/*
 *  Copyright (C) 2000 Helix Code Inc.
 *
 *  Authors: Michael Zucchi <notzed@helixcode.com>
 *
 *  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 "camel-mbox-summary.h"
#include <camel/camel-mime-message.h>

#include <sys/stat.h>
#include <sys/uio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>

#define io(x)
#define d(x)

#define CAMEL_MBOX_SUMMARY_VERSION (0x1000)

struct _CamelMboxSummaryPrivate {
};

#define _PRIVATE(o) (((CamelMboxSummary *)(o))->priv)

static int summary_header_load(CamelFolderSummary *, FILE *);
static int summary_header_save(CamelFolderSummary *, FILE *);

static CamelMessageInfo * message_info_new(CamelFolderSummary *, struct _header_raw *);
static CamelMessageInfo * message_info_new_from_parser(CamelFolderSummary *, CamelMimeParser *);
static CamelMessageInfo * message_info_load(CamelFolderSummary *, FILE *);
static int		  message_info_save(CamelFolderSummary *, FILE *, CamelMessageInfo *);
/*static void		  message_info_free(CamelFolderSummary *, CamelMessageInfo *);*/

static void camel_mbox_summary_class_init (CamelMboxSummaryClass *klass);
static void camel_mbox_summary_init       (CamelMboxSummary *obj);
static void camel_mbox_summary_finalise   (GtkObject *obj);

static CamelFolderSummaryClass *camel_mbox_summary_parent;

enum SIGNALS {
	LAST_SIGNAL
};

static guint signals[LAST_SIGNAL] = { 0 };

guint
camel_mbox_summary_get_type (void)
{
	static guint type = 0;
	
	if (!type) {
		GtkTypeInfo type_info = {
			"CamelMboxSummary",
			sizeof (CamelMboxSummary),
			sizeof (CamelMboxSummaryClass),
			(GtkClassInitFunc) camel_mbox_summary_class_init,
			(GtkObjectInitFunc) camel_mbox_summary_init,
			(GtkArgSetFunc) NULL,
			(GtkArgGetFunc) NULL
		};
		
		type = gtk_type_unique (camel_folder_summary_get_type (), &type_info);
	}
	
	return type;
}

static void
camel_mbox_summary_class_init (CamelMboxSummaryClass *klass)
{
	GtkObjectClass *object_class = (GtkObjectClass *) klass;
	CamelFolderSummaryClass *sklass = (CamelFolderSummaryClass *) klass;
	
	camel_mbox_summary_parent = gtk_type_class (camel_folder_summary_get_type ());

	object_class->finalize = camel_mbox_summary_finalise;

	sklass->summary_header_load = summary_header_load;
	sklass->summary_header_save = summary_header_save;

	sklass->message_info_new  = message_info_new;
	sklass->message_info_new_from_parser = message_info_new_from_parser;
	sklass->message_info_load = message_info_load;
	sklass->message_info_save = message_info_save;
	/*sklass->message_info_free = message_info_free;*/

	gtk_object_class_add_signals (object_class, signals, LAST_SIGNAL);
}

static void
camel_mbox_summary_init (CamelMboxSummary *obj)
{
	struct _CamelMboxSummaryPrivate *p;
	struct _CamelFolderSummary *s = (CamelFolderSummary *)obj;

	p = _PRIVATE(obj) = g_malloc0(sizeof(*p));

	/* subclasses need to set the right instance data sizes */
	s->message_info_size = sizeof(CamelMboxMessageInfo);
	s->content_info_size = sizeof(CamelMboxMessageContentInfo);

	/* and a unique file version */
	s->version = CAMEL_MBOX_SUMMARY_VERSION;
}

static void
camel_mbox_summary_finalise (GtkObject *obj)
{
	CamelMboxSummary *mbs = (CamelMboxSummary *)obj;

	g_free(mbs->folder_path);

	((GtkObjectClass *)(camel_mbox_summary_parent))->finalize((GtkObject *)obj);
}

/**
 * camel_mbox_summary_new:
 *
 * Create a new CamelMboxSummary object.
 * 
 * Return value: A new CamelMboxSummary widget.
 **/
CamelMboxSummary *
camel_mbox_summary_new (const char *filename, const char *mbox_name, ibex *index)
{
	CamelMboxSummary *new = CAMEL_MBOX_SUMMARY ( gtk_type_new (camel_mbox_summary_get_type ()));
	if (new) {
		/* ?? */
		camel_folder_summary_set_build_content((CamelFolderSummary *)new, TRUE);
		camel_folder_summary_set_filename((CamelFolderSummary *)new, filename);
		new->folder_path = g_strdup(mbox_name);
		new->index = index;
	}
	return new;
}


static int summary_header_load(CamelFolderSummary *s, FILE *in)
{
	CamelMboxSummary *mbs = (CamelMboxSummary *)s;

	if (((CamelFolderSummaryClass *)camel_mbox_summary_parent)->summary_header_load(s, in) == -1)
		return -1;

	return camel_folder_summary_decode_uint32(in, &mbs->folder_size);
}

static int summary_header_save(CamelFolderSummary *s, FILE *out)
{
	CamelMboxSummary *mbs = (CamelMboxSummary *)s;

	if (((CamelFolderSummaryClass *)camel_mbox_summary_parent)->summary_header_save(s, out) == -1)
		return -1;

	return camel_folder_summary_encode_uint32(out, mbs->folder_size);
}

static int
header_evolution_decode(const char *in, guint32 *uid, guint32 *flags)
{
        char *header;
        if (in
            && (header = header_token_decode(in))) {
                if (strlen(header) == strlen("00000000-0000")
                    && sscanf(header, "%08x-%04x", uid, flags) == 2) {
                        g_free(header);
                        return *uid;
                }
                g_free(header);
        }

        return -1;
}

static char *
header_evolution_encode(guint32 uid, guint32 flags)
{
	return g_strdup_printf("%08x-%04x", uid, flags & 0xffff);
}

static CamelMessageInfo * message_info_new(CamelFolderSummary *s, struct _header_raw *h)
{
	CamelMessageInfo *mi;

	mi = ((CamelFolderSummaryClass *)camel_mbox_summary_parent)->message_info_new(s, h);
	if (mi) {
		const char *xev;
		guint32 uid, flags;
		CamelMboxMessageInfo *mbi = (CamelMboxMessageInfo *)mi;

		xev = header_raw_find(&h, "X-Evolution", NULL);
		if (xev
		    && header_evolution_decode(xev, &uid, &flags) != -1) {
			g_free(mi->uid);
			mi->uid = g_strdup_printf("%u", uid);
			mi->flags = flags;
		} else {
			/* to indicate it has no xev header? */
			mi->flags |= CAMEL_MESSAGE_FOLDER_FLAGGED|CAMEL_MESSAGE_FOLDER_NOXEV;
			mi->uid = g_strdup_printf("%u", camel_folder_summary_next_uid(s));
		}
		mbi->frompos = -1;
	}
	return mi;
}

static CamelMessageInfo * message_info_new_from_parser(CamelFolderSummary *s, CamelMimeParser *mp)
{
	CamelMessageInfo *mi;
	CamelMboxSummary *mbs = (CamelMboxSummary *)s;

	mi = ((CamelFolderSummaryClass *)camel_mbox_summary_parent)->message_info_new_from_parser(s, mp);
	if (mi) {
		CamelMboxMessageInfo *mbi = (CamelMboxMessageInfo *)mi;

		mbi->frompos = camel_mime_parser_tell_start_from(mp);

		/* do we want to index this message as we add it, as well? */
		if (mbs->index_force
		    || (mi->flags & CAMEL_MESSAGE_FOLDER_FLAGGED) != 0
		    || !ibex_contains_name(mbs->index, mi->uid)) {
			camel_folder_summary_set_index(s, mbs->index);
		} else {
			camel_folder_summary_set_index(s, NULL);
		}
	}
	return mi;
}

static CamelMessageInfo * message_info_load(CamelFolderSummary *s, FILE *in)
{
	CamelMessageInfo *mi;

	io(printf("loading mbox message info\n"));

	mi = ((CamelFolderSummaryClass *)camel_mbox_summary_parent)->message_info_load(s, in);
	if (mi) {
		CamelMboxMessageInfo *mbi = (CamelMboxMessageInfo *)mi;

		camel_folder_summary_decode_uint32(in, &mbi->frompos);
	}
	return mi;
}

static int		  message_info_save(CamelFolderSummary *s, FILE *out, CamelMessageInfo *mi)
{
	CamelMboxMessageInfo *mbi = (CamelMboxMessageInfo *)mi;

	io(printf("saving mbox message info\n"));

	((CamelFolderSummaryClass *)camel_mbox_summary_parent)->message_info_save(s, out, mi);

	return camel_folder_summary_encode_uint32(out, mbi->frompos);
}

static int
summary_rebuild(CamelMboxSummary *mbs, off_t offset)
{
	CamelMimeParser *mp;
	int fd;
	int ok = 0;

	printf("(re)Building summary from %d (%s)\n", (int)offset, mbs->folder_path);

	fd = open(mbs->folder_path, O_RDONLY);
	mp = camel_mime_parser_new();
	camel_mime_parser_init_with_fd(mp, fd);
	camel_mime_parser_scan_from(mp, TRUE);
	camel_mime_parser_seek(mp, offset, SEEK_SET);

	if (offset > 0) {
		if (camel_mime_parser_step(mp, NULL, NULL) == HSCAN_FROM) {
			if (camel_mime_parser_tell_start_from(mp) != offset) {
				g_warning("The next message didn't start where I expected\nbuilding summary from start");
				camel_mime_parser_drop_step(mp);
				offset = 0;
				camel_mime_parser_seek(mp, offset, SEEK_SET);
				camel_folder_summary_clear((CamelFolderSummary *)mbs);
			} else {
				camel_mime_parser_unstep(mp);
			}
		} else {
			gtk_object_unref((GtkObject *)mp);
			/* end of file - no content? */
			return 0;
		}
	}

	while (camel_mime_parser_step(mp, NULL, NULL) == HSCAN_FROM) {
		CamelMessageInfo *info;

		info = camel_folder_summary_add_from_parser((CamelFolderSummary *)mbs, mp);
		if (info == NULL) {
			ok = -1;
			break;
		}

		g_assert(camel_mime_parser_step(mp, NULL, NULL) == HSCAN_FROM_END);
	}

	gtk_object_unref((GtkObject *)mp);

	return ok;
}

int
camel_mbox_summary_update(CamelMboxSummary *mbs, off_t offset)
{
	int ret;

	mbs->index_force = FALSE;
	ret = summary_rebuild(mbs, offset);

#if 0
#warning "Saving full summary and index after every summarisation is slow ..."
	if (ret != -1) {
		if (camel_folder_summary_save((CamelFolderSummary *)mbs) == -1)
			g_warning("Could not save summary: %s", strerror(errno));
		printf("summary saved\n");
		if (mbs->index)
			ibex_save(mbs->index);
		printf("ibex saved\n");
	}
#endif
	return ret;
}

int
camel_mbox_summary_load(CamelMboxSummary *mbs, int forceindex)
{
	CamelFolderSummary *s = (CamelFolderSummary *)mbs;
	struct stat st;
	int ret = 0;
	off_t minstart;

	mbs->index_force = forceindex;

	/* is the summary out of date? */
	if (stat(mbs->folder_path, &st) == -1) {
		camel_folder_summary_clear(s);
		printf("Cannot summarise folder: '%s': %s\n", mbs->folder_path, strerror(errno));
		return -1;
	}

	if (forceindex || camel_folder_summary_load(s) == -1) {
		camel_folder_summary_clear(s);
		ret = summary_rebuild(mbs, 0);
	} else {
		minstart = st.st_size;
#if 0
		/* find out the first unindexed message ... */
		/* TODO: For this to work, it has to check that the message is
		   indexable, and contains content ... maybe it cannot be done 
		   properly? */
		for (i=0;i<camel_folder_summary_count(s);i++) {
			CamelMessageInfo *mi = camel_folder_summary_index(s, i);
			if (!ibex_contains_name(mbs->index, mi->uid)) {
				minstart = ((CamelMboxMessageInfo *)mi)->frompos;
				printf("Found unindexed message: %s\n", mi->uid);
				break;
			}
		}
#endif
		/* is the summary uptodate? */
		if (st.st_size == mbs->folder_size && st.st_mtime == s->time) {
			printf("Summary time and date match mbox\n");
			if (minstart < st.st_size) {
				/* FIXME: Only clear the messages and reindex from this point forward */
				camel_folder_summary_clear(s);
				ret = summary_rebuild(mbs, 0);
			}
		} else {
			if (mbs->folder_size < st.st_size) {
				printf("Index is for a smaller mbox\n");
				if (minstart < mbs->folder_size) {
					/* FIXME: only make it rebuild as necessary */
					camel_folder_summary_clear(s);
					ret = summary_rebuild(mbs, 0);
				} else {
					ret = summary_rebuild(mbs, mbs->folder_size);
				}
			} else {
				printf("index is for a bigger mbox\n");
				camel_folder_summary_clear(s);
				ret = summary_rebuild(mbs, 0);
			}
		}
	}

	if (ret != -1) {
		mbs->folder_size = st.st_size;
		s->time = st.st_mtime;
		printf("saving summary\n");
		if (camel_folder_summary_save(s) == -1)
			g_warning("Could not save summary: %s", strerror(errno));
		printf("summary saved\n");
		if (mbs->index)
			ibex_save(mbs->index);
		printf("ibex saved\n");
	}

	return ret;
}

static int
header_write(int fd, struct _header_raw *header, char *xevline)
{
        struct iovec iv[4];
        int outlen = 0, len;

        iv[1].iov_base = ":";
        iv[1].iov_len = 1;
        iv[3].iov_base = "\n";
        iv[3].iov_len = 1;

        while (header) {
		if (strcasecmp(header->name, "X-Evolution")) {
			iv[0].iov_base = header->name;
			iv[0].iov_len = strlen(header->name);
			iv[2].iov_base = header->value;
			iv[2].iov_len = strlen(header->value);
		
			do {
				len = writev(fd, iv, 4);
			} while (len == -1 && errno == EINTR);
			
			if (len == -1)
				return -1;
			outlen += len;
		}
                header = header->next;
        }

        iv[0].iov_base = "X-Evolution: ";
        iv[0].iov_len = strlen(iv[0].iov_base);
        iv[1].iov_base = xevline;
        iv[1].iov_len = strlen(xevline);
        iv[2].iov_base = "\n\n";
        iv[2].iov_len = 2;

	do {
		len = writev(fd, iv, 3);
	} while (len == -1 && errno == EINTR);

	if (len == -1)
		return -1;

	outlen += 1;

	d(printf("Wrote %d bytes of headers\n", outlen));

        return outlen;
}

static int
copy_block(int fromfd, int tofd, off_t start, size_t bytes)
{
        char buffer[4096];
        int written = 0;

	d(printf("writing %d bytes ... ", bytes));

	if (lseek(fromfd, start, SEEK_SET) != start)
		return -1;

        while (bytes>0) {
                int toread, towrite;

                toread = bytes;
                if (bytes>4096)
                        toread = 4096;
                else
                        toread = bytes;
		do {
			towrite = read(fromfd, buffer, toread);
		} while (towrite == -1 && errno == EINTR);

		if (towrite == -1)
			return -1;

                /* check for 'end of file' */
                if (towrite == 0) {
			d(printf("end of file?\n"));
                        break;
		}

		do {
			toread = write(tofd, buffer, towrite);
		} while (toread == -1 && errno == EINTR);

		if (toread == -1)
			return -1;

                written += toread;
                bytes -= toread;
        }

        d(printf("written %d bytes\n", written));

        return written;
}

int
camel_mbox_summary_expunge(CamelMboxSummary *mbs)
{
	CamelMimeParser *mp=NULL;
	int i, count;
	CamelMboxMessageInfo *info;
	CamelFolderSummary *s = (CamelFolderSummary *)mbs;

	int fd=-1, fdout=-1;
	off_t offset = 0;
	char *tmpname=0;
	char *buffer, *xevnew = NULL;
	const char *xev;
	int len;
	guint32 uid, flags;
	int quick = TRUE, work = FALSE;

	/* make sure we're in sync */
	count = camel_folder_summary_count(s);
	if (count>0) {
		CamelMessageInfo *mi = camel_folder_summary_index(s, count-1);
		camel_mbox_summary_update(mbs, mi->content->endpos);
	} else {
		camel_mbox_summary_update(mbs, 0);
	}

	/* check if we have any work to do */
	d(printf("Performing expunge, %d messages in inbox\n", count));
	for (i=0;quick && i<count;i++) {
		info = (CamelMboxMessageInfo *)camel_folder_summary_index(s, i);
		if (info->info.flags & (CAMEL_MESSAGE_DELETED|CAMEL_MESSAGE_FOLDER_NOXEV))
			quick = FALSE;
		else
			work |= (info->info.flags & CAMEL_MESSAGE_FOLDER_FLAGGED) != 0;
	}

	d(printf("Options: %s %s\n", quick?"quick":"", work?"Work":""));

	if (quick && !work)
		return 0;

	fd = open(mbs->folder_path, O_RDWR);
	if (fd == -1)
		return -1;

	mp = camel_mime_parser_new();
	camel_mime_parser_scan_from(mp, TRUE);
	camel_mime_parser_init_with_fd(mp, fd);

	if (!quick) {
		tmpname = alloca(strlen(mbs->folder_path)+5);
		sprintf(tmpname, "%s.tmp", mbs->folder_path);
		d(printf("Writing tmp file to %s\n", tmpname));
	retry_out:
		fdout = open(tmpname, O_WRONLY|O_CREAT|O_EXCL, 0600);
		if (fdout == -1) {
			if (errno == EEXIST)
				if (unlink(tmpname) != -1)
					goto retry_out;
			tmpname = 0;
			goto error;
		}
	}

	for (i=0;i<count;i++) {
		off_t frompos, bodypos;
		off_t xevoffset;

		info = (CamelMboxMessageInfo *)camel_folder_summary_index(s, i);

		g_assert(info);

		d(printf("Looking at message %s\n", info->info.uid));

		if (info->info.flags & CAMEL_MESSAGE_DELETED) {
			d(printf("Deleting %s\n", info->info.uid));

			g_assert(!quick);
			offset -= (info->info.content->endpos - info->frompos);
			if (mbs->index)
				ibex_unindex(mbs->index, info->info.uid);
			camel_folder_summary_remove(s, (CamelMessageInfo *)info);
			count--;
			i--;
			info = NULL;
		} else if (info->info.flags & (CAMEL_MESSAGE_FOLDER_NOXEV|CAMEL_MESSAGE_FOLDER_FLAGGED)) {
			int xevok = FALSE;

			d(printf("Updating header for %s flags = %08x\n", info->info.uid, info->info.flags));

			/* find the next message, header parts */
			camel_mime_parser_seek(mp, info->frompos, SEEK_SET);
			if (camel_mime_parser_step(mp, &buffer, &len) != HSCAN_FROM)
				goto error;

			if (camel_mime_parser_tell_start_from(mp) != info->frompos) {
				g_error("Summary/mbox mismatch, aborting expunge");
				goto error;
			}
			
			if (camel_mime_parser_step(mp, &buffer, &len) == HSCAN_FROM_END)
				goto error;

			xev = camel_mime_parser_header(mp, "X-Evolution", (int *)&xevoffset);
			if (xev && header_evolution_decode(xev, &uid, &flags) != -1) {
				char name[64];

				sprintf(name, "%u", uid);
				if (strcmp(name, info->info.uid)) {
					d(printf("Summary mismatch, aborting leaving mailbox intact\n"));
					goto error;
				}
				xevok = TRUE;
			}
			xevnew = header_evolution_encode(strtoul(info->info.uid, NULL, 10), info->info.flags);
			if (quick) {
				if (!xevok) {
					g_error("The summary told me I had an X-Evolution header, but i dont!");
					goto error;
				}
				buffer = g_strdup_printf("X-Evolution: %s", xevnew);
				do {
					len = write(fd, buffer, strlen(buffer));
				} while (len == -1 && errno == EINTR);
				g_free(buffer);
				if (len == -1) {
					goto error;
				}
			} else {
				frompos = lseek(fdout, 0, SEEK_CUR);
				write(fdout, "From -\n", strlen("From -\n"));
				if (header_write(fdout, camel_mime_parser_headers_raw(mp), xevnew) == -1) {
					d(printf("Error writing to tmp mailbox\n"));
					goto error;
				}
				bodypos = lseek(fdout, 0, SEEK_CUR);
				d(printf("pos = %d, endpos = %d, bodypos = %d\n",
					 info->info.content->pos,
					 info->info.content->endpos,
					 info->info.content->bodypos));
				if (copy_block(fd, fdout, info->info.content->bodypos, info->info.content->endpos - info->info.content->bodypos) == -1) {
					g_warning("Cannot copy data to output fd");
					goto error;
				}
				info->frompos = frompos;
				offset = bodypos - info->info.content->bodypos;
			}
			g_free(xevnew); xevnew = NULL;
			camel_mime_parser_drop_step(mp);
			camel_mime_parser_drop_step(mp);
		} else {
			d(printf("Nothing to do for this message\n"));
		}
		if (!quick && info!=NULL && offset!=0) {
			camel_folder_summary_offset_content(info->info.content, offset);
			d(printf("pos = %d, endpos = %d, bodypos = %d\n",
				 info->info.content->pos,
				 info->info.content->endpos,
				 info->info.content->bodypos));
		}
	}

	d(printf("Closing folders\n"));

	if (close(fd) == -1) {
		g_warning("Cannot close source folder: %s", strerror(errno));
		goto error;
	}

	if (!quick) {
		struct stat st;

		if (close(fdout) == -1) {
			g_warning("Cannot close tmp folder: %s", strerror(errno));
			goto error;
		}

		if (rename(tmpname, mbs->folder_path) == -1) {
			g_warning("Cannot rename folder: %s", strerror(errno));
			goto error;
		}
		tmpname = 0;

		if (stat(mbs->folder_path, &st) == -1)
			goto error;

		s->flags |= CAMEL_SUMMARY_DIRTY;
		s->time = st.st_mtime;
		mbs->folder_size = st.st_size;
		camel_folder_summary_save(s);
		if (mbs->index)
			ibex_save(mbs->index);
	}

	gtk_object_unref((GtkObject *)mp);

	return 0;
error:
	d(printf("Error occured: %s\n", strerror(errno)));
	count = errno;

	close(fd);
	close(fdout);

	g_free(xevnew);

	if (tmpname)
		unlink(tmpname);
	if (mp)
		gtk_object_unref((GtkObject *)mp);

	errno = count;
	return -1;
}