#define _GNU_SOURCE   /* for program_invocation_name */
#include <assert.h>   /* for assert(3p) */
#include <errno.h>    /* for errno, program_invocation_name */
#include <error.h>    /* for error(3gnu) */
#include <fcntl.h>    /* for open(2) and O_RDONLY */
#include <getopt.h>   /* for getopt_long(3gnu), struct option, optind, optarg */
#include <inttypes.h> /* for PRI* */
#include <stdbool.h>  /* for bool, true, false */
#include <stdio.h>    /* for printf(3p), fprintf(3p), stderr */
#include <stdlib.h>   /* for free(3p), exit(3p), EXIT_SUCCESS, EXIT_FAILURE */
#include <string.h>   /* for strcmp(3p) */
#include <unistd.h>   /* for close(2) */

#include "extent-map.h" /* for uint32_t, fiemap stuff */ 

#define EXIT_INVALIDARGUMENT 2
#define errusage(format, ...) do { \
	error(0, 0, format, ## __VA_ARGS__); \
	fprintf(stderr, "Try '%s --help' for more information.\n", program_invocation_name); \
	exit(EXIT_INVALIDARGUMENT); \
} while(0)

bool indent;

int print_extent(struct fiemap_extent extent) {
	char *flagstr = strextentflags(extent.fe_flags);
	printf("%s"
	       "logical=%"PRIu64" "
	       "physical=%"PRIu64" "
	       "length=%"PRIu64" "
	       "flags=0x%08"PRIx32" (%s)\n",
	       indent ? "\t" : "",
	       extent.fe_logical,
	       extent.fe_physical,
	       extent.fe_length,
	       extent.fe_flags,
	       flagstr);
	free(flagstr);
	return 0;
}

void usage() {
	printf("Usage: %s [OPTIONS] FILENAME...\n"
	       "Print a file extent map.\n"
	       "\n"
	       "OPTIONS:\n"
	       "  --stream=data   Map extents in the data stream (default).\n"
	       "  --stream=xattr  Map extents in the extended attribute stream.\n"
	       "  --sync          Sync the file before mapping extents (default).\n"
	       "  --no-sync       Don't sync the file before mapping extents.\n"
	       "  -m, --machine   Display the output in a more machine-friendly format.\n"
	       "  -h, --help      Display this help and exit.\n",
	       program_invocation_name);
}

int main(int argc, char *argv[]) {
	char *stream = "data";
	bool machine = false;
	int sync = 1;
	struct option long_options[] = {
		{"stream",  optional_argument, NULL, 1},
		{"sync",    no_argument,       &sync, 1},
		{"no-sync", no_argument,       &sync, 0},
		{"help",    no_argument,       NULL, 'h'},
		{0},
	};
	int flag;
	while ((flag = getopt_long(argc, argv, "mh", long_options, NULL)) >= 0) {
		switch (flag) {
		case 0:
			break;
		case 1:
			stream = optarg;
			break;
		case 'm':
			machine = true;
			break;
		case 'h':
			usage();
			return EXIT_SUCCESS;
		case '?':
			fprintf(stderr, "Try '%s --help' for more information.\n", program_invocation_name);
			return EXIT_INVALIDARGUMENT;
		default:
			assert(0);
		}
	}
	if (argc - optind < 1)
		errusage("wrong number of arguments");

	uint32_t flags = sync ? FIEMAP_FLAG_SYNC : 0;
	if (strcmp(stream, "data") == 0) {
		/* do nothing */
	} else if (strcmp(stream, "xattr") == 0) {
		flags |= FIEMAP_FLAG_XATTR;
	} else {
		errusage("invalid stream name");
	}

	indent = (argc - optind) > 1 && !machine;

	int status = 0;
	for (int i = optind; i < argc; i++) {
		char *filename = argv[i];
		int fd = open(filename, O_RDONLY);
		if (fd < 0) {
			error(0, errno, "%s", filename);
			status |= EXIT_FAILURE;
			continue;
		}

		if (machine) {
			printf("%s", filename);
			putchar('\0');
		} else if (argc - optind > 1)
			printf("%s:\n", filename);

		int r = fiemap(fd, flags, print_extent);
		if (r < 0) {
			error(0, -r, "%s: FS_IOC_FIEMAP", filename);
			status |= EXIT_FAILURE;
		} else {
			status |= r;
		}
		if (machine)
			putchar('\0');
		close(fd);
	}
	return status;
}