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#include "openlr/paths_connector.hpp"
#include "openlr/helpers.hpp"
#include "base/checked_cast.hpp"
#include "base/stl_iterator.hpp"
#include <algorithm>
#include <map>
#include <queue>
#include <tuple>
using namespace std;
namespace openlr
{
namespace
{
bool ValidatePath(Graph::EdgeVector const & path,
double const distanceToNextPoint,
double const pathLengthTolerance)
{
double pathLen = 0.0;
for (auto const & e : path)
pathLen += EdgeLength(e);
double pathDiffPercent = AbsDifference(static_cast<double>(distanceToNextPoint), pathLen) /
static_cast<double>(distanceToNextPoint);
LOG(LDEBUG, ("Validating path:", LogAs2GisPath(path)));
if (pathDiffPercent > pathLengthTolerance)
{
LOG(LDEBUG,
("Shortest path doest not meet required length constraints, error:", pathDiffPercent));
return false;
}
return true;
}
} // namespace
PathsConnector::PathsConnector(double pathLengthTolerance, Graph & graph,
RoadInfoGetter & infoGetter, v2::Stats & stat)
: m_pathLengthTolerance(pathLengthTolerance)
, m_graph(graph)
, m_infoGetter(infoGetter)
, m_stat(stat)
{
}
bool PathsConnector::ConnectCandidates(vector<LocationReferencePoint> const & points,
vector<vector<Graph::EdgeVector>> const & lineCandidates,
vector<Graph::EdgeVector> & resultPath)
{
ASSERT(!points.empty(), ());
resultPath.resize(points.size() - 1);
// TODO(mgsergio): Discard last point on failure.
// TODO(mgsergio): Do not iterate more than kMaxRetries times.
// TODO(mgserigio): Make kMaxRetries depend on points number in the segment.
for (size_t i = 1; i < points.size(); ++i)
{
bool found = false;
auto const & point = points[i - 1];
auto const distanceToNextPoint = static_cast<double>(point.m_distanceToNextPoint);
auto const & fromCandidates = lineCandidates[i - 1];
auto const & toCandidates = lineCandidates[i];
auto & resultPathPart = resultPath[i - 1];
Graph::EdgeVector fakePath;
for (size_t fromInd = 0; fromInd < fromCandidates.size() && !found; ++fromInd)
{
for (size_t toInd = 0; toInd < toCandidates.size() && !found; ++toInd)
{
resultPathPart.clear();
found = ConnectAdjacentCandidateLines(fromCandidates[fromInd], toCandidates[toInd],
point.m_lfrcnp, distanceToNextPoint,
resultPathPart);
if (!found)
continue;
found = ValidatePath(resultPathPart, distanceToNextPoint, m_pathLengthTolerance);
if (fakePath.empty() && found &&
(resultPathPart.front().IsFake() || resultPathPart.back().IsFake()))
{
fakePath = resultPathPart;
found = false;
}
}
}
if (!fakePath.empty() && !found)
{
found = true;
resultPathPart = fakePath;
}
if (!found)
{
LOG(LDEBUG, ("No shortest path found"));
++m_stat.m_noShortestPathFound;
resultPathPart.clear();
return false;
}
}
ASSERT_EQUAL(resultPath.size(), points.size() - 1, ());
return true;
}
bool PathsConnector::FindShortestPath(Graph::Edge const & from, Graph::Edge const & to,
FunctionalRoadClass lowestFrcToNextPoint, uint32_t maxPathLength,
Graph::EdgeVector & path)
{
// TODO(mgsergio): Turn Dijkstra to A*.
uint32_t const kLengthToleranceM = 10;
struct State
{
State(Graph::Edge const & e, uint32_t const s) : m_edge(e), m_score(s) {}
bool operator>(State const & o) const
{
return make_tuple(m_score, m_edge) > make_tuple(o.m_score, o.m_edge);
}
Graph::Edge m_edge;
uint32_t m_score;
};
ASSERT(from.HasRealPart() && to.HasRealPart(), ());
priority_queue<State, vector<State>, greater<State>> q;
map<Graph::Edge, uint32_t> scores;
map<Graph::Edge, Graph::Edge> links;
q.emplace(from, 0);
scores[from] = 0;
while (!q.empty())
{
auto const state = q.top();
q.pop();
auto const & u = state.m_edge;
// TODO(mgsergio): Unify names: use either score or distance.
auto const us = state.m_score;
if (us > maxPathLength + kLengthToleranceM)
continue;
if (us > scores[u])
continue;
if (u == to)
{
for (auto e = u; e != from; e = links[e])
path.push_back(e);
path.push_back(from);
reverse(begin(path), end(path));
return true;
}
Graph::EdgeVector edges;
m_graph.GetOutgoingEdges(u.GetEndJunction(), edges);
for (auto const & e : edges)
{
if (!ConformLfrcnp(e, lowestFrcToNextPoint, 2 /* frcThreshold */, m_infoGetter))
continue;
// TODO(mgsergio): Use frc to filter edges.
// Only start and/or end of the route can be fake.
// Routes made only of fake edges are no used to us.
if (u.IsFake() && e.IsFake())
continue;
auto const it = scores.find(e);
auto const eScore = us + EdgeLength(e);
if (it == end(scores) || it->second > eScore)
{
scores[e] = eScore;
links[e] = u;
q.emplace(e, eScore);
}
}
}
return false;
}
bool PathsConnector::ConnectAdjacentCandidateLines(Graph::EdgeVector const & from,
Graph::EdgeVector const & to,
FunctionalRoadClass lowestFrcToNextPoint,
double distanceToNextPoint,
Graph::EdgeVector & resultPath)
{
ASSERT(!to.empty(), ());
if (auto const skip = PathOverlappingLen(from, to))
{
if (skip == -1)
return false;
copy(begin(from), end(from), back_inserter(resultPath));
copy(begin(to) + skip, end(to), back_inserter(resultPath));
return true;
}
ASSERT(from.back() != to.front(), ());
Graph::EdgeVector shortestPath;
auto const found =
FindShortestPath(from.back(), to.front(), lowestFrcToNextPoint, distanceToNextPoint, shortestPath);
if (!found)
return false;
// Skip the last edge from |from| because it already took its place at begin(shortestPath).
copy(begin(from), prev(end(from)), back_inserter(resultPath));
copy(begin(shortestPath), end(shortestPath), back_inserter(resultPath));
// Skip the first edge from |to| because it already took its place at prev(end(shortestPath)).
copy(next(begin(to)), end(to), back_inserter(resultPath));
return found;
}
} // namespace openlr
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