/*
 * Copyright (C) the libgit2 contributors. All rights reserved.
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */
#include "reflog.h"
#include "repository.h"
#include "filebuf.h"
#include "signature.h"
#include "refdb.h"
#include <git2/sys/refdb_backend.h>
git_reflog_entry *git_reflog_entry__alloc(void)
{
        return git__calloc(1, sizeof(git_reflog_entry));
}
void git_reflog_entry__free(git_reflog_entry *entry)
{
        git_signature_free(entry->committer);
        git__free(entry->msg);
        git__free(entry);
}
void git_reflog_free(git_reflog *reflog)
{
        size_t i;
        git_reflog_entry *entry;
        if (reflog == NULL)
                return;
        if (reflog->db)
                GIT_REFCOUNT_DEC(reflog->db, git_refdb__free);
        for (i=0; i < reflog->entries.length; i++) {
                entry = git_vector_get(&reflog->entries, i);
                git_reflog_entry__free(entry);
        }
        git_vector_free(&reflog->entries);
        git__free(reflog->ref_name);
        git__free(reflog);
}
int git_reflog_read(git_reflog **reflog, git_repository *repo,  const char *name)
{
        git_refdb *refdb;
        int error;
        assert(reflog && repo && name);
        if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
                return error;
        return git_refdb_reflog_read(reflog, refdb, name);
}
int git_reflog_write(git_reflog *reflog)
{
        git_refdb *db;
        assert(reflog && reflog->db);
        db = reflog->db;
        return db->backend->reflog_write(db->backend, reflog);
}
int git_reflog_append(git_reflog *reflog, const git_oid *new_oid, const git_signature *committer, const char *msg)
{
        git_reflog_entry *entry;
        const git_reflog_entry *previous;
        const char *newline;
        assert(reflog && new_oid && committer);
        entry = git__calloc(1, sizeof(git_reflog_entry));
        GITERR_CHECK_ALLOC(entry);
        if ((git_signature_dup(&entry->committer, committer)) < 0)
                goto cleanup;
        if (msg != NULL) {
                if ((entry->msg = git__strdup(msg)) == NULL)
                        goto cleanup;
                newline = strchr(msg, '\n');
                if (newline) {
                        if (newline[1] != '\0') {
                                giterr_set(GITERR_INVALID, "Reflog message cannot contain newline");
                                goto cleanup;
                        }
                        entry->msg[newline - msg] = '\0';
                }
        }
        previous = git_reflog_entry_byindex(reflog, 0);
        if (previous == NULL)
                git_oid_fromstr(&entry->oid_old, GIT_OID_HEX_ZERO);
        else
                git_oid_cpy(&entry->oid_old, &previous->oid_cur);
        git_oid_cpy(&entry->oid_cur, new_oid);
        if (git_vector_insert(&reflog->entries, entry) < 0)
                goto cleanup;
        return 0;
cleanup:
        git_reflog_entry__free(entry);
        return -1;
}
int git_reflog_rename(git_repository *repo, const char *old_name, const char *new_name)
{
        git_refdb *refdb;
        int error;
        if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
                return -1;
        return refdb->backend->reflog_rename(refdb->backend, old_name, new_name);
}
int git_reflog_delete(git_repository *repo, const char *name)
{
        git_refdb *refdb;
        int error;
        if ((error = git_repository_refdb__weakptr(&refdb, repo)) < 0)
                return -1;
        return refdb->backend->reflog_delete(refdb->backend, name);
}
size_t git_reflog_entrycount(git_reflog *reflog)
{
        assert(reflog);
        return reflog->entries.length;
}
const git_reflog_entry * git_reflog_entry_byindex(const git_reflog *reflog, size_t idx)
{
        assert(reflog);
        if (idx >= reflog->entries.length)
                return NULL;
        return git_vector_get(
                &reflog->entries, reflog_inverse_index(idx, reflog->entries.length));
}
const git_oid * git_reflog_entry_id_old(const git_reflog_entry *entry)
{
        assert(entry);
        return &entry->oid_old;
}
const git_oid * git_reflog_entry_id_new(const git_reflog_entry *entry)
{
        assert(entry);
        return &entry->oid_cur;
}
const git_signature * git_reflog_entry_committer(const git_reflog_entry *entry)
{
        assert(entry);
        return entry->committer;
}
const char * git_reflog_entry_message(const git_reflog_entry *entry)
{
        assert(entry);
        return entry->msg;
}
int git_reflog_drop(git_reflog *reflog, size_t idx, int rewrite_previous_entry)
{
        size_t entrycount;
        git_reflog_entry *entry, *previous;
        entrycount = git_reflog_entrycount(reflog);
        entry = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx);
        if (entry == NULL) {
                giterr_set(GITERR_REFERENCE, "No reflog entry at index %"PRIuZ, idx);
                return GIT_ENOTFOUND;
        }
        git_reflog_entry__free(entry);
        if (git_vector_remove(
                        &reflog->entries, reflog_inverse_index(idx, entrycount)) < 0)
                return -1;
        if (!rewrite_previous_entry)
                return 0;
        /* No need to rewrite anything when removing the most recent entry */
        if (idx == 0)
                return 0;
        /* Have the latest entry just been dropped? */
        if (entrycount == 1)
                return 0;
        entry = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx - 1);
        /* If the oldest entry has just been removed... */
        if (idx == entrycount - 1) {
                /* ...clear the oid_old member of the "new" oldest entry */
                if (git_oid_fromstr(&entry->oid_old, GIT_OID_HEX_ZERO) < 0)
                        return -1;
                return 0;
        }
        previous = (git_reflog_entry *)git_reflog_entry_byindex(reflog, idx);
        git_oid_cpy(&entry->oid_old, &previous->oid_cur);
        return 0;
}