#include <catch2/catch_test_macros.hpp>

import cargoxx.resolver;
import cargoxx.util;
import std;

using cargoxx::resolver::pc_scan;
using cargoxx::util::ErrorCode;

namespace {

auto fresh_store() -> std::filesystem::path {
    auto d = std::filesystem::temp_directory_path() /
             std::format("cargoxx-pc-scan-{}", std::random_device{}());
    std::filesystem::create_directories(d / "lib" / "pkgconfig");
    return d;
}

void touch_pc(const std::filesystem::path& store, std::string_view name,
              std::string_view content =
                  "Name: x\nDescription: x\nLibs: -lx\n") {
    std::ofstream{store / "lib" / "pkgconfig" / std::string{name}} << content;
}

} // namespace

TEST_CASE("pc_scan picks the exact-name .pc when present",
          "[resolver][pc_scan]") {
    auto store = fresh_store();
    touch_pc(store, "sqlite3.pc");

    auto r = pc_scan(store, "sqlite3");
    REQUIRE(r.has_value());
    REQUIRE(r->pc_module == "sqlite3");
    REQUIRE(r->pc_file.filename() == "sqlite3.pc");
}

TEST_CASE("pc_scan picks sqlite3.pc for nixpkgs name 'sqlite'",
          "[resolver][pc_scan]") {
    auto store = fresh_store();
    touch_pc(store, "sqlite3.pc");

    auto r = pc_scan(store, "sqlite");
    REQUIRE(r.has_value());
    REQUIRE(r->pc_module == "sqlite3");
}

TEST_CASE("pc_scan picks the best match among multiple .pc files",
          "[resolver][pc_scan]") {
    auto store = fresh_store();
    touch_pc(store, "zlib.pc");
    touch_pc(store, "sqlite3.pc");
    touch_pc(store, "unrelated.pc");

    auto r = pc_scan(store, "zlib");
    REQUIRE(r.has_value());
    REQUIRE(r->pc_module == "zlib");
}

TEST_CASE("pc_scan returns ResolutionUnknownPackage when nothing matches",
          "[resolver][pc_scan]") {
    auto store = fresh_store();
    touch_pc(store, "totally-unrelated.pc");

    auto r = pc_scan(store, "sqlite");
    REQUIRE_FALSE(r.has_value());
    REQUIRE(r.error().code == ErrorCode::ResolutionUnknownPackage);
}

TEST_CASE("pc_scan errors when lib/pkgconfig is missing",
          "[resolver][pc_scan]") {
    auto d = std::filesystem::temp_directory_path() /
             std::format("cargoxx-pc-empty-{}", std::random_device{}());
    std::filesystem::create_directories(d);

    auto r = pc_scan(d, "sqlite");
    REQUIRE_FALSE(r.has_value());
    REQUIRE(r.error().code == ErrorCode::ResolutionUnknownPackage);
}

TEST_CASE("pc_scan skips .pc files that look like junk",
          "[resolver][pc_scan]") {
    auto store = fresh_store();
    touch_pc(store, "sqlite3.pc", "this is not a real pc file\n");

    auto r = pc_scan(store, "sqlite3");
    REQUIRE_FALSE(r.has_value());
    REQUIRE(r.error().code == ErrorCode::ResolutionUnknownPackage);
}