/*
 * Inkscape::ResourceManager - tracks external resources such as image and css files.
 *
 * Copyright 2011  Jon A. Cruz  <jon@joncruz.org>
 *
 * Released under GNU GPL, read the file 'COPYING' for more information
 */

#include <string>
#include <vector>
#include <algorithm>
#include <gtkmm/recentmanager.h>
#include <glibmm/i18n.h>
#include <glibmm/convert.h>
#include <glibmm/fileutils.h>
#include <glibmm/miscutils.h>
#include <glibmm/uriutils.h>

#include "resource-manager.h"

#include "document.h"
#include "sp-object.h"
#include "xml/node.h"
#include "document-undo.h"
#include "verbs.h"

#include <set>

namespace Inkscape {

static std::vector<std::string> splitPath( std::string const &path )
{
    std::vector<std::string> parts;

    std::string prior;
    std::string tmp = path;
    while ( !tmp.empty() && (tmp != prior) ) {
        prior = tmp;

        parts.push_back( Glib::path_get_basename(tmp) );
        tmp = Glib::path_get_dirname(tmp);
    }
    if ( !parts.empty() ) {
        std::reverse(parts.begin(), parts.end());
        if ( (parts[0] == ".") && (path[0] != '.') ) {
            parts.erase(parts.begin());
        }
    }

    return parts;
}

static std::string convertPathToRelative( std::string const &path, std::string const &docbase )
{
    std::string result = path;

    if ( !path.empty() && Glib::path_is_absolute(path) ) {
        // Whack the parts into pieces

        std::vector<std::string> parts = splitPath(path);
        std::vector<std::string> baseParts = splitPath(docbase);

        // TODO debug g_message("+++++++++++++++++++++++++");
        for ( std::vector<std::string>::iterator it = parts.begin(); it != parts.end(); ++it ) {
            // TODO debug g_message("    [%s]", it->c_str());
        }
        // TODO debug g_message(" - - - - - - - - - - - - - - - ");
        for ( std::vector<std::string>::iterator it = baseParts.begin(); it != baseParts.end(); ++it ) {
            // TODO debug g_message("    [%s]", it->c_str());
        }
        // TODO debug g_message("+++++++++++++++++++++++++");

        if ( !parts.empty() && !baseParts.empty() && (parts[0] == baseParts[0]) ) {
            // Both paths have the same root. We can proceed.
            while ( !parts.empty() && !baseParts.empty() && (parts[0] == baseParts[0]) ) {
                parts.erase( parts.begin() );
                baseParts.erase( baseParts.begin() );
            }

            // TODO debug g_message("+++++++++++++++++++++++++");
            for ( std::vector<std::string>::iterator it = parts.begin(); it != parts.end(); ++it ) {
                // TODO debug g_message("    [%s]", it->c_str());
            }
            // TODO debug g_message(" - - - - - - - - - - - - - - - ");
            for ( std::vector<std::string>::iterator it = baseParts.begin(); it != baseParts.end(); ++it ) {
                // TODO debug g_message("    [%s]", it->c_str());
            }
            // TODO debug g_message("+++++++++++++++++++++++++");

            if ( !parts.empty() ) {
                result.clear();

                for ( size_t i = 0; i < baseParts.size(); ++i ) {
                    parts.insert(parts.begin(), "..");
                }
                result = Glib::build_filename( parts );
                // TODO debug g_message("----> [%s]", result.c_str());
            }
        }
    }

    return result;
}


class ResourceManagerImpl : public ResourceManager {
public:
    ResourceManagerImpl();
    virtual ~ResourceManagerImpl();

    virtual bool fixupBrokenLinks(SPDocument *doc);
    

    /**
     * Walk all links in a document and create a listing of unique broken links.
     *
     * @return a list of all broken links.
     */
    std::vector<Glib::ustring> findBrokenLinks(SPDocument *doc);

    /**
     * Resolve broken links as a whole and return a map for those that can be found.
     *
     * Note: this will allow for future enhancements including relinking to new locations
     * with the most broken files found, etc.
     *
     * @return a map of found links.
     */
    std::map<Glib::ustring, Glib::ustring> locateLinks(Glib::ustring const & docbase, std::vector<Glib::ustring> const & brokenLinks);

    bool extractFilepath( Glib::ustring const &href, std::string &uri );

    bool searchUpwards( std::string const &base, std::string const &subpath, std::string &dest );

protected:
};


ResourceManagerImpl::ResourceManagerImpl()
    : ResourceManager()
{
}

ResourceManagerImpl::~ResourceManagerImpl()
{
}

bool ResourceManagerImpl::extractFilepath( Glib::ustring const &href, std::string &uri )
{                    
    bool isFile = false;

    uri.clear();

    std::string scheme = Glib::uri_parse_scheme(href);
    if ( !scheme.empty() ) {
        // TODO debug g_message("Scheme is now [%s]", scheme.c_str());
        if ( scheme == "file" ) {
            // TODO debug g_message("--- is a file URI                 [%s]", href.c_str());

            // throws Glib::ConvertError:
            uri = Glib::filename_from_uri(href); // TODO see if we can get this to throw
            // TODO debug g_message("                                  [%s]", uri.c_str());
            isFile = true;
        }
    } else {
        // No scheme. Assuming it is a file path (absolute or relative).
        // throws Glib::ConvertError:
        uri = Glib::filename_from_utf8( href );
        isFile = true;
    }

    return isFile;
}


std::vector<Glib::ustring> ResourceManagerImpl::findBrokenLinks( SPDocument *doc )
{
    std::vector<Glib::ustring> result;
    std::set<Glib::ustring> uniques;

    if ( doc ) {
        GSList const *images = doc->getResourceList("image");
        for (GSList const *it = images; it; it = it->next) {
            Inkscape::XML::Node *ir = static_cast<SPObject *>(it->data)->getRepr();

            gchar const *href = ir->attribute("xlink:href");
            if ( href &&  ( uniques.find(href) == uniques.end() ) ) {
                std::string uri;
                if ( extractFilepath( href, uri ) ) {
                    if ( Glib::path_is_absolute(uri) ) {
                        if ( !Glib::file_test(uri, Glib::FILE_TEST_EXISTS) ) {
                            result.push_back(href);
                            uniques.insert(href);
                        }
                    } else {
                        std::string combined = Glib::build_filename(doc->getBase(), uri);
                        if ( !Glib::file_test(uri, Glib::FILE_TEST_EXISTS) ) {
                            result.push_back(href);
                            uniques.insert(href);
                        }
                    }
                }
            }
        }        
    }

    return result;
}


std::map<Glib::ustring, Glib::ustring> ResourceManagerImpl::locateLinks(Glib::ustring const & docbase, std::vector<Glib::ustring> const & brokenLinks)
{
    std::map<Glib::ustring, Glib::ustring> result;


    // Note: we use a vector because we want them to stay in order:
    std::vector<std::string> priorLocations;

    Glib::RefPtr<Gtk::RecentManager> recentMgr = Gtk::RecentManager::get_default();
    std::vector< Glib::RefPtr<Gtk::RecentInfo> > recentItems = recentMgr->get_items();
    for ( std::vector< Glib::RefPtr<Gtk::RecentInfo> >::iterator it = recentItems.begin(); it != recentItems.end(); ++it ) {
        Glib::ustring uri = (*it)->get_uri();
        std::string scheme = Glib::uri_parse_scheme(uri);
        if ( scheme == "file" ) {
            std::string path = Glib::filename_from_uri(uri);
            path = Glib::path_get_dirname(path);
            if ( std::find(priorLocations.begin(), priorLocations.end(), path) == priorLocations.end() ) {
                // TODO debug g_message("               ==>[%s]", path.c_str());
                priorLocations.push_back(path);
            }
        }
    }

    // At the moment we expect this list to contain file:// references, or simple relative or absolute paths.
    for ( std::vector<Glib::ustring>::const_iterator it = brokenLinks.begin(); it != brokenLinks.end(); ++it ) {
        // TODO debug g_message("========{%s}", it->c_str());

        std::string uri;
        if ( extractFilepath( *it, uri ) ) {
            // We were able to get some path. Check it
            std::string origPath = uri;

            if ( !Glib::path_is_absolute(uri) ) {
                uri = Glib::build_filename(docbase, uri);
                // TODO debug g_message("         not absolute. Fixing up as [%s]", uri.c_str());
            }

            if ( !Glib::file_test(uri, Glib::FILE_TEST_EXISTS) ) {
                // TODO debug g_message("                                  DOES NOT EXIST.");
                std::string remainder;
                bool exists = searchUpwards( docbase, origPath, remainder );

                if ( !exists ) {
                    // TODO debug g_message("Expanding the search...");

                    // Check if the MRU bases point us to it.
                    if ( !Glib::path_is_absolute(origPath) ) {
                        for ( std::vector<std::string>::iterator it = priorLocations.begin(); !exists && (it != priorLocations.end()); ++it ) {
                            exists = searchUpwards( *it, origPath, remainder );
                        }
                    }
                }

                if ( exists ) {
                    if ( Glib::path_is_absolute( remainder ) ) {
                        // TODO debug g_message("Need to convert to relative if possible [%s]", remainder.c_str());
                        remainder = convertPathToRelative( remainder, docbase );
                    }

                    bool isAbsolute = Glib::path_is_absolute( remainder );
                    Glib::ustring replacement = isAbsolute ? Glib::filename_to_uri( remainder ) : Glib::filename_to_utf8( remainder );
                    result[*it] = replacement;
                }
            }
        }
    }

    return result;
}

bool ResourceManagerImpl::fixupBrokenLinks(SPDocument *doc)
{
    bool changed = false;
    if ( doc ) {
        // TODO debug g_message("FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP");
        // TODO debug g_message("      base is [%s]", doc->getBase());

        std::vector<Glib::ustring> brokenHrefs = findBrokenLinks(doc);
        if ( !brokenHrefs.empty() ) {
            // TODO debug g_message("    FOUND SOME LINKS %d", static_cast<int>(brokenHrefs.size()));
            for ( std::vector<Glib::ustring>::iterator it = brokenHrefs.begin(); it != brokenHrefs.end(); ++it ) {
                // TODO debug g_message("        [%s]", it->c_str());
            }
        }

        std::map<Glib::ustring, Glib::ustring> mapping = locateLinks(doc->getBase(), brokenHrefs);
        for ( std::map<Glib::ustring, Glib::ustring>::iterator it = mapping.begin(); it != mapping.end(); ++it )
        {
            // TODO debug g_message("     [%s] ==> {%s}", it->first.c_str(), it->second.c_str());
        }

        bool savedUndoState = DocumentUndo::getUndoSensitive(doc);
        DocumentUndo::setUndoSensitive(doc, true);

        GSList const *images = doc->getResourceList("image");
        for (GSList const *it = images; it; it = it->next) {
            Inkscape::XML::Node *ir = static_cast<SPObject *>(it->data)->getRepr();

            gchar const *href = ir->attribute("xlink:href");
            if ( href ) {
                // TODO debug g_message("                  consider [%s]", href);
                
                if ( mapping.find(href) != mapping.end() ) {
                    // TODO debug g_message("                     Found a replacement");

                    ir->setAttribute( "xlink:href", mapping[href].c_str() );
                    if ( ir->attribute( "sodipodi:absref" ) ) {
                        ir->setAttribute( "sodipodi:absref", 0 ); // Remove this attribute
                    }

                    SPObject *updated = doc->getObjectByRepr(ir);
                    if (updated) {
                        // force immediate update of dependant attributes
                        updated->updateRepr();
                    }

                    changed = true;
                }
            }
        }
        if ( changed ) {
            DocumentUndo::done( doc, SP_VERB_DIALOG_XML_EDITOR, _("Fixup broken links") );
        }
        DocumentUndo::setUndoSensitive(doc, savedUndoState);
    }

    return changed;
}


bool ResourceManagerImpl::searchUpwards( std::string const &base, std::string const &subpath, std::string &dest )
{
    bool exists = false;
    // TODO debug g_message("............");

    std::vector<std::string> parts = splitPath(subpath);
    std::vector<std::string> baseParts = splitPath(base);

    while ( !exists && !baseParts.empty() ) {
        std::vector<std::string> current;
        current.insert(current.begin(), parts.begin(), parts.end());
        // TODO debug g_message("         ---{%s}", Glib::build_filename( baseParts ).c_str());
        while ( !exists && !current.empty() ) {
            std::vector<std::string> combined;
            combined.insert( combined.end(), baseParts.begin(), baseParts.end() );
            combined.insert( combined.end(), current.begin(), current.end() );
            std::string filepath = Glib::build_filename( combined );
            exists = Glib::file_test(filepath, Glib::FILE_TEST_EXISTS);
            // TODO debug g_message("            ...[%s] %s", filepath.c_str(), (exists ? "XXX" : ""));
            if ( exists ) {
                dest = filepath;
            }
            current.erase( current.begin() );
        }
        baseParts.pop_back();
    }

    return exists;
}


static ResourceManagerImpl* theInstance = 0;

ResourceManager::ResourceManager()
    : Glib::Object()
{
}

ResourceManager::~ResourceManager() {
}

ResourceManager& ResourceManager::getManager() {
    if ( !theInstance ) {
        theInstance = new ResourceManagerImpl();
    }

    return *theInstance;
}


} // namespace Inkscape

/*
  Local Variables:
  mode:c++
  c-file-style:"stroustrup"
  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  indent-tabs-mode:nil
  fill-column:99
  End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
