// SPDX-License-Identifier: LGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (C) 2026 Catcrafts®

import std;
import Crafter.Build;
namespace fs = std::filesystem;
using namespace Crafter;

// A CMake dependency configured with other inputs than this build's (another
// compiler or --sysroot, the flags crafter-build injects, which it records in
// <build>/.crafter-options) has to be built again from nothing. It was
// reconfigured in place, and CMake does not recompile what a changed
// --sysroot compiled (the Makefiles generator writes it into build.make,
// which make does not compare) and keeps the check results of the old
// configure. A mingw dependency built by a release that gave clang the
// host's /usr as the sysroot (issue #43) kept its objects reading
// __libc_single_threaded after the update.
//
// The dependency is a local repository with a one-file C library. A file
// planted in its build directory stands for what the old configure left,
// and the recorded inputs are rewritten the way another crafter-build would
// have left them. Everything is local; XDG_CACHE_HOME keeps the clone out of
// the real cache.

extern "C" int setenv(const char* name, const char* value, int overwrite);

namespace {
    std::int32_t failures = 0;

    void Check(bool cond, std::string_view msg) {
        if (!cond) {
            std::println(std::cerr, "FAIL: {}", msg);
            ++failures;
        }
    }

    void Git(const fs::path& dir, std::string_view args) {
        const std::string command = std::format("git -C {} {}", ShellQuote(dir.string()), args);
        auto result = RunCommandWithTimeout(command, std::chrono::seconds(60));
        if (result.exitCode != 0) throw std::runtime_error(std::format("{} failed: {}", command, result.output));
    }

    void Write(const fs::path& file, std::string_view text) {
        std::ofstream(file, std::ios::binary | std::ios::trunc) << text;
    }
}

int main() {
    const fs::path scratch = fs::temp_directory_path() / "crafter-build-external-reconfigure";
    fs::remove_all(scratch);
    fs::create_directories(scratch);
    setenv("XDG_CACHE_HOME", (scratch / "cache").c_str(), 1);
    setenv("GIT_CONFIG_NOSYSTEM", "1", 1);
    setenv("GIT_CONFIG_GLOBAL", "/dev/null", 1);
    for (const char* name : { "GIT_AUTHOR_NAME", "GIT_COMMITTER_NAME" }) setenv(name, "crafter-build test", 1);
    for (const char* name : { "GIT_AUTHOR_EMAIL", "GIT_COMMITTER_EMAIL" }) setenv(name, "test@example.invalid", 1);

    const fs::path repo = scratch / "reconf";
    fs::create_directories(repo);
    Write(repo / "lib.c", "int Reconfigured(void) { return 1; }\n");
    Write(repo / "CMakeLists.txt",
          "cmake_minimum_required(VERSION 3.16)\n"
          "project(reconf C)\n"
          "add_library(reconf STATIC lib.c)\n");
    Git(repo, "init -q -b main");
    Git(repo, "add .");
    Git(repo, "commit -q -m reconf");

    ExternalDependency dep;
    dep.name = "reconf";
    dep.source.url = std::format("file://{}", repo.string());
    dep.builder = ExternalBuilder::CMake;
    dep.libs = { "reconf" };
    std::string error = BuildExternal(dep, HostTarget());
    Check(error.empty(), std::format("the dependency builds: {}", error));

    const fs::path build = ExternalBuildDir(dep, HostTarget());
    const fs::path leftover = build / "left-by-the-old-configure";
    Write(leftover, "");
    error = BuildExternal(dep, HostTarget());
    Check(error.empty(), std::format("and builds again: {}", error));
    Check(fs::exists(leftover), "with the same inputs its build directory is kept");

    Write(build / ".crafter-options", " -DCMAKE_SYSROOT=/usr\n");
    error = BuildExternal(dep, HostTarget());
    Check(error.empty(), std::format("configured with other inputs, it builds: {}", error));
    Check(!fs::exists(leftover), "from an empty build directory");
    Check(fs::exists(build / "libreconf.a"), "and the library is built again");

    std::error_code ec;
    fs::remove_all(scratch, ec);
    if (failures > 0) {
        std::println(std::cerr, "{} assertions failed", failures);
        return 1;
    }
    return 0;
}