<?php

declare(strict_types=1);

namespace Package\Artifact;

use StaticPHP\Artifact\ArtifactDownloader;
use StaticPHP\Artifact\Downloader\DownloadResult;
use StaticPHP\Artifact\Downloader\Type\CheckUpdateResult;
use StaticPHP\Attribute\Artifact\AfterBinaryExtract;
use StaticPHP\Attribute\Artifact\CustomBinary;
use StaticPHP\Attribute\Artifact\CustomBinaryCheckUpdate;
use StaticPHP\Exception\DownloaderException;

class llvm_tools
{
    public const TOOLS = ['llvm-objcopy', 'llvm-strip', 'llvm-profdata'];

    #[CustomBinary('llvm-tools', [
        'linux-x86_64',
        'linux-aarch64',
        'macos-x86_64',
        'macos-aarch64',
    ])]
    public function downBinary(ArtifactDownloader $downloader): DownloadResult
    {
        $llvmVersion = $this->detectLlvmVersion()
            ?? throw new DownloaderException('Could not detect a clang version on host; install zig or clang first');
        $tarball = "llvm-project-{$llvmVersion}.src.tar.xz";
        $url = "https://github.com/llvm/llvm-project/releases/download/llvmorg-{$llvmVersion}/{$tarball}";
        $tarballPath = DOWNLOAD_PATH . '/' . $tarball;
        default_shell()->executeCurlDownload($url, $tarballPath, retries: $downloader->getRetry());
        return DownloadResult::archive($tarball, ['url' => $url, 'version' => $llvmVersion], extract: '{pkg_root_path}/llvm-tools-src', verified: false, version: $llvmVersion);
    }

    #[CustomBinaryCheckUpdate('llvm-tools', [
        'linux-x86_64',
        'linux-aarch64',
        'macos-x86_64',
        'macos-aarch64',
    ])]
    public function checkUpdateBinary(?string $old_version, ArtifactDownloader $downloader): CheckUpdateResult
    {
        $llvmVersion = $this->detectLlvmVersion()
            ?? throw new DownloaderException('Could not detect a clang version on host; install zig or clang first');
        return new CheckUpdateResult(
            old: $old_version,
            new: $llvmVersion,
            needUpdate: $old_version === null || $llvmVersion !== $old_version,
        );
    }

    #[AfterBinaryExtract('llvm-tools', [
        'linux-x86_64',
        'linux-aarch64',
        'macos-x86_64',
        'macos-aarch64',
    ])]
    public function postExtract(string $target_path): void
    {
        $this->buildForHost($target_path);
    }

    public function buildForHost(?string $sourceRoot = null): bool
    {
        $sourceRoot ??= PKG_ROOT_PATH . '/llvm-tools-src';
        $binDir = PKG_ROOT_PATH . '/llvm-tools/bin';
        if ($this->allBuilt($binDir)) {
            return true;
        }
        $llvmDir = "{$sourceRoot}/llvm";
        if (!is_dir($llvmDir)) {
            logger()->error("[llvm-tools] expected llvm/ subdir at {$llvmDir} (extraction layout changed?)");
            return false;
        }
        $cmake = trim((string) shell_exec('command -v cmake 2>/dev/null'));
        if ($cmake === '') {
            logger()->error('[llvm-tools] cmake not found on PATH; install cmake first.');
            return false;
        }
        $generator = trim((string) shell_exec('command -v ninja 2>/dev/null')) !== '' ? 'Ninja' : 'Unix Makefiles';
        $cc = PKG_ROOT_PATH . '/zig/zig-cc';
        $cxx = PKG_ROOT_PATH . '/zig/zig-c++';
        $buildDir = "{$sourceRoot}/build";
        $installDir = PKG_ROOT_PATH . '/llvm-tools';
        f_mkdir($buildDir, recursive: true);

        $cmakeArgs = [
            '-G', $generator,
            '-S', $llvmDir,
            '-B', $buildDir,
            '-DCMAKE_BUILD_TYPE=Release',
            '-DLLVM_ENABLE_PROJECTS=',
            '-DLLVM_TARGETS_TO_BUILD=',
            '-DLLVM_INCLUDE_BENCHMARKS=OFF',
            '-DLLVM_INCLUDE_TESTS=OFF',
            '-DLLVM_INCLUDE_EXAMPLES=OFF',
            '-DLLVM_INCLUDE_DOCS=OFF',
            '-DLLVM_ENABLE_ZLIB=OFF',
            '-DLLVM_ENABLE_ZSTD=OFF',
            '-DLLVM_ENABLE_LIBXML2=OFF',
            '-DLLVM_ENABLE_TERMINFO=OFF',
            '-DLLVM_ENABLE_LIBEDIT=OFF',
            '-DLLVM_ENABLE_LIBPFM=OFF',
            '-DLLVM_BUILD_LLVM_DYLIB=OFF',
            '-DLLVM_LINK_LLVM_DYLIB=OFF',
            '-DBUILD_SHARED_LIBS=OFF',
            '-DCMAKE_C_COMPILER=' . $cc,
            '-DCMAKE_CXX_COMPILER=' . $cxx,
            '-DCMAKE_INSTALL_PREFIX=' . $installDir,
        ];

        $savedTarget = getenv('SPC_TARGET');
        f_putenv('SPC_TARGET=' . GNU_ARCH . '-linux-musl');
        try {
            $cmd = escapeshellarg($cmake) . ' ' . implode(' ', array_map('escapeshellarg', $cmakeArgs)) . ' 2>&1';
            logger()->info("Configuring llvm-tools (generator: {$generator}, target: " . getenv('SPC_TARGET') . ')');
            exec($cmd, $out, $rc);
            if ($rc !== 0) {
                logger()->error('[llvm-tools] cmake configure failed: ' . implode("\n", $out));
                return false;
            }
            $jobs = (int) (getenv('SPC_CONCURRENCY') ?: CPU_COUNT);
            if ($jobs < 1) {
                $jobs = 1;
            }
            $targetArgs = '';
            foreach (self::TOOLS as $t) {
                $targetArgs .= ' --target ' . escapeshellarg($t);
            }
            $buildCmd = 'cmake --build ' . escapeshellarg($buildDir) . $targetArgs
                . ($generator === 'Ninja' ? " -j{$jobs}" : " -- -j{$jobs}");
            logger()->info('Building llvm-tools (' . implode(', ', self::TOOLS) . ')');
            exec($buildCmd . ' 2>&1', $out2, $rc2);
            if ($rc2 !== 0) {
                logger()->error('[llvm-tools] build failed: ' . implode("\n", array_slice($out2, -40)));
                return false;
            }
        } finally {
            f_putenv('SPC_TARGET=' . ($savedTarget === false ? '' : $savedTarget));
        }
        f_mkdir($binDir, recursive: true);
        foreach (self::TOOLS as $t) {
            $built = "{$buildDir}/bin/{$t}";
            $dst = "{$binDir}/{$t}";
            if (!is_file($built)) {
                logger()->error("[llvm-tools] expected output {$built} not found");
                return false;
            }
            if (!copy($built, $dst)) {
                logger()->error("[llvm-tools] failed to copy {$built} → {$dst}");
                return false;
            }
            chmod($dst, 0755);
            logger()->info("[llvm-tools] installed {$dst} (" . filesize($dst) . ' bytes)');
        }
        return true;
    }

    public function allBuilt(string $binDir): bool
    {
        foreach (self::TOOLS as $t) {
            $p = "{$binDir}/{$t}";
            if (!is_file($p) || !is_executable($p)) {
                return false;
            }
        }
        return true;
    }

    private function detectLlvmVersion(): ?string
    {
        $zig = PKG_ROOT_PATH . '/zig/zig';
        $verLine = trim((string) shell_exec(escapeshellarg($zig) . ' cc --version 2>/dev/null'));
        if (preg_match('/clang version (\d+\.\d+\.\d+)/', $verLine, $m)) {
            return $m[1];
        }
        return null;
    }
}