<?php

declare(strict_types=1);

namespace SPC\builder\linux;

use SPC\builder\unix\UnixBuilderBase;
use SPC\exception\PatchException;
use SPC\exception\WrongUsageException;
use SPC\store\Config;
use SPC\store\DirDiff;
use SPC\store\FileSystem;
use SPC\store\SourcePatcher;
use SPC\util\GlobalEnvManager;
use SPC\util\SPCConfigUtil;
use SPC\util\SPCTarget;

class LinuxBuilder extends UnixBuilderBase
{
    /** @var bool Micro patch phar flag */
    private bool $phar_patched = false;

    public function __construct(array $options = [])
    {
        $this->options = $options;

        GlobalEnvManager::init();
        GlobalEnvManager::afterInit();

        // concurrency
        $this->concurrency = (int) getenv('SPC_CONCURRENCY');
        // cflags
        $this->arch_c_flags = getenv('SPC_DEFAULT_C_FLAGS');
        $this->arch_cxx_flags = getenv('SPC_DEFAULT_CXX_FLAGS');
        $this->arch_ld_flags = getenv('SPC_DEFAULT_LD_FLAGS');

        // create pkgconfig and include dir (some libs cannot create them automatically)
        f_mkdir(BUILD_LIB_PATH . '/pkgconfig', recursive: true);
        f_mkdir(BUILD_INCLUDE_PATH, recursive: true);
    }

    /**
     * Build PHP from source.
     *
     * @param int $build_target Build target, use `BUILD_TARGET_*` constants
     */
    public function buildPHP(int $build_target = BUILD_TARGET_NONE): void
    {
        $cflags = $this->arch_c_flags;
        f_putenv('CFLAGS=' . $cflags);

        $this->emitPatchPoint('before-php-buildconf');
        SourcePatcher::patchBeforeBuildconf($this);

        shell()->cd(SOURCE_PATH . '/php-src')->exec(getenv('SPC_CMD_PREFIX_PHP_BUILDCONF'));

        $this->emitPatchPoint('before-php-configure');
        SourcePatcher::patchBeforeConfigure($this);

        $phpVersionID = $this->getPHPVersionID();
        $json_74 = $phpVersionID < 80000 ? '--enable-json ' : '';

        $opcache_jit = !$this->getOption('disable-opcache-jit', false);
        if ($opcache_jit && ($phpVersionID >= 80500 || $this->getExt('opcache'))) {
            // php 8.5 contains opcache extension by default,
            // if opcache_jit is enabled for 8.5 or opcache enabled,
            // we need to disable undefined behavior sanitizer.
            f_putenv('SPC_COMPILER_EXTRA=-fno-sanitize=undefined');
        }

        if ($this->getOption('enable-zts', false)) {
            $maxExecutionTimers = $phpVersionID >= 80100 ? '--enable-zend-max-execution-timers ' : '';
            $zts = '--enable-zts --disable-zend-signals ';
        } else {
            $maxExecutionTimers = '';
            $zts = '';
        }

        $config_file_path = $this->getOption('with-config-file-path', false) ?
            ('--with-config-file-path=' . $this->getOption('with-config-file-path') . ' ') : '';
        $config_file_scan_dir = $this->getOption('with-config-file-scan-dir', false) ?
            ('--with-config-file-scan-dir=' . $this->getOption('with-config-file-scan-dir') . ' ') : '';

        $enableCli = ($build_target & BUILD_TARGET_CLI) === BUILD_TARGET_CLI;
        $enableFpm = ($build_target & BUILD_TARGET_FPM) === BUILD_TARGET_FPM;
        $enableMicro = ($build_target & BUILD_TARGET_MICRO) === BUILD_TARGET_MICRO;
        $enableEmbed = ($build_target & BUILD_TARGET_EMBED) === BUILD_TARGET_EMBED;
        $enableFrankenphp = ($build_target & BUILD_TARGET_FRANKENPHP) === BUILD_TARGET_FRANKENPHP;
        $enableCgi = ($build_target & BUILD_TARGET_CGI) === BUILD_TARGET_CGI;

        // prepare build php envs
        // $musl_flag = SPCTarget::getLibc() === 'musl' ? ' -D__MUSL__' : ' -U__MUSL__';
        $php_configure_env = SystemUtil::makeEnvVarString([
            'CFLAGS' => getenv('SPC_CMD_VAR_PHP_MAKE_EXTRA_CFLAGS'),
            'CPPFLAGS' => '-I' . BUILD_INCLUDE_PATH, // . ' -Dsomethinghere', // . $musl_flag,
            'LDFLAGS' => '-L' . BUILD_LIB_PATH,
            // 'LIBS' => SPCTarget::getRuntimeLibs(), // do not pass static libraries here yet, they may contain polyfills for libc functions!
        ]);

        $phpvars = getenv('SPC_EXTRA_PHP_VARS') ?: '';

        $embed_type = getenv('SPC_CMD_VAR_PHP_EMBED_TYPE') ?: 'static';
        if ($embed_type !== 'static' && SPCTarget::isStatic()) {
            throw new WrongUsageException(
                'Linux does not support loading shared libraries when linking libc statically. ' .
                'Change SPC_CMD_VAR_PHP_EMBED_TYPE to static.'
            );
        }

        $this->seekPhpSrcLogFileOnException(fn () => shell()->cd(SOURCE_PATH . '/php-src')->exec(
            $php_configure_env . ' ' .
            getenv('SPC_CMD_PREFIX_PHP_CONFIGURE') . ' ' .
            ($enableCli ? '--enable-cli ' : '--disable-cli ') .
            ($enableFpm ? '--enable-fpm ' . ($this->getLib('libacl') !== null ? '--with-fpm-acl ' : '') : '--disable-fpm ') .
            ($enableEmbed ? "--enable-embed={$embed_type} " : '--disable-embed ') .
            ($enableMicro ? '--enable-micro=all-static ' : '--disable-micro ') .
            ($enableCgi ? '--enable-cgi ' : '--disable-cgi ') .
            $config_file_path .
            $config_file_scan_dir .
            $json_74 .
            $zts .
            $maxExecutionTimers .
            $phpvars . ' ' .
            $this->makeStaticExtensionArgs() . ' '
        ));

        $this->emitPatchPoint('before-php-make');
        SourcePatcher::patchBeforeMake($this);

        $this->cleanMake();

        if ($enableCli) {
            logger()->info('building cli');
            $this->buildCli();
        }
        if ($enableFpm) {
            logger()->info('building fpm');
            $this->buildFpm();
        }
        if ($enableCgi) {
            logger()->info('building cgi');
            $this->buildCgi();
        }
        if ($enableMicro) {
            logger()->info('building micro');
            $this->buildMicro();
        }
        if ($enableEmbed) {
            logger()->info('building embed');
            if ($enableMicro) {
                FileSystem::replaceFileStr(SOURCE_PATH . '/php-src/Makefile', 'OVERALL_TARGET =', 'OVERALL_TARGET = libphp.la');
            }
            $this->buildEmbed();
        }
        if ($enableFrankenphp) {
            logger()->info('building frankenphp');
            $this->buildFrankenphp();
        }
        $shared_extensions = array_map('trim', array_filter(explode(',', $this->getOption('build-shared'))));
        if (!empty($shared_extensions)) {
            if (SPCTarget::isStatic()) {
                throw new WrongUsageException(
                    "You're building against musl libc statically (the default on Linux), but you're trying to build shared extensions.\n" .
                    'Static musl libc does not implement `dlopen`, so your php binary is not able to load shared extensions.' . "\n" .
                    'Either use SPC_LIBC=glibc to link against glibc on a glibc OS, or use SPC_TARGET="native-native-musl -dynamic" to link against musl libc dynamically using `zig cc`.'
                );
            }
            logger()->info('Building shared extensions...');
            $this->buildSharedExts();
        }
    }

    public function testPHP(int $build_target = BUILD_TARGET_NONE)
    {
        $this->emitPatchPoint('before-sanity-check');
        $this->sanityCheck($build_target);
    }

    /**
     * Build cli sapi
     */
    protected function buildCli(): void
    {
        if ($this->getExt('readline') && SPCTarget::isStatic()) {
            SourcePatcher::patchFile('musl_static_readline.patch', SOURCE_PATH . '/php-src');
        }

        $vars = SystemUtil::makeEnvVarString($this->getMakeExtraVars());
        $concurrency = getenv('SPC_CONCURRENCY') ? '-j' . getenv('SPC_CONCURRENCY') : '';
        shell()->cd(SOURCE_PATH . '/php-src')
            ->exec('sed -i "s|//lib|/lib|g" Makefile')
            ->exec("make {$concurrency} {$vars} cli");

        if ($this->getExt('readline') && SPCTarget::isStatic()) {
            SourcePatcher::patchFile('musl_static_readline.patch', SOURCE_PATH . '/php-src', true);
        }

        $this->deploySAPIBinary(BUILD_TARGET_CLI);
    }

    protected function buildCgi(): void
    {
        $vars = SystemUtil::makeEnvVarString($this->getMakeExtraVars());
        $concurrency = getenv('SPC_CONCURRENCY') ? '-j' . getenv('SPC_CONCURRENCY') : '';
        shell()->cd(SOURCE_PATH . '/php-src')
            ->exec('sed -i "s|//lib|/lib|g" Makefile')
            ->exec("make {$concurrency} {$vars} cgi");

        $this->deploySAPIBinary(BUILD_TARGET_CGI);
    }

    /**
     * Build phpmicro sapi
     */
    protected function buildMicro(): void
    {
        if ($this->getPHPVersionID() < 80000) {
            throw new WrongUsageException('phpmicro only support PHP >= 8.0!');
        }
        try {
            if ($this->getExt('phar')) {
                $this->phar_patched = true;
                SourcePatcher::patchMicroPhar($this->getPHPVersionID());
            }

            $enable_fake_cli = $this->getOption('with-micro-fake-cli', false) ? ' -DPHP_MICRO_FAKE_CLI' : '';
            $vars = $this->getMakeExtraVars();

            // patch fake cli for micro
            $vars['EXTRA_CFLAGS'] .= $enable_fake_cli;
            $vars = SystemUtil::makeEnvVarString($vars);
            $concurrency = getenv('SPC_CONCURRENCY') ? '-j' . getenv('SPC_CONCURRENCY') : '';

            shell()->cd(SOURCE_PATH . '/php-src')
                ->exec('sed -i "s|//lib|/lib|g" Makefile')
                ->exec("make {$concurrency} {$vars} micro");

            // deploy micro.sfx
            $dst = $this->deploySAPIBinary(BUILD_TARGET_MICRO);

            // patch after UPX-ed micro.sfx
            $this->processUpxedMicroSfx($dst);
        } finally {
            if ($this->phar_patched) {
                SourcePatcher::unpatchMicroPhar();
            }
        }
    }

    /**
     * Build fpm sapi
     */
    protected function buildFpm(): void
    {
        $vars = SystemUtil::makeEnvVarString($this->getMakeExtraVars());
        $concurrency = getenv('SPC_CONCURRENCY') ? '-j' . getenv('SPC_CONCURRENCY') : '';
        shell()->cd(SOURCE_PATH . '/php-src')
            ->exec('sed -i "s|//lib|/lib|g" Makefile')
            ->exec("make {$concurrency} {$vars} fpm");

        $this->deploySAPIBinary(BUILD_TARGET_FPM);
    }

    /**
     * Build embed sapi
     */
    protected function buildEmbed(): void
    {
        $sharedExts = array_filter($this->exts, static fn ($ext) => $ext->isBuildShared());
        $sharedExts = array_filter($sharedExts, static function ($ext) {
            return Config::getExt($ext->getName(), 'build-with-php') === true;
        });
        $install_modules = $sharedExts ? 'install-modules' : '';

        // detect changes in module path
        $diff = new DirDiff(BUILD_MODULES_PATH, true);
        $vars = SystemUtil::makeEnvVarString($this->getMakeExtraVars());
        $concurrency = getenv('SPC_CONCURRENCY') ? '-j' . getenv('SPC_CONCURRENCY') : '';
        shell()->cd(SOURCE_PATH . '/php-src')
            ->exec('sed -i "s|//lib|/lib|g" Makefile')
            ->exec('sed -i "s|^EXTENSION_DIR = .*|EXTENSION_DIR = /' . basename(BUILD_MODULES_PATH) . '|" Makefile')
            ->exec("make {$concurrency} INSTALL_ROOT=" . BUILD_ROOT_PATH . " {$vars} install-sapi {$install_modules} install-build install-headers install-programs");

        // process libphp.so for shared embed
        $libphpSo = BUILD_LIB_PATH . '/libphp.so';
        $libphpSoDest = BUILD_LIB_PATH . '/libphp.so';
        if (file_exists($libphpSo)) {
            // deploy libphp.so
            preg_match('/-release\s+(\S*)/', getenv('SPC_CMD_VAR_PHP_MAKE_EXTRA_LDFLAGS'), $matches);
            if (!empty($matches[1])) {
                $libphpSoDest = str_replace('.so', '-' . $matches[1] . '.so', $libphpSo);
            }
            $this->deployBinary($libphpSo, $libphpSoDest, false);
        }

        // process shared extensions build-with-php
        $increment_files = $diff->getChangedFiles();
        foreach ($increment_files as $increment_file) {
            $this->deployBinary($increment_file, $increment_file, false);
        }

        // process libphp.a for static embed
        if (getenv('SPC_CMD_VAR_PHP_EMBED_TYPE') === 'static') {
            $AR = getenv('AR') ?: 'ar';
            f_passthru("{$AR} -t " . BUILD_LIB_PATH . "/libphp.a | grep '\\.a$' | xargs -n1 {$AR} d " . BUILD_LIB_PATH . '/libphp.a');
            // export dynamic symbols
            SystemUtil::exportDynamicSymbols(BUILD_LIB_PATH . '/libphp.a');
        }

        // patch embed php scripts
        $this->patchPhpScripts();
    }

    /**
     * Return extra variables for php make command.
     */
    private function getMakeExtraVars(): array
    {
        $config = (new SPCConfigUtil($this, ['libs_only_deps' => true, 'absolute_libs' => true]))->config($this->ext_list, $this->lib_list, $this->getOption('with-suggested-exts'), $this->getOption('with-suggested-libs'));
        $static = SPCTarget::isStatic() ? '-all-static' : '';
        $lib = BUILD_LIB_PATH;
        return array_filter([
            'EXTRA_CFLAGS' => getenv('SPC_CMD_VAR_PHP_MAKE_EXTRA_CFLAGS'),
            'EXTRA_LIBS' => $config['libs'],
            'EXTRA_LDFLAGS' => getenv('SPC_CMD_VAR_PHP_MAKE_EXTRA_LDFLAGS'),
            'EXTRA_LDFLAGS_PROGRAM' => "-L{$lib} {$static} -pie",
        ]);
    }

    /**
     * Patch micro.sfx after UPX compression.
     * micro needs special section handling in LinuxBuilder.
     * The micro.sfx does not support UPX directly, but we can remove UPX
     * info segment to adapt.
     * This will also make micro.sfx with upx-packed more like a malware fore antivirus
     */
    private function processUpxedMicroSfx(string $dst): void
    {
        if ($this->getOption('with-upx-pack') && version_compare($this->getMicroVersion(), '0.2.0') >= 0) {
            // strip first
            // cut binary with readelf
            [$ret, $out] = shell()->execWithResult("readelf -l {$dst} | awk '/LOAD|GNU_STACK/ {getline; print \$1, \$2, \$3, \$4, \$6, \$7}'");
            $out[1] = explode(' ', $out[1]);
            $offset = $out[1][0];
            if ($ret !== 0 || !str_starts_with($offset, '0x')) {
                throw new PatchException('phpmicro UPX patcher', 'Cannot find offset in readelf output');
            }
            $offset = hexdec($offset);
            // remove upx extra wastes
            file_put_contents($dst, substr(file_get_contents($dst), 0, $offset));
        }
    }
}