#include "line-source.h"

enum status line_source_init(
	struct line_source *src,
	const char *path,
	fx_stream *stream)
{
	memset(src, 0x0, sizeof *src);

	src->s_lines = fx_array_create();

	if (!src->s_lines) {
		return ERR_NO_MEMORY;
	}

	src->s_stream = stream;
	src->s_path = path;
	src->s_cursor.c_col = 1;
	src->s_cursor.c_row = 1;

	return SUCCESS;
}

void line_source_cleanup(struct line_source *src)
{
	if (src->s_linebuf_ptr) {
		fx_iterator_unref(src->s_linebuf_ptr);
	}

	if (src->s_lines) {
		fx_array_unref(src->s_lines);
	}

	memset(src, 0x0, sizeof *src);
}

const char *line_source_get_path(const struct line_source *src)
{
	return src->s_path;
}

const struct file_cell *line_source_get_cursor(const struct line_source *src)
{
	return &src->s_cursor;
}

static enum status refill_linebuf(struct line_source *src)
{
	if (!src->s_stream) {
		return ERR_EOF;
	}

	if (src->s_linebuf_ptr) {
		fx_iterator_unref(src->s_linebuf_ptr);
		src->s_linebuf_ptr = NULL;
	}

	fx_stringstream *s = fx_stringstream_create();

	fx_status status = fx_stream_read_line_s(src->s_stream, s);

	if (status == FX_ERR_NO_DATA) {
		return ERR_EOF;
	}

	if (!FX_OK(status)) {
		return ERR_INTERNAL_FAILURE;
	}

	fx_string *line = fx_string_create();
	fx_string_replace_all_with_stringstream(line, s);
	fx_stringstream_unref(s);

	fx_array_append(src->s_lines, line);
	fx_string_unref(line);

	src->s_linebuf = line;
	src->s_linebuf_ptr = fx_iterator_begin(src->s_linebuf);

	return SUCCESS;
}

static int peek(struct line_source *src)
{
	enum status status = SUCCESS;

	if (!src->s_linebuf_ptr || !fx_iterator_is_valid(src->s_linebuf_ptr)) {
		status = refill_linebuf(src);
	}

	if (status != SUCCESS) {
		return -status;
	}

	if (fx_string_get_size(src->s_linebuf, FX_STRLEN_NORMAL) == 0) {
		return -ERR_EOF;
	}

	fx_wchar c = fx_iterator_get_value(src->s_linebuf_ptr).v_int;
	return c;
}

static int advance(struct line_source *src)
{
	enum status status = SUCCESS;

	if (!fx_iterator_is_valid(src->s_linebuf_ptr)) {
		status = refill_linebuf(src);
	}

	if (status != SUCCESS) {
		return -status;
	}

	if (fx_string_get_size(src->s_linebuf, FX_STRLEN_NORMAL) == 0) {
		return -ERR_EOF;
	}

	fx_wchar c = fx_iterator_get_value(src->s_linebuf_ptr).v_int;
	fx_iterator_move_next(src->s_linebuf_ptr);

	src->s_cursor.c_col++;
	if (c == '\n') {
		src->s_cursor.c_col = 1;
		src->s_cursor.c_row++;
	}
	return c;
}

fx_wchar line_source_peekc(struct line_source *src)
{
	return peek(src);
}

fx_wchar line_source_getc(struct line_source *src)
{
	return advance(src);
}

enum status line_source_get_row(
	struct line_source *src,
	size_t row,
	const fx_string **out)
{
	if (row == 0) {
		return ERR_INVALID_ARGUMENT;
	}

	row--;

	if (row >= fx_array_size(src->s_lines)) {
		return ERR_EOF;
	}

	fx_string *line = fx_array_at(src->s_lines, row);
	*out = line;

	return SUCCESS;
}

bool line_source_input_available(struct line_source *src)
{
	return src->s_linebuf_ptr && fx_iterator_is_valid(src->s_linebuf_ptr);
}