#ifndef MATRIXGRAPH_H
#define MATRIXGRAPH_H

#include "DynamicArray.h"
#include "Exception.h"
#include "Graph.h"

namespace Kylin {

/**
 * MatrixGraph  row即为起始点Vertex的index,col即为终止点的index
 */
template <int N, typename VertexType, typename EdgeType>
class MatrixGraph : public Graph<VertexType, EdgeType> {
public:
    VertexType vertex(size_t index) const final {
        if (index >= vertexCount()) THROW_EXCEPTION(IndexOutOfBoundsException, "Index is out of bounds.");
        if (m_vetexes[index] != nullptr) {
            return *(m_vetexes[index]);
        } else {
            THROW_EXCEPTION(InvalidOperationException, "No value assigned to this vertex.");
        }
    }

    bool setVertex(size_t index, const VertexType &value) final {
        bool ret = ((0 <= index) && (index < vertexCount()));
        if (!ret) return false;
        auto data = m_vetexes[index];
        if (data == nullptr) data = new VertexType();
        if (data != nullptr) {
            *data = value;
            m_vetexes[index] = data;
        } else {
            THROW_EXCEPTION(NoEnoughMemoryException, "No memory to store new vertex value ...");
        }
        return ret;
    }

    /**
     * @brief 获取与Vertex[index]相邻接的顶点(Vertex[index]作为起始点)
     */
    DynamicArray<size_t> adjacent(size_t index) const final {
        if ((0 <= index) && (index < vertexCount())) {
            size_t n = 0;
            for (size_t j = 0; j < vertexCount(); j++) {
                if (m_edges[index][j] != nullptr) {
                    n++;
                }
            }
            DynamicArray<size_t> ret(n);
            for (size_t j = 0, k = 0; j < vertexCount(); j++) {
                if (m_edges[index][j] != nullptr) ret[k++] = j;
            }
            return ret;
        } else {
            THROW_EXCEPTION(InvalidParameterException, "Index is invalid...");
        }
    }

    std::optional<EdgeType> edge(size_t start, size_t end) const final {
        bool status = ((0 <= start) && (start < vertexCount())) && ((0 <= end) && (end < vertexCount()));
        if (!status) return std::optional<EdgeType>{};
        if (m_edges[start][end] != nullptr) {
            return std::optional<EdgeType>{*(m_edges[start][end])};
        } else {
            return std::optional<EdgeType>{};
        }
    }

    bool setEdge(size_t start, size_t end, const EdgeType &value) final {
        bool ret = ((0 <= start) && (start < vertexCount())) && ((0 <= end) && (end < vertexCount()));
        if (!ret) return false;
        auto ne = m_edges[start][end];
        if (ne == nullptr) {
            ne = new EdgeType();
            if (ne != nullptr) {
                *ne = value;
                m_edges[start][end] = ne;
                m_edgeCount++;
            } else {
                THROW_EXCEPTION(NoEnoughMemoryException, "No memory to store new edge value ...");
            }
        } else {
            *ne = value;
        }
        return ret;
    }

    bool removeEdge(size_t start, size_t end) final {
        bool ret = ((0 <= start) && (start < vertexCount())) && ((0 <= end) && (end < vertexCount()));
        if (!ret) return false;
        auto toDel = m_edges[start][end];
        m_edges[start][end] = nullptr;
        if (toDel != nullptr) {
            m_edgeCount--;
            delete toDel;
        }
        return ret;
    }

    size_t vertexCount() const final { return N; }

    size_t edgeCount() const final { return m_edgeCount; }

    size_t outDegree(size_t index) const final {
        size_t ret = 0;
        if ((0 <= index) && (index < vertexCount())) {
            for (size_t j = 0; j < vertexCount(); j++) {
                if (m_edges[index][j] != nullptr) ret++;
            }
        } else {
            THROW_EXCEPTION(InvalidParameterException, "Index i is invalid ...");
        }
        return ret;
    }

    size_t inDegree(size_t index) const final {
        size_t ret = 0;
        if ((0 <= index) && (index < vertexCount())) {
            for (size_t i = 0; i < vertexCount(); i++) {
                if (m_edges[i][index] != nullptr) ret++;
            }
        } else {
            THROW_EXCEPTION(InvalidParameterException, "Index j is invalid ...");
        }
        return ret;
    }

    ~MatrixGraph() {
        auto vetexes = vertexCount();
        for (size_t i = 0; i < vetexes; i++) {
            for (size_t j = 0; j < vetexes; j++) {
                delete m_edges[i][j];
            }
            delete m_vetexes[i];
        }
    }

protected:
    VertexType *m_vetexes[N] = {nullptr};
    EdgeType *m_edges[N][N] = {nullptr};
    size_t m_edgeCount = 0;
};
} // namespace Kylin
#endif // MATRIXGRAPH_H