/*
4coder_auto_indent.cpp - Commands for automatic indentation.
*/

// TOP

internal Batch_Edit*
make_batch_from_indentations(Application_Links *app, Arena *arena, Buffer_ID buffer, Range_i64 lines, i64 *indentations, Indent_Flag flags, i32 tab_width){
i64 *shifted_indentations = indentations - lines.first;

Batch_Edit *batch_first = 0;
Batch_Edit *batch_last = 0;

for (i64 line_number = lines.first;
     line_number <= lines.max;
     ++line_number){
i64 line_start_pos = get_line_start_pos(app, buffer, line_number);
Indent_Info indent_info = get_indent_info_line_number_and_start(app, buffer, line_number, line_start_pos, tab_width);

i64 correct_indentation = shifted_indentations[line_number];
if (indent_info.is_blank && HasFlag(flags, Indent_ClearLine)){
correct_indentation = 0;
}
if (correct_indentation <= -1){
correct_indentation = indent_info.indent_pos;
}

if (correct_indentation != indent_info.indent_pos){
u64 str_size = 0;
u8 *str = 0;
if (HasFlag(flags, Indent_UseTab)){
i64 tab_count = correct_indentation/tab_width;
i64 indent = tab_count*tab_width;
i64 space_count = correct_indentation - indent;
str_size = tab_count + space_count;
str = push_array(arena, u8, str_size);
block_fill_u8(str, tab_count, '\t');
block_fill_u8(str + tab_count, space_count, ' ');
}
else{
str_size = correct_indentation;
str = push_array(arena, u8, str_size);
block_fill_u8(str, str_size, ' ');
}

Batch_Edit *batch = push_array(arena, Batch_Edit, 1);
sll_queue_push(batch_first, batch_last, batch);
batch->edit.text = SCu8(str, str_size);
batch->edit.range = Ii64(line_start_pos, indent_info.first_char_pos);
}
}

return(batch_first);
}

internal void
set_line_indents(Application_Links *app, Arena *arena, Buffer_ID buffer, Range_i64 lines, i64 *indentations, Indent_Flag flags, i32 tab_width){
Batch_Edit *batch = make_batch_from_indentations(app, arena, buffer, lines, indentations, flags, tab_width);
if (batch != 0){
buffer_batch_edit(app, buffer, batch);
}
}

internal Token*
find_anchor_token(Application_Links *app, Buffer_ID buffer, Token_Array *tokens, i64 invalid_line){
ProfileScope(app, "find anchor token");
Token *result = 0;

if (tokens != 0 && tokens->tokens != 0){
result = tokens->tokens;
i64 invalid_pos = get_line_start_pos(app, buffer, invalid_line);
i32 scope_counter = 0;
i32 paren_counter = 0;
Token *token = tokens->tokens;
for (;;token += 1){
if (token->pos + token->size > invalid_pos){
break;
}
if (!HasFlag(token->flags,  TokenBaseFlag_PreprocessorBody)){
if (scope_counter == 0 && paren_counter == 0){
result = token;
}
switch (token->kind){
case TokenBaseKind_ScopeOpen:
{
scope_counter += 1;
}break;
case TokenBaseKind_ScopeClose:
{
paren_counter = 0;
if (scope_counter > 0){
scope_counter -= 1;
}
}break;
case TokenBaseKind_ParentheticalOpen:
{
paren_counter += 1;
}break;
case TokenBaseKind_ParentheticalClose:
{
if (paren_counter > 0){
paren_counter -= 1;
}
}break;
}
}
}
}

return(result);
}

internal Nest*
indent__new_nest(Arena *arena, Nest_Alloc *alloc){
Nest *new_nest = alloc->free_nest;
if (new_nest == 0){
new_nest = push_array(arena, Nest, 1);
}
else{
sll_stack_pop(alloc->free_nest);
}
return(new_nest);
}

internal void
indent__free_nest(Nest_Alloc *alloc, Nest *nest){
sll_stack_push(alloc->free_nest, nest);
}

internal b32
indent__unfinished_statement(Token *token, Nest *current_nest){
b32 result = false;
if (current_nest != 0 && current_nest->kind == TokenBaseKind_ScopeOpen){
result = true;
switch (token->kind){
case TokenBaseKind_ScopeOpen:
case TokenBaseKind_ScopeClose:
case TokenBaseKind_StatementClose:
{
result = false;
}break;
}
if (HasFlag(token->flags, TokenBaseFlag_PreprocessorBody)){
result = false;
}
}
return(result);
}

function void
line_indent_cache_update(Application_Links *app, Buffer_ID buffer, i32 tab_width, Indent_Line_Cache *line_cache){
if (line_cache->line_number_for_cached_indent != line_cache->where_token_starts){
ProfileScope(app, "get indent info");
line_cache->line_number_for_cached_indent = line_cache->where_token_starts;
line_cache->start_pos = get_line_start_pos(app, buffer, line_cache->where_token_starts);
Range_i64 range = Ii64(line_cache->start_pos, line_cache->one_past_last_pos);
line_cache->indent_info = get_indent_info_range(app, buffer, range, tab_width);
}
}

internal i64*
get_indentation_array(Application_Links *app, Arena *arena, Buffer_ID buffer, Range_i64 lines, Indent_Flag flags, i32 tab_width, i32 indent_width){
ProfileScope(app, "get indentation array");
i64 count = lines.max - lines.min + 1;
i64 *indentations = push_array(arena, i64, count);
i64 *shifted_indentations = indentations - lines.first;
block_fill_u64(indentations, sizeof(*indentations)*count, (u64)(-1));

#if 0
Managed_Scope scope = buffer_get_managed_scope(app, buffer);
Token_Array *tokens = scope_attachment(app, scope, attachment_tokens, Token_Array);
#endif

Token_Array token_array = get_token_array_from_buffer(app, buffer);
Token_Array *tokens = &token_array;

i64 anchor_line = clamp_bot(1, lines.first - 1);
Token *anchor_token = find_anchor_token(app, buffer, tokens, anchor_line);
if (anchor_token != 0 &&
    anchor_token >= tokens->tokens &&
    anchor_token < tokens->tokens + tokens->count){
i64 line = get_line_number_from_pos(app, buffer, anchor_token->pos);
line = clamp_top(line, lines.first);

Token_Iterator_Array token_it = token_iterator(0, tokens, anchor_token);

Scratch_Block scratch(app, arena);
Nest *nest = 0;
Nest_Alloc nest_alloc = {};

i64 line_last_indented = line - 1;
i64 last_indent = 0;
i64 actual_indent = 0;
b32 in_unfinished_statement = false;

Indent_Line_Cache line_cache = {};

for (;;){
Token *token = token_it_read(&token_it);

if (line_cache.where_token_starts == 0 ||
    token->pos >= line_cache.one_past_last_pos){
ProfileScope(app, "get line number");
line_cache.where_token_starts = get_line_number_from_pos(app, buffer, token->pos);
line_cache.one_past_last_pos = get_line_end_pos(app, buffer, line_cache.where_token_starts);
}

i64 current_indent = 0;
if (nest != 0){
current_indent = nest->indent;
}
i64 this_indent = current_indent;
i64 following_indent = current_indent;

b32 shift_by_actual_indent = false;
b32 ignore_unfinished_statement = false;
if (HasFlag(token->flags, TokenBaseFlag_PreprocessorBody)){
this_indent = 0;
}
else{
switch (token->kind){
case TokenBaseKind_ScopeOpen:
{
Nest *new_nest = indent__new_nest(arena, &nest_alloc);
sll_stack_push(nest, new_nest);
nest->kind = TokenBaseKind_ScopeOpen;
nest->indent = current_indent + indent_width;
following_indent = nest->indent;
ignore_unfinished_statement = true;
}break;

case TokenBaseKind_ScopeClose:
{
for (;nest != 0 && nest->kind != TokenBaseKind_ScopeOpen;){
Nest *n = nest;
sll_stack_pop(nest);
indent__free_nest(&nest_alloc, n);
}
if (nest != 0 && nest->kind == TokenBaseKind_ScopeOpen){
Nest *n = nest;
sll_stack_pop(nest);
indent__free_nest(&nest_alloc, n);
}
this_indent = 0;
if (nest != 0){
this_indent = nest->indent;
}
following_indent = this_indent;
ignore_unfinished_statement = true;
}break;

case TokenBaseKind_ParentheticalOpen:
{
Nest *new_nest = indent__new_nest(arena, &nest_alloc);
sll_stack_push(nest, new_nest);
nest->kind = TokenBaseKind_ParentheticalOpen;
line_indent_cache_update(app, buffer, tab_width, &line_cache);
nest->indent = (token->pos - line_cache.indent_info.first_char_pos) + 1;
following_indent = nest->indent;
shift_by_actual_indent = true;
}break;

case TokenBaseKind_ParentheticalClose:
{
if (nest != 0 && nest->kind == TokenBaseKind_ParentheticalOpen){
Nest *n = nest;
sll_stack_pop(nest);
indent__free_nest(&nest_alloc, n);
}
following_indent = 0;
if (nest != 0){
following_indent = nest->indent;
}
//ignore_unfinished_statement = true;
}break;
}

if (token->sub_kind == TokenCppKind_BlockComment ||
    token->sub_kind == TokenCppKind_LiteralStringRaw){
ignore_unfinished_statement = true;
}

if (in_unfinished_statement && !ignore_unfinished_statement){
this_indent += indent_width;
}
}

#define EMIT(N) \
Stmnt(if (lines.first <= line_it){shifted_indentations[line_it]=N;} \
if (line_it == lines.end){goto finished;} \
actual_indent = N; )

i64 line_it = line_last_indented;
if (lines.first <= line_cache.where_token_starts){
for (;line_it < line_cache.where_token_starts;){
line_it += 1;
if (line_it == line_cache.where_token_starts){
EMIT(this_indent);
}
else{
EMIT(last_indent);
}
}
}
else{
actual_indent = this_indent;
line_it = line_cache.where_token_starts;
}

i64 line_where_token_ends = get_line_number_from_pos(app, buffer, token->pos + token->size);
if (lines.first <= line_where_token_ends){
line_indent_cache_update(app, buffer, tab_width, &line_cache);
i64 line_where_token_starts_shift = this_indent - line_cache.indent_info.indent_pos;
for (;line_it < line_where_token_ends;){
line_it += 1;
i64 line_it_start_pos = get_line_start_pos(app, buffer, line_it);
Indent_Info line_it_indent_info = get_indent_info_line_number_and_start(app, buffer, line_it, line_it_start_pos, tab_width);
i64 new_indent = line_it_indent_info.indent_pos + line_where_token_starts_shift;
new_indent = clamp_bot(0, new_indent);
EMIT(new_indent);
}
}
else{
line_it = line_where_token_ends;
}
#undef EMIT

if (shift_by_actual_indent){
nest->indent += actual_indent;
following_indent += actual_indent;
}

if (token->kind != TokenBaseKind_Comment){
in_unfinished_statement = indent__unfinished_statement(token, nest);
if (in_unfinished_statement){
following_indent += indent_width;
}
}

last_indent = following_indent;
line_last_indented = line_it;

if (!token_it_inc_non_whitespace(&token_it)){
break;
}
}
}

finished:;
return(indentations);
}

internal b32
auto_indent_buffer(Application_Links *app, Buffer_ID buffer, Range_i64 pos, Indent_Flag flags, i32 tab_width, i32 indent_width){
ProfileScope(app, "auto indent buffer");
Token_Array token_array = get_token_array_from_buffer(app, buffer);
Token_Array *tokens = &token_array;

b32 result = false;
if (tokens->tokens != 0){
result = true;

Scratch_Block scratch(app);
Range_i64 line_numbers = {};
if (HasFlag(flags, Indent_FullTokens)){
i32 safety_counter = 0;
for (;;){
Range_i64 expanded = enclose_tokens(app, buffer, pos);
expanded = enclose_whole_lines(app, buffer, expanded);
if (expanded == pos){
break;
}
pos = expanded;
safety_counter += 1;
if (safety_counter == 20){
pos = buffer_range(app, buffer);
break;
}
}
}
line_numbers = get_line_range_from_pos_range(app, buffer, pos);

i64 *indentations = get_indentation_array(app, scratch, buffer, line_numbers, flags, tab_width, indent_width);
set_line_indents(app, scratch, buffer, line_numbers, indentations, flags, tab_width);
}

return(result);
}

function void
auto_indent_buffer(Application_Links *app, Buffer_ID buffer, Range_i64 pos, Indent_Flag flags){
i32 indent_width = (i32)def_get_config_u64(app, vars_save_string_lit("indent_width"));
i32 tab_width = (i32)def_get_config_u64(app, vars_save_string_lit("default_tab_width"));
tab_width = clamp_bot(1, tab_width);
AddFlag(flags, Indent_FullTokens);
b32 indent_with_tabs = def_get_config_b32(vars_save_string_lit("indent_with_tabs"));
if (indent_with_tabs){
AddFlag(flags, Indent_UseTab);
}
auto_indent_buffer(app, buffer, pos, flags, indent_width, tab_width);
}

function void
auto_indent_buffer(Application_Links *app, Buffer_ID buffer, Range_i64 pos){
auto_indent_buffer(app, buffer, pos, 0);
}

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

CUSTOM_COMMAND_SIG(auto_indent_whole_file)
CUSTOM_DOC("Audo-indents the entire current buffer.")
{
View_ID view = get_active_view(app, Access_ReadWriteVisible);
Buffer_ID buffer = view_get_buffer(app, view, Access_ReadWriteVisible);
i64 buffer_size = buffer_get_size(app, buffer);
auto_indent_buffer(app, buffer, Ii64(0, buffer_size));
}

CUSTOM_COMMAND_SIG(auto_indent_line_at_cursor)
CUSTOM_DOC("Auto-indents the line on which the cursor sits.")
{
View_ID view = get_active_view(app, Access_ReadWriteVisible);
Buffer_ID buffer = view_get_buffer(app, view, Access_ReadWriteVisible);
i64 pos = view_get_cursor_pos(app, view);
auto_indent_buffer(app, buffer, Ii64(pos));
move_past_lead_whitespace(app, view, buffer);
}

CUSTOM_COMMAND_SIG(auto_indent_range)
CUSTOM_DOC("Auto-indents the range between the cursor and the mark.")
{
View_ID view = get_active_view(app, Access_ReadWriteVisible);
Buffer_ID buffer = view_get_buffer(app, view, Access_ReadWriteVisible);
Range_i64 range = get_view_range(app, view);
auto_indent_buffer(app, buffer, range);
move_past_lead_whitespace(app, view, buffer);
}

CUSTOM_COMMAND_SIG(write_text_and_auto_indent)
CUSTOM_DOC("Inserts text and auto-indents the line on which the cursor sits if any of the text contains 'layout punctuation' such as ;:{}()[]# and new lines.")
{
ProfileScope(app, "write and auto indent");
User_Input in = get_current_input(app);
String_Const_u8 insert = to_writable(&in);
if (insert.str != 0 && insert.size > 0){
b32 do_auto_indent = false;
for (u64 i = 0; !do_auto_indent && i < insert.size; i += 1){
switch (insert.str[i]){
case ';': case ':':
case '{': case '}':
case '(': case ')':
case '[': case ']':
case '#':
case '\n': case '\t':
{
do_auto_indent = true;
}break;
}
}
if (do_auto_indent){
View_ID view = get_active_view(app, Access_ReadWriteVisible);
Buffer_ID buffer = view_get_buffer(app, view, Access_ReadWriteVisible);

Range_i64 pos = {};
if (view_has_highlighted_range(app, view)){
pos = get_view_range(app, view);
}
else{
pos.min = pos.max = view_get_cursor_pos(app, view);
}

write_text_input(app);

i64 end_pos = view_get_cursor_pos(app, view);
pos.min = Min(pos.min, end_pos);
pos.max = Max(pos.max, end_pos);

auto_indent_buffer(app, buffer, pos, 0);
move_past_lead_whitespace(app, view, buffer);
}
else{
write_text_input(app);
}
}
}

// BOTTOM

