/*
 * Copyright 2007 Jacek Caban for CodeWeavers
 * Copyright 2011 Owen Rudge for CodeWeavers
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */

#define NONAMELESSUNION
#define NONAMELESSSTRUCT

#include "hhctrl.h"
#include "stream.h"
#include "resource.h"

#include <wine/debug.h>

WINE_DEFAULT_DEBUG_CHANNEL(htmlhelp);

typedef enum {
    INSERT_NEXT,
    INSERT_CHILD
} insert_type_t;

static void free_content_item(ContentItem *item)
{
    ContentItem *next;

    while(item) {
        next = item->next;

        free_content_item(item->child);

        heap_free(item->name);
        heap_free(item->local);
        heap_free(item->merge.chm_file);
        heap_free(item->merge.chm_index);

        item = next;
    }
}

static void parse_obj_node_param(ContentItem *item, ContentItem *hhc_root, const char *text, UINT code_page)
{
    const char *ptr;
    LPWSTR *param, merge;
    int len;

    ptr = get_attr(text, "name", &len);
    if(!ptr) {
        WARN("name attr not found\n");
        return;
    }

    if(!strncasecmp("name", ptr, len)) {
        param = &item->name;
    }else if(!strncasecmp("merge", ptr, len)) {
        param = &merge;
    }else if(!strncasecmp("local", ptr, len)) {
        param = &item->local;
    }else {
        WARN("unhandled param %s\n", debugstr_an(ptr, len));
        return;
    }

    ptr = get_attr(text, "value", &len);
    if(!ptr) {
        WARN("value attr not found\n");
        return;
    }

    /*
     * "merge" parameter data (referencing another CHM file) can be incorporated into the "local" parameter
     * by specifying the filename in the format:
     *  MS-ITS:file.chm::/local_path.htm
     */
    if(param == &item->local && strstr(ptr, "::"))
    {
        const char *local = strstr(ptr, "::")+2;
        int local_len = len-(local-ptr);

        item->local = decode_html(local, local_len, code_page);
        param = &merge;
    }

    *param = decode_html(ptr, len, code_page);

    if(param == &merge) {
        SetChmPath(&item->merge, hhc_root->merge.chm_file, merge);
        heap_free(merge);
    }
}

static ContentItem *parse_hhc(HHInfo*,IStream*,ContentItem*,insert_type_t*);

static ContentItem *insert_item(ContentItem *item, ContentItem *new_item, insert_type_t insert_type)
{
    if(!item)
        return new_item;

    if(!new_item)
        return item;

    switch(insert_type) {
    case INSERT_NEXT:
        item->next = new_item;
        return new_item;
    case INSERT_CHILD:
        if(item->child) {
            ContentItem *iter = item->child;
            while(iter->next)
                iter = iter->next;
            iter->next = new_item;
        }else {
            item->child = new_item;
        }
        return item;
    }

    return NULL;
}

static ContentItem *parse_sitemap_object(HHInfo *info, stream_t *stream, ContentItem *hhc_root,
        insert_type_t *insert_type)
{
    strbuf_t node, node_name;
    ContentItem *item;

    *insert_type = INSERT_NEXT;

    strbuf_init(&node);
    strbuf_init(&node_name);

    item = heap_alloc_zero(sizeof(ContentItem));

    while(next_node(stream, &node)) {
        get_node_name(&node, &node_name);

        TRACE("%s\n", node.buf);

        if(!strcasecmp(node_name.buf, "/object"))
            break;
        if(!strcasecmp(node_name.buf, "param"))
            parse_obj_node_param(item, hhc_root, node.buf, info->pCHMInfo->codePage);

        strbuf_zero(&node);
    }

    strbuf_free(&node);
    strbuf_free(&node_name);

    if(item->merge.chm_index) {
        IStream *merge_stream;

        merge_stream = GetChmStream(info->pCHMInfo, item->merge.chm_file, &item->merge);
        if(merge_stream) {
            item->child = parse_hhc(info, merge_stream, hhc_root, insert_type);
            IStream_Release(merge_stream);
        }else {
            WARN("Could not get %s::%s stream\n", debugstr_w(item->merge.chm_file),
                 debugstr_w(item->merge.chm_file));

            if(!item->name) {
                free_content_item(item);
                item = NULL;
            }
        }

    }

    return item;
}

static ContentItem *parse_ul(HHInfo *info, stream_t *stream, ContentItem *hhc_root)
{
    strbuf_t node, node_name;
    ContentItem *ret = NULL, *prev = NULL, *new_item = NULL;
    insert_type_t it;

    strbuf_init(&node);
    strbuf_init(&node_name);

    while(next_node(stream, &node)) {
        get_node_name(&node, &node_name);

        TRACE("%s\n", node.buf);

        if(!strcasecmp(node_name.buf, "object")) {
            const char *ptr;
            int len;

            static const char sz_text_sitemap[] = "text/sitemap";

            ptr = get_attr(node.buf, "type", &len);

            if(ptr && len == sizeof(sz_text_sitemap)-1
               && !memcmp(ptr, sz_text_sitemap, len)) {
                new_item = parse_sitemap_object(info, stream, hhc_root, &it);
                prev = insert_item(prev, new_item, it);
                if(!ret)
                    ret = prev;
            }
        }else if(!strcasecmp(node_name.buf, "ul")) {
            new_item = parse_ul(info, stream, hhc_root);
            insert_item(prev, new_item, INSERT_CHILD);
        }else if(!strcasecmp(node_name.buf, "/ul")) {
            break;
        }

        strbuf_zero(&node);
    }

    strbuf_free(&node);
    strbuf_free(&node_name);

    return ret;
}

static ContentItem *parse_hhc(HHInfo *info, IStream *str, ContentItem *hhc_root,
        insert_type_t *insert_type)
{
    stream_t stream;
    strbuf_t node, node_name;
    ContentItem *ret = NULL, *prev = NULL;

    *insert_type = INSERT_NEXT;

    strbuf_init(&node);
    strbuf_init(&node_name);

    stream_init(&stream, str);

    while(next_node(&stream, &node)) {
        get_node_name(&node, &node_name);

        TRACE("%s\n", node.buf);

        if(!strcasecmp(node_name.buf, "ul")) {
            ContentItem *item = parse_ul(info, &stream, hhc_root);
            prev = insert_item(prev, item, INSERT_CHILD);
            if(!ret)
                ret = prev;
            *insert_type = INSERT_CHILD;
        }

        strbuf_zero(&node);
    }

    strbuf_free(&node);
    strbuf_free(&node_name);

    return ret;
}

static void insert_content_item(HWND hwnd, ContentItem *parent, ContentItem *item)
{
    TVINSERTSTRUCTW tvis;

    memset(&tvis, 0, sizeof(tvis));
    tvis.u.item.mask = TVIF_TEXT|TVIF_PARAM|TVIF_IMAGE|TVIF_SELECTEDIMAGE;
    tvis.u.item.cchTextMax = strlenW(item->name)+1;
    tvis.u.item.pszText = item->name;
    tvis.u.item.lParam = (LPARAM)item;
    tvis.u.item.iImage = item->child ? HHTV_FOLDER : HHTV_DOCUMENT;
    tvis.u.item.iSelectedImage = item->child ? HHTV_FOLDER : HHTV_DOCUMENT;
    tvis.hParent = parent ? parent->id : 0;
    tvis.hInsertAfter = TVI_LAST;

    item->id = (HTREEITEM)SendMessageW(hwnd, TVM_INSERTITEMW, 0, (LPARAM)&tvis);
}

static void fill_content_tree(HWND hwnd, ContentItem *parent, ContentItem *item)
{
    while(item) {
        if(item->name) {
            insert_content_item(hwnd, parent, item);
            fill_content_tree(hwnd, item, item->child);
        }else {
            fill_content_tree(hwnd, parent, item->child);
        }
        item = item->next;
    }
}

static void set_item_parents(ContentItem *parent, ContentItem *item)
{
    while(item) {
        item->parent = parent;
        set_item_parents(item, item->child);
        item = item->next;
    }
}

void InitContent(HHInfo *info)
{
    IStream *stream;
    insert_type_t insert_type;

    info->content = heap_alloc_zero(sizeof(ContentItem));
    SetChmPath(&info->content->merge, info->pCHMInfo->szFile, info->WinType.pszToc);

    stream = GetChmStream(info->pCHMInfo, info->pCHMInfo->szFile, &info->content->merge);
    if(!stream) {
        TRACE("Could not get content stream\n");
        return;
    }

    info->content->child = parse_hhc(info, stream, info->content, &insert_type);
    IStream_Release(stream);

    set_item_parents(NULL, info->content);
    fill_content_tree(info->tabs[TAB_CONTENTS].hwnd, NULL, info->content);
}

void ReleaseContent(HHInfo *info)
{
    free_content_item(info->content);
}

void ActivateContentTopic(HWND hWnd, LPCWSTR filename, ContentItem *item)
{
    if (lstrcmpiW(item->local, filename) == 0)
    {
        SendMessageW(hWnd, TVM_SELECTITEM, TVGN_CARET, (LPARAM) item->id);
        return;
    }

    if (item->next)
        ActivateContentTopic(hWnd, filename, item->next);

    if (item->child)
        ActivateContentTopic(hWnd, filename, item->child);
}