/*
 * This file is part of gerbolyze, a vector image preprocessing toolchain 
 * Copyright (C) 2021 Jan Sebastian Götte <gerbolyze@jaseg.de>
 * 
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#pragma once

#include <map>
#include <iostream>
#include <string>
#include <pugixml.hpp>
#include "svg_pattern.h"

namespace gerbolyze {

    constexpr char lib_version[] = "2.0";

    typedef std::array<double, 2> d2p;
    typedef std::vector<d2p> Polygon;

    enum GerberPolarityToken {
        GRB_POL_CLEAR,
        GRB_POL_DARK
    };

    class PolygonSink {
        public:
            virtual ~PolygonSink() {}
            virtual void header(d2p origin, d2p size) {(void) origin; (void) size;}
            virtual PolygonSink &operator<<(const Polygon &poly) = 0;
            virtual PolygonSink &operator<<(GerberPolarityToken pol) = 0;
            virtual void footer() {}
    };

    class Flattener_D;
    class Flattener : public PolygonSink {
        public:
            Flattener(PolygonSink &sink);
            virtual ~Flattener();
            virtual void header(d2p origin, d2p size);
            virtual Flattener &operator<<(const Polygon &poly);
            virtual Flattener &operator<<(GerberPolarityToken pol);
            virtual void footer();

        private:
            PolygonSink &m_sink;
            GerberPolarityToken m_current_polarity = GRB_POL_DARK;
            Flattener_D *d;
    };

    class StreamPolygonSink : public PolygonSink {
    public:
        StreamPolygonSink(std::ostream &out, bool only_polys=false) : m_only_polys(only_polys), m_out(out) {}
        virtual ~StreamPolygonSink() {}
        virtual void header(d2p origin, d2p size) { if (!m_only_polys) header_impl(origin, size); }
        virtual void footer() { if (!m_only_polys) { footer_impl(); } m_out.flush(); }

    protected:
        virtual void header_impl(d2p origin, d2p size) = 0;
        virtual void footer_impl() = 0;

        bool m_only_polys = false;
        std::ostream &m_out;
    };

    class SVGDocument {
        public:
            SVGDocument() : _valid(false) {}
            ~SVGDocument();

            /* true -> load successful */
            bool load(std::istream &in, std::string debug_out_filename="/tmp/kicad_svg_debug.svg");
            bool load(std::string filename, std::string debug_out_filename="/tmp/kicad_svg_debug.svg");
            /* true -> load successful */
            bool valid() const { return _valid; }
            operator bool() const { return valid(); }

            double mm_to_doc_units(double) const;
            double doc_units_to_mm(double) const;

            double width() const { return page_w_mm; }
            double height() const { return page_h_mm; }

            void render(PolygonSink &sink);
            void render_to_list(std::vector<std::pair<Polygon, GerberPolarityToken>> &out);

        private:
            friend class Pattern;

            cairo_t *cairo() { return cr; }
            const ClipperLib::Paths *lookup_clip_path(const pugi::xml_node &node);
            Pattern *lookup_pattern(const std::string id);

            void export_svg_group(const pugi::xml_node &group, ClipperLib::Paths &parent_clip_path);
            void export_svg_path(const pugi::xml_node &node, ClipperLib::Paths &clip_path);
            void setup_debug_output(std::string filename="");
            void setup_viewport_clip();
            void load_clips();
            void load_patterns();

            bool _valid;
            pugi::xml_document svg_doc;
            pugi::xml_node root_elem;
            pugi::xml_node defs_node;
            double vb_x, vb_y, vb_w, vb_h;
            double page_w, page_h;
            double page_w_mm, page_h_mm;
            std::map<std::string, Pattern> pattern_map;
            std::map<std::string, ClipperLib::Paths> clip_path_map;
            cairo_matrix_t viewport_matrix;
            ClipperLib::Paths vb_paths; /* viewport clip rect */

            cairo_t *cr = nullptr;
            cairo_surface_t *surface = nullptr;

            PolygonSink *polygon_sink = nullptr;

            static constexpr double dbg_fill_alpha = 0.8;
            static constexpr double dbg_stroke_alpha = 1.0;
            static constexpr double assumed_usvg_dpi = 96.0;
    };

    typedef std::function<void (const Polygon &, GerberPolarityToken)> lambda_sink_fun;
    class LambdaPolygonSink : public PolygonSink {
    public:
        LambdaPolygonSink(lambda_sink_fun lambda) : m_lambda(lambda) {}

        virtual LambdaPolygonSink &operator<<(const Polygon &poly);
        virtual LambdaPolygonSink &operator<<(GerberPolarityToken pol);
    private:
        GerberPolarityToken m_currentPolarity = GRB_POL_DARK;
        lambda_sink_fun m_lambda;
    };

    class SimpleGerberOutput : public StreamPolygonSink {
    public:
        SimpleGerberOutput(std::ostream &out, bool only_polys=false, int digits_int=4, int digits_frac=6, d2p offset={0,0});
        virtual ~SimpleGerberOutput() {}
        virtual SimpleGerberOutput &operator<<(const Polygon &poly);
        virtual SimpleGerberOutput &operator<<(GerberPolarityToken pol);
        virtual void header_impl(d2p origin, d2p size);
        virtual void footer_impl();

    private:
        int m_digits_int;
        int m_digits_frac;
        double m_width;
        double m_height;
        long long int m_gerber_scale;
        d2p m_offset;
    };

    class SimpleSVGOutput : public StreamPolygonSink {
    public:
        SimpleSVGOutput(std::ostream &out, bool only_polys=false, int digits_frac=6, std::string dark_color="#000000", std::string clear_color="#ffffff");
        virtual ~SimpleSVGOutput() {}
        virtual SimpleSVGOutput &operator<<(const Polygon &poly);
        virtual SimpleSVGOutput &operator<<(GerberPolarityToken pol);
        virtual void header_impl(d2p origin, d2p size);
        virtual void footer_impl();

    private:
        int m_digits_frac;
        std::string m_dark_color;
        std::string m_clear_color;
        std::string m_current_color;
        d2p m_offset;
    };

    /* TODO
    class SExpOutput : public StreamPolygonSink {
    public:
        virtual SExpOutput &operator<<(const Polygon &poly);
        virtual SExpOutput &operator<<(GerberPolarityToken pol);
        virtual void header_impl(d2p origin, d2p size);
        virtual void footer_impl();
    }
    */
}