#include <boost/algorithm/string/predicate.hpp>
#include <cmath>
#include "datastore_access.hpp"
#include "libyang_utils.hpp"
#include "utils.hpp"

leaf_data_ leafValueFromValue(const libyang::S_Value& value, LY_DATA_TYPE type)
{
    using namespace std::string_literals;
    switch (type) {
    case LY_TYPE_INT8:
        return value->int8();
    case LY_TYPE_INT16:
        return value->int16();
    case LY_TYPE_INT32:
        return value->int32();
    case LY_TYPE_INT64:
        return value->int64();
    case LY_TYPE_UINT8:
        return value->uint8();
    case LY_TYPE_UINT16:
        return value->uint16();
    case LY_TYPE_UINT32:
        return value->uint32();
    case LY_TYPE_UINT64:
        return value->uint64();
    case LY_TYPE_BOOL:
        return bool(value->bln());
    case LY_TYPE_STRING:
        return std::string(value->string());
    case LY_TYPE_ENUM:
        return enum_{std::string(value->enm()->name())};
    case LY_TYPE_IDENT:
        return identityRef_{value->ident()->module()->name(), value->ident()->name()};
    case LY_TYPE_BINARY:
        return binary_{value->binary()};
    case LY_TYPE_EMPTY:
        return empty_{};
    case LY_TYPE_DEC64:
    {
        auto v = value->dec64();
        return v.value * std::pow(10, -v.digits);
    }
    case LY_TYPE_LEAFREF:
    {
        libyang::Data_Node_Leaf_List toPrint{value->leafref()};
        return leafValueFromValue(toPrint.value(), toPrint.value_type());
    }
    default: // TODO: implement all types
        return "(can't print)"s;
    }
}

namespace {
void impl_lyNodesToTree(DatastoreAccess::Tree& res, const std::vector<std::shared_ptr<libyang::Data_Node>> items, std::optional<std::string> ignoredXPathPrefix)
{
    auto stripXPathPrefix = [&ignoredXPathPrefix] (auto path) {
        return ignoredXPathPrefix ? path.substr(ignoredXPathPrefix->size()) : path;
    };

    for (const auto& it : items) {
        if (it->schema()->nodetype() == LYS_CONTAINER) {
            if (libyang::Schema_Node_Container{it->schema()}.presence()) {
                // The fact that the container is included in the data tree
                // means that it is present and I don't need to check any
                // value.
                res.emplace_back(stripXPathPrefix(it->path()), special_{SpecialValue::PresenceContainer});
            }
        }
        if (it->schema()->nodetype() == LYS_LIST) {
            res.push_back({stripXPathPrefix(it->path()), special_{SpecialValue::List}});
        }
        if (it->schema()->nodetype() == LYS_LEAF || it->schema()->nodetype() == LYS_LEAFLIST) {
            libyang::Data_Node_Leaf_List leaf(it);
            auto value = leafValueFromValue(leaf.value(), leaf.value_type());
            res.emplace_back(stripXPathPrefix(it->path()), value);
        }
    }
}
}

// This is very similar to the fillMap lambda in SysrepoAccess, however,
// Sysrepo returns a weird array-like structure, while libnetconf
// returns libyang::Data_Node
void lyNodesToTree(DatastoreAccess::Tree& res, const std::vector<std::shared_ptr<libyang::Data_Node>> items, std::optional<std::string> ignoredXPathPrefix)
{
    for (auto it = items.begin(); it < items.end(); it++) {
        if ((*it)->schema()->nodetype() == LYS_LEAFLIST) {
            auto leafListPath = stripLeafListValueFromPath((*it)->path());
            res.emplace_back(leafListPath, special_{SpecialValue::LeafList});
            while (it != items.end() && boost::starts_with((*it)->path(), leafListPath)) {
                impl_lyNodesToTree(res, (*it)->tree_dfs(), ignoredXPathPrefix);
                it++;
            }
        } else {
            impl_lyNodesToTree(res, (*it)->tree_dfs(), ignoredXPathPrefix);
        }
    }
}