#include "commands.h"

#include <blue/cmd.h>
#include <zstd.h>
#include <stdio.h>
#include <stdlib.h>

enum {
	ARG_INPATH,
	OPT_OUTPATH,
	OPT_OUTPATH_PATH,
};

static int create(
	const b_command *self,
	const b_arglist *opt,
	const b_array *args)
{
	const char *in_path = NULL, *out_path = NULL;

	b_arglist_get_string(opt, B_COMMAND_INVALID_ID, ARG_INPATH, 0, &in_path);
	b_arglist_get_string(opt, OPT_OUTPATH, OPT_OUTPATH_PATH, 0, &out_path);

	printf("in path: %s\n", in_path);
	printf("out path: %s\n", out_path);

	size_t in_bufsz = ZSTD_CStreamInSize();
	size_t out_bufsz = ZSTD_CStreamOutSize();

	printf("in buffer: %zu\n", in_bufsz);
	printf("out buffer: %zu\n", out_bufsz);

	FILE *in = fopen(in_path, "rb");
	if (!in) {
		return -1;
	}

	FILE *out = fopen(out_path, "wb");
	if (!out) {
		return -1;
	}

	ZSTD_CCtx *zstd = ZSTD_createCCtx();
	ZSTD_CCtx_setParameter(zstd, ZSTD_c_compressionLevel, 22);
	ZSTD_CCtx_setParameter(zstd, ZSTD_c_checksumFlag, 1);

	void *in_buf = malloc(in_bufsz);
	void *out_buf = malloc(out_bufsz);

	size_t total = 0;

	while (1) {
		size_t r = fread(in_buf, 1, in_bufsz, in);
		if (r == 0) {
			break;
		}

		if ((total % 0x1000000) == 0) {
			printf("read %zu MB bytes\n", total / 1000000);
		}
		total += r;

		bool last_chunk = r < in_bufsz;
		ZSTD_EndDirective mode = last_chunk ? ZSTD_e_end : ZSTD_e_continue;

		ZSTD_inBuffer input = { in_buf, r, 0 };
		int finished;
		do {
			ZSTD_outBuffer output = { out_buf, out_bufsz, 0 };
			size_t remaining = ZSTD_compressStream2(zstd, &output, &input, mode);
			
			fwrite(out_buf, 1, output.pos, out);

			finished = last_chunk ? (remaining == 0) : (input.pos == input.size);
		} while (!finished);

		if (last_chunk) {
			break;
		}
	}

	ZSTD_freeCCtx(zstd);
	fclose(out);
	fclose(in);
	free(in_buf);
	free(out_buf);

	return 0;
}

B_COMMAND(CMD_CREATE, CMD_ROOT)
{
	B_COMMAND_NAME("create");
	B_COMMAND_SHORT_NAME('C');
	B_COMMAND_DESC("create an ec3 file");
	B_COMMAND_FLAGS(B_COMMAND_SHOW_HELP_BY_DEFAULT);
	B_COMMAND_FUNCTION(create);

	B_COMMAND_HELP_OPTION();

	B_COMMAND_OPTION(OPT_OUTPATH)
	{
		B_OPTION_SHORT_NAME('o');
		B_OPTION_LONG_NAME("out");
		B_OPTION_DESC("the path to save the new file to");

		B_OPTION_ARG(OPT_OUTPATH_PATH)
		{
			B_ARG_NAME("path");
			B_ARG_NR_VALUES(1);
		}
	}

	B_COMMAND_ARG(ARG_INPATH) {
		B_ARG_NAME("input file");
		B_ARG_NR_VALUES(1);
	}

	B_COMMAND_USAGE() {
		B_COMMAND_USAGE_ARG(ARG_INPATH);
		B_COMMAND_USAGE_OPT(OPT_OUTPATH);
	}
}