/*
 * GIT - The information manager from hell
 *
 * Copyright (C) Linus Torvalds, 2005
 */
#include "cache.h"

static int line_termination = '\n';
static int recursive = 0;

struct path_prefix {
        struct path_prefix *prev;
        const char *name;
};

#define DEBUG(fmt, ...) 

static int string_path_prefix(char *buff, size_t blen, struct path_prefix *prefix)
{
        int len = 0;
        if (prefix) {
                if (prefix->prev) {
                        len = string_path_prefix(buff,blen,prefix->prev);
                        buff += len;
                        blen -= len;
                        if (blen > 0) {
                                *buff = '/';
                                len++;
                                buff++;
                                blen--;
                        }
                }
                strncpy(buff,prefix->name,blen);
                return len + strlen(prefix->name);
        }

        return 0;
}

static void print_path_prefix(struct path_prefix *prefix)
{
        if (prefix) {
                if (prefix->prev) {
                        print_path_prefix(prefix->prev);
                        putchar('/');
                }
                fputs(prefix->name, stdout);
        }
}

/*
 * return:
 *      -1 if prefix is *not* a subset of path
 *       0 if prefix == path
 *       1 if prefix is a subset of path
 */
static int pathcmp(const char *path, struct path_prefix *prefix)
{
        char buff[PATH_MAX];
        int len,slen;

        if (prefix == NULL)
                return 1;

        len = string_path_prefix(buff, sizeof buff, prefix);
        slen = strlen(path);

        if (slen < len)
                return -1;

        if (strncmp(path,buff,len) == 0) {
                if (slen == len)
                        return 0;
                else
                        return 1;
        }

        return -1;
}       

/*
 * match may be NULL, or a *sorted* list of paths
 */
static void list_recursive(void *buffer,
                           const char *type,
                           unsigned long size,
                           struct path_prefix *prefix,
                           char **match, int matches)
{
        struct path_prefix this_prefix;
        this_prefix.prev = prefix;

        if (strcmp(type, "tree"))
                die("expected a 'tree' node");

        if (matches)
                recursive = 1;

        while (size) {
                int namelen = strlen(buffer)+1;
                void *eltbuf = NULL;
                char elttype[20];
                unsigned long eltsize;
                unsigned char *sha1 = buffer + namelen;
                char *path = strchr(buffer, ' ') + 1;
                unsigned int mode;
                const char *matched = NULL;
                int mtype = -1;
                int mindex;

                if (size < namelen + 20 || sscanf(buffer, "%o", &mode) != 1)
                        die("corrupt 'tree' file");
                buffer = sha1 + 20;
                size -= namelen + 20;

                this_prefix.name = path;
                for ( mindex = 0; mindex < matches; mindex++) {
                        mtype = pathcmp(match[mindex],&this_prefix);
                        if (mtype >= 0) {
                                matched = match[mindex];
                                break;
                        }
                }

                /*
                 * If we're not matching, or if this is an exact match,
                 * print out the info
                 */
                if (!matches || (matched != NULL && mtype == 0)) {
                        printf("%06o %s %s\t", mode,
                               S_ISDIR(mode) ? "tree" : "blob",
                               sha1_to_hex(sha1));
                        print_path_prefix(&this_prefix);
                        putchar(line_termination);
                }

                if (! recursive || ! S_ISDIR(mode))
                        continue;

                if (matches && ! matched)
                        continue;

                if (! (eltbuf = read_sha1_file(sha1, elttype, &eltsize)) ) {
                        error("cannot read %s", sha1_to_hex(sha1));
                        continue;
                }

                /* If this is an exact directory match, we may have
                 * directory files following this path. Match on them.
                 * Otherwise, we're at a pach subcomponent, and we need
                 * to try to match again.
                 */
                if (mtype == 0)
                        mindex++;

                list_recursive(eltbuf, elttype, eltsize, &this_prefix, &match[mindex], matches-mindex);
                free(eltbuf);
        }
}

static int qcmp(const void *a, const void *b)
{
        return strcmp(*(char **)a, *(char **)b);
}

static int list(unsigned char *sha1,char **path)
{
        void *buffer;
        unsigned long size;
        int npaths;

        for (npaths = 0; path[npaths] != NULL; npaths++)
                ;

        qsort(path,npaths,sizeof(char *),qcmp);

        buffer = read_object_with_reference(sha1, "tree", &size, NULL);
        if (!buffer)
                die("unable to read sha1 file");
        list_recursive(buffer, "tree", size, NULL, path, npaths);
        free(buffer);
        return 0;
}

static const char *ls_tree_usage = "git-ls-tree [-r] [-z] <key> [paths...]";

int main(int argc, char **argv)
{
        unsigned char sha1[20];

        while (1 < argc && argv[1][0] == '-') {
                switch (argv[1][1]) {
                case 'z':
                        line_termination = 0;
                        break;
                case 'r':
                        recursive = 1;
                        break;
                default:
                        usage(ls_tree_usage);
                }
                argc--; argv++;
        }

        if (argc < 2)
                usage(ls_tree_usage);
        if (get_sha1(argv[1], sha1) < 0)
                usage(ls_tree_usage);
        if (list(sha1, &argv[2]) < 0)
                die("list failed");
        return 0;
}