// © 2017 and later: Unicode, Inc. and others.

// License & terms of use: http://www.unicode.org/copyright.html

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

#ifndef __NUMBER_MODIFIERS_H__

#define __NUMBER_MODIFIERS_H__

#include <algorithm>

#include <cstdint>

#include "unicode/uniset.h"

#include "unicode/simpleformatter.h"

#include "standardplural.h"

#include "formatted_string_builder.h"

#include "number_types.h"

U_NAMESPACE_BEGIN namespace number {

namespace impl {

/**

 * The canonical implementation of {@link Modifier}, containing a prefix and suffix string.

 * TODO: This is not currently being used by real code and could be removed.

 */

class U_I18N_API ConstantAffixModifier : public Modifier, public UObject {

  public:

    ConstantAffixModifier(const UnicodeString &prefix, const UnicodeString &suffix, Field field,

                          bool strong)

            : fPrefix(prefix), fSuffix(suffix), fField(field), fStrong(strong) {}

    int32_t apply(FormattedStringBuilder &output, int32_t leftIndex, int32_t rightIndex,

                  UErrorCode &status) const U_OVERRIDE;

    int32_t getPrefixLength() const U_OVERRIDE;

    int32_t getCodePointCount() const U_OVERRIDE;

    bool isStrong() const U_OVERRIDE;

    bool containsField(Field field) const U_OVERRIDE;

    void getParameters(Parameters& output) const U_OVERRIDE;

    bool semanticallyEquivalent(const Modifier& other) const U_OVERRIDE;

  private:

    UnicodeString fPrefix;

    UnicodeString fSuffix;

    Field fField;

    bool fStrong;

};

/**

 * The second primary implementation of {@link Modifier}, this one consuming a {@link SimpleFormatter}

 * pattern.

 */

class U_I18N_API SimpleModifier : public Modifier, public UMemory {

  public:

    SimpleModifier(const SimpleFormatter &simpleFormatter, Field field, bool strong);

    SimpleModifier(const SimpleFormatter &simpleFormatter, Field field, bool strong,

                   const Modifier::Parameters parameters);

    // Default constructor for LongNameHandler.h

    SimpleModifier();

    int32_t apply(FormattedStringBuilder &output, int32_t leftIndex, int32_t rightIndex,

                  UErrorCode &status) const U_OVERRIDE;

    int32_t getPrefixLength() const U_OVERRIDE;

    int32_t getCodePointCount() const U_OVERRIDE;

    bool isStrong() const U_OVERRIDE;

    bool containsField(Field field) const U_OVERRIDE;

    void getParameters(Parameters& output) const U_OVERRIDE;

    bool semanticallyEquivalent(const Modifier& other) const U_OVERRIDE;

    /**

     * TODO: This belongs in SimpleFormatterImpl. The only reason I haven't moved it there yet is because

     * FormattedStringBuilder is an internal class and SimpleFormatterImpl feels like it should not depend on it.

     *

     * <p>

     * Formats a value that is already stored inside the StringBuilder <code>result</code> between the indices

     * <code>startIndex</code> and <code>endIndex</code> by inserting characters before the start index and after the

     * end index.

     *

     * <p>

     * This is well-defined only for patterns with exactly one argument.

     *

     * @param result

     *            The StringBuilder containing the value argument.

     * @param startIndex

     *            The left index of the value within the string builder.

     * @param endIndex

     *            The right index of the value within the string builder.

     * @return The number of characters (UTF-16 code points) that were added to the StringBuilder.

     */

    int32_t

    formatAsPrefixSuffix(FormattedStringBuilder& result, int32_t startIndex, int32_t endIndex,

                         UErrorCode& status) const;

    /**

     * TODO: Like above, this belongs with the rest of the SimpleFormatterImpl code.

     * I put it here so that the SimpleFormatter uses in FormattedStringBuilder are near each other.

     *

     * <p>

     * Applies the compiled two-argument pattern to the FormattedStringBuilder.

     *

     * <p>

     * This method is optimized for the case where the prefix and suffix are often empty, such as

     * in the range pattern like "{0}-{1}".

     */

    static int32_t

    formatTwoArgPattern(const SimpleFormatter& compiled, FormattedStringBuilder& result,

                        int32_t index, int32_t* outPrefixLength, int32_t* outSuffixLength,

                        Field field, UErrorCode& status);

  private:

    UnicodeString fCompiledPattern;

    Field fField;

    bool fStrong = false;

    int32_t fPrefixLength = 0;

    int32_t fSuffixOffset = -1;

    int32_t fSuffixLength = 0;

    Modifier::Parameters fParameters;

};

/**

 * An implementation of {@link Modifier} that allows for multiple types of fields in the same modifier. Constructed

 * based on the contents of two {@link FormattedStringBuilder} instances (one for the prefix, one for the suffix).

 */

class U_I18N_API ConstantMultiFieldModifier : public Modifier, public UMemory {

  public:

    ConstantMultiFieldModifier(

            const FormattedStringBuilder &prefix,

            const FormattedStringBuilder &suffix,

            bool overwrite,

            bool strong,

            const Modifier::Parameters parameters)

      : fPrefix(prefix),

        fSuffix(suffix),

        fOverwrite(overwrite),

        fStrong(strong),

        fParameters(parameters) {}

    ConstantMultiFieldModifier(

            const FormattedStringBuilder &prefix,

            const FormattedStringBuilder &suffix,

            bool overwrite,

            bool strong)

      : fPrefix(prefix),

        fSuffix(suffix),

        fOverwrite(overwrite),

        fStrong(strong) {}

    int32_t apply(FormattedStringBuilder &output, int32_t leftIndex, int32_t rightIndex,

                  UErrorCode &status) const U_OVERRIDE;

    int32_t getPrefixLength() const U_OVERRIDE;

    int32_t getCodePointCount() const U_OVERRIDE;

    bool isStrong() const U_OVERRIDE;

    bool containsField(Field field) const U_OVERRIDE;

    void getParameters(Parameters& output) const U_OVERRIDE;

    bool semanticallyEquivalent(const Modifier& other) const U_OVERRIDE;

  protected:

    // NOTE: In Java, these are stored as array pointers. In C++, the FormattedStringBuilder is stored by

    // value and is treated internally as immutable.

    FormattedStringBuilder fPrefix;

    FormattedStringBuilder fSuffix;

    bool fOverwrite;

    bool fStrong;

    Modifier::Parameters fParameters;

};

/** Identical to {@link ConstantMultiFieldModifier}, but supports currency spacing. */

class U_I18N_API CurrencySpacingEnabledModifier : public ConstantMultiFieldModifier {

  public:

    /** Safe code path */

    CurrencySpacingEnabledModifier(

            const FormattedStringBuilder &prefix,

            const FormattedStringBuilder &suffix,

            bool overwrite,

            bool strong,

            const DecimalFormatSymbols &symbols,

            UErrorCode &status);

    int32_t apply(FormattedStringBuilder &output, int32_t leftIndex, int32_t rightIndex,

                  UErrorCode &status) const U_OVERRIDE;

    /** Unsafe code path */

    static int32_t

    applyCurrencySpacing(FormattedStringBuilder &output, int32_t prefixStart, int32_t prefixLen,

                         int32_t suffixStart, int32_t suffixLen, const DecimalFormatSymbols &symbols,

                         UErrorCode &status);

  private:

    UnicodeSet fAfterPrefixUnicodeSet;

    UnicodeString fAfterPrefixInsert;

    UnicodeSet fBeforeSuffixUnicodeSet;

    UnicodeString fBeforeSuffixInsert;

    enum EAffix {

        PREFIX, SUFFIX

    };

    enum EPosition {

        IN_CURRENCY, IN_NUMBER

    };

    /** Unsafe code path */

    static int32_t applyCurrencySpacingAffix(FormattedStringBuilder &output, int32_t index, EAffix affix,

                                             const DecimalFormatSymbols &symbols, UErrorCode &status);

    static UnicodeSet

    getUnicodeSet(const DecimalFormatSymbols &symbols, EPosition position, EAffix affix,

                  UErrorCode &status);

    static UnicodeString

    getInsertString(const DecimalFormatSymbols &symbols, EAffix affix, UErrorCode &status);

};

/** A Modifier that does not do anything. */

class U_I18N_API EmptyModifier : public Modifier, public UMemory {

  public:

    explicit EmptyModifier(bool isStrong) : fStrong(isStrong) {}

    int32_t apply(FormattedStringBuilder &output, int32_t leftIndex, int32_t rightIndex,

                  UErrorCode &status) const U_OVERRIDE {

        (void)output;

        (void)leftIndex;

        (void)rightIndex;

        (void)status;

        return 0;

    }

    int32_t getPrefixLength() const U_OVERRIDE {

        return 0;

    }

    int32_t getCodePointCount() const U_OVERRIDE {

        return 0;

    }

    bool isStrong() const U_OVERRIDE {

        return fStrong;

    }

    bool containsField(Field field) const U_OVERRIDE {

        (void)field;

        return false;

    }

    void getParameters(Parameters& output) const U_OVERRIDE {

        output.obj = nullptr;

    }

    bool semanticallyEquivalent(const Modifier& other) const U_OVERRIDE {

        return other.getCodePointCount() == 0;

    }

  private:

    bool fStrong;

};

/**

 * This implementation of ModifierStore adopts Modifier pointers.

 */

class U_I18N_API AdoptingModifierStore : public ModifierStore, public UMemory {

  public:

    virtual ~AdoptingModifierStore();

    static constexpr StandardPlural::Form DEFAULT_STANDARD_PLURAL = StandardPlural::OTHER;

    AdoptingModifierStore() = default;

    // No copying!

    AdoptingModifierStore(const AdoptingModifierStore &other) = delete;

    /**

     * Sets the Modifier with the specified signum and plural form.

     */

    void adoptModifier(Signum signum, StandardPlural::Form plural, const Modifier *mod) {

        U_ASSERT(mods[getModIndex(signum, plural)] == nullptr);

        mods[getModIndex(signum, plural)] = mod;

    }

    /**

     * Sets the Modifier with the specified signum.

     * The modifier will apply to all plural forms.

     */

    void adoptModifierWithoutPlural(Signum signum, const Modifier *mod) {

        U_ASSERT(mods[getModIndex(signum, DEFAULT_STANDARD_PLURAL)] == nullptr);

        mods[getModIndex(signum, DEFAULT_STANDARD_PLURAL)] = mod;

    }

    /** Returns a reference to the modifier; no ownership change. */

    const Modifier *getModifier(Signum signum, StandardPlural::Form plural) const U_OVERRIDE {

        const Modifier* modifier = mods[getModIndex(signum, plural)];

        if (modifier == nullptr && plural != DEFAULT_STANDARD_PLURAL) {

            modifier = mods[getModIndex(signum, DEFAULT_STANDARD_PLURAL)];

        }

        return modifier;

    }

    /** Returns a reference to the modifier; no ownership change. */

    const Modifier *getModifierWithoutPlural(Signum signum) const {

        return mods[getModIndex(signum, DEFAULT_STANDARD_PLURAL)];

    }

  private:

    // NOTE: mods is zero-initialized (to nullptr)

    const Modifier *mods[4 * StandardPlural::COUNT] = {};

    inline static int32_t getModIndex(Signum signum, StandardPlural::Form plural) {

        U_ASSERT(signum >= 0 && signum < SIGNUM_COUNT);

        U_ASSERT(plural >= 0 && plural < StandardPlural::COUNT);

        return static_cast<int32_t>(plural) * SIGNUM_COUNT + signum;

    }

};

} // namespace impl

} // namespace number

U_NAMESPACE_END

#endif //__NUMBER_MODIFIERS_H__

#endif /* #if !UCONFIG_NO_FORMATTING */