<?php

namespace App\Http\Controllers\Admin;

use App\Http\Controllers\Controller;
use App\Models\Amministratore;
use App\Models\GesconImportMapping;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\Auth;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Config;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;
use Carbon\Carbon;

class FornitoriImportController extends Controller
{
    private function progressKey(): string
    {
        return 'fornitori_import:' . (Auth::id() ?? 'guest');
    }

    private function currentAdminId(): ?int
    {
        $user = Auth::user();
        if (!$user) return null;
        $am = Amministratore::where('user_id', $user->id)->first();
        return $am?->id;
    }

    public function stagingTables(): JsonResponse
    {
        $conn = Config::get('database.connections.gescon_import') ? 'gescon_import' : Config::get('database.default');
        $driver = DB::connection($conn)->getDriverName();
        $tables = [];
        try {
            if ($driver === 'mysql') {
                $dbName = DB::connection($conn)->getDatabaseName();
                $rows = DB::connection($conn)->select(
                    'SELECT table_name FROM information_schema.tables WHERE table_schema = ? AND (table_name LIKE ? OR table_name LIKE ?) ORDER BY table_name',
                    [$dbName, 'mdb%fornit%', 'mdb%Supplier%']
                );
                $tables = array_map(fn($r) => $r->table_name, $rows);
            } elseif ($driver === 'pgsql') {
                $rows = DB::connection($conn)->select(
                    "SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname NOT IN ('pg_catalog','information_schema') AND (tablename ILIKE 'mdb%fornit%' OR tablename ILIKE 'mdb%supplier%') ORDER BY tablename"
                );
                $tables = array_map(fn($r) => $r->tablename, $rows);
            }
        } catch (\Throwable $e) {
            $tables = [];
        }
        return new JsonResponse(['tables' => $tables, 'connection' => $conn]);
    }

    public function stagingColumns(Request $request): JsonResponse
    {
        $request->validate(['table' => 'required|string']);
        $conn = Config::get('database.connections.gescon_import') ? 'gescon_import' : Config::get('database.default');
        $table = $request->string('table')->toString();
        if (!DB::connection($conn)->getSchemaBuilder()->hasTable($table)) {
            return new JsonResponse(['ok' => false, 'error' => 'Tabella di staging non trovata'], 404);
        }
        $driver = DB::connection($conn)->getDriverName();
        $cols = [];
        try {
            if ($driver === 'mysql') {
                $dbName = DB::connection($conn)->getDatabaseName();
                $rows = DB::connection($conn)->select('SELECT column_name FROM information_schema.columns WHERE table_schema = ? AND table_name = ? ORDER BY ordinal_position', [$dbName, $table]);
                $cols = array_map(fn($r) => $r->column_name, $rows);
            } elseif ($driver === 'pgsql') {
                $rows = DB::connection($conn)->select("SELECT column_name FROM information_schema.columns WHERE table_name = ? ORDER BY ordinal_position", [$table]);
                $cols = array_map(fn($r) => $r->column_name, $rows);
            }
        } catch (\Throwable $e) {
            $cols = [];
        }
        return new JsonResponse(['ok' => true, 'columns' => $cols]);
    }

    public function init(Request $request): JsonResponse
    {
        $request->validate(['staging_table' => 'required|string']);
        $conn = Config::get('database.connections.gescon_import') ? 'gescon_import' : Config::get('database.default');
        $table = $request->string('staging_table')->toString();
        if (!DB::connection($conn)->getSchemaBuilder()->hasTable($table)) {
            return new JsonResponse(['ok' => false, 'error' => 'Tabella di staging non trovata', 'table' => $table], 400);
        }
        $total = (int) DB::connection($conn)->table($table)->count();
        $state = [
            'table' => $table,
            'connection' => $conn,
            'total' => $total,
            'processed' => 0,
            'last_id' => 0,
            'status' => 'running',
            'started_at' => Carbon::now()->toISOString(),
        ];
        Cache::put($this->progressKey(), $state, Carbon::now()->addHours(2));
        return new JsonResponse(['ok' => true, 'progress' => $state]);
    }

    public function progress(): JsonResponse
    {
        $state = Cache::get($this->progressKey());
        if (!$state) return new JsonResponse(['ok' => false, 'error' => 'Nessun import attivo']);
        $pct = $state['total'] > 0 ? (int) floor(($state['processed'] / $state['total']) * 100) : 0;
        $state['percent'] = max(0, min(100, $pct));
        return new JsonResponse(['ok' => true, 'progress' => $state]);
    }

    public function processChunk(Request $request): JsonResponse
    {
        $chunk = max(1, min(2000, (int) $request->input('chunk', 500)));
        $state = Cache::get($this->progressKey());
        if (!$state) return new JsonResponse(['ok' => false, 'error' => 'Import non inizializzato'], 400);
        if (($state['status'] ?? '') === 'completed') return new JsonResponse(['ok' => true, 'progress' => $state]);

        $conn = $state['connection'];
        $table = $state['table'];
        $lastId = (int) ($state['last_id'] ?? 0);
        if (!DB::connection($conn)->getSchemaBuilder()->hasTable($table)) {
            return new JsonResponse(['ok' => false, 'error' => 'Tabella di staging non trovata', 'table' => $table], 400);
        }
        $rows = DB::connection($conn)->table($table)
            ->where('id', '>', $lastId)
            ->orderBy('id')
            ->limit($chunk)
            ->get();

        if ($rows->isEmpty()) {
            $state['status'] = 'completed';
            $state['completed_at'] = Carbon::now()->toISOString();
            Cache::put($this->progressKey(), $state, Carbon::now()->addHours(2));
            return new JsonResponse(['ok' => true, 'progress' => $state]);
        }

        $adminId = $this->currentAdminId();
        $imported = 0;
        $mapping = GesconImportMapping::where('user_id', Auth::id())->where('legacy_code', 'fornitori')->first();
        $mapCfg = (array) ($mapping?->meta['mapping'] ?? []);

        foreach ($rows as $r) {
            $data = (array) $r;
            $rec = $this->mapFornitoreRecord($data, $mapCfg);
            if (!$rec) {
                $lastId = $r->id;
                continue;
            }
            try {
                $this->upsertFornitore($rec, $adminId);
                $imported++;
            } catch (\Throwable $e) {
                Log::warning('Fornitori import: errore record', ['id' => $r->id, 'err' => $e->getMessage()]);
            }
            $lastId = $r->id;
        }

        $state['processed'] = (int) $state['processed'] + $rows->count();
        $state['last_id'] = $lastId;
        if ($state['processed'] >= $state['total']) {
            $state['status'] = 'completed';
            $state['completed_at'] = Carbon::now()->toISOString();
        }
        Cache::put($this->progressKey(), $state, Carbon::now()->addHours(2));
        return new JsonResponse(['ok' => true, 'progress' => $state, 'chunk_imported' => $imported]);
    }

    private function mapFornitoreRecord(array $row, array $mapCfg): ?array
    {
        // normalize keys
        $lower = [];
        foreach ($row as $k => $v) {
            $lower[Str::snake(strtolower((string)$k))] = is_string($v) ? trim($v) : $v;
        }
        $pick = function (?string $cfgKey, array $candidates) use ($lower, $mapCfg) {
            $src = $cfgKey && isset($mapCfg[$cfgKey]) ? $mapCfg[$cfgKey] : null;
            if ($src && array_key_exists($src, $lower)) return $lower[$src];
            foreach ($candidates as $c) {
                if (array_key_exists($c, $lower) && $lower[$c] !== null && $lower[$c] !== '') return $lower[$c];
            }
            return null;
        };

        $ragsoc = $pick('fornitore.ragione_sociale', ['ragione_sociale', 'ragsoc', 'denominazione', 'nome', 'descrizione']);
        $piva = $pick('fornitore.partita_iva', ['partita_iva', 'piva', 'p_iva', 'p.iva']);
        $cf = $pick('fornitore.codice_fiscale', ['codice_fiscale', 'cf']);
        $indirizzo = $pick('fornitore.indirizzo', ['indirizzo', 'address', 'via']);
        $cap = $pick('fornitore.cap', ['cap', 'zip']);
        $citta = $pick('fornitore.comune', ['comune', 'citta', 'città', 'city']);
        $prov = $pick('fornitore.provincia', ['provincia', 'prov', 'pr']);
        $email = $pick('fornitore.email', ['email', 'pec']);
        $tel = $pick('fornitore.telefono', ['telefono', 'tel', 'phone']);

        if (!$ragsoc && !$piva && !$cf) return null;

        return [
            'ragione_sociale' => $ragsoc ?: ($cf ?: $piva),
            'partita_iva' => $piva ?: null,
            'codice_fiscale' => $cf ?: null,
            'indirizzo' => $indirizzo ?: null,
            'cap' => $cap ?: null,
            'citta' => $citta ?: null,
            'provincia' => $prov ? (strlen($prov) > 2 ? substr($prov, 0, 2) : strtoupper($prov)) : null,
            'email' => $email ?: null,
            'telefono' => $tel ?: null,
        ];
    }

    private function upsertFornitore(array $rec, ?int $amministratoreId): void
    {
        $base = [
            'ragione_sociale' => $rec['ragione_sociale'],
            'indirizzo' => $rec['indirizzo'],
            'cap' => $rec['cap'],
            'citta' => $rec['citta'],
            'provincia' => $rec['provincia'],
            'email' => $rec['email'],
            'telefono' => $rec['telefono'],
            'updated_at' => Carbon::now(),
        ];
        if ($amministratoreId) $base['amministratore_id'] = $amministratoreId;

        // Prefer P.IVA then CF then ragione_sociale unique-ish
        if (!empty($rec['partita_iva'])) {
            DB::table('fornitori')->updateOrInsert(
                ['partita_iva' => $rec['partita_iva']],
                array_merge($base, [
                    'codice_fiscale' => $rec['codice_fiscale'],
                    'created_at' => DB::raw('COALESCE(created_at, NOW())'),
                ])
            );
            return;
        }
        if (!empty($rec['codice_fiscale'])) {
            $existing = DB::table('fornitori')->where('codice_fiscale', $rec['codice_fiscale'])->first();
            if ($existing) {
                DB::table('fornitori')->where('id', $existing->id)->update($base);
            } else {
                DB::table('fornitori')->insert(array_merge($base, [
                    'codice_fiscale' => $rec['codice_fiscale'],
                    'created_at' => Carbon::now(),
                ]));
            }
            return;
        }
        // Fallback by ragione_sociale
        if (!empty($rec['ragione_sociale'])) {
            $existing = DB::table('fornitori')->where('ragione_sociale', $rec['ragione_sociale'])->first();
            if ($existing) {
                DB::table('fornitori')->where('id', $existing->id)->update($base);
            } else {
                DB::table('fornitori')->insert(array_merge($base, ['created_at' => Carbon::now()]));
            }
        }
    }
}