#include "cache.h"
#include "remote.h"
#include "strbuf.h"
#include "url.h"
#include "exec_cmd.h"
#include "run-command.h"
#include "vcs-svn/svndump.h"
#include "notes.h"
#include "argv-array.h"

static const char *url;
static const char *private_ref;
static const char *remote_ref = "refs/heads/master";

static int cmd_capabilities(const char *line);
static int cmd_import(const char *line);
static int cmd_list(const char *line);

typedef int (*input_command_handler)(const char *);
struct input_command_entry {
        const char *name;
        input_command_handler fn;
        unsigned char batchable;        /* whether the command starts or is part of a batch */
};

static const struct input_command_entry input_command_list[] = {
        { "capabilities", cmd_capabilities, 0 },
        { "import", cmd_import, 1 },
        { "list", cmd_list, 0 },
        { NULL, NULL }
};

static int cmd_capabilities(const char *line)
{
        printf("import\n");
        printf("bidi-import\n");
        printf("refspec %s:%s\n\n", remote_ref, private_ref);
        fflush(stdout);
        return 0;
}

static void terminate_batch(void)
{
        /* terminate a current batch's fast-import stream */
        printf("done\n");
        fflush(stdout);
}

static int cmd_import(const char *line)
{
        int code;
        int dumpin_fd;
        unsigned int startrev = 0;
        struct argv_array svndump_argv = ARGV_ARRAY_INIT;
        struct child_process svndump_proc;

        memset(&svndump_proc, 0, sizeof(struct child_process));
        svndump_proc.out = -1;
        argv_array_push(&svndump_argv, "svnrdump");
        argv_array_push(&svndump_argv, "dump");
        argv_array_push(&svndump_argv, url);
        argv_array_pushf(&svndump_argv, "-r%u:HEAD", startrev);
        svndump_proc.argv = svndump_argv.argv;

        code = start_command(&svndump_proc);
        if (code)
                die("Unable to start %s, code %d", svndump_proc.argv[0], code);
        dumpin_fd = svndump_proc.out;

        svndump_init_fd(dumpin_fd, STDIN_FILENO);
        svndump_read(url, private_ref);
        svndump_deinit();
        svndump_reset();

        close(dumpin_fd);
        code = finish_command(&svndump_proc);
        if (code)
                warning("%s, returned %d", svndump_proc.argv[0], code);
        argv_array_clear(&svndump_argv);

        return 0;
}

static int cmd_list(const char *line)
{
        printf("? %s\n\n", remote_ref);
        fflush(stdout);
        return 0;
}

static int do_command(struct strbuf *line)
{
        const struct input_command_entry *p = input_command_list;
        static struct string_list batchlines = STRING_LIST_INIT_DUP;
        static const struct input_command_entry *batch_cmd;
        /*
         * commands can be grouped together in a batch.
         * Batches are ended by \n. If no batch is active the program ends.
         * During a batch all lines are buffered and passed to the handler function
         * when the batch is terminated.
         */
        if (line->len == 0) {
                if (batch_cmd) {
                        struct string_list_item *item;
                        for_each_string_list_item(item, &batchlines)
                                batch_cmd->fn(item->string);
                        terminate_batch();
                        batch_cmd = NULL;
                        string_list_clear(&batchlines, 0);
                        return 0;       /* end of the batch, continue reading other commands. */
                }
                return 1;       /* end of command stream, quit */
        }
        if (batch_cmd) {
                if (prefixcmp(batch_cmd->name, line->buf))
                        die("Active %s batch interrupted by %s", batch_cmd->name, line->buf);
                /* buffer batch lines */
                string_list_append(&batchlines, line->buf);
                return 0;
        }

        for (p = input_command_list; p->name; p++) {
                if (!prefixcmp(line->buf, p->name) && (strlen(p->name) == line->len ||
                                line->buf[strlen(p->name)] == ' ')) {
                        if (p->batchable) {
                                batch_cmd = p;
                                string_list_append(&batchlines, line->buf);
                                return 0;
                        }
                        return p->fn(line->buf);
                }
        }
        die("Unknown command '%s'\n", line->buf);
        return 0;
}

int main(int argc, const char **argv)
{
        struct strbuf buf = STRBUF_INIT, url_sb = STRBUF_INIT,
                        private_ref_sb = STRBUF_INIT;
        static struct remote *remote;
        const char *url_in;

        git_extract_argv0_path(argv[0]);
        setup_git_directory();
        if (argc < 2 || argc > 3) {
                usage("git-remote-svn <remote-name> [<url>]");
                return 1;
        }

        remote = remote_get(argv[1]);
        url_in = (argc == 3) ? argv[2] : remote->url[0];

        end_url_with_slash(&url_sb, url_in);
        url = url_sb.buf;

        strbuf_addf(&private_ref_sb, "refs/svn/%s/master", remote->name);
        private_ref = private_ref_sb.buf;

        while (1) {
                if (strbuf_getline(&buf, stdin, '\n') == EOF) {
                        if (ferror(stdin))
                                die("Error reading command stream");
                        else
                                die("Unexpected end of command stream");
                }
                if (do_command(&buf))
                        break;
                strbuf_reset(&buf);
        }

        strbuf_release(&buf);
        strbuf_release(&url_sb);
        strbuf_release(&private_ref_sb);
        return 0;
}