/**
 * @file lv_bifi.h
 *
 */

#ifndef LV_BIDI_H
#define LV_BIDI_H

#ifdef __cplusplus
extern "C" {
#endif

/*********************
 *      INCLUDES
 *********************/
#include "../lv_conf_internal.h"

#include <stdbool.h>
#include <stdint.h>

/*********************
 *      DEFINES
 *********************/
/* Special non printable  strong characters.
 * They can be inserted to texts to affect the run's direction*/
#define LV_BIDI_LRO  "\xE2\x80\xAD" /*U+202D*/
#define LV_BIDI_RLO  "\xE2\x80\xAE" /*U+202E*/

/**********************
 *      TYPEDEFS
 **********************/
enum
{
    /*The first 4 values are stored in `lv_obj_t` on 2 bits*/
    LV_BIDI_DIR_LTR      = 0x00,
    LV_BIDI_DIR_RTL      = 0x01,
    LV_BIDI_DIR_AUTO     = 0x02,
    LV_BIDI_DIR_INHERIT  = 0x03,

    LV_BIDI_DIR_NEUTRAL  = 0x20,
    LV_BIDI_DIR_WEAK     = 0x21,
};

typedef uint8_t lv_bidi_dir_t;

/**********************
 * GLOBAL PROTOTYPES
 **********************/
#if LV_USE_BIDI

/**
 * Convert a text to get the characters in the correct visual order according to
 * Unicode Bidirectional Algorithm
 * @param str_in the text to process
 * @param str_out store the result here. Has the be `strlen(str_in)` length
 * @param base_dir `LV_BIDI_DIR_LTR` or `LV_BIDI_DIR_RTL`
 */
void lv_bidi_process(const char * str_in, char * str_out, lv_bidi_dir_t base_dir);

/**
 * Auto-detect the direction of a text based on the first strong character
 * @param txt the text to process
 * @return `LV_BIDI_DIR_LTR` or `LV_BIDI_DIR_RTL`
 */
lv_bidi_dir_t lv_bidi_detect_base_dir(const char * txt);

/**
 * Get the direction of a character
 * @param letter an Unicode character
 * @return `LV_BIDI_DIR_RTL/LTR/WEAK/NEUTRAL`
 */
lv_bidi_dir_t lv_bidi_get_letter_dir(uint32_t letter);

/**
 * Tell whether a character is weak or not
 * @param letter an Unicode character
 * @return true/false
 */
bool lv_bidi_letter_is_weak(uint32_t letter);

/**
 * Tell whether a character is RTL or not
 * @param letter an Unicode character
 * @return true/false
 */
bool lv_bidi_letter_is_rtl(uint32_t letter);

/**
 * Tell whether a character is neutral or not
 * @param letter an Unicode character
 * @return true/false
 */
bool lv_bidi_letter_is_neutral(uint32_t letter);

/**
 * Get the logical position of a character in a line
 * @param str_in the input string. Can be only one line.
 * @param bidi_txt internally the text is bidi processed which buffer can be get here.
 * If not required anymore has to freed with `lv_mem_free()`
 * Can be `NULL` is unused
 * @param len length of the line in character count
 * @param base_dir base direction of the text: `LV_BIDI_DIR_LTR` or `LV_BIDI_DIR_RTL`
 * @param vicual_pos the visual character position which logical position should be get
 * @param is_rtl tell the the char at `viasual_pos` is RTL or LTR context
 * @return the logical character position
 */
uint16_t lv_bidi_get_logical_pos(const char * str_in, char **bidi_txt, uint32_t len, lv_bidi_dir_t base_dir, uint32_t visual_pos, bool *is_rtl);

/**
 * Get the visual position of a character in a line
 * @param str_in the input string. Can be only one line.
 * @param bidi_txt internally the text is bidi processed which buffer can be get here.
 * If not required anymore has to freed with `lv_mem_free()`
 * Can be `NULL` is unused
 * @param len length of the line in character count
 * @param base_dir base direction of the text: `LV_BIDI_DIR_LTR` or `LV_BIDI_DIR_RTL`
 * @param logical_pos the logical character position which visual position should be get
 * @param is_rtl tell the the char at `logical_pos` is RTL or LTR context
 * @return the visual character position
 */
uint16_t lv_bidi_get_visual_pos(const char * str_in, char **bidi_txt, uint16_t len, lv_bidi_dir_t base_dir, uint32_t logical_pos, bool *is_rtl);

/**
 * Bidi process a paragraph of text
 * @param str_in the string to process
 * @param str_out store the result here
 * @param len length of teh text
 * @param base_dir base dir of the text
 * @param pos_conv_out an `uint16_t` array to store the related logical position of the character.
 * Can be `NULL` is unused
 * @param pos_conv_len length of `pos_conv_out` in element count
 */
void lv_bidi_process_paragraph(const char * str_in, char * str_out, uint32_t len, lv_bidi_dir_t base_dir, uint16_t *pos_conv_out, uint16_t pos_conv_len);

/**
 * Get the next paragraph from a text
 * @param txt the text to process
 * @return the length of the current paragraph in byte count
 */
uint32_t lv_bidi_get_next_paragraph(const char * txt);

/**********************
 *      MACROS
 **********************/

#endif /*LV_USE_BIDI*/

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif /*LV_BIDI_H*/