#include "vdm/rules/collision.hpp"

#include <functional>
#include <set>
#include <string>
#include <string_view>

#include "vtest.hpp"

using vdm::rules::CollisionPolicy;
using vdm::rules::resolve_collision;

namespace {
std::function<bool(std::string_view)> exists_in(const std::set<std::string> &names) {
    return [&names](std::string_view s) { return names.count(std::string(s)) > 0; };
}
}  // namespace

VT_TEST(collision_no_collision_returns_desired) {
    std::set<std::string> existing = {"other.txt"};
    VT_CHECK_EQ(resolve_collision("file.txt", exists_in(existing)), std::string("file.txt"));
}

VT_TEST(collision_renames_on_conflict) {
    std::set<std::string> existing = {"file.txt"};
    VT_CHECK_EQ(resolve_collision("file.txt", exists_in(existing)), std::string("file (1).txt"));
}

VT_TEST(collision_finds_first_free_slot) {
    std::set<std::string> existing = {"file.txt", "file (1).txt", "file (2).txt"};
    VT_CHECK_EQ(resolve_collision("file.txt", exists_in(existing)), std::string("file (3).txt"));
}

VT_TEST(collision_no_extension) {
    std::set<std::string> existing = {"README"};
    VT_CHECK_EQ(resolve_collision("README", exists_in(existing)), std::string("README (1)"));
}

VT_TEST(collision_dotfile_treated_as_no_extension) {
    std::set<std::string> existing = {".gitignore"};
    VT_CHECK_EQ(resolve_collision(".gitignore", exists_in(existing)),
               std::string(".gitignore (1)"));
}

VT_TEST(collision_overwrite_policy_ignores_existence) {
    std::set<std::string> existing = {"file.txt"};
    VT_CHECK_EQ(resolve_collision("file.txt", exists_in(existing), CollisionPolicy::overwrite),
               std::string("file.txt"));
}

VT_TEST(collision_gives_up_after_max_attempts_without_fabricating) {
    auto always_exists = [](std::string_view) { return true; };
    auto out = resolve_collision("file.txt", always_exists, CollisionPolicy::rename, 3);
    VT_CHECK_EQ(out, std::string("file (3).txt"));  // last attempted, still colliding
}