdp->cmd );
                        free( cmdp );
                        if (!tcmd || tcmd == cmdp)
                                return resp;
                }
        }
        /* not reached */
}

static void
imap_close_server( imap_store_t *ictx )
{
        imap_t *imap = ictx->imap;

        if (imap->buf.sock.fd != -1) {
                imap_exec( ictx, NULL, "LOGOUT" );
                close( imap->buf.sock.fd );
        }
        free_list( imap->ns_personal );
        free_list( imap->ns_other );
        free_list( imap->ns_shared );
        free( imap );
}

static void
imap_close_store( store_t *ctx )
{
        imap_close_server( (imap_store_t *)ctx );
        free_generic_messages( ctx->msgs );
        free( ctx );
}

static store_t *
imap_open_store( imap_server_conf_t *srvc )
{
        imap_store_t *ctx;
        imap_t *imap;
        char *arg, *rsp;
        struct hostent *he;
        struct sockaddr_in addr;
        int s, a[2], preauth;
        pid_t pid;

        ctx = xcalloc( sizeof(*ctx), 1 );

        ctx->imap = imap = xcalloc( sizeof(*imap), 1 );
        imap->buf.sock.fd = -1;
        imap->in_progress_append = &imap->in_progress;

        /* open connection to IMAP server */

        if (srvc->tunnel) {
                imap_info( "Starting tunnel '%s'... ", srvc->tunnel );

                if (socketpair( PF_UNIX, SOCK_STREAM, 0, a )) {
                        perror( "socketpair" );
                        exit( 1 );
                }

                pid = fork();
                if (pid < 0)
                        _exit( 127 );
                if (!pid) {
                        if (dup2( a[0], 0 ) == -1 || dup2( a[0], 1 ) == -1)
                                _exit( 127 );
                        close( a[0] );
                        close( a[1] );
                        execl( "/bin/sh", "sh", "-c", srvc->tunnel, NULL );
                        _exit( 127 );
                }

                close (a[0]);

                imap->buf.sock.fd = a[1];

                imap_info( "ok\n" );
        } else {
                memset( &addr, 0, sizeof(addr) );
                addr.sin_port = htons( srvc->port );
                addr.sin_family = AF_INET;

                imap_info( "Resolving %s... ", srvc->host );
                he = gethostbyname( srvc->host );
                if (!he) {
                        perror( "gethostbyname" );
                        goto bail;
                }
                imap_info( "ok\n" );

                addr.sin_addr.s_addr = *((int *) he->h_addr_list[0]);

                s = socket( PF_INET, SOCK_STREAM, 0 );

                imap_info( "Connecting to %s:%hu... ", inet_ntoa( addr.sin_addr ), ntohs( addr.sin_port ) );
                if (connect( s, (struct sockaddr *)&addr, sizeof(addr) )) {
                        close( s );
                        perror( "connect" );
                        goto bail;
                }
                imap_info( "ok\n" );

                imap->buf.sock.fd = s;

        }

        /* read the greeting string */
        if (buffer_gets( &imap->buf, &rsp )) {
                fprintf( stderr, "IMAP error: no greeting response\n" );
                goto bail;
        }
        arg = next_arg( &rsp );
        if (!arg || *arg != '*' || (arg = next_arg( &rsp )) == NULL) {
                fprintf( stderr, "IMAP error: invalid greeting response\n" );
                goto bail;
        }
        preauth = 0;
        if (!strcmp( "PREAUTH", arg ))
                preauth = 1;
        else if (strcmp( "OK", arg ) != 0) {
                fprintf( stderr, "IMAP error: unknown greeting response\n" );
                goto bail;
        }
        parse_response_code( ctx, NULL, rsp );
        if (!imap->caps && imap_exec( ctx, NULL, "CAPABILITY" ) != RESP_OK)
                goto bail;

        if (!preauth) {

                imap_info ("Logging in...\n");
                if (!srvc->user) {
                        fprintf( stderr, "Skipping server %s, no user\n", srvc->host );
                        goto bail;
                }
                if (!srvc->pass) {
                        char prompt[80];
                        sprintf( prompt, "Password (%s@%s): ", srvc->user, srvc->host );
                        arg = getpass( prompt );
                        if (!arg) {
                                perror( "getpass" );
                                exit( 1 );
                        }
                        if (!*arg) {
                                fprintf( stderr, "Skipping account %s@%s, no password\n", srvc->user, srvc->host );
                                goto bail;
                        }
                        /*
                         * getpass() returns a pointer to a static buffer.  make a copy
                         * for long term storage.
                         */
                        srvc->pass = xstrdup( arg );
                }
                if (CAP(NOLOGIN)) {
                        fprintf( stderr, "Skipping account %s@%s, server forbids LOGIN\n", srvc->user, srvc->host );
                        goto bail;
                }
                imap_warn( "*** IMAP Warning *** Password is being sent in the clear\n" );
                if (imap_exec( ctx, NULL, "LOGIN \"%s\" \"%s\"", srvc->user, srvc->pass ) != RESP_OK) {
                        fprintf( stderr, "IMAP error: LOGIN failed\n" );
                        goto bail;
                }
        } /* !preauth */

        ctx->prefix = "";
        ctx->trashnc = 1;
        return (store_t *)ctx;

  bail:
        imap_close_store( &ctx->gen );
        return NULL;
}

static int
imap_make_flags( int flags, char *buf )
{
        const char *s;
        unsigned i, d;

        for (i = d = 0; i < ARRAY_SIZE(Flags); i++)
                if (flags & (1 << i)) {
                        buf[d++] = ' ';
                        buf[d++] = '\\';
                        for (s = Flags[i]; *s; s++)
                                buf[d++] = *s;
                }
        buf[0] = '(';
        buf[d++] = ')';
        return d;
}

#define TUIDL 8

static int
imap_store_msg( store_t *gctx, msg_data_t *data, int *uid )
{
        imap_store_t *ctx = (imap_store_t *)gctx;
        imap_t *imap = ctx->imap;
        struct imap_cmd_cb cb;
        char *fmap, *buf;
        const char *prefix, *box;
        int ret, i, j, d, len, extra, nocr;
        int start, sbreak = 0, ebreak = 0;
        char flagstr[128], tuid[TUIDL * 2 + 1];

        memset( &cb, 0, sizeof(cb) );

        fmap = data->data;
        len = data->len;
        nocr = !data->crlf;
        extra = 0, i = 0;
        if (!CAP(UIDPLUS) && uid) {
          nloop:
                start = i;
                while (i < len)
                        if (fmap[i++] == '\n') {
                                extra += nocr;
                                if (i - 2 + nocr == start) {
                                        sbreak = ebreak = i - 2 + nocr;
                                        goto mktid;
                                }
                                if (!memcmp( fmap + start, "X-TUID: ", 8 )) {
                                        extra -= (ebreak = i) - (sbreak = start) + nocr;
                                        goto mktid;
                                }
                                goto nloop;
                        }
                /* invalid message */
                free( fmap );
                return DRV_MSG_BAD;
         mktid:
                for (j = 0; j < TUIDL; j++)
                        sprintf( tuid + j * 2, "%02x", arc4_getbyte() );
                extra += 8 + TUIDL * 2 + 2;
        }
        if (nocr)
                for (; i < len; i++)
                        if (fmap[i] == '\n')
                                extra++;

        cb.dlen = len + extra;
        buf = cb.data = xmalloc( cb.dlen );
        i = 0;
        if (!CAP(UIDPLUS) && uid) {
                if (nocr) {
                        for (; i < sbreak; i++)
                                if (fmap[i] == '\n') {
                                        *buf++ = '\r';
                                        *buf++ = '\n';
                                } else
                                        *buf++ = fmap[i];
                } else {
                        memcpy( buf, fmap, sbreak );
                        buf += sbreak;
                }
                memcpy( buf, "X-TUID: ", 8 );
                buf += 8;
                memcpy( buf, tuid, TUIDL * 2 );
                buf += TUIDL * 2;
                *buf++ = '\r';
                *buf++ = '\n';
                i = ebreak;
        }
        if (nocr) {
                for (; i < len; i++)
                        if (fmap[i] == '\n') {
                                *buf++ = '\r';
                                *buf++ = '\n';
                        } else
                                *buf++ = fmap[i];
        } else
                memcpy( buf, fmap + i, len - i );

        free( fmap );

        d = 0;
        if (data->flags) {
                d = imap_make_flags( data->flags, flagstr );
                flagstr[d++] = ' ';
        }
        flagstr[d] = 0;

        if (!uid) {
                box = gctx->conf->trash;
                prefix = ctx->prefix;
                cb.create = 1;
                if (ctx->trashnc)
                        imap->caps = imap->rcaps & ~(1 << LITERALPLUS);
        } else {
                box = gctx->name;
                prefix = !strcmp( box, "INBOX" ) ? "" : ctx->prefix;
                cb.create = 0;
        }
        cb.ctx = uid;
        ret = imap_exec_m( ctx, &cb, "APPEND \"%s%s\" %s", prefix, box, flagstr );
        imap->caps = imap->rcaps;
        if (ret != DRV_OK)
                return ret;
        if (!uid)
                ctx->trashnc = 0;
        else
                gctx->count++;

        return DRV_OK;
}

#define CHUNKSIZE 0x1000

static int
read_message( FILE *f, msg_data_t *msg )
{
        int len, r;

        memset( msg, 0, sizeof *msg );
        len = CHUNKSIZE;
        msg->data = xmalloc( len+1 );
        msg->data[0] = 0;

        while(!feof( f )) {
                if (msg->len >= len) {
                        void *p;
                        len += CHUNKSIZE;
                        p = xrealloc(msg->data, len+1);
                        if (!p)
                                break;
                        msg->data = p;
                }
                r = fread( &msg->data[msg->len], 1, len - msg->len, f );
                if (r <= 0)
                        break;
                msg->len += r;
        }
        msg->data[msg->len] = 0;
        return msg->len;
}

static int
count_messages( msg_data_t *msg )
{
        int count = 0;
        char *p = msg->data;

        while (1) {
                if (!prefixcmp(p, "From ")) {
                        count++;
                        p += 5;
                }
                p = strstr( p+5, "\nFrom ");
                if (!p)
                        break;
                p++;
        }
        return count;
}

static int
split_msg( msg_data_t *all_msgs, msg_data_t *msg, int *ofs )
{
        char *p, *data;

        memset( msg, 0, sizeof *msg );
        if (*ofs >= all_msgs->len)
                return 0;

        data = &all_msgs->data[ *ofs ];
        msg->len = all_msgs->len - *ofs;

        if (msg->len < 5 || prefixcmp(data, "From "))
                return 0;

        p = strchr( data, '\n' );
        if (p) {
                p = &p[1];
                msg->len -= p-data;
                *ofs += p-data;
                data = p;
        }

        p = strstr( data, "\nFrom " );
        if (p)
                msg->len = &p[1] - data;

        msg->data = xmalloc( msg->len + 1 );
        if (!msg->data)
                return 0;

        memcpy( msg->data, data, msg->len );
        msg->data[ msg->len ] = 0;

        *ofs += msg->len;
        return 1;
}

static imap_server_conf_t server =
{
        NULL,   /* name */
        NULL,   /* tunnel */
        NULL,   /* host */
        0,      /* port */
        NULL,   /* user */
        NULL,   /* pass */
};

static char *imap_folder;

static int
git_imap_config(const char *key, const char *val)
{
        char imap_key[] = "imap.";

        if (strncmp( key, imap_key, sizeof imap_key - 1 ))
                return 0;
        key += sizeof imap_key - 1;

        if (!strcmp( "folder", key )) {
                imap_folder = xstrdup( val );
        } else if (!strcmp( "host", key )) {
                {
                        if (!prefixcmp(val, "imap:"))
                                val += 5;
                        if (!server.port)
                                server.port = 143;
                }
                if (!prefixcmp(val, "//"))
                        val += 2;
                server.host = xstrdup( val );
        }
        else if (!strcmp( "user", key ))
                server.user = xstrdup( val );
        else if (!strcmp( "pass", key ))
                server.pass = xstrdup( val );
        else if (!strcmp( "port", key ))
                server.port = git_config_int( key, val );
        else if (!strcmp( "tunnel", key ))
                server.tunnel = xstrdup( val );
        return 0;
}

int
main(int argc, char **argv)
{
        msg_data_t all_msgs, msg;
        store_t *ctx = NULL;
        int uid = 0;
        int ofs = 0;
        int r;
        int total, n = 0;

        /* init the random number generator */
        arc4_init();

        git_config( git_imap_config );

        if (!imap_folder) {
                fprintf( stderr, "no imap store specified\n" );
                return 1;
        }

        /* read the messages */
        if (!read_message( stdin, &all_msgs )) {
                fprintf(stderr,"nothing to send\n");
                return 1;
        }

        total = count_messages( &all_msgs );
        if (!total) {
                fprintf(stderr,"no messages to send\n");
                return 1;
        }

        /* write it to the imap server */
        ctx = imap_open_store( &server );
        if (!ctx) {
                fprintf( stderr,"failed to open store\n");
                return 1;
        }

        fprintf( stderr, "sending %d message%s\n", total, (total!=1)?"s":"" );
        ctx->name = imap_folder;
        while (1) {
                unsigned percent = n * 100 / total;
                fprintf( stderr, "%4u%% (%d/%d) done\r", percent, n, total );
                if (!split_msg( &all_msgs, &msg, &ofs ))
                        break;
                r = imap_store_msg( ctx, &msg, &uid );
                if (r != DRV_OK) break;
                n++;
        }
        fprintf( stderr,"\n" );

        imap_close_store( ctx );

        return 0;
}