/*

 * libgit2 "cat-file" example - shows how to print data from the ODB

 *

 * Written by the libgit2 contributors

 *

 * To the extent possible under law, the author(s) have dedicated all copyright

 * and related and neighboring rights to this software to the public domain

 * worldwide. This software is distributed without any warranty.

 *

 * You should have received a copy of the CC0 Public Domain Dedication along

 * with this software. If not, see

 * <http://creativecommons.org/publicdomain/zero/1.0/>.

 */

#include "common.h"

static void print_signature(const char *header, const git_signature *sig)

{

	char sign;

	int offset, hours, minutes;

	if (!sig)

		return;

	offset = sig->when.offset;

	if (offset < 0) {

		sign = '-';

		offset = -offset;

	} else {

		sign = '+';

	}

	hours   = offset / 60;

	minutes = offset % 60;

	printf("%s %s <%s> %ld %c%02d%02d\n",

		   header, sig->name, sig->email, (long)sig->when.time,

		   sign, hours, minutes);

}

/** Printing out a blob is simple, get the contents and print */

static void show_blob(const git_blob *blob)

{

	/* ? Does this need crlf filtering? */

	fwrite(git_blob_rawcontent(blob), (size_t)git_blob_rawsize(blob), 1, stdout);

}

/** Show each entry with its type, id and attributes */

static void show_tree(const git_tree *tree)

{

	size_t i, max_i = (int)git_tree_entrycount(tree);

	char oidstr[GIT_OID_HEXSZ + 1];

	const git_tree_entry *te;

	for (i = 0; i < max_i; ++i) {

		te = git_tree_entry_byindex(tree, i);

		git_oid_tostr(oidstr, sizeof(oidstr), git_tree_entry_id(te));

		printf("%06o %s %s\t%s\n",

			git_tree_entry_filemode(te),

			git_object_type2string(git_tree_entry_type(te)),

			oidstr, git_tree_entry_name(te));

	}

}

/**

 * Commits and tags have a few interesting fields in their header.

 */

static void show_commit(const git_commit *commit)

{

	unsigned int i, max_i;

	char oidstr[GIT_OID_HEXSZ + 1];

	git_oid_tostr(oidstr, sizeof(oidstr), git_commit_tree_id(commit));

	printf("tree %s\n", oidstr);

	max_i = (unsigned int)git_commit_parentcount(commit);

	for (i = 0; i < max_i; ++i) {

		git_oid_tostr(oidstr, sizeof(oidstr), git_commit_parent_id(commit, i));

		printf("parent %s\n", oidstr);

	}

	print_signature("author", git_commit_author(commit));

	print_signature("committer", git_commit_committer(commit));

	if (git_commit_message(commit))

		printf("\n%s\n", git_commit_message(commit));

}

static void show_tag(const git_tag *tag)

{

	char oidstr[GIT_OID_HEXSZ + 1];

	git_oid_tostr(oidstr, sizeof(oidstr), git_tag_target_id(tag));;

	printf("object %s\n", oidstr);

	printf("type %s\n", git_object_type2string(git_tag_target_type(tag)));

	printf("tag %s\n", git_tag_name(tag));

	print_signature("tagger", git_tag_tagger(tag));

	if (git_tag_message(tag))

		printf("\n%s\n", git_tag_message(tag));

}

enum {

	SHOW_TYPE = 1,

	SHOW_SIZE = 2,

	SHOW_NONE = 3,

	SHOW_PRETTY = 4

};

/* Forward declarations for option-parsing helper */

struct opts {

	const char *dir;

	const char *rev;

	int action;

	int verbose;

};

static void parse_opts(struct opts *o, int argc, char *argv[]);

/** Entry point for this command */

int main(int argc, char *argv[])

{

	git_repository *repo;

	struct opts o = { ".", NULL, 0, 0 };

	git_object *obj = NULL;

	char oidstr[GIT_OID_HEXSZ + 1];

	git_libgit2_init();

	parse_opts(&o, argc, argv);

	check_lg2(git_repository_open_ext(&repo, o.dir, 0, NULL),

			"Could not open repository", NULL);

	check_lg2(git_revparse_single(&obj, repo, o.rev),

			"Could not resolve", o.rev);

	if (o.verbose) {

		char oidstr[GIT_OID_HEXSZ + 1];

		git_oid_tostr(oidstr, sizeof(oidstr), git_object_id(obj));

		printf("%s %s\n--\n",

			git_object_type2string(git_object_type(obj)), oidstr);

	}

	switch (o.action) {

	case SHOW_TYPE:

		printf("%s\n", git_object_type2string(git_object_type(obj)));

		break;

	case SHOW_SIZE: {

		git_odb *odb;

		git_odb_object *odbobj;

		check_lg2(git_repository_odb(&odb, repo), "Could not open ODB", NULL);

		check_lg2(git_odb_read(&odbobj, odb, git_object_id(obj)),

			"Could not find obj", NULL);

		printf("%ld\n", (long)git_odb_object_size(odbobj));

		git_odb_object_free(odbobj);

		git_odb_free(odb);

		}

		break;

	case SHOW_NONE:

		/* just want return result */

		break;

	case SHOW_PRETTY:

		switch (git_object_type(obj)) {

		case GIT_OBJ_BLOB:

			show_blob((const git_blob *)obj);

			break;

		case GIT_OBJ_COMMIT:

			show_commit((const git_commit *)obj);

			break;

		case GIT_OBJ_TREE:

			show_tree((const git_tree *)obj);

			break;

		case GIT_OBJ_TAG:

			show_tag((const git_tag *)obj);

			break;

		default:

			printf("unknown %s\n", oidstr);

			break;

		}

		break;

	}

	git_object_free(obj);

	git_repository_free(repo);

	git_libgit2_shutdown();

	return 0;

}

/** Print out usage information */

static void usage(const char *message, const char *arg)

{

	if (message && arg)

		fprintf(stderr, "%s: %s\n", message, arg);

	else if (message)

		fprintf(stderr, "%s\n", message);

	fprintf(stderr,

			"usage: cat-file (-t | -s | -e | -p) [-v] [-q] "

			"[-h|--help] [--git-dir=<dir>] <object>\n");

	exit(1);

}

/** Parse the command-line options taken from git */

static void parse_opts(struct opts *o, int argc, char *argv[])

{

	struct args_info args = ARGS_INFO_INIT;

	for (args.pos = 1; args.pos < argc; ++args.pos) {

		char *a = argv[args.pos];

		if (a[0] != '-') {

			if (o->rev != NULL)

				usage("Only one rev should be provided", NULL);

			else

				o->rev = a;

		}

		else if (!strcmp(a, "-t"))

			o->action = SHOW_TYPE;

		else if (!strcmp(a, "-s"))

			o->action = SHOW_SIZE;

		else if (!strcmp(a, "-e"))

			o->action = SHOW_NONE;

		else if (!strcmp(a, "-p"))

			o->action = SHOW_PRETTY;

		else if (!strcmp(a, "-q"))

			o->verbose = 0;

		else if (!strcmp(a, "-v"))

			o->verbose = 1;

		else if (!strcmp(a, "--help") || !strcmp(a, "-h"))

			usage(NULL, NULL);

		else if (!match_str_arg(&o->dir, &args, "--git-dir"))

			usage("Unknown option", a);

	}

	if (!o->action || !o->rev)

		usage(NULL, NULL);

}