#include "builtin.h"
#include "cache.h"
#include "pack.h"
#include "pack-revindex.h"
#include "parse-options.h"

#define MAX_CHAIN 50

#define VERIFY_PACK_VERBOSE 01
#define VERIFY_PACK_STAT_ONLY 02

static void show_pack_info(struct packed_git *p, unsigned int flags)
{
        uint32_t nr_objects, i;
        int cnt;
        int stat_only = flags & VERIFY_PACK_STAT_ONLY;
        unsigned long chain_histogram[MAX_CHAIN+1], baseobjects;

        nr_objects = p->num_objects;
        memset(chain_histogram, 0, sizeof(chain_histogram));
        baseobjects = 0;

        for (i = 0; i < nr_objects; i++) {
                const unsigned char *sha1;
                unsigned char base_sha1[20];
                const char *type;
                unsigned long size;
                unsigned long store_size;
                off_t offset;
                unsigned int delta_chain_length;

                sha1 = nth_packed_object_sha1(p, i);
                if (!sha1)
                        die("internal error pack-check nth-packed-object");
                offset = nth_packed_object_offset(p, i);
                type = packed_object_info_detail(p, offset, &size, &store_size,
                                                 &delta_chain_length,
                                                 base_sha1);
                if (!stat_only)
                        printf("%s ", sha1_to_hex(sha1));
                if (!delta_chain_length) {
                        if (!stat_only)
                                printf("%-6s %lu %lu %"PRIuMAX"\n",
                                       type, size, store_size, (uintmax_t)offset);
                        baseobjects++;
                }
                else {
                        if (!stat_only)
                                printf("%-6s %lu %lu %"PRIuMAX" %u %s\n",
                                       type, size, store_size, (uintmax_t)offset,
                                       delta_chain_length, sha1_to_hex(base_sha1));
                        if (delta_chain_length <= MAX_CHAIN)
                                chain_histogram[delta_chain_length]++;
                        else
                                chain_histogram[0]++;
                }
        }

        if (baseobjects)
                printf("non delta: %lu object%s\n",
                       baseobjects, baseobjects > 1 ? "s" : "");

        for (cnt = 1; cnt <= MAX_CHAIN; cnt++) {
                if (!chain_histogram[cnt])
                        continue;
                printf("chain length = %d: %lu object%s\n", cnt,
                       chain_histogram[cnt],
                       chain_histogram[cnt] > 1 ? "s" : "");
        }
        if (chain_histogram[0])
                printf("chain length > %d: %lu object%s\n", MAX_CHAIN,
                       chain_histogram[0],
                       chain_histogram[0] > 1 ? "s" : "");
}

static int verify_one_pack(const char *path, unsigned int flags)
{
        char arg[PATH_MAX];
        int len;
        int verbose = flags & VERIFY_PACK_VERBOSE;
        int stat_only = flags & VERIFY_PACK_STAT_ONLY;
        struct packed_git *pack;
        int err;

        len = strlcpy(arg, path, PATH_MAX);
        if (len >= PATH_MAX)
                return error("name too long: %s", path);

        /*
         * In addition to "foo.idx" we accept "foo.pack" and "foo";
         * normalize these forms to "foo.idx" for add_packed_git().
         */
        if (has_extension(arg, ".pack")) {
                strcpy(arg + len - 5, ".idx");
                len--;
        } else if (!has_extension(arg, ".idx")) {
                if (len + 4 >= PATH_MAX)
                        return error("name too long: %s.idx", arg);
                strcpy(arg + len, ".idx");
                len += 4;
        }

        /*
         * add_packed_git() uses our buffer (containing "foo.idx") to
         * build the pack filename ("foo.pack").  Make sure it fits.
         */
        if (len + 1 >= PATH_MAX) {
                arg[len - 4] = '\0';
                return error("name too long: %s.pack", arg);
        }

        pack = add_packed_git(arg, len, 1);
        if (!pack)
                return error("packfile %s not found.", arg);

        install_packed_git(pack);

        if (!stat_only)
                err = verify_pack(pack);
        else
                err = open_pack_index(pack);

        if (verbose || stat_only) {
                if (err)
                        printf("%s: bad\n", pack->pack_name);
                else {
                        show_pack_info(pack, flags);
                        if (!stat_only)
                                printf("%s: ok\n", pack->pack_name);
                }
        }

        return err;
}

static const char * const verify_pack_usage[] = {
        "git verify-pack [-v|--verbose] [-s|--stat-only] <pack>...",
        NULL
};

int cmd_verify_pack(int argc, const char **argv, const char *prefix)
{
        int err = 0;
        unsigned int flags = 0;
        int i;
        const struct option verify_pack_options[] = {
                OPT_BIT('v', "verbose", &flags, "verbose",
                        VERIFY_PACK_VERBOSE),
                OPT_BIT('s', "stat-only", &flags, "show statistics only",
                        VERIFY_PACK_STAT_ONLY),
                OPT_END()
        };

        git_config(git_default_config, NULL);
        argc = parse_options(argc, argv, prefix, verify_pack_options,
                             verify_pack_usage, 0);
        if (argc < 1)
                usage_with_options(verify_pack_usage, verify_pack_options);
        for (i = 0; i < argc; i++) {
                if (verify_one_pack(argv[i], flags))
                        err = 1;
                discard_revindex();
        }

        return err;
}