// © 2020 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 __UNITS_DATA_H__

#define __UNITS_DATA_H__

#include <limits>

#include "charstr.h"

#include "cmemory.h"

#include "fixedstring.h"

#include "unicode/stringpiece.h"

#include "unicode/uobject.h"

U_NAMESPACE_BEGIN

namespace units {

/**

 * Encapsulates "convertUnits" information from units resources, specifying how

 * to convert from one unit to another.

 *

 * Information in this class is still in the form of strings: symbolic constants

 * need to be interpreted. Rationale: symbols can cancel out for higher

 * precision conversion - going from feet to inches should cancel out the

 * `ft_to_m` constant.

 */

class ConversionRateInfo : public UMemory {

  public:

    ConversionRateInfo() {}

    ConversionRateInfo(StringPiece sourceUnit, StringPiece baseUnit, StringPiece factor,

                       StringPiece offset, UErrorCode &status)

        : sourceUnit(sourceUnit), baseUnit(baseUnit), factor(factor), offset(offset),

          specialMappingName(), systems() {

        if (this->sourceUnit.isEmpty() != sourceUnit.empty() ||

            this->baseUnit.isEmpty() != baseUnit.empty() ||

            this->factor.isEmpty() != factor.empty() ||

            this->offset.isEmpty() != offset.empty()) {

            status = U_MEMORY_ALLOCATION_ERROR;

        }

    }

    FixedString sourceUnit;

    FixedString baseUnit;

    FixedString factor;

    FixedString offset;

    FixedString specialMappingName; // the name of a special mapping used instead of factor + optional offset.

    FixedString systems;

};

/**

 * Returns ConversionRateInfo for all supported conversions.

 *

 * @param result Receives the set of conversion rates.

 * @param status Receives status.

 */

void U_I18N_API getAllConversionRates(MaybeStackVector<ConversionRateInfo> &result, UErrorCode &status);

/**

 * Contains all the supported conversion rates.

 */

class ConversionRates {

  public:

    /**

     * Constructor

     *

     * @param status Receives status.

     */

    ConversionRates(UErrorCode &status) { getAllConversionRates(conversionInfo_, status); }

    /**

     * Returns a pointer to the conversion rate info that match the `source`.

     *

     * @param source Contains the source.

     * @param status Receives status.

     */

    const ConversionRateInfo *extractConversionInfo(StringPiece source, UErrorCode &status) const;

  private:

    MaybeStackVector<ConversionRateInfo> conversionInfo_;

};

// Encapsulates unitPreferenceData information from units resources, specifying

// a sequence of output unit preferences.

struct UnitPreference : public UMemory {

    // Set geq to 1.0 by default

    UnitPreference() : geq(1.0) {}

    FixedString unit;

    double geq;

    UnicodeString skeleton;

    UnitPreference(const UnitPreference &other) {

        this->unit = other.unit;

        this->geq = other.geq;

        this->skeleton = other.skeleton;

    }

};

/**

 * Metadata about the preferences in UnitPreferences::unitPrefs_.

 *

 * This class owns all of its data.

 *

 * UnitPreferenceMetadata lives in the anonymous namespace, because it should

 * only be useful to internal code and unit testing code.

 */

class UnitPreferenceMetadata : public UMemory {

  public:

    UnitPreferenceMetadata() {}

    // Constructor, makes copies of the parameters passed to it.

    UnitPreferenceMetadata(StringPiece category, StringPiece usage, StringPiece region,

                           int32_t prefsOffset, int32_t prefsCount, UErrorCode &status);

    // Unit category (e.g. "length", "mass", "electric-capacitance").

    CharString category;

    // Usage (e.g. "road", "vehicle-fuel", "blood-glucose"). Every category

    // should have an entry for "default" usage. TODO(hugovdm): add a test for

    // this.

    CharString usage;

    // Region code (e.g. "US", "CZ", "001"). Every usage should have an entry

    // for the "001" region ("world"). TODO(hugovdm): add a test for this.

    CharString region;

    // Offset into the UnitPreferences::unitPrefs_ list where the relevant

    // preferences are found.

    int32_t prefsOffset;

    // The number of preferences that form this set.

    int32_t prefsCount;

    int32_t compareTo(const UnitPreferenceMetadata &other) const;

    int32_t compareTo(const UnitPreferenceMetadata &other, bool *foundCategory, bool *foundUsage,

                      bool *foundRegion) const;

};

/**

 * Unit Preferences information for various locales and usages.

 */

class U_I18N_API_CLASS UnitPreferences {

  public:

    /**

     * Constructor, loads all the preference data.

     *

     * @param status Receives status.

     */

    U_I18N_API UnitPreferences(UErrorCode& status);

    /**

     * Returns the set of unit preferences in the particular category that best

     * matches the specified usage and region.

     *

     * If region can't be found, falls back to global (001). If usage can't be

     * found, falls back to "default".

     *

     * @param category The category within which to look up usage and region.

     * (TODO(hugovdm): improve docs on how to find the category, once the lookup

     * function is added.)

     * @param usage The usage parameter. (TODO(hugovdm): improve this

     * documentation. Add reference to some list of usages we support.) If the

     * given usage is not found, the method automatically falls back to

     * "default".

     * @param region The region whose preferences are desired. If there are no

     * specific preferences for the requested region, the method automatically

     * falls back to region "001" ("world").

     * @param outPreferences A pointer into an array of preferences: essentially

     * an array slice in combination with preferenceCount.

     * @param preferenceCount The number of unit preferences that belong to the

     * result set.

     * @param status Receives status.

     */

    U_I18N_API MaybeStackVector<UnitPreference> getPreferencesFor(StringPiece category,

                                                                  StringPiece usage,

                                                                  const Locale& locale,

                                                                  UErrorCode& status) const;

  protected:

    // Metadata about the sets of preferences, this is the index for looking up

    // preferences in the unitPrefs_ list.

    MaybeStackVector<UnitPreferenceMetadata> metadata_;

    // All the preferences as a flat list: which usage and region preferences

    // are associated with is stored in `metadata_`.

    MaybeStackVector<UnitPreference> unitPrefs_;

};

} // namespace units

U_NAMESPACE_END

#endif //__UNITS_DATA_H__

#endif /* #if !UCONFIG_NO_FORMATTING */