/*
 * Copyright (c) 2006 Franck Bui-Huu
 * Copyright (c) 2006 Rene Scharfe
 */
#include <time.h>
#include "cache.h"
#include "builtin.h"
#include "archive.h"
#include "commit.h"
#include "tree-walk.h"
#include "exec_cmd.h"
#include "pkt-line.h"

static const char archive_usage[] = \
"git-archive --format=<fmt> [--prefix=<prefix>/] [<extra>] <tree-ish> [path...]";

struct archiver archivers[] = {
        { "" /* dummy */ },
};

static int run_remote_archiver(struct archiver *ar, int argc,
                               const char **argv)
{
        char *url, buf[1024];
        int fd[2], i, len, rv;
        pid_t pid;

        sprintf(buf, "git-upload-archive");

        url = xstrdup(ar->remote);
        pid = git_connect(fd, url, buf);
        if (pid < 0)
                return pid;

        for (i = 1; i < argc; i++) {
                if (!strncmp(argv[i], "--remote=", 9))
                        continue;
                packet_write(fd[1], "argument %s\n", argv[i]);
        }
        packet_flush(fd[1]);

        len = packet_read_line(fd[0], buf, sizeof(buf));
        if (!len)
                die("git-archive: expected ACK/NAK, got EOF");
        if (buf[len-1] == '\n')
                buf[--len] = 0;
        if (strcmp(buf, "ACK")) {
                if (len > 5 && !strncmp(buf, "NACK ", 5))
                        die("git-archive: NACK %s", buf + 5);
                die("git-archive: protocol error");
        }

        len = packet_read_line(fd[0], buf, sizeof(buf));
        if (len)
                die("git-archive: expected a flush");

        /* Now, start reading from fd[0] and spit it out to stdout */
        rv = copy_fd(fd[0], 1);

        close(fd[0]);
        rv |= finish_connect(pid);

        return !!rv;
}

static int init_archiver(const char *name, struct archiver *ar)
{
        int rv = -1, i;

        for (i = 0; i < ARRAY_SIZE(archivers); i++) {
                if (!strcmp(name, archivers[i].name)) {
                        memcpy(ar, &archivers[i], sizeof(struct archiver));
                        rv = 0;
                        break;
                }
        }
        return rv;
}

void parse_pathspec_arg(const char **pathspec, struct archiver_args *ar_args)
{
        ar_args->pathspec = get_pathspec(ar_args->base, pathspec);
}

void parse_treeish_arg(const char **argv, struct archiver_args *ar_args,
                       const char *prefix)
{
        const char *name = argv[0];
        const unsigned char *commit_sha1;
        time_t archive_time;
        struct tree *tree;
        struct commit *commit;
        unsigned char sha1[20];

        if (get_sha1(name, sha1))
                die("Not a valid object name");

        commit = lookup_commit_reference_gently(sha1, 1);
        if (commit) {
                commit_sha1 = commit->object.sha1;
                archive_time = commit->date;
        } else {
                commit_sha1 = NULL;
                archive_time = time(NULL);
        }

        tree = parse_tree_indirect(sha1);
        if (tree == NULL)
                die("not a tree object");

        if (prefix) {
                unsigned char tree_sha1[20];
                unsigned int mode;
                int err;

                err = get_tree_entry(tree->object.sha1, prefix,
                                     tree_sha1, &mode);
                if (err || !S_ISDIR(mode))
                        die("current working directory is untracked");

                free(tree);
                tree = parse_tree_indirect(tree_sha1);
        }
        ar_args->tree = tree;
        ar_args->commit_sha1 = commit_sha1;
        ar_args->time = archive_time;
}

static const char *default_parse_extra(struct archiver *ar,
                                       const char **argv)
{
        static char msg[64];

        snprintf(msg, sizeof(msg) - 4, "'%s' format does not handle %s",
                 ar->name, *argv);

        return strcat(msg, "...");
}

int parse_archive_args(int argc, const char **argv, struct archiver *ar)
{
        const char *extra_argv[MAX_EXTRA_ARGS];
        int extra_argc = 0;
        const char *format = NULL; /* might want to default to "tar" */
        const char *remote = NULL;
        const char *base = "";
        int list = 0;
        int i;

        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];

                if (!strcmp(arg, "--list") || !strcmp(arg, "-l")) {
                        list = 1;
                        continue;
                }
                if (!strncmp(arg, "--format=", 9)) {
                        format = arg + 9;
                        continue;
                }
                if (!strncmp(arg, "--prefix=", 9)) {
                        base = arg + 9;
                        continue;
                }
                if (!strncmp(arg, "--remote=", 9)) {
                        remote = arg + 9;
                        continue;
                }
                if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                if (arg[0] == '-') {
                        if (extra_argc > MAX_EXTRA_ARGS - 1)
                                die("Too many extra options");
                        extra_argv[extra_argc++] = arg;
                        continue;
                }
                break;
        }

        if (list) {
                if (!remote) {
                        for (i = 0; i < ARRAY_SIZE(archivers); i++)
                                printf("%s\n", archivers[i].name);
                        exit(0);
                }
                die("--list and --remote are mutually exclusive");
        }

        if (argc - i < 1)
                usage(archive_usage);
        if (!format)
                die("You must specify an archive format");
        if (init_archiver(format, ar) < 0)
                die("Unknown archive format '%s'", format);

        if (extra_argc && !remote) {
                if (!ar->parse_extra) {
                        die("%s", default_parse_extra(ar, extra_argv));
                }
                ar->args.extra = ar->parse_extra(extra_argc, extra_argv);
        }
        ar->remote = remote;
        ar->args.base = base;

        return i;
}

int cmd_archive(int argc, const char **argv, const char *prefix)
{
        struct archiver ar;
        int tree_idx;

        tree_idx = parse_archive_args(argc, argv, &ar);

        if (ar.remote)
                return run_remote_archiver(&ar, argc, argv);

        if (prefix == NULL)
                prefix = setup_git_directory();

        argv += tree_idx;
        parse_treeish_arg(argv, &ar.args, prefix);
        parse_pathspec_arg(argv + 1, &ar.args);

        return ar.write_archive(&ar.args);
}