#include "builtin.h"
#include "config.h"
#include "dir.h"
#include "lockfile.h"
#include "parse-options.h"
#include "commit-graph.h"

static char const * const builtin_commit_graph_usage[] = {
        N_("git commit-graph [--object-dir <objdir>]"),
        N_("git commit-graph read [--object-dir <objdir>]"),
        N_("git commit-graph write [--object-dir <objdir>] [--stdin-packs|--stdin-commits]"),
        NULL
};

static const char * const builtin_commit_graph_read_usage[] = {
        N_("git commit-graph read [--object-dir <objdir>]"),
        NULL
};

static const char * const builtin_commit_graph_write_usage[] = {
        N_("git commit-graph write [--object-dir <objdir>] [--stdin-packs|--stdin-commits]"),
        NULL
};

static struct opts_commit_graph {
        const char *obj_dir;
        int stdin_packs;
        int stdin_commits;
} opts;

static int graph_read(int argc, const char **argv)
{
        struct commit_graph *graph = NULL;
        char *graph_name;

        static struct option builtin_commit_graph_read_options[] = {
                OPT_STRING(0, "object-dir", &opts.obj_dir,
                        N_("dir"),
                        N_("The object directory to store the graph")),
                OPT_END(),
        };

        argc = parse_options(argc, argv, NULL,
                             builtin_commit_graph_read_options,
                             builtin_commit_graph_read_usage, 0);

        if (!opts.obj_dir)
                opts.obj_dir = get_object_directory();

        graph_name = get_commit_graph_filename(opts.obj_dir);
        graph = load_commit_graph_one(graph_name);

        if (!graph)
                die("graph file %s does not exist", graph_name);
        FREE_AND_NULL(graph_name);

        printf("header: %08x %d %d %d %d\n",
                ntohl(*(uint32_t*)graph->data),
                *(unsigned char*)(graph->data + 4),
                *(unsigned char*)(graph->data + 5),
                *(unsigned char*)(graph->data + 6),
                *(unsigned char*)(graph->data + 7));
        printf("num_commits: %u\n", graph->num_commits);
        printf("chunks:");

        if (graph->chunk_oid_fanout)
                printf(" oid_fanout");
        if (graph->chunk_oid_lookup)
                printf(" oid_lookup");
        if (graph->chunk_commit_data)
                printf(" commit_metadata");
        if (graph->chunk_large_edges)
                printf(" large_edges");
        printf("\n");

        return 0;
}

static int graph_write(int argc, const char **argv)
{
        const char **pack_indexes = NULL;
        int packs_nr = 0;
        const char **commit_hex = NULL;
        int commits_nr = 0;
        const char **lines = NULL;
        int lines_nr = 0;
        int lines_alloc = 0;

        static struct option builtin_commit_graph_write_options[] = {
                OPT_STRING(0, "object-dir", &opts.obj_dir,
                        N_("dir"),
                        N_("The object directory to store the graph")),
                OPT_BOOL(0, "stdin-packs", &opts.stdin_packs,
                        N_("scan pack-indexes listed by stdin for commits")),
                OPT_BOOL(0, "stdin-commits", &opts.stdin_commits,
                        N_("start walk at commits listed by stdin")),
                OPT_END(),
        };

        argc = parse_options(argc, argv, NULL,
                             builtin_commit_graph_write_options,
                             builtin_commit_graph_write_usage, 0);

        if (opts.stdin_packs && opts.stdin_commits)
                die(_("cannot use both --stdin-commits and --stdin-packs"));
        if (!opts.obj_dir)
                opts.obj_dir = get_object_directory();

        if (opts.stdin_packs || opts.stdin_commits) {
                struct strbuf buf = STRBUF_INIT;
                lines_nr = 0;
                lines_alloc = 128;
                ALLOC_ARRAY(lines, lines_alloc);

                while (strbuf_getline(&buf, stdin) != EOF) {
                        ALLOC_GROW(lines, lines_nr + 1, lines_alloc);
                        lines[lines_nr++] = strbuf_detach(&buf, NULL);
                }

                if (opts.stdin_packs) {
                        pack_indexes = lines;
                        packs_nr = lines_nr;
                }
                if (opts.stdin_commits) {
                        commit_hex = lines;
                        commits_nr = lines_nr;
                }
        }

        write_commit_graph(opts.obj_dir,
                           pack_indexes,
                           packs_nr,
                           commit_hex,
                           commits_nr);

        return 0;
}

int cmd_commit_graph(int argc, const char **argv, const char *prefix)
{
        static struct option builtin_commit_graph_options[] = {
                OPT_STRING(0, "object-dir", &opts.obj_dir,
                        N_("dir"),
                        N_("The object directory to store the graph")),
                OPT_END(),
        };

        if (argc == 2 && !strcmp(argv[1], "-h"))
                usage_with_options(builtin_commit_graph_usage,
                                   builtin_commit_graph_options);

        git_config(git_default_config, NULL);
        argc = parse_options(argc, argv, prefix,
                             builtin_commit_graph_options,
                             builtin_commit_graph_usage,
                             PARSE_OPT_STOP_AT_NON_OPTION);

        if (argc > 0) {
                if (!strcmp(argv[0], "read"))
                        return graph_read(argc, argv);
                if (!strcmp(argv[0], "write"))
                        return graph_write(argc, argv);
        }

        usage_with_options(builtin_commit_graph_usage,
                           builtin_commit_graph_options);
}