#include "source-accessor.hh"
#include "archive.hh"

namespace nix {

static std::atomic<size_t> nextNumber{0};

SourceAccessor::SourceAccessor()
    : number(++nextNumber)
{
}

bool SourceAccessor::pathExists(const CanonPath & path)
{
    return maybeLstat(path).has_value();
}

std::string SourceAccessor::readFile(const CanonPath & path)
{
    StringSink sink;
    std::optional<uint64_t> size;
    readFile(path, sink, [&](uint64_t _size)
    {
        size = _size;
    });
    assert(size && *size == sink.s.size());
    return std::move(sink.s);
}

void SourceAccessor::readFile(
    const CanonPath & path,
    Sink & sink,
    std::function<void(uint64_t)> sizeCallback)
{
    auto s = readFile(path);
    sizeCallback(s.size());
    sink(s);
}

Hash SourceAccessor::hashPath(
    const CanonPath & path,
    PathFilter & filter,
    HashType ht)
{
    HashSink sink(ht);
    dumpPath(path, sink, filter);
    return sink.finish().first;
}

SourceAccessor::Stat SourceAccessor::lstat(const CanonPath & path)
{
    if (auto st = maybeLstat(path))
        return *st;
    else
        throw Error("path '%s' does not exist", showPath(path));
}

std::string SourceAccessor::showPath(const CanonPath & path)
{
    return path.abs();
}

}