#include <voxula/internals/utility/ini.h>
#include <stdlib.h>
#include <string.h>

char * vx_parse_ini_section_name(
    vx_arena_s *arena,
    const char *source,
    uint32_t offset,
    uint32_t *len_name
) {
    ++offset; // Jump over the starting square bracket
    uint32_t start_offset = offset;

    while(source[offset] != 0)
    {
        if(source[offset] == ']')
        {
            ++offset;
        }
        ++offset;
    }
    uint32_t name_word_length = offset - start_offset;
    char *name = malloc(name_word_length + 1);
    memcpy(name, &source[start_offset], name_word_length);
    name[name_word_length] = 0;

    if(len_name)
    {
        *len_name = name_word_length;
    }
    return name;
}

vx_ini_value_s vx_parse_ini_value(vx_ini_s *ini, const char *source, uint32_t offset, uint32_t *out_length)
{
    // For string values
    if(source[offset] == '"')
    {
        vx_ini_value_s value;
        uint32_t start_offset = offset;

        if(source[offset + 1] == '"')
        {
            // If this is an empty string
            if(source[offset + 2] != '"')
            {
                value.type = VX_INI_VALUE_STRING;
                value.specifics.string = vx_arena_alloc(ini->string_arena, 1);
                value.specifics.string[0] = 0;
                return value;
            }
            // If this is a multi-line string
            offset += 3; // Jump over the quotation marks so they can't be picked up as the ending ones.
            uint32_t string_data_start = offset;
            while(source[offset != 0])
            {
                if(source[offset] != '"')
                {
                    ++offset;
                    continue;
                }
                if(source[offset + 1] != '"')
                {
                    ++offset;
                    continue;
                }
                if(source[offset + 2] != '"')
                {
                    ++offset;
                    continue;
                }
                break;
            }
            value.type = VX_INI_VALUE_STRING;
            value.specifics.string = vx_arena_dupe_string_up_to(ini->string_arena, &source[string_data_start], offset - string_data_start);
            return value;
        }
        // A regular, single-line string
        ++offset;
        while(source[offset] != 0)
        {
            if(source[offset] == '\n')
            {
                break;
            }
            if(source[offset] == '"')
            {
                break;
            }
            ++offset;
        }
        value.type = VX_INI_VALUE_STRING;
        value.specifics.string = vx_arena_dupe_string_up_to(ini->string_arena, &source[start_offset], offset - start_offset);
        return value;
    }
    if(vx_is_ascii_digit(source[offset]))
    {
        vx_ini_value_s value;
        uint32_t start_offset = offset;
        while(source[offset] != 0)
        {
            if( ! vx_is_ascii_digit(source[offset]))
            {
                break;
            }
            ++offset;
        }
        // todo(delayed): Add floating-point numbers

        char *integer_string = vx_arena_dupe_string_up_to(ini->string_arena, &source[start_offset], offset - start_offset);

        value.type = VX_INI_VALUE_INTEGER;
        value.specifics.integer = atol(integer_string);
        return value;
    }
    vx_ini_value_s value;
    value.type = VX_INI_VALUE_NULL;
    return value;
}

vx_ini_field_s vx_parse_ini_field(vx_ini_s *ini, const char *source, uint32_t offset, uint32_t *out_length)
{
    uint32_t start_offset = offset;

    // Get the field's name
    while(source[offset] != 0)
    {
        if( ! vx_is_ascii_letter(source[offset])
          && (source[offset] != '_'))
        {
            break;
        }
        ++offset;
    }
    vx_ini_field_s field;
    field.len_name = offset - start_offset;
    field.name = vx_arena_dupe_string_up_to(ini->string_arena, &source[offset], field.len_name);

    uint32_t len_value;
    field.value = vx_parse_ini_value(ini, source, offset, &len_value);
    if(out_length)
    {
        *out_length = (offset - start_offset) + len_value;
    }
    return field;
}

vx_ini_section_s vx_parse_ini_section(vx_ini_s *ini, const char *source, uint32_t offset, uint32_t *out_length)
{
    uint32_t start_offset = offset;
    vx_ini_section_s section;

    section.name = vx_parse_ini_section_name(ini->string_arena, source, offset, &section.len_name);
    offset += section.len_name + 2;
    section.num_fields = 0;
    section.fields_capacity = 32;
    section.fields = malloc(section.fields_capacity * sizeof(vx_ini_field_s));

    while(source[offset] != 0)
    {
        // Skip comments
        if(source[offset] == '#')
        {
            while(source[offset] != 0)
            {
                if(source[offset] == '\n')
                {
                    break;
                }
                ++offset;
            }
            ++offset;
        }
        // Get all the fields of this section
        while(source[offset] != 0)
        {
            if(vx_is_ascii_letter(source[offset]
                || (source[offset] == '_'))
            ) {
                break;
            }
            if(source[offset] == '[')
            {
                break;
            }
        }
        if(source[offset] == '[')
        {
            break;
        }
        uint32_t bytes_to_jump = 0;
        vx_parse_ini_field(ini, source, offset, &bytes_to_jump);
        offset += bytes_to_jump;
    }
    ++offset;
    return section;
}

vx_ini_s vx_parse_ini(const char *source)
{
    uint32_t len_source = strlen(source);

    vx_ini_s ini;
    ini.num_sections = 0;
    ini.sections_capacity = 64;
    ini.sections = malloc(ini.sections_capacity * sizeof(vx_ini_section_s));
    ini.string_arena = vx_new_arena(len_source * 2);

    uint32_t offset = 0;
    while(offset < len_source)
    {
        if(source[offset] == '[')
        {
            uint32_t len_section;
            ini.sections[ini.num_sections] = vx_parse_ini_section(&ini, source, offset, &len_section);
            offset += len_section;
        }
    }
    return ini;
}

void vx_delete_ini(vx_ini_s *ini)
{

}

vx_ini_value_s vx_get_ini(vx_ini_s *ini, const char *field)
{
    uint32_t splitter = 0;
    while(field[splitter] != 0)
    {
        if(field[splitter] == '.')
        {
            break;
        }
        ++splitter;
    }
    
}