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

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

#define USES_ZLIB_COMPRESSION 1

const struct archiver archivers[] = {
        { "tar", write_tar_archive },
        { "zip", write_zip_archive, USES_ZLIB_COMPRESSION },
};

static int run_remote_archiver(const char *remote, int argc,
                               const char **argv)
{
        char *url, buf[LARGE_PACKET_MAX];
        int fd[2], i, len, rv;
        struct child_process *conn;
        const char *exec = "git-upload-archive";
        int exec_at = 0;

        for (i = 1; i < argc; i++) {
                const char *arg = argv[i];
                if (!prefixcmp(arg, "--exec=")) {
                        if (exec_at)
                                die("multiple --exec specified");
                        exec = arg + 7;
                        exec_at = i;
                        break;
                }
        }

        url = xstrdup(remote);
        conn = git_connect(fd, url, exec, 0);

        for (i = 1; i < argc; i++) {
                if (i == exec_at)
                        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 && !prefixcmp(buf, "NACK "))
                        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 = recv_sideband("archive", fd[0], 1, 2);
        close(fd[0]);
        close(fd[1]);
        rv |= finish_connect(conn);

        return !!rv;
}

static const struct archiver *lookup_archiver(const char *name)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(archivers); i++) {
                if (!strcmp(name, archivers[i].name))
                        return &archivers[i];
        }
        return NULL;
}

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;
        const 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");

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

int parse_archive_args(int argc, const char **argv, const struct archiver **ar,
                struct archiver_args *args)
{
        const char *format = "tar";
        const char *base = "";
        int compression_level = -1;
        int verbose = 0;
        int i;

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

                if (!strcmp(arg, "--list") || !strcmp(arg, "-l")) {
                        for (i = 0; i < ARRAY_SIZE(archivers); i++)
                                printf("%s\n", archivers[i].name);
                        exit(0);
                }
                if (!strcmp(arg, "--verbose") || !strcmp(arg, "-v")) {
                        verbose = 1;
                        continue;
                }
                if (!prefixcmp(arg, "--format=")) {
                        format = arg + 9;
                        continue;
                }
                if (!prefixcmp(arg, "--prefix=")) {
                        base = arg + 9;
                        continue;
                }
                if (!strcmp(arg, "--")) {
                        i++;
                        break;
                }
                if (arg[0] == '-' && isdigit(arg[1]) && arg[2] == '\0') {
                        compression_level = arg[1] - '0';
                        continue;
                }
                if (arg[0] == '-')
                        die("Unknown argument: %s", arg);
                break;
        }

        /* We need at least one parameter -- tree-ish */
        if (argc - 1 < i)
                usage(archive_usage);
        *ar = lookup_archiver(format);
        if (!*ar)
                die("Unknown archive format '%s'", format);

        args->compression_level = Z_DEFAULT_COMPRESSION;
        if (compression_level != -1) {
                if ((*ar)->flags & USES_ZLIB_COMPRESSION)
                        args->compression_level = compression_level;
                else {
                        die("Argument not supported for format '%s': -%d",
                                        format, compression_level);
                }
        }
        args->verbose = verbose;
        args->base = base;
        args->baselen = strlen(base);

        return i;
}

static const char *extract_remote_arg(int *ac, const char **av)
{
        int ix, iy, cnt = *ac;
        int no_more_options = 0;
        const char *remote = NULL;

        for (ix = iy = 1; ix < cnt; ix++) {
                const char *arg = av[ix];
                if (!strcmp(arg, "--"))
                        no_more_options = 1;
                if (!no_more_options) {
                        if (!prefixcmp(arg, "--remote=")) {
                                if (remote)
                                        die("Multiple --remote specified");
                                remote = arg + 9;
                                continue;
                        }
                        if (arg[0] != '-')
                                no_more_options = 1;
                }
                if (ix != iy)
                        av[iy] = arg;
                iy++;
        }
        if (remote) {
                av[--cnt] = NULL;
                *ac = cnt;
        }
        return remote;
}

int cmd_archive(int argc, const char **argv, const char *prefix)
{
        const struct archiver *ar = NULL;
        struct archiver_args args;
        int tree_idx;
        const char *remote = NULL;

        remote = extract_remote_arg(&argc, argv);
        if (remote)
                return run_remote_archiver(remote, argc, argv);

        setvbuf(stderr, NULL, _IOLBF, BUFSIZ);

        tree_idx = parse_archive_args(argc, argv, &ar, &args);
        if (prefix == NULL)
                prefix = setup_git_directory();

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

        return ar->write_archive(&args);
}