/* See LICENSE file for copyright and license details. */
#include "common.h"


static void
print_line(struct libpatch_diff2_printer *printer, const struct libpatch_file *file, size_t lineno)
{
	printer->put_line(printer, file->lines[lineno]);
	printer->put_newline(printer);
	if (lineno + 1 == file->nlines && !file->lf_terminated) {
		printer->put_no_newline(printer, "\\ No newline at end of file");
		printer->put_newline(printer);
	}
}


static void
print_change(struct libpatch_diff2_printer *printer, int fileno, int both, const struct libpatch_file *file, size_t lineno)
{
	printer->put_change_prefix(printer, both ? "! " : fileno == 1 ? "- " : "+ ", fileno, 0, lineno);
	print_line(printer, file, lineno);
}


static void
print_context(struct libpatch_diff2_printer *printer, int fileno, const struct libpatch_file *file, size_t lineno)
{
	printer->put_context_prefix(printer, "  ", fileno == 1, fileno == 2, lineno);
	print_line(printer, file, lineno);
}


static void
print_hunk_head(struct libpatch_diff2_printer *printer, const char *prefix, const char *suffix,
                size_t lineno, size_t len, int file)
{
	printer->put_hunk_head_prefix(printer, prefix, file);
	printer->put_whitespace(printer, " ");
	printer->put_hunk_start(printer, "", lineno + (size_t)(len > 0), file);
	if (len > 1)
		printer->put_hunk_end(printer, ",", lineno + len, file);
	printer->put_whitespace(printer, " ");
	printer->put_hunk_head_suffix(printer, suffix, file);
	printer->put_newline(printer);
}


int
libpatch_format_copied_patch(struct libpatch_diff2_printer *printer, struct libpatch_diff2 *diff, size_t difflen,
                             const struct libpatch_file *file1, const struct libpatch_file *file2)
{
#define HUNK(FNO, FI, FN)\
	do {\
		for (; i < n; i++) {\
			if (changed_saved) {\
				changed_saved -= 1;\
			} else if (diff[i].repetition & 0x03) {\
				for (changed_saved = 0; changed_saved < n - i;)\
					changed |= diff[i + changed_saved++].repetition;\
				changed_saved -= 1;\
			} else {\
				changed = 0;\
			}\
			for (j = 0; j < diff[i].repetition; j++) {\
				if (diff[i].change == LIBPATCH_DIFF2_FILE##FNO##_ONLY ||\
				    diff[i].change == LIBPATCH_DIFF2_TWO_FILE_CHANGE)\
					print_change(printer, FNO, changed == 0x03, file##FNO, FI++);\
				else if (diff[i].change == LIBPATCH_DIFF2_CONTEXT)\
					print_context(printer, FNO, file##FNO, FI++);\
			}\
		}\
	} while (0)

	size_t i, i0, j, n, ai, bi, an, bn, changed_saved = 0;
	int changed = 0, have;

	printer->put_label_prefix(printer, "***", 1);
	printer->put_whitespace(printer, " ");
	if (file1->label)
		printer->put_label(printer, file1->label, 1);
	printer->put_newline(printer);

	printer->put_label_prefix(printer, "---", 2);
	printer->put_whitespace(printer, " ");
	if (file2->label)
		printer->put_label(printer, file2->label, 2);
	printer->put_newline(printer);

	ai = 0;
	bi = 0;
	for (i = 0; (n = libpatch_next_hunk(diff, difflen, &i, &ai, &bi, &an, &bn, 0));) {
		have = 0;
		for (n += j = i; j < n; j++)
			have |= diff[j].change;

		printer->put_syntactical_garbage(printer, "***************");
		printer->put_newline(printer);
		if (have & 1) {
			i0 = i;
			print_hunk_head(printer, "***", "****", ai, an, 1);
			HUNK(1, ai, an);
			i = i0;
		}
		print_hunk_head(printer, "---", "----", bi, bn, 2);
		HUNK(2, bi, bn);
	}

	return 0;
}