<?php

namespace App\Services\Documents;

use App\Models\Contract;
use App\Models\DocumentTemplate;
use App\Models\User;
use App\Services\Documents\Exceptions\UnresolvedTokensException;
use Carbon\Carbon;
use Illuminate\Support\Facades\Storage;
use Illuminate\Support\Str;
use ZipArchive;

class DocxTemplateRenderer
{
    public function __construct(
        private TokenScanner $scanner = new TokenScanner,
        private TokenValueResolver $resolver = new TokenValueResolver,
    ) {}

    /**
     * @return array{fileName:string,relativePath:string,size:int,checksum:string}
     */
    public function render(DocumentTemplate $template, Contract $contract, User $user): array
    {
        $disk = 'public';
        $templateStream = Storage::disk($disk)->get($template->file_path);

        // Work in temp file
        $tmpIn = tempnam(sys_get_temp_dir(), 'tmpl');
        file_put_contents($tmpIn, $templateStream);

        $zip = new ZipArchive;
        $zip->open($tmpIn);
        $docXml = $zip->getFromName('word/document.xml');
        if ($docXml === false) {
            throw new \RuntimeException('Manjkajoča document.xml');
        }

        $tokens = $this->scanner->scan($docXml);
        // Determine effective unresolved policy early (template override -> global -> config)
        $globalSettingsEarly = app(\App\Services\Documents\DocumentSettings::class)->get();
        $effectivePolicy = $template->fail_on_unresolved ? 'fail' : ($globalSettingsEarly->unresolved_policy ?? config('documents.unresolved_policy', 'fail'));
        // Resolve with support for custom.* tokens: per-generation overrides and defaults from template meta or global settings.
        $customOverrides = request()->input('custom', []); // if called via HTTP context; otherwise pass explicitly from caller
        $customDefaults = is_array($template->meta['custom_defaults'] ?? null) ? $template->meta['custom_defaults'] : null;
        $resolved = $this->resolver->resolve(
            $tokens,
            $template,
            $contract,
            $user,
            $effectivePolicy,
            is_array($customOverrides) ? $customOverrides : [],
            $customDefaults,
            'empty'
        );
        $values = $resolved['values'];
        $initialUnresolved = $resolved['unresolved'];
        $customTypes = $resolved['customTypes'] ?? [];
        // Formatting options
        $fmt = $template->formatting_options ?? [];
        $decimals = (int) ($fmt['number_decimals'] ?? 2);
        $decSep = $fmt['decimal_separator'] ?? '.';
        $thouSep = $fmt['thousands_separator'] ?? ',';
        $currencySymbol = $fmt['currency_symbol'] ?? null;
        $currencyPos = $fmt['currency_position'] ?? 'before';
        $currencySpace = (bool) ($fmt['currency_space'] ?? false);
        $globalSettings = app(\App\Services\Documents\DocumentSettings::class)->get();
        $globalDateFormats = $globalSettings->date_formats ?? [];
        foreach ($values as $k => $v) {
            $isTypedDate = ($customTypes[$k] ?? null) === 'date';
            $isTypedNumber = ($customTypes[$k] ?? null) === 'number';
            // Date formatting (typed or heuristic based on key ending with _date or .date)
            if (is_string($v) && ($isTypedDate || $k === 'generation.date' || preg_match('/(^|\.)[A-Za-z_]*date$/i', $k))) {
                $dateFmtOverrides = $fmt['date_formats'] ?? [];
                $desiredFormat = $dateFmtOverrides[$k]
                    ?? ($globalDateFormats[$k] ?? null)
                    ?? ($fmt['default_date_format'] ?? null)
                    ?? ($template->date_format ?: null)
                    ?? ($globalSettings->date_format ?? null)
                    ?? config('documents.date_format', 'Y-m-d');
                if ($desiredFormat) {
                    try {
                        $dt = Carbon::parse($v);
                        $values[$k] = $dt->format($desiredFormat);

                        continue; // skip numeric detection below
                    } catch (\Throwable $e) {
                        // swallow
                    }
                }
            }
            // Number formatting: only for explicitly typed numbers or common monetary fields
            $isFinanceField = (bool) preg_match('/(^|\.)\b(amount|balance|total|price|cost)\b$/i', $k);
            if (($isTypedNumber || $isFinanceField) && is_numeric($v)) {
                $num = number_format((float) $v, $decimals, $decSep, $thouSep);
                if ($currencySymbol && $isFinanceField) {
                    $space = $currencySpace ? ' ' : '';
                    if ($currencyPos === 'after') {
                        $num = $num.$space.$currencySymbol;
                    } else {
                        $num = $currencySymbol.$space.$num;
                    }
                }
                $values[$k] = $num;
            }
        }
        // Replace tokens
        foreach ($values as $token => $val) {
            $docXml = str_replace('{{'.$token.'}}', htmlspecialchars($val), $docXml);
        }
        // After replacement: check unresolved patterns
        if (! empty($initialUnresolved)) {
            if ($effectivePolicy === 'blank') {
                foreach ($initialUnresolved as $r) {
                    $docXml = str_replace('{{'.$r.'}}', '', $docXml);
                }
            } elseif ($effectivePolicy === 'keep') {
                // keep unresolved markers
            } else { // fail
                throw new UnresolvedTokensException($initialUnresolved, 'Neuspešna zamenjava tokenov');
            }
        }

        $zip->addFromString('word/document.xml', $docXml);
        $zip->close();

        $output = file_get_contents($tmpIn);
        $checksum = hash('sha256', $output);
        $size = strlen($output);

        // Filename pattern & date format precedence: template override -> global settings -> config fallback
        $globalSettings = $globalSettings ?? app(\App\Services\Documents\DocumentSettings::class)->get();
        $pattern = $template->output_filename_pattern
            ?: ($globalSettings->file_name_pattern ?? config('documents.file_name_pattern'));
        $dateFormat = $template->date_format
            ?: ($globalSettings->date_format ?? config('documents.date_format', 'Y-m-d'));
        $replacements = [
            '{slug}' => $template->slug,
            '{version}' => 'v'.$template->version,
            '{generation.date}' => now()->format($dateFormat),
            '{generation.timestamp}' => (string) now()->timestamp,
        ];
        // Also allow any token ({{x.y}}) style replaced pattern variants: convert {contract.reference}
        foreach ($values as $token => $val) {
            $replacements['{'.$token.'}'] = Str::slug((string) $val) ?: 'value';
        }
        $fileName = strtr($pattern, $replacements);
        if (! str_ends_with(strtolower($fileName), '.docx')) {
            $fileName .= '.docx';
        }
        $relativeDir = 'contracts/'.$contract->uuid.'/generated/'.now()->toDateString();
        $relativePath = $relativeDir.'/'.$fileName;
        Storage::disk($disk)->put($relativePath, $output);

        return [
            'fileName' => $fileName,
            'relativePath' => $relativePath,
            'size' => $size,
            'checksum' => $checksum,
        ];
    }
}