#include "RestrictionMap.h"
#include "NodeBasedGraph.h"

RestrictionMap::RestrictionMap(const std::shared_ptr<NodeBasedDynamicGraph> &graph,
                               const std::vector<TurnRestriction> &input_restrictions_list)
    : m_count(0), m_graph(graph)
{
    // decompose restirction consisting of a start, via and end note into a start-edge
    // and all end-nodes
    for (auto &restriction : input_restrictions_list)
    {
        std::pair<NodeID, NodeID> restriction_source =
            std::make_pair(restriction.fromNode, restriction.viaNode);
        unsigned index;
        auto restriction_iter = m_restriction_map.find(restriction_source);
        if (restriction_iter == m_restriction_map.end())
        {
            index = m_restriction_bucket_list.size();
            m_restriction_bucket_list.resize(index + 1);
            m_restriction_map.emplace(restriction_source, index);
        }
        else
        {
            index = restriction_iter->second;
            // Map already contains an is_only_*-restriction
            if (m_restriction_bucket_list.at(index).begin()->second)
            {
                continue;
            }
            else if (restriction.flags.isOnly)
            {
                // We are going to insert an is_only_*-restriction. There can be only one.
                m_count -= m_restriction_bucket_list.at(index).size();
                m_restriction_bucket_list.at(index).clear();
            }
        }
        ++m_count;
        m_restriction_bucket_list.at(index)
            .push_back(std::make_pair(restriction.toNode, restriction.flags.isOnly));
    }
}

/**
 * Replace end v with w in each turn restriction containing u as via node
 *
 * Note: We need access to node based graph.
 */
void RestrictionMap::FixupArrivingTurnRestriction(const NodeID u, const NodeID v, const NodeID w)
{
    BOOST_ASSERT(u != std::numeric_limits<unsigned>::max());
    BOOST_ASSERT(v != std::numeric_limits<unsigned>::max());
    BOOST_ASSERT(w != std::numeric_limits<unsigned>::max());

    // find all possible start edges
    // it is more efficent to get a (small) list of potential start edges
    // than iterating over all buckets
    std::vector<NodeID> predecessors;
    for (EdgeID current_edge_id = m_graph->BeginEdges(u); current_edge_id < m_graph->EndEdges(u);
         ++current_edge_id)
    {
        const EdgeData &edge_data = m_graph->GetEdgeData(current_edge_id);
        const NodeID target = m_graph->GetTarget(current_edge_id);
        if (edge_data.backward && (v != target))
        {
            predecessors.push_back(target);
        }
    }

    for (const NodeID x : predecessors)
    {
        const std::pair<NodeID, NodeID> restr_start = std::make_pair(x, u);
        auto restriction_iterator = m_restriction_map.find(restr_start);
        if (restriction_iterator == m_restriction_map.end())
            continue;

        const unsigned index = restriction_iterator->second;
        auto &bucket = m_restriction_bucket_list.at(index);
        for (RestrictionTarget &restriction_target : bucket)
        {
            if (v == restriction_target.first)
            {
                restriction_target.first = w;
            }
        }
    }
}

/**
 * Replaces the start edge (v, w) with (u, w), only start node changes.
 */
void RestrictionMap::FixupStartingTurnRestriction(const NodeID u, const NodeID v, const NodeID w)
{
    BOOST_ASSERT(u != std::numeric_limits<unsigned>::max());
    BOOST_ASSERT(v != std::numeric_limits<unsigned>::max());
    BOOST_ASSERT(w != std::numeric_limits<unsigned>::max());

    const std::pair<NodeID, NodeID> old_start = std::make_pair(v, w);

    auto restriction_iterator = m_restriction_map.find(old_start);
    if (restriction_iterator != m_restriction_map.end())
    {
        const unsigned index = restriction_iterator->second;
        // remove old restriction start (v,w)
        m_restriction_map.erase(restriction_iterator);

        // insert new restriction start (u,w) (point to index)
        const std::pair<NodeID, NodeID> new_start = std::make_pair(u, w);
        m_restriction_map.insert(std::make_pair(new_start, index));
    }
}

/*
 * Check if the edge (u, v) is contained in any turn restriction.
 * If so returns id of first target node.
 */
NodeID RestrictionMap::CheckForEmanatingIsOnlyTurn(const NodeID u, const NodeID v) const
{
    BOOST_ASSERT(u != std::numeric_limits<unsigned>::max());
    BOOST_ASSERT(v != std::numeric_limits<unsigned>::max());

    const std::pair<NodeID, NodeID> restriction_source = std::make_pair(u, v);
    auto restriction_iter = m_restriction_map.find(restriction_source);

    if (restriction_iter != m_restriction_map.end())
    {
        const unsigned index = restriction_iter->second;
        auto &bucket = m_restriction_bucket_list.at(index);
        for (const RestrictionSource &restriction_target : bucket)
        {
            if (restriction_target.second)
            {
                return restriction_target.first;
            }
        }
    }

    return std::numeric_limits<unsigned>::max();
}

/**
 * Checks if the turn described by start u, via v and targed w is covert by any turn restriction.
 */
bool RestrictionMap::CheckIfTurnIsRestricted(const NodeID u, const NodeID v, const NodeID w) const
{
    BOOST_ASSERT(u != std::numeric_limits<unsigned>::max());
    BOOST_ASSERT(v != std::numeric_limits<unsigned>::max());
    BOOST_ASSERT(w != std::numeric_limits<unsigned>::max());

    const std::pair<NodeID, NodeID> restriction_source = std::make_pair(u, v);
    auto restriction_iter = m_restriction_map.find(restriction_source);

    if (restriction_iter != m_restriction_map.end())
    {
        const unsigned index = restriction_iter->second;
        auto &bucket = m_restriction_bucket_list.at(index);
        for (const RestrictionTarget &restriction_target : bucket)
        {
            if ((w == restriction_target.first) && // target found
                (!restriction_target.second)       // and not an only_-restr.
                )
            {
                return true;
            }
        }
    }

    return false;
}