#include <errno.h>        /* for errno */
#include <error.h>        /* for error(3gnu) */
#include <inttypes.h>     /* PRI* */
#include <linux/fiemap.h> /* for FIEMAP_EXTENT_* */
#include <stdbool.h>      /* for bool, true, false */
#include <stdio.h>        /* sprintf(3p) */
#include <stdlib.h>       /* for malloc(3p), EXIT_FAILURE */
#include <string.h>       /* for strlen(3p), strcpy(3p) */

#include "extent-map.h"

struct flag {
	char *name;
	uint32_t value;
	bool active;
};

char *strextentflags(uint32_t flags) {
	struct flag known_flags[] = {
		{"LAST", FIEMAP_EXTENT_LAST, false},
		{"UNKNOWN", FIEMAP_EXTENT_UNKNOWN, false},
		{"DELALLOC", FIEMAP_EXTENT_DELALLOC, false},
		{"ENCODED", FIEMAP_EXTENT_ENCODED, false},
		{"DATA_ENCRYPTED", FIEMAP_EXTENT_DATA_ENCRYPTED, false},
		{"NOT_ALIGNED", FIEMAP_EXTENT_NOT_ALIGNED, false},
		{"DATA_INLINE", FIEMAP_EXTENT_DATA_INLINE, false},
		{"DATA_TAIL", FIEMAP_EXTENT_DATA_TAIL, false},
		{"UNWRITTEN", FIEMAP_EXTENT_UNWRITTEN, false},
		{"MERGED", FIEMAP_EXTENT_MERGED, false},
		{"SHARED", FIEMAP_EXTENT_SHARED, false},
	};
	size_t flagstr_cap = 0;
	for (size_t i = 0; i < sizeof(known_flags)/sizeof(known_flags[0]); i++) {
		if (!(flags & known_flags[i].value))
			continue;
		known_flags[i].active = true;
		flags ^= known_flags[i].value;
		switch (known_flags[i].value) {
		case FIEMAP_EXTENT_UNKNOWN:
			if (flags & FIEMAP_EXTENT_DELALLOC) {
				known_flags[i].name = "(UNKNOWN|DELALLOC)";
				flags ^= FIEMAP_EXTENT_DELALLOC;
			}
			break;
		case FIEMAP_EXTENT_ENCODED:
			if (flags & FIEMAP_EXTENT_DATA_ENCRYPTED) {
				known_flags[i].name = "(ENCODED|DATA_ENCRYPTED)";
				flags ^= FIEMAP_EXTENT_DATA_ENCRYPTED;
			}
			break;
		case FIEMAP_EXTENT_NOT_ALIGNED:
			switch (flags & (FIEMAP_EXTENT_DATA_INLINE|FIEMAP_EXTENT_DATA_TAIL)) {
			case FIEMAP_EXTENT_DATA_INLINE:
				known_flags[i].name = "(NOT_ALIGNED|DATA_INLINE)";
				flags ^= FIEMAP_EXTENT_DATA_INLINE;
				break;
			case FIEMAP_EXTENT_DATA_TAIL:
				known_flags[i].name = "(NOT_ALIGNED|DATA_TAIL)";
				flags ^= FIEMAP_EXTENT_DATA_TAIL;
				break;
			case FIEMAP_EXTENT_DATA_INLINE|FIEMAP_EXTENT_DATA_TAIL:
				known_flags[i].name = "(NOT_ALIGNED|DATA_INLINE|DATA_TAIL)";
				flags ^= FIEMAP_EXTENT_DATA_INLINE|FIEMAP_EXTENT_DATA_TAIL;
				break;
			}
			break;
		}
		if (flagstr_cap)
			flagstr_cap++;
		flagstr_cap += strlen(known_flags[i].name);
	}
	if (flags)
		flagstr_cap += (flagstr_cap ? 1 : 0) + 10;
	char *flagstr = malloc(flagstr_cap+1);
	if (!flagstr)
		error(EXIT_FAILURE, errno, "malloc");
	size_t flagstr_len = 0;
	for (size_t i = 0; i < sizeof(known_flags)/sizeof(known_flags[0]); i++) {
		if (!known_flags[i].active)
			continue;
		if (flagstr_len)
			flagstr[flagstr_len++] = '|';
		strcpy(&flagstr[flagstr_len], known_flags[i].name);
		flagstr_len += strlen(known_flags[i].name);
	}
	if (flags) {
		if (flagstr_len)
			flagstr[flagstr_len++] = '|';
		sprintf(&flagstr[flagstr_len], "0x%08"PRIx32, flags);
	};
	return flagstr;
}