ATBTariffCalculator/CalculatorCInterface/calculator_c_interface_lib.cpp

#include "calculator_c_interface_lib.h"

//#include <git2/common.h>

#include <QMap>
#include <QString>
#include <QDir>


#include <git2.h>
#include <stdio.h>
#include <stdint.h>

static QMap<QString, git_repository *> customerRepoMap;

#ifndef _WIN32
# include <unistd.h>
#endif
#include <errno.h>

#ifdef __cplusplus
extern "C" {
#endif

// see https://libgit2.org/libgit2/ex/HEAD/checkout.html

/* Define t/he printf format specifier to use for size_t output */
#if defined(_MSC_VER) || defined(__MINGW32__)
#	define PRIuZ "Illu"
#	define PRIxZ "Illx"
#	define PRIdZ "Illd"
#else
#	define PRIuZ "zu"
#	define PRIxZ "zx"
#	define PRIdZ "zd"
#endif

typedef struct {
    unsigned int force : 1;
    unsigned int progress : 1;
    unsigned int perf : 1;
} checkout_options;

static void print_checkout_progress(const char *path, size_t completed_steps, size_t total_steps, void *payload) {
    (void)payload;
    if (path == NULL) {
        printf("checkout started: %" PRIuZ " steps\n", total_steps);
    } else {
        printf("checkout: %s %" PRIuZ "/%" PRIuZ "\n", path, completed_steps, total_steps);
    }
}

static void print_perf_data(const git_checkout_perfdata *perfdata, void *payload) {
    (void)payload;
    printf("perf: stat: %" PRIuZ " mkdir: %" PRIuZ " chmod: %" PRIuZ "\n",
           perfdata->stat_calls, perfdata->mkdir_calls, perfdata->chmod_calls);
}

static int resolve_refish(git_annotated_commit **commit, git_repository *repo, const char *refish)
{
    git_reference *ref;
    git_object *obj;
    int err = 0;

    assert(commit != NULL);

    err = git_reference_dwim(&ref, repo, refish);
    if (err == GIT_OK) {
        git_annotated_commit_from_ref(commit, repo, ref);
        git_reference_free(ref);
        return 0;
    }

    err = git_revparse_single(&obj, repo, refish);
    if (err == GIT_OK) {
        err = git_annotated_commit_lookup(commit, repo, git_object_id(obj));
        git_object_free(obj);
    }

    return err;
}

static int perform_checkout_ref(git_repository *repo,
                                git_annotated_commit *target,
                                const char *target_ref, checkout_options *opts) {
    git_checkout_options checkout_opts;
    git_reference *ref = NULL, *branch = NULL;
    git_commit *target_commit = NULL;
    int err;

    if ((err = git_checkout_options_init(&checkout_opts, GIT_CHECKOUT_OPTIONS_VERSION)) < 0) {
        fprintf(stderr, "error checkout options init %s\n", git_error_last()->message);
        return err;
    }

    // Setup our checkout options from the parsed options

    checkout_opts.checkout_strategy = GIT_CHECKOUT_SAFE;

    // if (opts->force)
    //    checkout_opts.checkout_strategy = GIT_CHECKOUT_FORCE;

    // if (opts->progress)
    //    checkout_opts.progress_cb = print_checkout_progress;

    // if (opts->perf)
    //    checkout_opts.perfdata_cb = print_perf_data;

    // Grab the commit we're interested to move to

    err = git_commit_lookup(&target_commit, repo, git_annotated_commit_id(target));
    if (err != 0) {
        fprintf(stderr, "failed to lookup commit: %s\n", git_error_last()->message);
        goto cleanup;
    }

    // Perform the checkout so the workdir corresponds to what target_commit contains.
    // Note that it's okay to pass a git_commit here, because it will be peeled to a tree.

    err = git_checkout_tree(repo, (const git_object *)target_commit, &checkout_opts);
    if (err != 0) {
        fprintf(stderr, "failed to checkout tree: %s\n", git_error_last()->message);
        goto cleanup;
    }

    // Now that the checkout has completed, we have to update HEAD.
    // Depending on the "origin" of target (ie. it's an OID or a branch name), we might need to detach HEAD.

    if (git_annotated_commit_ref(target)) {
        const char *target_head;

        if ((err = git_reference_lookup(&ref, repo, git_annotated_commit_ref(target))) < 0)
            goto error;

        if (git_reference_is_remote(ref)) {
            if ((err = git_branch_create_from_annotated(&branch, repo, target_ref, target, 0)) < 0)
                goto error;
            target_head = git_reference_name(branch);
        } else {
            target_head = git_annotated_commit_ref(target);
        }

        err = git_repository_set_head(repo, target_head);
    } else {
        err = git_repository_set_head_detached_from_annotated(repo, target);
    }

error:
    if (err != 0) {
        fprintf(stderr, "failed to update HEAD reference: %s\n", git_error_last()->message);
        goto cleanup;
    }

cleanup:
    git_commit_free(target_commit);
    git_reference_free(branch);
    git_reference_free(ref);

    return err;
}

static int guess_refish(git_annotated_commit **out, git_repository *repo, const char *ref) {
    git_strarray remotes = { NULL, 0 };
    git_reference *remote_ref = NULL;
    int error;
    size_t i;

    if ((error = git_remote_list(&remotes, repo)) < 0) {
        fprintf(stderr, "error git_remote_list %s\n", git_error_last()->message);
        goto out;
    }

    for (i = 0; i < remotes.count; i++) {
        char *refname = NULL;
        size_t reflen;

        reflen = snprintf(refname, 0, "refs/remotes/%s/%s", remotes.strings[i], ref);
        if ((refname = (char *)malloc(reflen + 1)) == NULL) {
            error = -1;
            fprintf(stderr, "%s:%d malloc failed\n", __func__, __LINE__);
            goto next;
        }
        snprintf(refname, reflen + 1, "refs/remotes/%s/%s", remotes.strings[i], ref);

        if ((error = git_reference_lookup(&remote_ref, repo, refname)) < 0) {
            fprintf(stderr, "git reference lookup %s\n", git_error_last()->message);
            goto next;
        }

        break;
    next:
        free(refname);
        refname = NULL;
        if (error < 0 && error != GIT_ENOTFOUND) {
            break;
        }
    }

    if (!remote_ref) {
        error = GIT_ENOTFOUND;
        goto out;
    }

    if ((error = git_annotated_commit_from_ref(out, repo, remote_ref)) < 0)
        goto out;

out:
    git_reference_free(remote_ref);
    git_strarray_dispose(&remotes);
    return error;
}

TariffCalculatorHandle NewTariffCalculator(void) {
    return new TariffCalculator();
}

void DeleteTariffCalculator(TariffCalculatorHandle handle) {
    delete handle;
}

int InitGitLibrary(void) {
    return git_libgit2_init();
}

int ShutdownGitLibrary(void) {

    for (auto key : customerRepoMap.keys()) {
        git_repository_free(customerRepoMap.value(key));
    }
    customerRepoMap.clear();
    return git_libgit2_shutdown();
}

int CloneRepository(char const *url, char const *local_path) {

    QString localRepoPath(QDir::cleanPath(QString(local_path) + QDir::separator() + ".git"));
    QDir localRepoDir(localRepoPath);

    if (localRepoDir.exists()) {
        fprintf(stderr, "local repository path %s already exists\n",
                localRepoPath.toUtf8().constData());
        return -1;
    }

    git_repository *out;
    git_clone_options opts;
    int res = 0;

    if ((res = git_clone_options_init(&opts, GIT_CLONE_OPTIONS_VERSION)) == 0) {
        opts.checkout_branch = "master";

        fprintf(stderr, "%s:%d %s %s\n", __func__, __LINE__, url, local_path);

        if ((res = git_clone(&out, url, local_path, &opts)) < 0) {
            git_error const *error = git_error_last();
            fprintf(stderr, "%s:%d error: %s\n", __func__, __LINE__, error->message);
        } else {
            QString localRepoPath = QDir::cleanPath(QString(local_path) + QDir::separator() + ".git");
            customerRepoMap.insert(localRepoPath, out);
        }
    } else {
        git_error const *error = git_error_last();
        fprintf(stderr, "%s:%d error: %s\n", __func__, __LINE__, error->message);
    }
    return res;
}

int CheckoutLocalBranch(char const *local_path, char const *branch_name) {
    int err = 0;
    checkout_options opts;
    git_repository_state_t state = GIT_REPOSITORY_STATE_NONE;
    git_annotated_commit *checkout_target = NULL;
    git_repository *repo = NULL;
    git_reference *branch_ref = NULL;

    QString localRepoPath(QDir::cleanPath(QString(local_path) + QDir::separator() + ".git"));
    QDir localRepoDir(localRepoPath);

    if (!localRepoDir.exists()) {
        fprintf(stderr, "local repository path %s does not exist\n",
                localRepoPath.toUtf8().constData());
        return -1;
    }

    if (!customerRepoMap.contains(localRepoPath)) {
        if ((err = git_repository_open(&repo, localRepoPath.toUtf8().constData())) != 0) {
            fprintf(stderr, "repository %s cannot be opened: %s\n",
                    localRepoPath.toUtf8().constData(), git_error_last()->message);
            return -1;
        }
        customerRepoMap.insert(localRepoPath, repo);
    }

    if (customerRepoMap.contains(localRepoPath)) {
        repo = customerRepoMap[localRepoPath];

        // Make sure we're not about to checkout while something else is going on
        if ((state = (git_repository_state_t)git_repository_state(repo)) != GIT_REPOSITORY_STATE_NONE) {
            fprintf(stderr, "repository %s is in unexpected state %d\n",
                    localRepoPath.toUtf8().constData(), state);
            err = -1;
        } else {
            fprintf(stderr, "repository %s is in state %d\n",
                    localRepoPath.toUtf8().constData(), state);

            if ((err = resolve_refish(&checkout_target, repo, branch_name)) < 0 &&
                (err = guess_refish(&checkout_target, repo, branch_name)) < 0) {
                fprintf(stderr, "failed to resolve %s: %s\n", branch_name, git_error_last()->message);
            } else {
                if ((err = perform_checkout_ref(repo, checkout_target, branch_name, &opts)) == 0) {
                    fprintf(stderr, "%s:%d checkout ok\n", __func__, __LINE__);
                    if ((err = git_branch_lookup(&branch_ref, repo, branch_name, GIT_BRANCH_LOCAL)) != 0) {
                        if (err == GIT_ENOTFOUND) {
                            fprintf(stderr, "local branch %s not found\n", branch_name);
                        } else {
                            fprintf(stderr, "local branch %s not found: %s\n",
                                    branch_name, git_error_last()->message);
                        }
                    }
                }
            }
        }
    }

    if (branch_ref) {
        git_reference_free(branch_ref);
    }

    if (checkout_target) {
        git_annotated_commit_free(checkout_target);
    }

    return err;
}

int CommitFile(char const *local_path, char const *file_name) {
    assert(local_path != NULL);
    assert(file_name != NULL);

    QString const currentWD = QDir::currentPath();
    QString localPath(path);

    if (!localPath.exists()) {
        fprintf(stderr, "local path %s for file %s does not exist\n",
                localRepoPath.toUtf8().constData(), file_name);
        return -1;
    }

    if (QDir::setCurrent(localPath)) {

    }

    QDir::setCurrent(currentWD);

    return 0;
}

#ifdef __cplusplus
}
#endif