#include <cpphibernate/driver/mariadb/types.h>

#include <cpphibernate/types.inl>
#include <cpphibernate/driver/mariadb/impl/filter.inl>
#include <cpphibernate/driver/mariadb/classes/tables/table.inl>
#include <cpphibernate/driver/mariadb/context/create_update_context.inl>

using namespace ::cpphibernate;
using namespace ::cpphibernate::mariadb;

static std::string build_create_update_query(
    const table_t& table,
    const filter_t * filter,
    const field_t * owner);

static std::string execute_create_update(
    const table_t& table,
    const create_update_context& context,
    ::cppmariadb::statement * statement);

/* table_t */

std::string table_t::create_update(const create_update_context& context) const
    { return create_update_exec(context); }

std::string table_t::create_update_exec(const create_update_context& context) const
{
    auto * statement = context.is_update()
        ? get_statement_update(*context.filter, context.owner_field)
        : get_statement_insert_into();
    return execute_create_update(*this, context, statement);
}

::cppmariadb::statement* table_t::get_statement_insert_into() const
{
    if (!_statement_insert_into)
    {
        auto query = build_create_update_query(*this, nullptr, nullptr);
        _statement_insert_into.reset(new ::cppmariadb::statement(query));
    }
    return _statement_insert_into->empty()
        ? nullptr
        : _statement_insert_into.get();
}

::cppmariadb::statement* table_t::get_statement_update(const filter_t& filter, const field_t * owner) const
{
    auto key = std::make_tuple(filter.cache_id, owner);
    auto it  = _statement_update.find(key);
    if (it == _statement_update.end())
    {
        auto query = build_create_update_query(*this, &filter, owner);
             it    = _statement_update.emplace(key, ::cppmariadb::statement(query)).first;
    }
    return it->second.empty()
        ? nullptr
        : &it->second;
}

std::string build_create_update_query(const table_t& table, const filter_t* filter, const field_t* owner)
{
    std::ostringstream os;

    size_t index     = 0;
    bool   is_update = static_cast<bool>(filter);
    bool   is_create = !is_update;

    /* INSER INTO / UPDATE */
    os  <<  (is_update
            ? "UPDATE"
            : "INSERT INTO")
        <<  " `"
        <<  table.name
        <<  "`";

    /* primary key */
    if (is_create)
    {
        assert(table.primary_key_field);
        auto& key_info = *table.primary_key_field;
        if (!key_info.value_is_auto_incremented)
        {
            if (index++)
                os << ", ";
            else
                os << " SET ";
            os  <<  "`"
                <<  key_info.name
                <<  "`="
                <<  key_info.convert_to_open
                <<  "?"
                <<  key_info.name
                <<  "?"
                <<  key_info.convert_to_close;
        }
    }

    /* base table key fields */
    if (    static_cast<bool>(table.base_table)
        && (    is_create
            || !filter->is_excluded(*table.base_table)))
    {
        if (index++)
            os << ", ";
        else
            os << " SET ";
        auto& base_table_info = *table.base_table;
        assert(base_table_info.primary_key_field);
        auto& key_info = *base_table_info.primary_key_field;
        os  <<  "`"
            <<  key_info.name
            <<  "`="
            <<  key_info.convert_to_open
            <<  "?"
            <<  key_info.name
            <<  "?"
            <<  key_info.convert_to_close;
    }

    /* foreign table one fields */
    for (auto& ptr : table.foreign_table_one_fields)
    {
        assert(static_cast<bool>(ptr));
        auto& field_info = *ptr;
        if (is_update && filter->is_excluded(field_info))
            continue;
        assert(field_info.referenced_table);
        assert(field_info.referenced_table->primary_key_field);
        if (field_info.referenced_table->is_used_in_container)
            continue;
        if (index++)
            os << ", ";
        else
            os << " SET ";
        auto&  key_info = *field_info.referenced_table->primary_key_field;
        os  <<  "`"
            <<  key_info.table.name
            <<  "_id_"
            <<  field_info.name
            <<  "`="
            <<  key_info.convert_to_open
            <<  "?"
            <<  key_info.table.name
            <<  "_id_"
            <<  field_info.name
            <<  "?"
            <<  key_info.convert_to_close;
    }

    /* foreign fields */
    for (auto& ptr : table.foreign_key_fields)
    {
        assert(static_cast<bool>(ptr));
        if (is_update && ptr != owner)
            continue;
        if (index++)
            os << ", ";
        else
            os << " SET ";
        auto&  field_info = *ptr;
        assert(field_info.table.primary_key_field);
        auto&  key_info = *field_info.table.primary_key_field;
        os  <<  "`"
            <<  field_info.table.name
            <<  "_id_"
            <<  field_info.name
            <<  "`="
            <<  key_info.convert_to_open
            <<  "?"
            <<  field_info.table.name
            <<  "_id_"
            <<  field_info.name
            <<  "?"
            <<  key_info.convert_to_close;
        if (field_info.value_is_ordered)
        {
            if (index++)
                os << ", ";
            else
                os << " SET ";
            os  <<  "`"
                <<  field_info.table.name
                <<  "_index_"
                <<  field_info.name
                <<  "`=?\?";
        }
    }

    /* data fields */
    for (auto& ptr : table.data_fields)
    {
        assert(ptr);
        auto& field_info = *ptr;
        if (is_update && filter->is_excluded(field_info))
            continue;
        if (index++)
            os << ", ";
        else
            os << " SET ";
        os  <<  "`"
            <<  field_info.name
            <<  "`="
            <<  field_info.convert_to_open
            <<  "?"
            <<  field_info.name
            <<  "?"
            <<  field_info.convert_to_close;
    }

    /* type field for derived tables */
    if (   !table.derived_tables.empty()
        && !table.base_table
        &&  is_create)
    {
        if (index++)
            os << ", ";
        else
            os << " SET ";
        os  <<  "`__type`=?__type?";
    }

    /* where primary key (for update) */
    if (is_update)
    {
        assert(table.primary_key_field);
        auto& key_info = *table.primary_key_field;
        os  <<  " WHERE `"
            <<  key_info.name
            <<  "`="
            <<  key_info.convert_to_open
            <<  "?"
            <<  key_info.name
            <<  "?"
            <<  key_info.convert_to_close;
    }

    return index == 0 && !(table.primary_key_field->value_is_auto_incremented && is_create)
        ? std::string()
        : os.str();
}

std::string execute_create_update(
    const table_t& table,
    const create_update_context& context,
    ::cppmariadb::statement * statement)
{
    auto& connection = context.connection;
    auto* filter     = context.filter;

    size_t  index       = 0;
    bool    is_update   = context.is_update();
    bool    is_create   = context.is_create();

    std::string primary_key;
    if (statement) statement->clear();

    /* primary key */
    assert(table.primary_key_field);
    if (is_update)
    {
        primary_key = table.get_primary_key(context);
    }
    else if (!table.primary_key_field->value_is_auto_incremented)
    {
        primary_key = table.primary_key_field->generate_value(context.connection);
        if (statement) statement->set(index, primary_key);
        ++index;
    }

    /* base_key */
    if (    table.base_table
        && (    is_create
            || !filter->is_excluded(*table.base_table)))
    {
        auto new_context = context;
        if (!new_context.derived_table)
            new_context.derived_table = &table;
        std::string key = table.base_table->create_update_exec(new_context);
        if (statement) statement->set(index, std::move(key));
        ++index;
    }

    if (is_update && filter->is_excluded(table))
        return primary_key;

    /* foreign table one fields */
    for (auto& ptr : table.foreign_table_one_fields)
    {
        assert(ptr);
        assert(ptr->referenced_table);

        auto& field = *ptr;
        if (is_update && filter->is_excluded(field))
            continue;
        if (field.referenced_table->is_used_in_container)
            continue;

        /* insert/update dataset */
        value_t key = field.foreign_create_update(context);
        if (key.has_value())
        {
            if (statement) statement->set(index, *key);
        }
        else if (field.value_is_nullable)
        {
            if (statement) statement->set_null(index);
        }
        else
        {
            throw exception("Received null key for non nullable foreign dataset!");
        }
        ++index;

        /* cleanup old dataset (if new one was created) */
        if (context.is_update())
        {
            field.foreign_one_delete(context, primary_key, key);
        }
    }

    /* foreign key fields */
    for (auto& ptr : table.foreign_key_fields)
    {
        assert(ptr);
        if (is_update && ptr != context.owner_field)
            continue;

        auto& field_info = *ptr;
        bool set_value =
                context.owner_field
            &&  ptr == context.owner_field;

        if (set_value)
        {
            assert(!context.owner_key.empty());
            if (statement) statement->set(index, context.owner_key);
        }
        else
        {
            if (statement) statement->set_null(index);
        }
        ++index;

        if (field_info.value_is_ordered)
        {
            if (set_value)
            {
                if (statement) statement->set(index, context.index);
            }
            else
            {
                if (statement) statement->set(index, 0);
            }
            ++index;
        }
    }

    /* data fields */
    for (auto& ptr : table.data_fields)
    {
        assert(ptr);
        if (is_update && filter->is_excluded(*ptr))
            continue;

        auto& field_info = *ptr;
        auto  value      = field_info.get(context);

        if (value.has_value())
        {
            if (statement) statement->set(index, *value);
        }
        else
        {
            if (statement) statement->set_null(index);
        }
        ++index;
    }

    /* type field for derived tables */
    if (   !table.derived_tables.empty()
        && !table.base_table
        &&  is_create)
    {
        if (statement) statement->set(index, context.derived_table
            ? context.derived_table->id
            : table.id);
        ++index;
    }

    /* where primary key (for update) */
    if (is_update)
    {
        assert(table.primary_key_field);
        if (statement) statement->set(index, *table.primary_key_field->get(context));
        ++index;
    }

    /* execute */
    if (statement)
    {
        if (is_create)
        {
            cpphibernate_log_debug("execute INSERT query: " << std::endl << statement->query(connection) << std::endl);
        }
        else
        {
            cpphibernate_log_debug("execute UPDATE query: " << std::endl << statement->query(connection) << std::endl);
        }

        if (    table.primary_key_field->value_is_auto_incremented
            &&  is_create)
        {
            auto id = connection.execute_id(*statement);
            primary_key = cppcore::to_string(id);
        }
        else
        {
            auto count = connection.execute_rows(*statement);
            if (count > 1)
                throw exception("Expected one/ row to be inserted/updated!");
            cpphibernate_log_debug(count << " rows inserted/updated" << std::endl);
        }
        table.primary_key_field->set(context, primary_key);
    }

    /* foreign table many fields */
    for (auto& ptr : table.foreign_table_fields)
    {
        assert(ptr);
        assert(ptr->referenced_table);

        auto& field     = *ptr;
        auto& ref_table = *field.referenced_table;

        if (!ref_table.is_used_in_container)
            continue;

        if (    is_update
            && (    filter->is_excluded(field)
                ||  filter->is_excluded(ref_table)))
            continue;

        /* set foreign keys of existing elements to null */
        if (context.is_update())
        {
            field.foreign_many_update(context, primary_key);
        }

        /* update elements */
        auto next_context = context;
        next_context.owner_field   = ptr;
        next_context.owner_key     = primary_key;
        next_context.derived_table = nullptr;
        field.foreign_create_update(next_context);

        /* delete non referenced elements */
        if (context.is_update())
        {
            table_t::table_set processed;
            ref_table.cleanup(context, processed, true, true);
        }
    }

    return primary_key;
}