/********************************************************************\
 * gnc-tax-table-xml-v2.c -- tax table xml i/o implementation       *
 *                                                                  *
 * Copyright (C) 2002 Derek Atkins <warlord@MIT.EDU>                *
 *                                                                  *
 * 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, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
 * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
 *                                                                  *
\********************************************************************/
extern "C"
{
#include <config.h>

#include <glib.h>
#include <stdlib.h>
#include <string.h>
#include "gncEntry.h"
#include "gncTaxTableP.h"
}

#include "gnc-xml-helper.h"
#include "sixtp.h"
#include "sixtp-utils.h"
#include "sixtp-parsers.h"
#include "sixtp-utils.h"
#include "sixtp-dom-parsers.h"
#include "sixtp-dom-generators.h"

#include "gnc-xml.h"
#include "io-gncxml-gen.h"
#include "io-gncxml-v2.h"

#include "gnc-tax-table-xml-v2.h"

#define _GNC_MOD_NAME   GNC_ID_TAXTABLE

static QofLogModule log_module = GNC_MOD_IO;

const gchar* taxtable_version_string = "2.0.0";

/* ids */
#define gnc_taxtable_string "gnc:GncTaxTable"
#define taxtable_guid_string "taxtable:guid"
#define taxtable_name_string "taxtable:name"
#define taxtable_refcount_string "taxtable:refcount"
#define taxtable_invisible_string "taxtable:invisible"
#define taxtable_parent_string "taxtable:parent"
#define taxtable_child_string "taxtable:child"
#define taxtable_entries_string "taxtable:entries"
#define taxtable_slots_string "taxtable:slots"

#define gnc_taxtableentry_string "gnc:GncTaxTableEntry"
#define ttentry_account_string "tte:acct"
#define ttentry_type_string "tte:type"
#define ttentry_amount_string "tte:amount"

static void
maybe_add_guid (xmlNodePtr ptr, const char* tag, GncTaxTable* table)
{
    if (table)
        xmlAddChild (ptr, guid_to_dom_tree (tag,
                                            qof_instance_get_guid (QOF_INSTANCE (table))));
}

static xmlNodePtr
ttentry_dom_tree_create (GncTaxTableEntry* entry)
{
    xmlNodePtr ret;
    Account* account;
    gnc_numeric amount;

    ret = xmlNewNode (NULL, BAD_CAST gnc_taxtableentry_string);

    account = gncTaxTableEntryGetAccount (entry);
    if (account)
        xmlAddChild (ret, guid_to_dom_tree (ttentry_account_string,
                                            qof_instance_get_guid (QOF_INSTANCE (account))));

    amount = gncTaxTableEntryGetAmount (entry);
    xmlAddChild (ret, gnc_numeric_to_dom_tree (ttentry_amount_string, &amount));

    xmlAddChild (ret, text_to_dom_tree (ttentry_type_string,
                                        gncAmountTypeToString (
                                            gncTaxTableEntryGetType (entry))));

    return ret;
}

static xmlNodePtr
taxtable_dom_tree_create (GncTaxTable* table)
{
    xmlNodePtr ret, entries;
    GList* list;

    ret = xmlNewNode (NULL, BAD_CAST gnc_taxtable_string);
    xmlSetProp (ret, BAD_CAST "version", BAD_CAST taxtable_version_string);

    maybe_add_guid (ret, taxtable_guid_string, table);
    xmlAddChild (ret, text_to_dom_tree (taxtable_name_string,
                                        gncTaxTableGetName (table)));

    xmlAddChild (ret, int_to_dom_tree (taxtable_refcount_string,
                                       gncTaxTableGetRefcount (table)));
    xmlAddChild (ret, int_to_dom_tree (taxtable_invisible_string,
                                       gncTaxTableGetInvisible (table)));

    /* We should not be our own child */
    if (gncTaxTableGetChild (table) != table)
        maybe_add_guid (ret, taxtable_child_string, gncTaxTableGetChild (table));

    maybe_add_guid (ret, taxtable_parent_string, gncTaxTableGetParent (table));

    entries = xmlNewChild (ret, NULL, BAD_CAST taxtable_entries_string, NULL);
    for (list = gncTaxTableGetEntries (table); list; list = list->next)
    {
        GncTaxTableEntry* entry = static_cast<decltype (entry)> (list->data);
        xmlAddChild (entries, ttentry_dom_tree_create (entry));
    }

    /* xmlAddChild won't do anything with a NULL, so tests are superfluous. */
    xmlAddChild (ret, qof_instance_slots_to_dom_tree (taxtable_slots_string,
                                                      QOF_INSTANCE (table)));
    return ret;
}

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

struct ttentry_pdata
{
    GncTaxTableEntry* ttentry;
    QofBook* book;
};

static gboolean
ttentry_acct_handler (xmlNodePtr node, gpointer ttentry_pdata)
{
    struct ttentry_pdata* pdata = static_cast<decltype (pdata)> (ttentry_pdata);
    GncGUID* guid;
    Account* acc;

    guid = dom_tree_to_guid (node);
    g_return_val_if_fail (guid, FALSE);
    acc = xaccAccountLookup (guid, pdata->book);
    guid_free (guid);
    g_return_val_if_fail (acc, FALSE);

    gncTaxTableEntrySetAccount (pdata->ttentry, acc);
    return TRUE;
}

static gboolean
ttentry_type_handler (xmlNodePtr node, gpointer ttentry_pdata)
{
    struct ttentry_pdata* pdata = static_cast<decltype (pdata)> (ttentry_pdata);
    GncAmountType type;
    char* str;
    gboolean ret;

    str = dom_tree_to_text (node);
    g_return_val_if_fail (str, FALSE);

    ret = gncAmountStringToType (str, &type);
    g_free (str);

    if (ret)
        gncTaxTableEntrySetType (pdata->ttentry, type);

    return ret;
}

static gboolean
ttentry_amount_handler (xmlNodePtr node, gpointer ttentry_pdata)
{
    struct ttentry_pdata* pdata = static_cast<decltype (pdata)> (ttentry_pdata);
    gnc_numeric* num = dom_tree_to_gnc_numeric (node);
    g_return_val_if_fail (num, FALSE);

    gncTaxTableEntrySetAmount (pdata->ttentry, *num);
    g_free (num);
    return TRUE;
}

static struct dom_tree_handler ttentry_handlers_v2[] =
{
    { ttentry_account_string, ttentry_acct_handler, 0, 0 },
    { ttentry_type_string, ttentry_type_handler, 1, 0 },
    { ttentry_amount_string, ttentry_amount_handler, 1, 0 },
    { NULL, 0, 0, 0 }
};

static GncTaxTableEntry*
dom_tree_to_ttentry (xmlNodePtr node, QofBook* book)
{
    struct ttentry_pdata ttentry_pdata;
    gboolean successful;

    ttentry_pdata.ttentry = gncTaxTableEntryCreate ();
    ttentry_pdata.book = book;

    successful = dom_tree_generic_parse (node, ttentry_handlers_v2,
                                         &ttentry_pdata);

    if (!successful)
    {
        PERR ("failed to parse tax table entry tree");
        gncTaxTableEntryDestroy (ttentry_pdata.ttentry);
        ttentry_pdata.ttentry = NULL;
    }

    return ttentry_pdata.ttentry;
}

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

struct taxtable_pdata
{
    GncTaxTable* table;
    QofBook* book;
};

static gboolean
set_parent_child (xmlNodePtr node, struct taxtable_pdata* pdata,
                  void (*func) (GncTaxTable*, GncTaxTable*))
{
    GncGUID* guid;
    GncTaxTable* table;

    guid = dom_tree_to_guid (node);
    g_return_val_if_fail (guid, FALSE);
    table = gncTaxTableLookup (pdata->book, guid);

    /* Ignore pointers to self */
    if (table == pdata->table)
    {
        PINFO ("found a self-referential parent/child; ignoring.\n");
        return TRUE;
    }

    if (!table)
    {
        table = gncTaxTableCreate (pdata->book);
        gncTaxTableBeginEdit (table);
        gncTaxTableSetGUID (table, guid);
        gncTaxTableCommitEdit (table);
    }
    guid_free (guid);
    g_return_val_if_fail (table, FALSE);
    func (pdata->table, table);

    return TRUE;
}

static gboolean
taxtable_guid_handler (xmlNodePtr node, gpointer taxtable_pdata)
{
    struct taxtable_pdata* pdata = static_cast<decltype (pdata)> (taxtable_pdata);
    GncGUID* guid;
    GncTaxTable* table;

    guid = dom_tree_to_guid (node);
    g_return_val_if_fail (guid, FALSE);
    table = gncTaxTableLookup (pdata->book, guid);
    if (table)
    {
        gncTaxTableDestroy (pdata->table);
        pdata->table = table;
        gncTaxTableBeginEdit (table);
    }
    else
    {
        gncTaxTableSetGUID (pdata->table, guid);
    }

    guid_free (guid);

    return TRUE;
}

static gboolean
taxtable_name_handler (xmlNodePtr node, gpointer taxtable_pdata)
{
    struct taxtable_pdata* pdata = static_cast<decltype (pdata)> (taxtable_pdata);
    char* txt = dom_tree_to_text (node);
    g_return_val_if_fail (txt, FALSE);

    gncTaxTableSetName (pdata->table, txt);
    g_free (txt);
    return TRUE;
}

static gboolean
taxtable_refcount_handler (xmlNodePtr node, gpointer taxtable_pdata)
{
    struct taxtable_pdata* pdata = static_cast<decltype (pdata)> (taxtable_pdata);
    gint64 val;

    dom_tree_to_integer (node, &val);
    gncTaxTableSetRefcount (pdata->table, val);
    return TRUE;
}

static gboolean
taxtable_invisible_handler (xmlNodePtr node, gpointer taxtable_pdata)
{
    struct taxtable_pdata* pdata = static_cast<decltype (pdata)> (taxtable_pdata);
    gint64 val;

    dom_tree_to_integer (node, &val);
    if (val)
        gncTaxTableMakeInvisible (pdata->table);
    return TRUE;
}

static gboolean
taxtable_parent_handler (xmlNodePtr node, gpointer taxtable_pdata)
{
    struct taxtable_pdata* pdata = static_cast<decltype (pdata)> (taxtable_pdata);
    return set_parent_child (node, pdata, gncTaxTableSetParent);
}

static gboolean
taxtable_child_handler (xmlNodePtr node, gpointer taxtable_pdata)
{
    struct taxtable_pdata* pdata = static_cast<decltype (pdata)> (taxtable_pdata);
    return set_parent_child (node, pdata, gncTaxTableSetChild);
}

static gboolean
taxtable_entries_handler (xmlNodePtr node, gpointer taxtable_pdata)
{
    struct taxtable_pdata* pdata = static_cast<decltype (pdata)> (taxtable_pdata);
    xmlNodePtr mark;

    g_return_val_if_fail (node, FALSE);
    g_return_val_if_fail (node->xmlChildrenNode, FALSE);

    for (mark = node->xmlChildrenNode; mark; mark = mark->next)
    {
        GncTaxTableEntry* entry;

        if (g_strcmp0 ("text", (char*)mark->name) == 0)
            continue;

        if (g_strcmp0 (gnc_taxtableentry_string, (char*)mark->name))
            return FALSE;

        entry = dom_tree_to_ttentry (mark, pdata->book);

        if (entry)
            gncTaxTableAddEntry (pdata->table, entry);
        else
            return FALSE;

    }
    return TRUE;
}

static gboolean
taxtable_slots_handler (xmlNodePtr node, gpointer taxtable_pdata)
{
    struct taxtable_pdata* pdata = static_cast<decltype (pdata)> (taxtable_pdata);

    return dom_tree_create_instance_slots (node, QOF_INSTANCE (pdata->table));
}

static struct dom_tree_handler taxtable_handlers_v2[] =
{
    { taxtable_guid_string, taxtable_guid_handler, 1, 0 },
    { taxtable_name_string, taxtable_name_handler, 1, 0 },
    { taxtable_refcount_string, taxtable_refcount_handler, 1, 0 },
    { taxtable_invisible_string, taxtable_invisible_handler, 1, 0 },
    { taxtable_parent_string, taxtable_parent_handler, 0, 0 },
    { taxtable_child_string, taxtable_child_handler, 0, 0 },
    { taxtable_entries_string, taxtable_entries_handler, 1, 0 },
    { taxtable_slots_string, taxtable_slots_handler, 0, 0 },
    { NULL, 0, 0, 0 }
};

static GncTaxTable*
dom_tree_to_taxtable (xmlNodePtr node, QofBook* book)
{
    struct taxtable_pdata taxtable_pdata;
    gboolean successful;

    taxtable_pdata.table = gncTaxTableCreate (book);
    taxtable_pdata.book = book;
    gncTaxTableBeginEdit (taxtable_pdata.table);

    successful = dom_tree_generic_parse (node, taxtable_handlers_v2,
                                         &taxtable_pdata);

    if (successful)
        gncTaxTableCommitEdit (taxtable_pdata.table);
    else
    {
        PERR ("failed to parse tax table tree");
        gncTaxTableDestroy (taxtable_pdata.table);
        taxtable_pdata.table = NULL;
    }

    return taxtable_pdata.table;
}

static gboolean
gnc_taxtable_end_handler (gpointer data_for_children,
                          GSList* data_from_children, GSList* sibling_data,
                          gpointer parent_data, gpointer global_data,
                          gpointer* result, const gchar* tag)
{
    GncTaxTable* table;
    xmlNodePtr tree = (xmlNodePtr)data_for_children;
    gxpf_data* gdata = (gxpf_data*)global_data;
    QofBook* book = static_cast<decltype (book)> (gdata->bookdata);

    if (parent_data)
    {
        return TRUE;
    }

    /* OK.  For some messed up reason this is getting called again with a
       NULL tag.  So we ignore those cases */
    if (!tag)
    {
        return TRUE;
    }

    g_return_val_if_fail (tree, FALSE);

    table = dom_tree_to_taxtable (tree, book);
    if (table != NULL)
    {
        gdata->cb (tag, gdata->parsedata, table);
    }

    xmlFreeNode (tree);

    return table != NULL;
}

static sixtp*
taxtable_sixtp_parser_create (void)
{
    return sixtp_dom_parser_new (gnc_taxtable_end_handler, NULL, NULL);
}

static void
do_count (QofInstance* table_p, gpointer count_p)
{
    int* count = static_cast<decltype (count)> (count_p);
    (*count)++;
}

static int
taxtable_get_count (QofBook* book)
{
    int count = 0;
    qof_object_foreach (_GNC_MOD_NAME, book, do_count, (gpointer) &count);
    return count;
}

static void
xml_add_taxtable (QofInstance* table_p, gpointer out_p)
{
    xmlNodePtr node;
    GncTaxTable* table = (GncTaxTable*) table_p;
    FILE* out = static_cast<decltype (out)> (out_p);

    if (ferror (out))
        return;

    node = taxtable_dom_tree_create (table);
    xmlElemDump (out, NULL, node);
    xmlFreeNode (node);
    if (ferror (out) || fprintf (out, "\n") < 0)
        return;
}

static gboolean
taxtable_write (FILE* out, QofBook* book)
{
    qof_object_foreach_sorted (_GNC_MOD_NAME, book, xml_add_taxtable,
                               (gpointer) out);
    return ferror (out) == 0;
}


static gboolean
taxtable_is_grandchild (GncTaxTable* table)
{
    return (gncTaxTableGetParent (gncTaxTableGetParent (table)) != NULL);
}

static GncTaxTable*
taxtable_find_senior (GncTaxTable* table)
{
    GncTaxTable* temp, *parent, *gp = NULL;

    temp = table;
    do
    {
        /* See if "temp" is a grandchild */
        parent = gncTaxTableGetParent (temp);
        if (!parent)
            break;
        gp = gncTaxTableGetParent (parent);
        if (!gp)
            break;

        /* Yep, this is a grandchild.  Move up one generation and try again */
        temp = parent;
    }
    while (TRUE);

    /* Ok, at this point temp points to the most senior child and parent
     * should point to the top taxtable (and gp should be NULL).  If
     * parent is NULL then we are the most senior child (and have no
     * children), so do nothing.  If temp == table then there is no
     * grandparent, so do nothing.
     *
     * Do something if parent != NULL && temp != table
     */
    g_assert (gp == NULL);

    /* return the most senior table */
    return temp;
}

/* build a list of tax tables that are grandchildren or bogus (empty entry list). */
static void
taxtable_scrub_cb (QofInstance* table_p, gpointer list_p)
{
    GncTaxTable* table = GNC_TAXTABLE (table_p);
    GList** list = static_cast<decltype (list)> (list_p);

    if (taxtable_is_grandchild (table) || gncTaxTableGetEntries (table) == NULL)
        *list = g_list_prepend (*list, table);
}

/* for each entry, check the tax tables.  If the tax tables are
 * grandchildren, then fix them to point to the most senior child
 */
static void
taxtable_scrub_entries (QofInstance* entry_p, gpointer ht_p)
{
    GHashTable* ht = static_cast<decltype (ht)> (ht_p);
    GncEntry* entry = GNC_ENTRY (entry_p);
    GncTaxTable* table, *new_tt;
    gint32 count;

    table = gncEntryGetInvTaxTable (entry);
    if (table)
    {
        if (taxtable_is_grandchild (table))
        {
            gchar guidstr[GUID_ENCODING_LENGTH + 1];
            guid_to_string_buff (qof_instance_get_guid (QOF_INSTANCE (entry)), guidstr);
            PINFO ("Fixing i-taxtable on entry %s\n", guidstr);
            new_tt = taxtable_find_senior (table);
            gncEntryBeginEdit (entry);
            gncEntrySetInvTaxTable (entry, new_tt);
            gncEntryCommitEdit (entry);
            table = new_tt;
        }
        if (table)
        {
            count = GPOINTER_TO_INT (g_hash_table_lookup (ht, table));
            count++;
            g_hash_table_insert (ht, table, GINT_TO_POINTER (count));
        }
    }

    table = gncEntryGetBillTaxTable (entry);
    if (table)
    {
        if (taxtable_is_grandchild (table))
        {
            gchar guidstr[GUID_ENCODING_LENGTH + 1];
            guid_to_string_buff (qof_instance_get_guid (QOF_INSTANCE (entry)), guidstr);
            PINFO ("Fixing b-taxtable on entry %s\n", guidstr);
            new_tt = taxtable_find_senior (table);
            gncEntryBeginEdit (entry);
            gncEntrySetBillTaxTable (entry, new_tt);
            gncEntryCommitEdit (entry);
            table = new_tt;
        }
        if (table)
        {
            count = GPOINTER_TO_INT (g_hash_table_lookup (ht, table));
            count++;
            g_hash_table_insert (ht, table, GINT_TO_POINTER (count));
        }
    }
}

static void
taxtable_scrub_cust (QofInstance* cust_p, gpointer ht_p)
{
    GHashTable* ht = static_cast<decltype (ht)> (ht_p);
    GncCustomer* cust = GNC_CUSTOMER (cust_p);
    GncTaxTable* table;
    gint32 count;

    table = gncCustomerGetTaxTable (cust);
    if (table)
    {
        count = GPOINTER_TO_INT (g_hash_table_lookup (ht, table));
        count++;
        g_hash_table_insert (ht, table, GINT_TO_POINTER (count));
    }
}

static void
taxtable_scrub_vendor (QofInstance* vendor_p, gpointer ht_p)
{
    GHashTable* ht = static_cast<decltype (ht)> (ht_p);
    GncVendor* vendor = GNC_VENDOR (vendor_p);
    GncTaxTable* table;
    gint32 count;

    table = gncVendorGetTaxTable (vendor);
    if (table)
    {
        count = GPOINTER_TO_INT (g_hash_table_lookup (ht, table));
        count++;
        g_hash_table_insert (ht, table, GINT_TO_POINTER (count));
    }
}

static void
taxtable_reset_refcount (gpointer key, gpointer value, gpointer notused)
{
    GncTaxTable* table = static_cast<decltype (table)> (key);
    gint32 count = GPOINTER_TO_INT (value);

    if (count != gncTaxTableGetRefcount (table) &&
        !gncTaxTableGetInvisible (table))
    {
        gchar guidstr[GUID_ENCODING_LENGTH + 1];
        guid_to_string_buff (qof_instance_get_guid (QOF_INSTANCE (table)), guidstr);
        PWARN ("Fixing refcount on taxtable %s (%" G_GINT64_FORMAT " -> %d)\n",
               guidstr, gncTaxTableGetRefcount (table), count);
        gncTaxTableSetRefcount (table, count);
    }
}

static void
taxtable_scrub (QofBook* book)
{
    GList* list = NULL;
    GList* node;
    GncTaxTable* parent, *table;
    GHashTable* ht = g_hash_table_new (g_direct_hash, g_direct_equal);

    qof_object_foreach (GNC_ID_ENTRY, book, taxtable_scrub_entries, ht);
    qof_object_foreach (GNC_ID_CUSTOMER, book, taxtable_scrub_cust, ht);
    qof_object_foreach (GNC_ID_VENDOR, book, taxtable_scrub_vendor, ht);
    qof_object_foreach (GNC_ID_TAXTABLE, book, taxtable_scrub_cb, &list);

    /* destroy the list of "grandchildren" tax tables */
    for (node = list; node; node = node->next)
    {
        gchar guidstr[GUID_ENCODING_LENGTH + 1];
        table = static_cast<decltype (table)> (node->data);

        guid_to_string_buff (qof_instance_get_guid (QOF_INSTANCE (table)), guidstr);
        PINFO ("deleting grandchild taxtable: %s\n", guidstr);

        /* Make sure the parent has no children */
        parent = gncTaxTableGetParent (table);
        gncTaxTableSetChild (parent, NULL);

        /* Destroy this tax table */
        gncTaxTableBeginEdit (table);
        gncTaxTableDestroy (table);
    }

    /* reset the refcounts as necessary */
    g_hash_table_foreach (ht, taxtable_reset_refcount, NULL);

    g_list_free (list);
    g_hash_table_destroy (ht);
}

static gboolean
taxtable_ns (FILE* out)
{
    g_return_val_if_fail (out, FALSE);
    return
        gnc_xml2_write_namespace_decl (out, "taxtable")
        && gnc_xml2_write_namespace_decl (out, "tte");
}

void
gnc_taxtable_xml_initialize (void)
{
    static GncXmlDataType_t be_data =
    {
        GNC_FILE_BACKEND_VERS,
        gnc_taxtable_string,
        taxtable_sixtp_parser_create,
        NULL,           /* add_item */
        taxtable_get_count,
        taxtable_write,
        taxtable_scrub,
        taxtable_ns,
    };

    gnc_xml_register_backend(be_data);
}