/**
 * @file
 *
 * @brief   Class definitions to support JSON Schema constraints
 *
 * This file contains class definitions for all of the constraints required to
 * support JSON Schema. These classes all inherit from the BasicConstraint
 * template class, which implements the common parts of the Constraint
 * interface.
 *
 * @see BasicConstraint
 * @see Constraint
 */

#pragma once

#include <limits>
#include <map>
#include <set>
#include <string>
#include <vector>

#include <valijson/adapters/frozen_value.hpp>
#include <valijson/constraints/basic_constraint.hpp>
#include <valijson/internal/custom_allocator.hpp>
#include <valijson/schema.hpp>
#include <valijson/exceptions.hpp>

namespace valijson {

class ValidationResults;

namespace constraints {

/**
 * @brief  Represents an 'allOf' constraint.
 *
 * An allOf constraint provides a collection of sub-schemas that a value must
 * validate against. If a value fails to validate against any of these sub-
 * schemas, then validation fails.
 */
class AllOfConstraint : public BasicConstraint<AllOfConstraint> {
   public:
    AllOfConstraint() : m_subschemas(Allocator::rebind<const Subschema *>::other(m_allocator)) {}

    AllOfConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_subschemas(Allocator::rebind<const Subschema *>::other(m_allocator)) {}

    void addSubschema(const Subschema *subschema) { m_subschemas.push_back(subschema); }

    template <typename FunctorType>
    void applyToSubschemas(const FunctorType &fn) const {
        unsigned int index = 0;
        for (const Subschema *subschema : m_subschemas) {
            if (!fn(index, subschema)) {
                return;
            }

            index++;
        }
    }

   private:
    typedef std::vector<const Subschema *, internal::CustomAllocator<const Subschema *>> Subschemas;

    /// Collection of sub-schemas, all of which must be satisfied
    Subschemas m_subschemas;
};

/**
 * @brief  Represents an 'anyOf' constraint
 *
 * An anyOf constraint provides a collection of sub-schemas that a value can
 * validate against. If a value validates against one of these sub-schemas,
 * then the validation passes.
 */
class AnyOfConstraint : public BasicConstraint<AnyOfConstraint> {
   public:
    AnyOfConstraint() : m_subschemas(Allocator::rebind<const Subschema *>::other(m_allocator)) {}

    AnyOfConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_subschemas(Allocator::rebind<const Subschema *>::other(m_allocator)) {}

    void addSubschema(const Subschema *subschema) { m_subschemas.push_back(subschema); }

    template <typename FunctorType>
    void applyToSubschemas(const FunctorType &fn) const {
        unsigned int index = 0;
        for (const Subschema *subschema : m_subschemas) {
            if (!fn(index, subschema)) {
                return;
            }

            index++;
        }
    }

   private:
    typedef std::vector<const Subschema *, internal::CustomAllocator<const Subschema *>> Subschemas;

    /// Collection of sub-schemas, at least one of which must be satisfied
    Subschemas m_subschemas;
};

/**
 * @brief  Represents a combination 'if', 'then' and 'else' constraints
 *
 * The schema provided by an 'if' constraint is used as the expression for a conditional. When the
 * target validates against that schema, the 'then' subschema will be also be tested. Otherwise,
 * the 'else' subschema will be tested.
 */
class ConditionalConstraint : public BasicConstraint<ConditionalConstraint> {
   public:
    ConditionalConstraint() : m_ifSubschema(nullptr), m_thenSubschema(nullptr), m_elseSubschema(nullptr) {}

    ConditionalConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_ifSubschema(nullptr), m_thenSubschema(nullptr), m_elseSubschema(nullptr) {}

    const Subschema *getIfSubschema() const { return m_ifSubschema; }

    const Subschema *getThenSubschema() const { return m_thenSubschema; }

    const Subschema *getElseSubschema() const { return m_elseSubschema; }

    void setIfSubschema(const Subschema *subschema) { m_ifSubschema = subschema; }

    void setThenSubschema(const Subschema *subschema) { m_thenSubschema = subschema; }

    void setElseSubschema(const Subschema *subschema) { m_elseSubschema = subschema; }

   private:
    const Subschema *m_ifSubschema;
    const Subschema *m_thenSubschema;
    const Subschema *m_elseSubschema;
};

class ConstConstraint : public BasicConstraint<ConstConstraint> {
   public:
    ConstConstraint() : m_value(nullptr) {}

    ConstConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_value(nullptr) {}

    ConstConstraint(const ConstConstraint &other) : BasicConstraint(other), m_value(other.m_value->clone()) {}

    adapters::FrozenValue *getValue() const { return m_value.get(); }

    void setValue(const adapters::Adapter &value) { m_value = std::unique_ptr<adapters::FrozenValue>(value.freeze()); }

   private:
    std::unique_ptr<adapters::FrozenValue> m_value;
};

/**
 * @brief  Represents a 'contains' constraint
 *
 * A 'contains' constraint specifies a schema that must be satisfied by at least one
 * of the values in an array.
 */
class ContainsConstraint : public BasicConstraint<ContainsConstraint> {
   public:
    ContainsConstraint() : m_subschema(nullptr) {}

    ContainsConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_subschema(nullptr) {}

    const Subschema *getSubschema() const { return m_subschema; }

    void setSubschema(const Subschema *subschema) { m_subschema = subschema; }

   private:
    const Subschema *m_subschema;
};

/**
 * @brief  Represents a 'dependencies' constraint.
 *
 * A dependency constraint ensures that a given property is valid only if the
 * properties that it depends on are present.
 */
class DependenciesConstraint : public BasicConstraint<DependenciesConstraint> {
   public:
    DependenciesConstraint()
        : m_propertyDependencies(std::less<String>(), m_allocator), m_schemaDependencies(std::less<String>(), m_allocator) {}

    DependenciesConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn),
          m_propertyDependencies(std::less<String>(), m_allocator),
          m_schemaDependencies(std::less<String>(), m_allocator) {}

    template <typename StringType>
    DependenciesConstraint &addPropertyDependency(const StringType &propertyName, const StringType &dependencyName) {
        const String key(propertyName.c_str(), m_allocator);
        auto itr = m_propertyDependencies.find(key);
        if (itr == m_propertyDependencies.end()) {
            itr =
                m_propertyDependencies.insert(PropertyDependencies::value_type(key, PropertySet(std::less<String>(), m_allocator)))
                    .first;
        }

        itr->second.insert(String(dependencyName.c_str(), m_allocator));

        return *this;
    }

    template <typename StringType, typename ContainerType>
    DependenciesConstraint &addPropertyDependencies(const StringType &propertyName, const ContainerType &dependencyNames) {
        const String key(propertyName.c_str(), m_allocator);
        auto itr = m_propertyDependencies.find(key);
        if (itr == m_propertyDependencies.end()) {
            itr =
                m_propertyDependencies.insert(PropertyDependencies::value_type(key, PropertySet(std::less<String>(), m_allocator)))
                    .first;
        }

        typedef typename ContainerType::value_type ValueType;
        for (const ValueType &dependencyName : dependencyNames) {
            itr->second.insert(String(dependencyName.c_str(), m_allocator));
        }

        return *this;
    }

    template <typename StringType>
    DependenciesConstraint &addSchemaDependency(const StringType &propertyName, const Subschema *schemaDependency) {
        if (m_schemaDependencies.insert(SchemaDependencies::value_type(String(propertyName.c_str(), m_allocator), schemaDependency))
                .second) {
            return *this;
        }

        throwRuntimeError(
            "Dependencies constraint already contains a dependent "
            "schema for the property '" +
            propertyName + "'");
    }

    template <typename FunctorType>
    void applyToPropertyDependencies(const FunctorType &fn) const {
        for (const PropertyDependencies::value_type &v : m_propertyDependencies) {
            if (!fn(v.first, v.second)) {
                return;
            }
        }
    }

    template <typename FunctorType>
    void applyToSchemaDependencies(const FunctorType &fn) const {
        for (const SchemaDependencies::value_type &v : m_schemaDependencies) {
            if (!fn(v.first, v.second)) {
                return;
            }
        }
    }

   private:
    typedef std::set<String, std::less<String>, internal::CustomAllocator<String>> PropertySet;

    typedef std::map<String, PropertySet, std::less<String>, internal::CustomAllocator<std::pair<const String, PropertySet>>>
        PropertyDependencies;

    typedef std::map<String, const Subschema *, std::less<String>,
                     internal::CustomAllocator<std::pair<const String, const Subschema *>>>
        SchemaDependencies;

    /// Mapping from property names to their property-based dependencies
    PropertyDependencies m_propertyDependencies;

    /// Mapping from property names to their schema-based dependencies
    SchemaDependencies m_schemaDependencies;
};

/**
 * @brief  Represents an 'enum' constraint
 *
 * An enum constraint provides a collection of permissible values for a JSON
 * node. The node will only validate against this constraint if it matches one
 * or more of the values in the collection.
 */
class EnumConstraint : public BasicConstraint<EnumConstraint> {
   public:
    EnumConstraint() : m_enumValues(Allocator::rebind<const EnumValue *>::other(m_allocator)) {}

    EnumConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_enumValues(Allocator::rebind<const EnumValue *>::other(m_allocator)) {}

    EnumConstraint(const EnumConstraint &other)
        : BasicConstraint(other), m_enumValues(Allocator::rebind<const EnumValue *>::other(m_allocator)) {
#if VALIJSON_USE_EXCEPTIONS
        try {
#endif
            // Clone individual enum values
            for (const EnumValue *otherValue : other.m_enumValues) {
                const EnumValue *value = otherValue->clone();
#if VALIJSON_USE_EXCEPTIONS
                try {
#endif
                    m_enumValues.push_back(value);
#if VALIJSON_USE_EXCEPTIONS
                } catch (...) {
                    delete value;
                    value = nullptr;
                    throw;
                }
            }
        } catch (...) {
            // Delete values already added to constraint
            for (const EnumValue *value : m_enumValues) {
                delete value;
            }
            throw;
#endif
        }
    }

    ~EnumConstraint() override {
        for (const EnumValue *value : m_enumValues) {
            delete value;
        }
    }

    void addValue(const adapters::Adapter &value) {
        // TODO: Freeze value using custom alloc/free functions
        m_enumValues.push_back(value.freeze());
    }

    void addValue(const adapters::FrozenValue &value) {
        // TODO: Clone using custom alloc/free functions
        m_enumValues.push_back(value.clone());
    }

    template <typename FunctorType>
    void applyToValues(const FunctorType &fn) const {
        for (const EnumValue *value : m_enumValues) {
            if (!fn(*value)) {
                return;
            }
        }
    }

   private:
    typedef adapters::FrozenValue EnumValue;

    typedef std::vector<const EnumValue *, internal::CustomAllocator<const EnumValue *>> EnumValues;

    EnumValues m_enumValues;
};

/**
 * @brief  Represents non-singular 'items' and 'additionalItems' constraints
 *
 * Unlike the SingularItemsConstraint class, this class represents an 'items'
 * constraint that specifies an array of sub-schemas, which should be used to
 * validate each item in an array, in sequence. It also represents an optional
 * 'additionalItems' sub-schema that should be used when an array contains
 * more values than there are sub-schemas in the 'items' constraint.
 *
 * The prefix 'Linear' comes from the fact that this class contains a list of
 * sub-schemas that corresponding array items must be validated against, and
 * this validation is performed linearly (i.e. in sequence).
 */
class LinearItemsConstraint : public BasicConstraint<LinearItemsConstraint> {
   public:
    LinearItemsConstraint()
        : m_itemSubschemas(Allocator::rebind<const Subschema *>::other(m_allocator)), m_additionalItemsSubschema(nullptr) {}

    LinearItemsConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn),
          m_itemSubschemas(Allocator::rebind<const Subschema *>::other(m_allocator)),
          m_additionalItemsSubschema(nullptr) {}

    void addItemSubschema(const Subschema *subschema) { m_itemSubschemas.push_back(subschema); }

    template <typename FunctorType>
    void applyToItemSubschemas(const FunctorType &fn) const {
        unsigned int index = 0;
        for (const Subschema *subschema : m_itemSubschemas) {
            if (!fn(index, subschema)) {
                return;
            }

            index++;
        }
    }

    const Subschema *getAdditionalItemsSubschema() const { return m_additionalItemsSubschema; }

    size_t getItemSubschemaCount() const { return m_itemSubschemas.size(); }

    void setAdditionalItemsSubschema(const Subschema *subschema) { m_additionalItemsSubschema = subschema; }

   private:
    typedef std::vector<const Subschema *, internal::CustomAllocator<const Subschema *>> Subschemas;

    Subschemas m_itemSubschemas;

    const Subschema *m_additionalItemsSubschema;
};

/**
 * @brief   Represents 'maximum' and 'exclusiveMaximum' constraints
 */
class MaximumConstraint : public BasicConstraint<MaximumConstraint> {
   public:
    MaximumConstraint() : m_maximum(std::numeric_limits<double>::infinity()), m_exclusiveMaximum(false) {}

    MaximumConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_maximum(std::numeric_limits<double>::infinity()), m_exclusiveMaximum(false) {}

    bool getExclusiveMaximum() const { return m_exclusiveMaximum; }

    void setExclusiveMaximum(bool newExclusiveMaximum) { m_exclusiveMaximum = newExclusiveMaximum; }

    double getMaximum() const { return m_maximum; }

    void setMaximum(double newMaximum) { m_maximum = newMaximum; }

   private:
    double m_maximum;
    bool m_exclusiveMaximum;
};

/**
 * @brief   Represents a 'maxItems' constraint
 */
class MaxItemsConstraint : public BasicConstraint<MaxItemsConstraint> {
   public:
    MaxItemsConstraint() : m_maxItems(std::numeric_limits<uint64_t>::max()) {}

    MaxItemsConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_maxItems(std::numeric_limits<uint64_t>::max()) {}

    uint64_t getMaxItems() const { return m_maxItems; }

    void setMaxItems(uint64_t newMaxItems) { m_maxItems = newMaxItems; }

   private:
    uint64_t m_maxItems;
};

/**
 * @brief   Represents a 'maxLength' constraint
 */
class MaxLengthConstraint : public BasicConstraint<MaxLengthConstraint> {
   public:
    MaxLengthConstraint() : m_maxLength(std::numeric_limits<uint64_t>::max()) {}

    MaxLengthConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_maxLength(std::numeric_limits<uint64_t>::max()) {}

    uint64_t getMaxLength() const { return m_maxLength; }

    void setMaxLength(uint64_t newMaxLength) { m_maxLength = newMaxLength; }

   private:
    uint64_t m_maxLength;
};

/**
 * @brief   Represents a 'maxProperties' constraint
 */
class MaxPropertiesConstraint : public BasicConstraint<MaxPropertiesConstraint> {
   public:
    MaxPropertiesConstraint() : m_maxProperties(std::numeric_limits<uint64_t>::max()) {}

    MaxPropertiesConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_maxProperties(std::numeric_limits<uint64_t>::max()) {}

    uint64_t getMaxProperties() const { return m_maxProperties; }

    void setMaxProperties(uint64_t newMaxProperties) { m_maxProperties = newMaxProperties; }

   private:
    uint64_t m_maxProperties;
};

/**
 * @brief   Represents 'minimum' and 'exclusiveMinimum' constraints
 */
class MinimumConstraint : public BasicConstraint<MinimumConstraint> {
   public:
    MinimumConstraint() : m_minimum(-std::numeric_limits<double>::infinity()), m_exclusiveMinimum(false) {}

    MinimumConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_minimum(-std::numeric_limits<double>::infinity()), m_exclusiveMinimum(false) {}

    bool getExclusiveMinimum() const { return m_exclusiveMinimum; }

    void setExclusiveMinimum(bool newExclusiveMinimum) { m_exclusiveMinimum = newExclusiveMinimum; }

    double getMinimum() const { return m_minimum; }

    void setMinimum(double newMinimum) { m_minimum = newMinimum; }

   private:
    double m_minimum;
    bool m_exclusiveMinimum;
};

/**
 * @brief   Represents a 'minItems' constraint
 */
class MinItemsConstraint : public BasicConstraint<MinItemsConstraint> {
   public:
    MinItemsConstraint() : m_minItems(0) {}

    MinItemsConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_minItems(0) {}

    uint64_t getMinItems() const { return m_minItems; }

    void setMinItems(uint64_t newMinItems) { m_minItems = newMinItems; }

   private:
    uint64_t m_minItems;
};

/**
 * @brief   Represents a 'minLength' constraint
 */
class MinLengthConstraint : public BasicConstraint<MinLengthConstraint> {
   public:
    MinLengthConstraint() : m_minLength(0) {}

    MinLengthConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_minLength(0) {}

    int64_t getMinLength() const { return m_minLength; }

    void setMinLength(uint64_t newMinLength) { m_minLength = newMinLength; }

   private:
    uint64_t m_minLength;
};

/**
 * @brief   Represents a 'minProperties' constraint
 */
class MinPropertiesConstraint : public BasicConstraint<MinPropertiesConstraint> {
   public:
    MinPropertiesConstraint() : m_minProperties(0) {}

    MinPropertiesConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_minProperties(0) {}

    uint64_t getMinProperties() const { return m_minProperties; }

    void setMinProperties(uint64_t newMinProperties) { m_minProperties = newMinProperties; }

   private:
    uint64_t m_minProperties;
};

/**
 * @brief  Represents either 'multipleOf' or 'divisibleBy' constraints where
 *         the divisor is a floating point number
 */
class MultipleOfDoubleConstraint : public BasicConstraint<MultipleOfDoubleConstraint> {
   public:
    MultipleOfDoubleConstraint() : m_value(1.) {}

    MultipleOfDoubleConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_value(1.) {}

    double getDivisor() const { return m_value; }

    void setDivisor(double newValue) { m_value = newValue; }

   private:
    double m_value;
};

/**
 * @brief  Represents either 'multipleOf' or 'divisibleBy' constraints where
 *         the divisor is of integer type
 */
class MultipleOfIntConstraint : public BasicConstraint<MultipleOfIntConstraint> {
   public:
    MultipleOfIntConstraint() : m_value(1) {}

    MultipleOfIntConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_value(1) {}

    int64_t getDivisor() const { return m_value; }

    void setDivisor(int64_t newValue) { m_value = newValue; }

   private:
    int64_t m_value;
};

/**
 * @brief   Represents a 'not' constraint
 */
class NotConstraint : public BasicConstraint<NotConstraint> {
   public:
    NotConstraint() : m_subschema(nullptr) {}

    NotConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_subschema(nullptr) {}

    const Subschema *getSubschema() const { return m_subschema; }

    void setSubschema(const Subschema *subschema) { m_subschema = subschema; }

   private:
    const Subschema *m_subschema;
};

/**
 * @brief   Represents a 'oneOf' constraint.
 */
class OneOfConstraint : public BasicConstraint<OneOfConstraint> {
   public:
    OneOfConstraint() : m_subschemas(Allocator::rebind<const Subschema *>::other(m_allocator)) {}

    OneOfConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_subschemas(Allocator::rebind<const Subschema *>::other(m_allocator)) {}

    void addSubschema(const Subschema *subschema) { m_subschemas.push_back(subschema); }

    template <typename FunctorType>
    void applyToSubschemas(const FunctorType &fn) const {
        unsigned int index = 0;
        for (const Subschema *subschema : m_subschemas) {
            if (!fn(index, subschema)) {
                return;
            }

            index++;
        }
    }

   private:
    typedef std::vector<const Subschema *, internal::CustomAllocator<const Subschema *>> Subschemas;

    /// Collection of sub-schemas, exactly one of which must be satisfied
    Subschemas m_subschemas;
};

/**
 * @brief   Represents a 'pattern' constraint
 */
class PatternConstraint : public BasicConstraint<PatternConstraint> {
   public:
    PatternConstraint() : m_pattern(Allocator::rebind<char>::other(m_allocator)) {}

    PatternConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_pattern(Allocator::rebind<char>::other(m_allocator)) {}

    template <typename AllocatorType>
    bool getPattern(std::basic_string<char, std::char_traits<char>, AllocatorType> &result) const {
        result.assign(m_pattern.c_str());
        return true;
    }

    template <typename AllocatorType>
    std::basic_string<char, std::char_traits<char>, AllocatorType> getPattern(const AllocatorType &alloc = AllocatorType()) const {
        return std::basic_string<char, std::char_traits<char>, AllocatorType>(m_pattern.c_str(), alloc);
    }

    template <typename AllocatorType>
    void setPattern(const std::basic_string<char, std::char_traits<char>, AllocatorType> &pattern) {
        m_pattern.assign(pattern.c_str());
    }

   private:
    String m_pattern;
};

class PolyConstraint : public Constraint {
   public:
    bool accept(ConstraintVisitor &visitor) const override { return visitor.visit(*static_cast<const PolyConstraint *>(this)); }

    Constraint *clone(CustomAlloc allocFn, CustomFree freeFn) const override {
        void *ptr = allocFn(sizeOf());
        if (!ptr) {
            throwRuntimeError("Failed to allocate memory for cloned constraint");
        }

#if VALIJSON_USE_EXCEPTIONS
        try {
#endif
            return cloneInto(ptr);
#if VALIJSON_USE_EXCEPTIONS
        } catch (...) {
            freeFn(ptr);
            throw;
        }
#else
        // pretend to use freeFn to avoid warning in GCC 8.3
        (void)freeFn;
#endif
    }

    virtual bool validate(const adapters::Adapter &target, const std::vector<std::string> &context,
                          valijson::ValidationResults *results) const = 0;

   private:
    virtual Constraint *cloneInto(void *) const = 0;

    virtual size_t sizeOf() const = 0;
};

/**
 * @brief   Represents a combination of 'properties', 'patternProperties' and
 *          'additionalProperties' constraints
 */
class PropertiesConstraint : public BasicConstraint<PropertiesConstraint> {
   public:
    PropertiesConstraint()
        : m_properties(std::less<String>(), m_allocator),
          m_patternProperties(std::less<String>(), m_allocator),
          m_additionalProperties(nullptr) {}

    PropertiesConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn),
          m_properties(std::less<String>(), m_allocator),
          m_patternProperties(std::less<String>(), m_allocator),
          m_additionalProperties(nullptr) {}

    bool addPatternPropertySubschema(const char *patternProperty, const Subschema *subschema) {
        return m_patternProperties.insert(PropertySchemaMap::value_type(String(patternProperty, m_allocator), subschema)).second;
    }

    template <typename AllocatorType>
    bool addPatternPropertySubschema(const std::basic_string<char, std::char_traits<char>, AllocatorType> &patternProperty,
                                     const Subschema *subschema) {
        return addPatternPropertySubschema(patternProperty.c_str(), subschema);
    }

    bool addPropertySubschema(const char *propertyName, const Subschema *subschema) {
        return m_properties.insert(PropertySchemaMap::value_type(String(propertyName, m_allocator), subschema)).second;
    }

    template <typename AllocatorType>
    bool addPropertySubschema(const std::basic_string<char, std::char_traits<char>, AllocatorType> &propertyName,
                              const Subschema *subschema) {
        return addPropertySubschema(propertyName.c_str(), subschema);
    }

    template <typename FunctorType>
    void applyToPatternProperties(const FunctorType &fn) const {
        typedef typename PropertySchemaMap::value_type ValueType;
        for (const ValueType &value : m_patternProperties) {
            if (!fn(value.first, value.second)) {
                return;
            }
        }
    }

    template <typename FunctorType>
    void applyToProperties(const FunctorType &fn) const {
        typedef typename PropertySchemaMap::value_type ValueType;
        for (const ValueType &value : m_properties) {
            if (!fn(value.first, value.second)) {
                return;
            }
        }
    }

    const Subschema *getAdditionalPropertiesSubschema() const { return m_additionalProperties; }

    void setAdditionalPropertiesSubschema(const Subschema *subschema) { m_additionalProperties = subschema; }

   private:
    typedef std::map<String, const Subschema *, std::less<String>,
                     internal::CustomAllocator<std::pair<const String, const Subschema *>>>
        PropertySchemaMap;

    PropertySchemaMap m_properties;
    PropertySchemaMap m_patternProperties;

    const Subschema *m_additionalProperties;
};

class PropertyNamesConstraint : public BasicConstraint<PropertyNamesConstraint> {
   public:
    PropertyNamesConstraint() : m_subschema(nullptr) {}

    PropertyNamesConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_subschema(nullptr) {}

    const Subschema *getSubschema() const { return m_subschema; }

    void setSubschema(const Subschema *subschema) { m_subschema = subschema; }

   private:
    const Subschema *m_subschema;
};

/**
 * @brief   Represents a 'required' constraint
 */
class RequiredConstraint : public BasicConstraint<RequiredConstraint> {
   public:
    RequiredConstraint() : m_requiredProperties(std::less<String>(), m_allocator) {}

    RequiredConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn), m_requiredProperties(std::less<String>(), m_allocator) {}

    bool addRequiredProperty(const char *propertyName) {
        return m_requiredProperties.insert(String(propertyName, Allocator::rebind<char>::other(m_allocator))).second;
    }

    template <typename AllocatorType>
    bool addRequiredProperty(const std::basic_string<char, std::char_traits<char>, AllocatorType> &propertyName) {
        return addRequiredProperty(propertyName.c_str());
    }

    template <typename FunctorType>
    void applyToRequiredProperties(const FunctorType &fn) const {
        for (const String &propertyName : m_requiredProperties) {
            if (!fn(propertyName)) {
                return;
            }
        }
    }

   private:
    typedef std::set<String, std::less<String>, internal::CustomAllocator<String>> RequiredProperties;

    RequiredProperties m_requiredProperties;
};

/**
 * @brief  Represents an 'items' constraint that specifies one sub-schema
 *
 * A value is considered valid against this constraint if it is an array, and
 * each item in the array validates against the sub-schema specified by this
 * constraint.
 *
 * The prefix 'Singular' comes from the fact that array items must validate
 * against exactly one sub-schema.
 */
class SingularItemsConstraint : public BasicConstraint<SingularItemsConstraint> {
   public:
    SingularItemsConstraint() : m_itemsSubschema(nullptr) {}

    SingularItemsConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn), m_itemsSubschema(nullptr) {}

    const Subschema *getItemsSubschema() const { return m_itemsSubschema; }

    void setItemsSubschema(const Subschema *subschema) { m_itemsSubschema = subschema; }

   private:
    const Subschema *m_itemsSubschema;
};

/**
 * @brief   Represents a 'type' constraint.
 */
class TypeConstraint : public BasicConstraint<TypeConstraint> {
   public:
    enum JsonType { kAny, kArray, kBoolean, kInteger, kNull, kNumber, kObject, kString };

    TypeConstraint()
        : m_namedTypes(std::less<JsonType>(), m_allocator),
          m_schemaTypes(Allocator::rebind<const Subschema *>::other(m_allocator)) {}

    TypeConstraint(CustomAlloc allocFn, CustomFree freeFn)
        : BasicConstraint(allocFn, freeFn),
          m_namedTypes(std::less<JsonType>(), m_allocator),
          m_schemaTypes(Allocator::rebind<const Subschema *>::other(m_allocator)) {}

    void addNamedType(JsonType type) { m_namedTypes.insert(type); }

    void addSchemaType(const Subschema *subschema) { m_schemaTypes.push_back(subschema); }

    template <typename FunctorType>
    void applyToNamedTypes(const FunctorType &fn) const {
        for (const JsonType namedType : m_namedTypes) {
            if (!fn(namedType)) {
                return;
            }
        }
    }

    template <typename FunctorType>
    void applyToSchemaTypes(const FunctorType &fn) const {
        unsigned int index = 0;
        for (const Subschema *subschema : m_schemaTypes) {
            if (!fn(index, subschema)) {
                return;
            }

            index++;
        }
    }

    template <typename AllocatorType>
    static JsonType jsonTypeFromString(const std::basic_string<char, std::char_traits<char>, AllocatorType> &typeName) {
        if (typeName.compare("any") == 0) {
            return kAny;
        } else if (typeName.compare("array") == 0) {
            return kArray;
        } else if (typeName.compare("boolean") == 0) {
            return kBoolean;
        } else if (typeName.compare("integer") == 0) {
            return kInteger;
        } else if (typeName.compare("null") == 0) {
            return kNull;
        } else if (typeName.compare("number") == 0) {
            return kNumber;
        } else if (typeName.compare("object") == 0) {
            return kObject;
        } else if (typeName.compare("string") == 0) {
            return kString;
        }

        throwRuntimeError("Unrecognised JSON type name '" + std::string(typeName.c_str()) + "'");
        abort();
    }

   private:
    typedef std::set<JsonType, std::less<JsonType>, internal::CustomAllocator<JsonType>> NamedTypes;

    typedef std::vector<const Subschema *, Allocator::rebind<const Subschema *>::other> SchemaTypes;

    /// Set of named JSON types that serve as valid types
    NamedTypes m_namedTypes;

    /// Set of sub-schemas that serve as valid types
    SchemaTypes m_schemaTypes;
};

/**
 * @brief   Represents a 'uniqueItems' constraint
 */
class UniqueItemsConstraint : public BasicConstraint<UniqueItemsConstraint> {
   public:
    UniqueItemsConstraint() = default;

    UniqueItemsConstraint(CustomAlloc allocFn, CustomFree freeFn) : BasicConstraint(allocFn, freeFn) {}
};

}  // namespace constraints
}  // namespace valijson