// Copyright 2020 Daniel Parker
// Distributed under the Boost license, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

// See https://github.com/danielaparker/jsoncons for latest version

#ifndef JSONCONS_JSONSCHEMA_SUBSCHEMA_HPP
#define JSONCONS_JSONSCHEMA_SUBSCHEMA_HPP

#include <jsoncons/config/jsoncons_config.hpp>
#include <jsoncons/uri.hpp>
#include <jsoncons/json.hpp>
#include <jsoncons_ext/jsonpointer/jsonpointer.hpp>
#include <jsoncons_ext/jsonschema/jsonschema_error.hpp>
#include <jsoncons_ext/jsonschema/schema_location.hpp>

namespace jsoncons {
namespace jsonschema {

    // Interface for validation error handlers
    class error_reporter
    {
        bool fail_early_;
        std::size_t error_count_;
    public:
        error_reporter(bool fail_early = false)
            : fail_early_(fail_early), error_count_(0)
        {
        }

        virtual ~error_reporter() = default;

        void error(const validation_output& o)
        {
            ++error_count_;
            do_error(o);
        }

        std::size_t error_count() const
        {
            return error_count_;
        }

        bool fail_early() const
        {
            return fail_early_;
        }

    private:
        virtual void do_error(const validation_output& /* e */) = 0;
    };

    template <class Json>
    class keyword_validator 
    {
        std::string absolute_keyword_location_;
    public:
        using self_pointer = keyword_validator<Json>*;

        keyword_validator(const std::string& absolute_keyword_location)
            : absolute_keyword_location_(absolute_keyword_location)
        {
        }

        keyword_validator(const keyword_validator&) = delete;
        keyword_validator(keyword_validator&&) = default;
        keyword_validator& operator=(const keyword_validator&) = delete;
        keyword_validator& operator=(keyword_validator&&) = default;

        virtual ~keyword_validator() = default;

        const std::string& absolute_keyword_location() const
        {
            return absolute_keyword_location_;
        }

        void validate(const Json& instance, 
                      const jsonpointer::json_pointer& instance_location, 
                      error_reporter& reporter, 
                      Json& patch) const 
        {
            do_validate(instance, 
                        instance_location,
                        reporter,
                        patch);
        }

        virtual jsoncons::optional<Json> get_default_value(const jsonpointer::json_pointer&, const Json&, error_reporter&) const
        {
            return jsoncons::optional<Json>();
        }

    private:
        virtual void do_validate(const Json& instance, 
                                 const jsonpointer::json_pointer& instance_location, 
                                 error_reporter& reporter, 
                                 Json& patch) const = 0;
    };

    template <class Json>
    std::vector<schema_location> update_uris(const Json& schema,
                                         const std::vector<schema_location>& uris,
                                         const std::vector<std::string>& keys)
    {
        // Exclude uri's that are not plain name identifiers
        std::vector<schema_location> new_uris;
        for (const auto& uri : uris)
        {
            if (!uri.has_identifier())
                new_uris.push_back(uri);
        }

        // Append the keys for this sub-schema to the uri's
        for (const auto& key : keys)
        {
            for (auto& uri : new_uris)
            {
                auto new_u = uri.append(key);
                uri = schema_location(new_u);
            }
        }
        if (schema.type() == json_type::object_value)
        {
            auto it = schema.find("$id"); // If $id is found, this schema can be referenced by the id
            if (it != schema.object_range().end()) 
            {
                std::string id = it->value().template as<std::string>(); 
                // Add it to the list if it is not already there
                if (std::find(new_uris.begin(), new_uris.end(), id) == new_uris.end())
                {
                    schema_location relative(id); 
                    schema_location new_uri = relative.resolve(new_uris.back());
                    new_uris.emplace_back(new_uri); 
                }
            }
        }

        return new_uris;
    }

} // namespace jsonschema
} // namespace jsoncons

#endif // JSONCONS_JSONSCHEMA_RULE_HPP