/*
 * Miscellaneous helpers for common operations.
 */

// TOP

static void
exec_command(Application_Links *app, Custom_Command_Function *func){
    func(app);
}

static void
exec_command(Application_Links *app, Generic_Command cmd){
    if (cmd.cmdid < cmdid_count){
        exec_command(app, cmd.cmdid);
    }
    else{
        exec_command(app, cmd.command);
    }
}

static int32_t
key_is_unmodified(Key_Event_Data *key){
    int8_t *mods = key->modifiers;
    int32_t unmodified = (!mods[MDFR_CONTROL_INDEX] && !mods[MDFR_ALT_INDEX]);
    return(unmodified);
}

static uint32_t
to_writable_character(User_Input in, uint8_t *character){
    uint32_t result = 0;
    if (in.type == UserInputKey){
        if (in.key.character != 0){
            u32_to_utf8_unchecked(in.key.character, character, &result);
        }
    }
    return(result);
}

static uint32_t
to_writable_character(Key_Event_Data key, uint8_t *character){
    uint32_t result = 0;
    if (key.character != 0){
        u32_to_utf8_unchecked(key.character, character, &result);
    }
    return(result);
}

static bool32
backspace_utf8(String *str){
    bool32 result = false;
    uint8_t *s = (uint8_t*)str->str;
    if (str->size > 0){
        uint32_t i = str->size-1;
        for (; i > 0; --i){
            if (s[i] <= 0x7F || s[i] >= 0xC0){
                break;
            }
        }
        str->size = i;
        result = true;
    }
    return(result);
}

static bool32
query_user_general(Application_Links *app, Query_Bar *bar, bool32 force_number){
    bool32 success = true;
    
    // NOTE(allen|a3.4.4): It will not cause an *error* if we continue on after failing to.
    // start a query bar, but it will be unusual behavior from the point of view of the
    // user, if this command starts intercepting input even though no prompt is shown.
    // This will only happen if you have a lot of bars open already or if the current view
    // doesn't support query bars.
    if (start_query_bar(app, bar, 0) == 0) return 0;
    
    for (;;){
        // NOTE(allen|a3.4.4): This call will block until the user does one of the input
        // types specified in the flags.  The first set of flags are inputs you'd like to intercept
        // that you don't want to abort on.  The second set are inputs that you'd like to cause
        // the command to abort.  If an event satisfies both flags, it is treated as an abort.
        User_Input in = get_user_input(app, EventOnAnyKey, EventOnEsc | EventOnButton);
        
        // NOTE(allen|a3.4.4): The responsible thing to do on abort is to end the command
        // without waiting on get_user_input again.
        if (in.abort){
            success = false;
            break;
        }
        
        uint8_t character[4];
        uint32_t length = 0;
        bool32 good_character = false;
        if (key_is_unmodified(&in.key)){
            if (force_number){
                if (in.key.character >= '0' && in.key.character <= '9'){
                    good_character = true;
                    length = to_writable_character(in, character);
                }
            }
            else{
                length = to_writable_character(in, character);
                if (length != 0){
                    good_character = true;
                }
            }
        }
        
        // NOTE(allen|a3.4.4): All we have to do to update the query bar is edit our
        // local Query_Bar struct!  This is handy because it means our Query_Bar
        // is always correct for typical use without extra work updating the bar.
        if (in.type == UserInputKey){
            if (in.key.keycode == '\n' || in.key.keycode == '\t'){
                break;
            }
            else if (in.key.keycode == key_back){
                backspace_utf8(&bar->string);
            }
            else if (good_character){
                append_ss(&bar->string, make_string(character, length));
            }
        }
    }
    
    terminate_with_null(&bar->string);
    
    return(success);
}

static int32_t
query_user_string(Application_Links *app, Query_Bar *bar){
    int32_t success = query_user_general(app, bar, false);
    return(success);
}

static int32_t
query_user_number(Application_Links *app, Query_Bar *bar){
    int32_t success = query_user_general(app, bar, true);
    return(success);
}

static void
init_theme_zero(Theme *theme){
    for (int32_t i = 0; i < Stag_COUNT; ++i){
        theme->colors[i] = 0;
    }
}

static char
buffer_get_char(Application_Links *app, Buffer_Summary *buffer, int32_t pos){
    char result = ' ';
    *buffer = get_buffer(app, buffer->buffer_id, AccessAll);
    if (pos < buffer->size){
        buffer_read_range(app, buffer, pos, pos+1, &result);
    }
    return(result);
}

static Buffer_Identifier
buffer_identifier(char *str, int32_t len){
    Buffer_Identifier identifier;
    identifier.name = str;
    identifier.name_len = len;
    identifier.id = 0;
    return(identifier);
}

static Buffer_Identifier
buffer_identifier(Buffer_ID id){
    Buffer_Identifier identifier;
    identifier.name = 0;
    identifier.name_len = 0;
    identifier.id = id;
    return(identifier);
}

static Range
make_range(int32_t p1, int32_t p2){
    Range range;
    if (p1 < p2){
        range.min = p1;
        range.max = p2;
    }
    else{
        range.min = p2;
        range.max = p1;
    }
    return(range);
}

static void
adjust_all_buffer_wrap_widths(Application_Links *app, int32_t wrap_width, int32_t min_base_width){
    for (Buffer_Summary buffer = get_buffer_first(app, AccessAll);
         buffer.exists;
         get_buffer_next(app, &buffer, AccessAll)){
        buffer_set_setting(app, &buffer, BufferSetting_WrapPosition, wrap_width);
        buffer_set_setting(app, &buffer, BufferSetting_MinimumBaseWrapPosition, min_base_width);
    }
}

// TODO(allen): Setup buffer seeking to do character_pos and get View_Summary out of this parameter list.
static int32_t
character_pos_to_pos(Application_Links *app, View_Summary *view, Buffer_Summary *buffer, int32_t character_pos){
    int32_t result = 0;
    Full_Cursor cursor = {0};
    if (view_compute_cursor(app, view, seek_character_pos(character_pos), &cursor)){
        result = cursor.pos;
    }
    return(result);
}

static float
get_view_y(View_Summary *view){
    float y = view->cursor.wrapped_y;
    if (view->unwrapped_lines){
        y = view->cursor.unwrapped_y;
    }
    return(y);
}

static float
get_view_x(View_Summary *view){
    float x = view->cursor.wrapped_x;
    if (view->unwrapped_lines){
        x = view->cursor.unwrapped_x;
    }
    return(x);
}

static Range
get_view_range(View_Summary *view){
    return(make_range(view->cursor.pos, view->mark.pos));
}



// BOTTOM