/*
This Source Code Form is subject to the
terms of the Mozilla Public License, v.
2.0. If a copy of the MPL was not
distributed with this file, You can
obtain one at
http://mozilla.org/MPL/2.0/.
*/

#include "stdafx.h"

#include "material.h"
#include "renderer.h"
#include "utilities.h"
#include "sn_utils.h"
#include "Globals.h"

bool
opengl_material::deserialize( cParser &Input, bool const Loadnow ) {

    bool result { false };
    while( true == deserialize_mapping( Input, 0, Loadnow ) ) {
        result = true; // once would suffice but, eh
    }

    has_alpha = (
        texture1 != null_handle ?
            GfxRenderer->Texture( texture1 ).has_alpha :
            false );

    return result;
}

// imports member data pair from the config file
bool
opengl_material::deserialize_mapping( cParser &Input, int const Priority, bool const Loadnow ) {
    // NOTE: comma can be part of legacy file names, so we don't treat it as a separator here
    std::string const key { Input.getToken<std::string>( true, "\n\r\t  ;[]" ) };
    // key can be an actual key or block end
    if( ( true == key.empty() ) || ( key == "}" ) ) { return false; }

    if( Priority != -1 ) {
        // regular attribute processing mode
        if( key == Global.Weather ) {
            // weather textures override generic (pri 0) and seasonal (pri 1) textures
            // seasonal weather textures (pri 1+2=3) override generic weather (pri 2) textures
            // skip the opening bracket
            auto const value { Input.getToken<std::string>( true, "\n\r\t ;" ) };
            while( true == deserialize_mapping( Input, Priority + 2, Loadnow ) ) {
                ; // all work is done in the header
            }
        }
        else if( key == Global.Season ) {
            // seasonal textures override generic textures
            // skip the opening bracket
            auto const value { Input.getToken<std::string>( true, "\n\r\t ;" ) };
            while( true == deserialize_mapping( Input, Priority + 1, Loadnow ) ) {
                ; // all work is done in the header
            }
        }
        else if( ( key == "texture1:" )
              || ( key == "texture_diffuse:" ) ) {
            auto const value { deserialize_random_set( Input ) };
            if( ( texture1 == null_handle )
             || ( Priority > priority1 ) ) {
                texture1 = GfxRenderer->Fetch_Texture( value, Loadnow );
                priority1 = Priority;
            }
        }
        else if( ( key == "texture2:" )
              || ( key == "texture_normalmap:" ) ) {
            auto const value { deserialize_random_set( Input ) };
            if( ( texture2 == null_handle )
             || ( Priority > priority2 ) ) {
                texture2 = GfxRenderer->Fetch_Texture( value, Loadnow );
                priority2 = Priority;
            }
        }
        else if( key == "size:" ) {
            Input.getTokens( 2 );
            Input
                >> size.x
                >> size.y;
        }
        else {
            auto const value { Input.getToken<std::string>( true, "\n\r\t ;" ) };
            if( value == "{" ) {
                // unrecognized or ignored token, but comes with attribute block and potential further nesting
                // go through it and discard the content
                while( true == deserialize_mapping( Input, -1, Loadnow ) ) {
                    ; // all work is done in the header
                }
            }
        }
    }
    else {
        // discard mode; ignores all retrieved tokens
        auto const value { Input.getToken<std::string>( true, "\n\r\t ;" ) };
        if( value == "{" ) {
            // ignored tokens can come with their own blocks, ignore these recursively
            // go through it and discard the content
            while( true == deserialize_mapping( Input, -1, Loadnow ) ) {
                ; // all work is done in the header
            }
        }
    }

    return true; // return value marks a key: value pair was extracted, nothing about whether it's recognized
}


// create material object from data stored in specified file.
// NOTE: the deferred load parameter is passed to textures defined by material, the material itself is always loaded immediately
material_handle
material_manager::create( std::string const &Filename, bool const Loadnow ) {

    auto filename { Filename };

    if( filename.find( '|' ) != std::string::npos )
        filename.erase( filename.find( '|' ) ); // po | może być nazwa kolejnej tekstury

    // discern references to textures generated by a script
    // TBD: support file: for file resources?
    auto const isgenerated { filename.find( "make:" ) == 0 };

    // process supplied resource name
    if( isgenerated ) {
        // generated resource
        // scheme:(user@)path?query

        // remove scheme indicator
        filename.erase( 0, filename.find(':') + 1 );
        // TBD, TODO: allow shader specification as part of the query?
        replace_slashes( filename );
        erase_leading_slashes( filename );
    }
    else {
        // regular file resource
        // (filepath/)filename.extension

        erase_extension( filename );
        replace_slashes( filename );
        erase_leading_slashes( filename );
    }

    auto const databanklookup { find_in_databank( ToLower( filename ) ) };
    if( databanklookup != null_handle ) {
        return databanklookup;
    }

    opengl_material material;
    material_handle materialhandle { null_handle };

    auto const locator {
        isgenerated ?
            std::make_pair( filename, "make:" ) :
            find_on_disk( filename ) };

    if( ( false == isgenerated )
     && ( false == locator.first.empty() ) ) {
        // try to parse located file resource
        cParser materialparser( locator.first + locator.second, cParser::buffer_FILE );
        if( true == material.deserialize( materialparser, Loadnow ) ) {
            material.name = locator.first;
        }
    }
    else {
        // if there's no .mat file, this can be either autogenerated texture,
        // or legacy method of referring just to diffuse texture directly.
        // wrap basic material around it in either case
        material.texture1 = GfxRenderer->Fetch_Texture( Filename, Loadnow );
        if( material.texture1 != null_handle ) {
            // use texture path and name to tell the newly created materials apart
            material.name = GfxRenderer->Texture( material.texture1 ).name;
            material.has_alpha = GfxRenderer->Texture( material.texture1 ).has_alpha;
        }
    }

    if( false == material.name.empty() ) {
        // if we have material name it means resource was processed succesfully
        materialhandle = m_materials.size();
        m_materials.emplace_back( material );
        m_materialmappings.emplace( material.name, materialhandle );
    }
    else {
        // otherwise record our failure to process the resource, to speed up subsequent attempts
        m_materialmappings.emplace( filename, materialhandle );
    }

    return materialhandle;
};

// checks whether specified material is in the material bank. returns handle to the material, or a null handle
material_handle
material_manager::find_in_databank( std::string const &Materialname ) const {

    std::vector<std::string> const filenames {
        Global.asCurrentTexturePath + Materialname,
        Materialname,
        szTexturePath + Materialname };

    for( auto const &filename : filenames ) {
        auto const lookup { m_materialmappings.find( filename ) };
        if( lookup != m_materialmappings.end() ) {
            return lookup->second;
        }
    }
    // all lookups failed
    return null_handle;
}

// checks whether specified file exists.
// NOTE: technically could be static, but we might want to switch from global texture path to instance-specific at some point
std::pair<std::string, std::string>
material_manager::find_on_disk( std::string const &Materialname ) const {

    auto const materialname { ToLower( Materialname ) };
    return (
        FileExists(
            { Global.asCurrentTexturePath + materialname, materialname, szTexturePath + materialname },
            { ".mat" } ) );
}

//---------------------------------------------------------------------------