#include <bshell/file.h>
#include <bshell/line-source.h>
#include <errno.h>
#include <fx/collections/array.h>
#include <fx/string.h>
#include <stdlib.h>
#include <string.h>

static enum bshell_status get_name(
	struct bshell_line_source *src,
	char *buf,
	size_t count,
	size_t *nr_read)
{
	struct bshell_file *f = (struct bshell_file *)src;
	*nr_read = snprintf(buf, count, "%s", f->f_path);
	return BSHELL_SUCCESS;
}

static enum bshell_status get_row(
	struct bshell_line_source *src,
	size_t row,
	char *buf,
	size_t count,
	size_t *nr_read)
{
	struct bshell_file *f = (struct bshell_file *)src;
	size_t nr_rows = fx_array_get_size(f->f_lines);

	if (row > nr_rows) {
		return BSHELL_ERR_EOF;
	}

	fx_value *line_v = fx_array_get_ref(f->f_lines, row - 1);
	fx_string *line = NULL;
	fx_value_get_object(line_v, &line);

	const char *line_str = fx_string_get_cstr(line);
	size_t line_len = fx_string_get_size(line, FX_STRLEN_NORMAL);
	size_t copy_len = fx_min(ulong, count, line_len);

	memcpy(buf, line_str, copy_len);
	buf[copy_len] = 0;
	buf[strcspn(buf, "\n")] = 0;
	*nr_read = copy_len;

	return BSHELL_SUCCESS;
}

static enum bshell_status readline(
	struct bshell_line_source *src,
	fx_stringstream *out)
{
	struct bshell_file *f = (struct bshell_file *)src;
	fx_wchar c = FX_WCHAR_INVALID;
	size_t nr_read = 0;

	while (1) {
		fx_status status = fx_stream_read_char(f->f_strp, &c);
		if (!FX_OK(status)) {
			break;
		}

		fx_stream_write_char(out, c);
		nr_read++;

		if (c == '\n') {
			break;
		}
	}

	if (nr_read == 0) {
		return BSHELL_ERR_EOF;
	}

	return BSHELL_SUCCESS;
}

enum bshell_status bshell_file_open(const char *path, struct bshell_file **out)
{
	FILE *fp = fopen(path, "r");
	if (!fp) {
		return bshell_status_from_errno(errno);
	}

	fx_stream *strp = fx_stream_open_fp(fp);

	struct bshell_file *file = malloc(sizeof *file);
	if (!file) {
		fclose(fp);
		return BSHELL_ERR_NO_MEMORY;
	}

	memset(file, 0x0, sizeof *file);

	file->f_base.s_get_name = get_name;
	file->f_base.s_get_row = get_row;
	file->f_base.s_readline = readline;
	file->f_fp = fp;
	file->f_strp = strp;
	file->f_path = fx_strdup(path);
	file->f_lines = fx_array_create();

	*out = file;

	return BSHELL_SUCCESS;
}

void bshell_file_close(struct bshell_file *file)
{
	fx_stream_unref(file->f_strp);
	fx_array_unref(file->f_lines);
	free(file->f_path);
	fclose(file->f_fp);
	free(file);
}