#include "VertexArray.hpp"

namespace nb {

using VAOErrorCodes = VAOError::Codes;
const std::string VAOError::type = "nb::VAOError";
const ErrorCodeMap VAOError::ErrorMessages = {
    { VAOErrorCodes::UNDEFINED, "Error" },
    { VAOErrorCodes::INVALID_ATTRIBUTE, "Targeting invalid attribute"},
    { VAOErrorCodes::INVALID_VAO, "Targeting invalid VAO" }
};

VAO::VAO(const VertexAttributePointerList& attr_ptrs) {
    attributes(attr_ptrs);
}

VAO::VAO(VAO&& other) {
    *this = std::move(other);
}

VAO& VAO::operator=(VAO&& rhs) {
    _id = rhs._id;
    _attrs = rhs._attrs;

    rhs._id = 0;
    rhs._attrs = {};

    return *this;
}

VertexAttributePointerList VAO::attributes() const {
    return _attrs;
}

VertexAttributePointerList VAO::attributes(const VertexAttributePointerList& attrs_) {
    declare();
    disable();
    _attrs = attrs_;
    bind();
    for (auto attr_ptr : attrs_) {
        attr_ptr.buffer->bind();
        GLuint idx = attr_ptr.index; 
        glVertexAttribPointer(
            idx,
            attr_ptr.attribute.GLSLSize,
            attr_ptr.attribute.GLSLType,
            attr_ptr.attribute.GLSLNormalization,
            attr_ptr.attribute.layout.stride,
            (void*)attr_ptr.attribute.layout.offset
        );
        glEnableVertexAttribArray(idx);
    }
    unbind();
    return _attrs;
}

VertexAttributePointer VAO::attr(GLuint idx) const {
    for (auto attr_ptr : _attrs) {
        if (idx == attr_ptr.index) {
            return attr_ptr;
        }
    }
    THROW(BufferError(Codes::INVALID_ATTRIBUTE));
}

void VAO::enable() const {
    if (_id) {
        bind();
        for(auto attr_ptr : _attrs) {
            glEnableVertexAttribArray(attr_ptr.index);
        }
        unbind();
    }
}

void VAO::enable(GLuint idx) const {
    if(_id) {
        bind();
        glEnableVertexAttribArray(attr(idx).index); 
        unbind();
    }
}

void VAO::disable() const {
    if(_id) {
        bind();
        for(auto attr_ptr : _attrs) {
            glDisableVertexAttribArray(attr_ptr.index); 
        }
        unbind();
    }
}

void VAO::disable(GLuint idx) const {
    if(_id) {
        bind();
        glDisableVertexAttribArray(attr(idx).index); 
        unbind();
    }
}

VertexGroup::VertexGroup(VertexGroup&& other) {
    *this = std::move(other);
}

VertexGroup& VertexGroup::operator=(VertexGroup&& rhs) {
    _vertex_data = rhs._vertex_data;
    _elmt_buf = std::move(rhs._elmt_buf);
    _vao = std::move(rhs._vao);

    rhs._vertex_data = {};
    rhs._elmt_buf = ElementBuffer<false>();
    rhs._vao = VAO();

    return *this;
}

size_t VertexGroup::buffer(VertexBuffer<false>&& buf_) {
    _vertex_data.emplace_back(
        std::make_shared<VertexBuffer<false>>(std::move(buf_))
    );
    VertexBuffer<false>* buf_ptr  = _vertex_data.back().get();
    VertexAttributePointerList attrs = _vao.attributes();
    GLuint idx = attrs.size();
    for (auto attr : buf_ptr->attributes) {
        attrs.emplace_back(
            VertexAttributePointer{attr, buf_ptr,idx}
        );
        idx++;
    }
    _vao.attributes(attrs);
    return _vertex_data.size();
}

VertexBuffer<false>& VertexGroup::buffer(size_t idx) {
    return *_vertex_data[idx];
}

std::vector<std::shared_ptr<VertexBuffer<false>>> VertexGroup::buffers() {
    return _vertex_data;
}

size_t VertexGroup::buffers(std::vector<VertexBuffer<false>>&& bufs_) {
    _vertex_data.clear();
    for (auto& buf : bufs_) {
        _vertex_data.emplace_back(
            std::make_shared<VertexBuffer<false>>(std::move(buf))
        );
    }
    VertexAttributePointerList attr_ptrs;
    GLuint idx = 0;
    for (auto buf : _vertex_data) {
        for (auto attr : buf->attributes) {
            attr_ptrs.emplace_back(
                VertexAttributePointer{attr, buf.get(), idx}
            );
            idx++;
        }
    }
    _vao.attributes(attr_ptrs);
    return _vertex_data.size();
}

VertexBuffer<false>&& VertexGroup::dropBuffer(size_t idx) {
    if (idx >= _vertex_data.size()) {
        THROW(BufferError(BufferError::Codes::INVALID_BUFFER));
    }
    std::vector<VertexBuffer<false>> tmp;
    std::shared_ptr<VertexBuffer<false>> ret_ptr;
    size_t i = 0;
    for (auto buf : _vertex_data) {
        if (i == idx) {
            ret_ptr = std::make_shared<VertexBuffer<false>>(std::move(tmp[idx]));
        } else {
            tmp.emplace_back(std::move(*buf));
        }
        i++;
    }
    buffers(std::move(tmp));
    return std::move(*ret_ptr);
}

VertexAttributePointer VertexGroup::attribute(size_t idx_) const {
    return _vao.attr(idx_);
}

void VertexGroup::enableAttr(GLuint idx) {
    bind();
    _vao.enable(idx);
    unbind();
}

void VertexGroup::disableAttr(GLuint idx) {
    bind();
    _vao.disable(idx);
    unbind();
}

void VertexGroup::disableBuffer(size_t idx) {
    auto buf_ptr = _vertex_data[idx].get();
    bind();
    for (auto attr : _vao.attributes()) {
        if (attr.buffer == buf_ptr) {
            _vao.disable(attr.index);
        }
    }
    unbind();
}

void VertexGroup::enableBuffer(size_t idx) {
    auto buf_ptr = _vertex_data[idx].get();
    bind();
    for (auto attr : _vao.attributes()) {
        if (attr.buffer == buf_ptr) {
            _vao.enable(attr.index);
        }
    }
    unbind();
}

void VertexGroup::enable() { _vao.enable(); }

void VertexGroup::disable() { _vao.disable(); }

} // namespace nb