<?php

namespace App\Support;

use Illuminate\Support\Str;
use RuntimeException;
use Symfony\Component\Process\Process;
use ZipArchive;

class DocTextExtractor
{
    public static function extract(string $path, string $extension): string
    {
        $extension = strtolower(ltrim($extension, '.'));

        return match ($extension) {
            'docx' => self::extractDocx($path),
            'doc' => self::extractDoc($path),
            default => throw new RuntimeException('仅支持 .doc / .docx 申报表'),
        };
    }

    public static function extractDocx(string $path): string
    {
        $zip = new ZipArchive();
        if ($zip->open($path) !== true) {
            throw new RuntimeException('无法读取 docx 文件');
        }

        $xml = $zip->getFromName('word/document.xml');
        $zip->close();

        if (! is_string($xml) || trim($xml) === '') {
            throw new RuntimeException('docx 文档内容为空');
        }

        $dom = new \DOMDocument();
        $dom->preserveWhiteSpace = false;
        @$dom->loadXML($xml);
        $xpath = new \DOMXPath($dom);
        $xpath->registerNamespace('w', 'http://schemas.openxmlformats.org/wordprocessingml/2006/main');

        $lines = [];
        $bodyNodes = $xpath->query('//w:body/*');
        if ($bodyNodes === false) {
            return '';
        }

        foreach ($bodyNodes as $node) {
            $local = $node->localName ?? $node->nodeName;
            if ($local === 'p') {
                $text = self::textFromNode($xpath, $node);
                $lines[] = self::normalizeLine($text);
                continue;
            }
            if ($local === 'tbl') {
                $rowNodes = $xpath->query('.//w:tr', $node);
                if ($rowNodes === false) {
                    continue;
                }
                foreach ($rowNodes as $row) {
                    $cellTexts = [];
                    $cellNodes = $xpath->query('./w:tc', $row);
                    if ($cellNodes === false) {
                        continue;
                    }
                    foreach ($cellNodes as $cell) {
                        $cellTexts[] = self::normalizeLine(self::textFromNode($xpath, $cell));
                    }
                    if (count($cellTexts) === 1) {
                        $lines[] = $cellTexts[0];
                    } else {
                        foreach ($cellTexts as $cellText) {
                            $lines[] = $cellText;
                        }
                    }
                }
            }
        }

        return self::joinLines($lines);
    }

    public static function extractDoc(string $path): string
    {
        $textutil = self::resolveBinary('textutil');
        if ($textutil !== null) {
            $out = self::runCommand([$textutil, '-convert', 'txt', '-stdout', $path], 45);
            if (is_string($out) && trim($out) !== '') {
                return self::normalizeText($out);
            }
        }

        $soffice = self::resolveBinary('soffice');
        if ($soffice !== null) {
            $tmpDir = sys_get_temp_dir().'/study-tour-doc-'.Str::random(8);
            if (! @mkdir($tmpDir, 0700, true) && ! is_dir($tmpDir)) {
                throw new RuntimeException('无法创建临时目录');
            }
            self::runCommand([
                $soffice,
                '--headless',
                '--convert-to',
                'txt:Text',
                '--outdir',
                $tmpDir,
                $path,
            ], 120);
            $base = pathinfo($path, PATHINFO_FILENAME);
            $txtPath = $tmpDir.'/'.$base.'.txt';
            if (is_file($txtPath)) {
                $text = file_get_contents($txtPath) ?: '';
                @unlink($txtPath);
                @rmdir($tmpDir);

                if (trim($text) !== '') {
                    return self::normalizeText($text);
                }
            }
            @array_map('unlink', glob($tmpDir.'/*') ?: []);
            @rmdir($tmpDir);
        }

        throw new RuntimeException('无法解析 .doc 文件，请安装 LibreOffice（soffice），或改用 .docx 格式');
    }

    private static function textFromNode(\DOMXPath $xpath, \DOMNode $node): string
    {
        $parts = [];
        $textNodes = $xpath->query('.//w:t', $node);
        if ($textNodes !== false) {
            foreach ($textNodes as $textNode) {
                $parts[] = $textNode->textContent ?? '';
            }
        }

        return trim(implode('', $parts));
    }

    private static function normalizeLine(string $text): string
    {
        $text = str_replace(["\xc2\xa0", "\xef\xbb\xbf"], ' ', $text);
        $text = preg_replace('/\s+/u', ' ', $text) ?? $text;

        return trim($text);
    }

    private static function joinLines(array $lines): string
    {
        $normalized = array_map(fn ($line) => self::normalizeLine((string) $line), $lines);

        return self::normalizeText(implode("\n", $normalized));
    }

    private static function normalizeText(string $text): string
    {
        $text = str_replace(["\r\n", "\r", "\f"], "\n", $text);
        $text = preg_replace("/\n{3,}/", "\n\n", $text) ?? $text;

        return trim($text);
    }

    private static function resolveBinary(string $command): ?string
    {
        $candidates = [$command];
        if ($command === 'soffice') {
            $candidates = array_merge($candidates, [
                '/usr/bin/soffice',
                '/usr/local/bin/soffice',
                '/opt/libreoffice/program/soffice',
                '/usr/lib/libreoffice/program/soffice',
            ]);
        }
        if ($command === 'textutil') {
            $candidates[] = '/usr/bin/textutil';
        }

        foreach ($candidates as $candidate) {
            if ($candidate === $command) {
                if (self::isExecutableOnPath($command)) {
                    return $command;
                }
                continue;
            }
            if (is_file($candidate) && is_executable($candidate)) {
                return $candidate;
            }
        }

        return null;
    }

    private static function isExecutableOnPath(string $command): bool
    {
        $pathEnv = getenv('PATH');
        if (! is_string($pathEnv) || $pathEnv === '') {
            $pathEnv = '/usr/local/bin:/usr/bin:/bin';
        }

        foreach (explode(':', $pathEnv) as $dir) {
            $dir = trim($dir);
            if ($dir === '') {
                continue;
            }
            $full = rtrim($dir, '/').'/'.$command;
            if (is_file($full) && is_executable($full)) {
                return true;
            }
        }

        return false;
    }

    /**
     * @param  array<int, string>  $command
     */
    private static function runCommand(array $command, int $timeoutSeconds = 30): ?string
    {
        $process = new Process($command);
        $process->setTimeout($timeoutSeconds);

        try {
            $process->mustRun();
        } catch (\Throwable) {
            return null;
        }

        $output = $process->getOutput();

        return is_string($output) && $output !== '' ? $output : null;
    }
}