/*
// Copyright (c) 2019 Intel Corporation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
*/

///////////////////////////////////////////////////////////////////////////////////////////////////

#pragma once

#include "api/CPP/program.hpp"

#include "refcounted_obj.h"
#include "engine_impl.h"

#include <list>

namespace cldnn
{

struct topology_impl;
struct primitive_impl;
struct program_node;
class layout_optimizer;
class pass_manager;
class program_impl_wrapper;
/*
    cldnn_program implementation
*/
struct program_impl : public refcounted_obj<program_impl>
{
    friend class calculate_prior_boxes;             // to be removed when possible
    friend class graph_initializations;             // to be removed when possible
    friend class prepare_padding;                   // to be removed when possible
    friend class propagate_constants;               // to be removed when possible
    friend class prepare_primitive_fusing;          // to be removed when possible
    friend class prepare_conv_eltw_fusing;          // to be removed when possible
    friend class prepare_conv_eltw_read_write_opt;  // to be removed when possible
    friend class reorder_inputs;                    // to be removed when possible
    friend class program_impl_wrapper;              // this class is intended to extend the interface of program_impl for 
                                                    // the usage within tests_core_internal project only
public:
    struct nodes_ordering
    {
    public:
        typedef std::list<program_node*> list_of_nodes;
        typedef list_of_nodes::const_iterator const_iterator;
        typedef list_of_nodes::iterator node_iterator;
        const_iterator begin() const { return _processing_order.begin(); }
        const_iterator end() const { return _processing_order.end(); }

        void calc_processing_order_visit(program_node* node);
        void calc_processing_order(program_impl& p);
        int32_t get_processing_number(program_node* node) const { return get_processing_number(get_processing_iterator(*node)); }
        // int32_t get_processing_number(const_iterator iter) const { return 1+(int32_t)std::distance(begin(), iter); }
        int32_t get_processing_number(node_iterator iter) const { return 1 + (int32_t)std::distance(_processing_order.begin(), const_iterator(iter)); }
        void calculate_BFS_processing_order();
        size_t size() { return _processing_order.size(); }
        bool is_correct(program_node* node);
        
        node_iterator get_processing_iterator(program_node& node) const
        {
            return processing_order_iterators.at(&node);
        }
        void clear()
        {
            processing_order_iterators.clear();
            _processing_order.clear();
        }

        void insert(program_node* key_node, program_node* node)
        {
            node_iterator _where = processing_order_iterators.at(key_node);
            processing_order_iterators[node] = _processing_order.insert(_where, node);
        }

        void insert_next(program_node* key_node, program_node* node)
        {
            node_iterator _where = std::next(processing_order_iterators.at(key_node));
            processing_order_iterators[node] = _processing_order.insert(_where, node);
        }

        void erase(program_node* key_node)
        {
            node_iterator i = processing_order_iterators.at(key_node);
            processing_order_iterators.erase(key_node);
            _processing_order.erase(i);
        }

    private:
        list_of_nodes _processing_order;
        std::map<program_node*, node_iterator> processing_order_iterators;
    };

    template <class T>
    struct single_element_container
    {
        single_element_container(T& t) : elem(&t)
        {}
        constexpr size_t size() const { return 1; }
        single_element_container begin() const { return single_element_container(elem); }
        single_element_container end() const { return single_element_container(nullptr); }
        single_element_container& operator ++() { elem = nullptr; return *this; }
        bool operator !=(single_element_container const& sec) { return elem != sec.elem; }

       T operator *() { return *elem; }

    private:
        single_element_container(T* t) : elem(t)
        {}

        T* elem;
    };
    program_impl(engine_impl& engine_ref, topology_impl const& topology, build_options const& options, bool is_internal, bool no_optimizations=false);
    /* constructor used to build a program from subset of nodes of other program (used in propagate_constants) */
    program_impl(engine_impl& engine_ref, std::set<std::shared_ptr<program_node>> const &nodes, build_options const& options, bool is_internal);
    ~program_impl();
    engine_impl& get_engine() const { return *engine; }
    const build_options& get_options() const { return options; }
    std::list<program_node*>& get_inputs() { return inputs; }     // ToDo: redesign trim to ouptut pass to make it const as_well as get_engine and get options 
    std::vector<program_node*>& get_outputs() { return outputs; }  // ToDo: redesign reorder-inputs pass to make it const as_well as get_engine and get options 
    bool is_debug_build() const { return options.get<build_option_type::debug>()->enabled(); }
    const nodes_ordering& get_processing_order() const;
    nodes_ordering& get_processing_order();
    const std::list<primitive_id>& get_optimized_out() const { return optimized_out; }
    bool has_node(const primitive_id& prim) const { return nodes_map.count(prim) > 0; }
    program_node& get_node(primitive_id const& id);
    program_node const& get_node(primitive_id const& id) const;
    std::shared_ptr<program_node> get_node_ptr(const primitive_id& prim) { return nodes_map.at(prim);  }
    std::shared_ptr<program_node> get_node_ptr(const primitive_id& prim) const { return nodes_map.at(prim); }
    void dump_memory_pool() const;

    //returns already existing program_node for given primitive 'prim' (lookup in 'nodes_map')
    //if it was previously created, otherwise creates and then returns program_node
    program_node& get_or_create(std::shared_ptr<primitive> prim);

    // Inserts given program_node 'node' as an intermediate node between 'next' and it's
    //  dependency at 'prev_idx' index.
    void add_intermediate(program_node& node, program_node& next, size_t prev_idx,
                          bool connect_int_node_with_old_dep = true,
                          bool move_usrs_of_prev_to_node = false);

    // Gets or creates program_node for given primitive 'prim' and inserts it as an intermediate
    // node between 'next' and it's dependency at 'prev_idx' index.
    void add_intermediate(std::shared_ptr<primitive> prim, program_node& next, size_t prev_idx, 
        bool connect_int_node_with_old_dep = true,
        bool move_usrs_of_prev_to_node = false);

    //removes a node from the graph and deletes it afterwards,
    //prereq: node cannot be marked as output and has to have exactly one dependency
    //returns if 'node' has been extracted and removed successfully
    bool extract_and_remove(program_node& node);

    //returns if 'node' has been removed
    bool remove_if_dangling(program_node& node);

    void mark_if_constant(program_node& node);
    // mark if the node is in data flow assuming that all dependencies are marked properly
    void mark_if_data_flow(program_node& node);
    //Reverses connection - user becomes dependency.

    void remove_nodes(std::list<program_node*>& to_remove);
    void dump_program(const char* stage, bool with_full_info, std::function<bool(program_node const&)> const& filter = nullptr) const;

private:
    uint32_t prog_id = 0;
    engine_impl::ptr engine;
    build_options options;
    std::list<program_node*> inputs;
    std::vector<program_node*> outputs;
    nodes_ordering processing_order;
    std::unique_ptr<pass_manager> pm;

    std::map<primitive_id, std::shared_ptr<program_node>> nodes_map;
    std::list<primitive_id> optimized_out;

    /*
    ** High-level functions, in order of usage
    */
    /* build nodes internal structure based on topology */
    void prepare_nodes(topology_impl const& topology);
    /* build nodes internal structure based on the subset of nodes of other program  (used in propagate_constants) */
    void prepare_nodes(std::set<std::shared_ptr<program_node>> const& nodes);
    void add_node_dependencies(program_node* node_ptr);
    void copy_node_dependencies(program_node* dest, program_node* src);
    void build_program(bool is_internal);
    void init_graph();
    void set_options();

    void run_graph_compilation();
    void pre_optimize_graph(bool is_internal);
    void post_optimize_graph(bool is_internal);
    void cleanup();

    /*
    ** Analysis functions
    */
    // TODO: Remove once we will get full support for input/output padding in all primitive implementations.
    bool analyze_output_size_handling_need();

    // handle split, deconvolution and upsampling
    void handle_reshape();

    /*
    ** Optimization functions
    */
    void apply_needed_padding(program_node& node, program_node& prev_node, const padding& needed_padding);

    /*
    ** Memory pool functions
    */
    void prepare_memory_dependencies();
    void basic_memory_dependencies();
    void skipped_branch_memory_dependencies();
    void oooq_memory_dependencies();
    std::string get_memory_dependencies_string() const;

    /*
    ** Utilities
    */
    void add_split_outputs();
    // mark if the node is constant assuming that all dependencies are marked properly
    void reverse_connection(program_node& dep_node, program_node& user_node);

    void add_connection(program_node& prev, program_node& next);

    void remove_connection(program_node& prev, program_node& next);

    void remove_all_connections(program_node& node);

    void rename(program_node & node, primitive_id const & new_id);
    void swap_names(program_node& node1, program_node& node2);
    void replace_all_usages(program_node& old_node, program_node& new_node);

    //old_node - node which will be replaced
    //new_node - node which will replace the old one
    void replace(program_node& old_node, program_node& new_node);
};

}

API_CAST(::cldnn_program, cldnn::program_impl)
