* SPDX-License-Identifier: BSD-4-Clause

/* $NetBSD: io.c,v 1.237 2025/01/04 10:28:08 rillig Exp $ */

/*-
* SPDX-License-Identifier: BSD-4-Clause
*
* Copyright (c) 1985 Sun Microsystems, Inc.
* Copyright (c) 1980, 1993
* The Regents of the University of California. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
__RCSID("$NetBSD: io.c,v 1.237 2025/01/04 10:28:08 rillig Exp $");

#include <err.h>
#include <stdio.h>

#include "indent.h"

struct input_state in = {
.token_end_line = 1,
};

struct output_state out;
enum indent_enabled indent_enabled;
static int out_ind; /* width of the line that is being written */
static unsigned newlines = 2; /* the total of written and buffered newlines;
* 0 in the middle of a line, 1 after a single
* finished line, anything > 1 are trailing
* blank lines */
static unsigned buffered_newlines; /* not yet written */
static int paren_indent; /* total indentation when parenthesized */

static void
inp_read_next_line(void)
{
buf_clear(&in.line);

for (;;) {
int ch = getc(in.f);
if (ch == EOF) {
if (indent_enabled == indent_on) {
buf_add_char(&in.line, ' ');
buf_add_char(&in.line, '\n');
}
had_eof = true;
break;
}

if (ch != '\0')
buf_add_char(&in.line, (char)ch);
if (ch == '\n')
break;
}
buf_terminate(&in.line);
in.p = in.line.s;
}

void
inp_read_line(void)
{
if (indent_enabled == indent_on)
buf_clear(&out.indent_off_text);
buf_add_chars(&out.indent_off_text, in.line.s, in.line.len);
inp_read_next_line();
}

void
inp_skip(void)
{
in.p++;
if ((size_t)(in.p - in.line.s) >= in.line.len)
inp_read_line();
}

char
inp_next(void)
{
char ch = in.p[0];
inp_skip();
return ch;
}

static void
add_buffered_newline(void)
{
buffered_newlines++;
newlines++;
out_ind = 0;
}

static void
write_buffered_newlines(void)
{
for (; buffered_newlines > 0; buffered_newlines--) {
if (fputc('\n', output) == EOF)
err(1, "cannot write output");
debug_println("write_newline");
}
}

static void
write_range(const char *s, size_t len)
{
write_buffered_newlines();
if (fwrite(s, 1, len, output) != len)
err(1, "cannot write output");
debug_printf("write_range ");
debug_vis_range(s, len);
debug_println("");
for (size_t i = 0; i < len; i++)
newlines = s[i] == '\n' ? newlines + 1 : 0;
out_ind = ind_add(out_ind, s, len);
}

static void
write_indent(int new_ind)
{
write_buffered_newlines();

int ind = out_ind;

if (opt.use_tabs) {
int n = new_ind / opt.tabsize - ind / opt.tabsize;
if (n > 0) {
ind = ind - ind % opt.tabsize + n * opt.tabsize;
while (n-- > 0)
if (fputc('\t', output) == EOF)
err(1, "cannot write output");
newlines = 0;
}
}

for (; ind < new_ind; ind++) {
if (fputc(' ', output) == EOF)
err(1, "cannot write output");
newlines = 0;
}

debug_println("write_indent %d", ind);
out_ind = ind;
}

static bool
want_blank_line(void)
{
debug_println("%s: %s -> %s", __func__,
line_kind_name[out.prev_line_kind], line_kind_name[out.line_kind]);
debug_blank_line();

if (((ps.blank_line_after_decl && ps.declaration == decl_no)
|| ps.badp == badp_yes)
&& (lab.len > 0 || code.len > 0)) {
ps.blank_line_after_decl = false;
ps.badp = badp_none;
return true;
}

if (opt.blank_line_around_conditional_compilation) {
if (out.prev_line_kind != lk_pre_if
&& out.line_kind == lk_pre_if)
return true;
if (out.prev_line_kind == lk_pre_endif
&& out.line_kind != lk_pre_endif)
return true;
}
if (opt.blank_line_after_proc && out.prev_line_kind == lk_func_end
&& out.line_kind != lk_pre_endif && out.line_kind != lk_pre_other)
return true;
if (opt.blank_line_before_block_comment
&& out.line_kind == lk_block_comment)
return true;
return false;
}

static bool
is_blank_line_optional(void)
{
if (out.prev_line_kind == lk_stmt_head)
return newlines >= 1;
if (ps.psyms.len >= 3)
return newlines >= 2;
return newlines >= 3;
}

static int
compute_case_label_indent(void)
{
size_t i = ps.psyms.len - 1;
while (i > 0 && ps.psyms.sym[i] != psym_switch_expr)
i--;
float case_ind = (float)ps.psyms.ind_level[i] + opt.case_indent;
// TODO: case_ind may become negative here.
return (int)(case_ind * (float)opt.indent_size);
}

int
compute_label_indent(void)
{
if (out.line_kind == lk_case_or_default)
return compute_case_label_indent();
if (lab.s[0] == '#')
return 0;
// TODO: the indentation may become negative here.
return opt.indent_size * (ps.ind_level - 2);
}

static void
output_line_label(void)
{
write_indent(compute_label_indent());
write_range(lab.s, lab.len);
}

static int
compute_lined_up_code_indent(int base_ind)
{
int ind = paren_indent;
int overflow = ind_add(ind, code.s, code.len) - opt.max_line_length;
if (overflow >= 0
&& ind_add(base_ind, code.s, code.len) < opt.max_line_length) {
ind -= 2 + overflow;
if (ind < base_ind)
ind = base_ind;
}

if (ps.extra_expr_indent != eei_no
&& ind == base_ind + opt.indent_size)
ind += opt.continuation_indent;
return ind;
}

int
compute_code_indent(void)
{
int base_ind = ps.ind_level * opt.indent_size;

if (ps.ind_paren_level == 0) {
if (ps.line_is_stmt_cont)
return base_ind + opt.continuation_indent;
return base_ind;
}

if (opt.lineup_to_parens) {
if (opt.lineup_to_parens_always)
return paren_indent;
return compute_lined_up_code_indent(base_ind);
}

int rel_ind = opt.continuation_indent * ps.ind_paren_level;
if (ps.extra_expr_indent != eei_no && rel_ind == opt.indent_size)
rel_ind += opt.continuation_indent;
return base_ind + rel_ind;
}

static void
output_line_code(void)
{
int target_ind = compute_code_indent();
for (size_t i = 0; i < ps.paren.len; i++) {
int paren_ind = ps.paren.item[i].indent;
if (paren_ind >= 0) {
ps.paren.item[i].indent =
-1 - (paren_ind + target_ind);
debug_println(
"setting paren_indents[%zu] from %d to %d "
"for column %d",
i, paren_ind,
ps.paren.item[i].indent, target_ind + 1);
}
}

if (lab.len > 0 && target_ind <= out_ind)
write_range(" ", 1);
write_indent(target_ind);
write_range(code.s, code.len);
}

static void
output_comment(void)
{
int target_ind = ps.comment_ind;
const char *p;

if (ps.comment_cont)
target_ind += ps.comment_shift;
ps.comment_cont = true;

/* consider the original indentation in case this is a box comment */
for (p = com.s; *p == '\t'; p++)
target_ind += opt.tabsize;

for (; target_ind < 0; p++) {
if (*p == ' ')
target_ind++;
else if (*p == '\t')
target_ind = next_tab(target_ind);
else {
target_ind = 0;
break;
}
}

if (out_ind > target_ind)
add_buffered_newline();

while (com.s + com.len > p && ch_isspace(com.s[com.len - 1]))
com.len--;
buf_terminate(&com);

write_indent(target_ind);
write_range(p, com.len - (size_t)(p - com.s));
}

/*
* Write a line of formatted source to the output file. The line consists of
* the label, the code and the comment.
*/
static void
output_indented_line(void)
{
if (lab.len == 0 && code.len == 0 && com.len == 0)
out.line_kind = lk_blank;

if (want_blank_line() && newlines < 2 && out.line_kind != lk_blank)
add_buffered_newline();

/* This kludge aligns function definitions correctly. */
if (ps.ind_level == 0)
ps.line_is_stmt_cont = false;

if (opt.blank_line_after_decl && ps.declaration == decl_end
&& ps.psyms.len > 2) {
ps.declaration = decl_no;
ps.blank_line_after_decl = true;
}

if (opt.swallow_optional_blank_lines
&& out.line_kind == lk_blank
&& is_blank_line_optional())
return;

if (lab.len > 0)
output_line_label();
if (code.len > 0)
output_line_code();
if (com.len > 0)
output_comment();
add_buffered_newline();
if (out.line_kind != lk_blank)
write_buffered_newlines();

out.prev_line_kind = out.line_kind;
}

static bool
is_stmt_cont(void)
{
if (ps.psyms.len >= 2
&& ps.psyms.sym[ps.psyms.len - 2] == psym_lbrace_enum
&& ps.prev_lsym == lsym_comma
&& ps.paren.len == 0)
return false;
return ps.in_stmt_or_decl
&& (!ps.in_decl || ps.in_init)
&& ps.init_level == 0;
}

static void
prepare_next_line(void)
{
ps.line_has_decl = ps.in_decl;
ps.line_has_func_def = false;
ps.line_is_stmt_cont = is_stmt_cont();
ps.decl_indent_done = false;
if (ps.extra_expr_indent == eei_last)
ps.extra_expr_indent = eei_no;
if (!(ps.psyms.sym[ps.psyms.len - 1] == psym_if_expr_stmt_else
&& ps.paren.len > 0))
ps.ind_level = ps.ind_level_follow;
ps.ind_paren_level = (int)ps.paren.len;
ps.want_blank = false;
if ((ps.badp == badp_seen_lbrace || ps.badp == badp_seen_decl)
&& !ps.in_decl)
ps.badp = badp_yes;

if (ps.paren.len > 0) {
/* TODO: explain what negative indentation means */
paren_indent = -1 - ps.paren.item[ps.paren.len - 1].indent;
debug_println("paren_indent is now %d", paren_indent);
}

out.line_kind = lk_other;
}

void
output_line(void)
{
debug_blank_line();
debug_buffers(__func__);

if (indent_enabled == indent_on)
output_indented_line();
else if (indent_enabled == indent_last_off_line) {
indent_enabled = indent_on;
write_range(out.indent_off_text.s, out.indent_off_text.len);
buf_clear(&out.indent_off_text);
}

buf_clear(&lab);
buf_clear(&code);
buf_clear(&com);

prepare_next_line();
}

void
finish_output(void)
{
output_line();
if (indent_enabled != indent_on) {
indent_enabled = indent_last_off_line;
output_line();
}
if (fflush(output) != 0)
err(1, "output file");
}