/*
4coder_seek.cpp - Procedures and commands for jumping through code to useful stop boundaries.
*/

// TOP

void
buffer_seek_delimiter_forward(Application_Links *app, Buffer_ID buffer, i32 pos, char delim, i32 *result){
    Character_Predicate predicate = character_predicate_from_character((u8)delim);
    buffer_seek_character_class(app, buffer, &predicate, Scan_Forward, pos, result);
}

void
buffer_seek_delimiter_backward(Application_Links *app, Buffer_ID buffer, i32 pos, char delim, i32 *result){
    Character_Predicate predicate = character_predicate_from_character((u8)delim);
    buffer_seek_character_class(app, buffer, &predicate, Scan_Backward, pos, result);
}

static void
buffer_seek_string_forward(Application_Links *app, Buffer_ID buffer_id, i32 pos, i32 end, String_Const_u8 needle_string, i32 *result){
    i32 buffer_size = 0;
    buffer_get_size(app, buffer_id, &buffer_size);
    if (buffer_size > end){
        *result = buffer_size;
    }
    else{
        *result = end;
    }
    
    Scratch_Block scratch(app);
    if (0 < needle_string.size){
        if (buffer_exists(app, buffer_id)){
            u8 first_char = string_get_character(needle_string, 0);
            
            u8 *read_buffer = push_array(scratch, u8, needle_string.size);
            String_Const_u8 read_str = SCu8(read_buffer, needle_string.size);
            
            char chunk[1024];
            Stream_Chunk stream = {};
            stream.max_end = end;
            
            if (init_stream_chunk(&stream, app, buffer_id, pos, chunk, sizeof(chunk))){
                b32 still_looping = true;
                do{
                    for(; pos < stream.end; ++pos){
                        u8 at_pos = stream.data[pos];
                        if (at_pos == first_char){
                            buffer_read_range(app, buffer_id, pos, (i32)(pos + needle_string.size), (char*)read_buffer);
                            if (string_match(needle_string, read_str)){
                                *result = pos;
                                goto finished;
                            }
                        }
                    }
                    still_looping = forward_stream_chunk(&stream);
                }while (still_looping);
            }
        }
        
        if (end == 0){
            *result = buffer_size;
        }
        else{
            *result = end;
        }
        
        finished:;
    }
}

static void
buffer_seek_string_backward(Application_Links *app, Buffer_ID buffer_id, i32 pos, i32 min, String_Const_u8 needle_string, i32 *result){
    Scratch_Block scratch(app);
    *result = min - 1;
    if (0 < needle_string.size && buffer_exists(app, buffer_id)){
        u8 first_char = string_get_character(needle_string, 0);
        
        u8 *read_buffer = push_array(scratch, u8, needle_string.size);
        String_Const_u8 read_str = SCu8(read_buffer, needle_string.size);
        
        char chunk[1024];
        Stream_Chunk stream = {};
        stream.min_start = min;
        
        if (init_stream_chunk(&stream, app, buffer_id, pos, chunk, sizeof(chunk))){
            b32 still_looping = true;
            do{
                for(; pos >= stream.start; --pos){
                    u8 at_pos = stream.data[pos];
                    if (at_pos == first_char){
                        buffer_read_range(app, buffer_id, pos, (i32)(pos + needle_string.size), (char*)read_buffer);
                        if (string_match(needle_string, read_str)){
                            *result = pos;
                            goto finished;
                        }
                    }
                }
                still_looping = backward_stream_chunk(&stream);
            }while (still_looping);
        }
        finished:;
    }
}

static void
buffer_seek_string_insensitive_forward(Application_Links *app, Buffer_ID buffer_id, i32 pos, i32 end, String_Const_u8 needle_string, i32 *result){
    i32 buffer_size = 0;
    buffer_get_size(app, buffer_id, &buffer_size);
    if (buffer_size > end){
        *result = buffer_size;
    }
    else{
        *result = end;
    }
    
    Scratch_Block scratch(app);
    if (0 < needle_string.size && buffer_exists(app, buffer_id)){
        u8 first_char = character_to_upper(string_get_character(needle_string, 0));
        
        u8 *read_buffer = push_array(scratch, u8, needle_string.size);
        String_Const_u8 read_str = SCu8(read_buffer, needle_string.size);
        
        char chunk[1024];
        Stream_Chunk stream = {};
        stream.max_end = end;
        
        if (init_stream_chunk(&stream, app, buffer_id, pos, chunk, sizeof(chunk))){
            b32 still_looping = true;
            do{
                for(; pos < stream.end; ++pos){
                    u8 at_pos = character_to_upper(stream.data[pos]);
                    if (at_pos == first_char){
                        buffer_read_range(app, buffer_id, pos, (i32)(pos + needle_string.size), (char*)read_buffer);
                        if (string_match_insensitive(needle_string, read_str)){
                            *result = pos;
                            goto finished;
                        }
                    }
                }
                still_looping = forward_stream_chunk(&stream);
            }while (still_looping);
        }
        finished:;
    }
}

static void
buffer_seek_string_insensitive_backward(Application_Links *app, Buffer_ID buffer_id, i32 pos, i32 min, String_Const_u8 needle_string, i32 *result){
    Scratch_Block scratch(app);
    *result = min - 1;
    if (0 < needle_string.size && buffer_exists(app, buffer_id)){
        u8 first_char = character_to_upper(string_get_character(needle_string, 0));
        
        u8 *read_buffer = push_array(scratch, u8, needle_string.size);
        String_Const_u8 read_str = SCu8(read_buffer, needle_string.size);
        
        char chunk[1024];
        Stream_Chunk stream = {};
        stream.min_start = min;
        
        if (init_stream_chunk(&stream, app, buffer_id, pos, chunk, sizeof(chunk))){
            b32 still_looping = true;
            do{
                for(; pos >= stream.start; --pos){
                    u8 at_pos = character_to_upper(stream.data[pos]);
                    if (at_pos == first_char){
                        buffer_read_range(app, buffer_id, pos, (i32)(pos + needle_string.size), (char*)read_buffer);
                        if (string_match_insensitive(needle_string, read_str)){
                            *result = pos;
                            goto finished;
                        }
                    }
                }
                still_looping = backward_stream_chunk(&stream);
            }while (still_looping);
        }
        finished:;
    }
}

static void
buffer_seek_string(Application_Links *app, Buffer_ID buffer_id, i32 pos, i32 end, i32 min, String_Const_u8 str, i32 *result, Buffer_Seek_String_Flags flags){
    switch (flags & 3){
        case 0:
        {
            buffer_seek_string_forward(app, buffer_id, pos, end, str, result);
        }break;
        
        case BufferSeekString_Backward:
        {
            buffer_seek_string_backward(app, buffer_id, pos, min, str, result);
        }break;
        
        case BufferSeekString_CaseInsensitive:
        {
            buffer_seek_string_insensitive_forward(app, buffer_id, pos, end, str, result);
        }break;
        
        case BufferSeekString_Backward|BufferSeekString_CaseInsensitive:
        {
            buffer_seek_string_insensitive_backward(app, buffer_id, pos, min, str, result);
        }break;
    }
}

////////////////////////////////

internal void
seek_pos_of_textual_line(Application_Links *app, Side side){
    View_ID view = 0;
    get_active_view(app, AccessProtected, &view);
    Buffer_ID buffer_id = 0;
    view_get_buffer(app, view, AccessProtected, &buffer_id);
    i32 pos = 0;
    view_get_cursor_pos(app, view, &pos);
    i32 new_pos = get_line_side_pos_from_pos(app, buffer_id, pos, side);
    view_set_cursor(app, view, seek_pos(new_pos), true);
    no_mark_snap_to_cursor_if_shift(app, view);
}

internal void
seek_pos_of_visual_line(Application_Links *app, Side side){
    View_ID view = 0;
    get_active_view(app, AccessProtected, &view);
    i32 pos = 0;
    view_get_cursor_pos(app, view, &pos);
    Full_Cursor cursor = {};
    view_compute_cursor(app, view, seek_pos(pos), &cursor);
    f32 y = cursor.wrapped_y;
    f32 x = (side == Side_Min)?(0.f):(max_f32);
    view_set_cursor(app, view, seek_wrapped_xy(x, y, true), true);
    no_mark_snap_to_cursor_if_shift(app, view);
}

CUSTOM_COMMAND_SIG(seek_beginning_of_textual_line)
CUSTOM_DOC("Seeks the cursor to the beginning of the line across all text.")
{
    seek_pos_of_textual_line(app, Side_Min);
}

CUSTOM_COMMAND_SIG(seek_end_of_textual_line)
CUSTOM_DOC("Seeks the cursor to the end of the line across all text.")
{
    seek_pos_of_textual_line(app, Side_Max);
}

CUSTOM_COMMAND_SIG(seek_beginning_of_line)
CUSTOM_DOC("Seeks the cursor to the beginning of the visual line.")
{
    seek_pos_of_visual_line(app, Side_Min);
}

CUSTOM_COMMAND_SIG(seek_end_of_line)
CUSTOM_DOC("Seeks the cursor to the end of the visual line.")
{
    seek_pos_of_visual_line(app, Side_Max);
}

CUSTOM_COMMAND_SIG(goto_beginning_of_file)
CUSTOM_DOC("Sets the cursor to the beginning of the file.")
{
    View_ID view = 0;
    get_active_view(app, AccessProtected, &view);
    view_set_cursor(app, view, seek_pos(0), true);
    no_mark_snap_to_cursor_if_shift(app, view);
}

CUSTOM_COMMAND_SIG(goto_end_of_file)
CUSTOM_DOC("Sets the cursor to the end of the file.")
{
    View_ID view = 0;
    get_active_view(app, AccessProtected, &view);
    Buffer_ID buffer_id = 0;
    view_get_buffer(app, view, AccessProtected, &buffer_id);
    i32 size = 0;
    buffer_get_size(app, buffer_id, &size);
    view_set_cursor(app, view, seek_pos(size), true);
    no_mark_snap_to_cursor_if_shift(app, view);
}

// BOTTOM