Index.h

// SPDX-License-Identifier: GPL-2.0-only

#pragma once

#include <filesystem>
#include <functional>
#include <optional>
#include <string>
#include <vector>

#include <git2.h>

#include "../helpers/Unique.h"
#include "Repo.h"

namespace SlGit {

class Tree;

class IndexIterator {
    using GitTy = git_index_iterator;
    using Holder = SlHelpers::UniqueHolder<GitTy>;

    friend class Index;
    friend class Repo;
public:
    IndexIterator &operator++() {
        increment();
        return *this;
    }
    IndexIterator operator++(int) = delete;

    IndexIterator &operator--() = delete;
    IndexIterator operator--(int) = delete;

    bool operator ==(const IndexIterator &other) const noexcept {
        return m_current == other.m_current;
    }
    bool operator !=(const IndexIterator &other) const noexcept {
        return !(*this == other);
    }
    const git_index_entry &operator *() const noexcept { return *m_current; }
    const git_index_entry *operator ->() const noexcept { return m_current; }

    std::string path() const noexcept { return m_current->path; }
    std::string_view pathSV() const noexcept { return m_current->path; }

    GitTy *iterator() const noexcept { return m_iterator.get(); }
    operator GitTy *() const noexcept { return iterator(); }
private:
    IndexIterator() noexcept : m_current(nullptr) {}
    explicit IndexIterator(GitTy *iterator) noexcept : m_iterator(iterator) { increment(); }

    void increment() {
        if (git_index_iterator_next(&m_current, iterator()))
            m_current = nullptr;
    }

    Holder m_iterator;
    const git_index_entry *m_current;
};

class Index {
    using GitTy = git_index;
    using Holder = SlHelpers::UniqueHolder<GitTy>;

    friend class Repo;
public:
    using MatchCB = std::function<int(const std::filesystem::path &, const std::string &)>;

    Index() = delete;

    static std::optional<Index> open(const std::filesystem::path &path) noexcept;
    static std::optional<Index> create() noexcept;

    bool read(bool force = true) const noexcept {
        return !Repo::setLastError(git_index_read(index(), force));
    }
    bool write() const noexcept { return !Repo::setLastError(git_index_write(index())); }
    bool readTree(const Tree &tree) const noexcept;
    std::optional<Tree> writeTree(const Repo &repo) const noexcept;

    size_t entrycount() const noexcept { return git_index_entrycount(index()); }
    const git_index_entry *entryByIndex(size_t idx) const noexcept {
        return git_index_get_byindex(index(), idx);
    }
    const git_index_entry *entryByPath(const std::filesystem::path &path,
                       git_index_stage_t stage = GIT_INDEX_STAGE_NORMAL) const noexcept {
        return git_index_get_bypath(index(), path.c_str(), stage);
    }

    bool addByPath(const std::filesystem::path &path) const noexcept {
        return !Repo::setLastError(git_index_add_bypath(index(), path.c_str()));
    }
    bool removeByPath(const std::filesystem::path &path) const noexcept {
        return !Repo::setLastError(git_index_remove_bypath(index(), path.c_str()));
    }

    int addAll(const std::vector<std::string> &paths, unsigned int flags,
           const MatchCB *cb = nullptr) const;
    int removeAll(const std::vector<std::string> &paths, const MatchCB *cb = nullptr) const;
    int updateAll(const std::vector<std::string> &paths, const MatchCB *cb = nullptr) const;

    bool hasConflicts() const noexcept { return git_index_has_conflicts(index()); }

    IndexIterator begin() noexcept { return cbegin(); }
    IndexIterator end() noexcept { return IndexIterator(); }

    IndexIterator cbegin() const noexcept;
    IndexIterator cend() const noexcept { return IndexIterator(); }

    GitTy *index() const noexcept { return m_index.get(); }
    operator GitTy *() const noexcept { return index(); }
private:
    explicit Index(GitTy *index) noexcept : m_index(index) { }

    static int matchCB(const char *path, const char *matched_pathspec, void *payload);

    Holder m_index;
};

}