<?php

namespace App\Http\Controllers\API\v1\Voter;

use App\Http\Controllers\Controller;
use App\Http\Controllers\Util;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;

/**
 * Import keanggotaan JSON (match by no_anggota) into voter money columns for the current election.
 * Expected row keys: no_anggota, pelaburan, pelaburan_2, saham, yuran. Null/empty → 0.
 */
class ImportKeanggotaanJsonController extends Controller
{
    private const UPDATABLE_FIELDS = [
        'pelaburan',
        'pelaburan_2',
        'saham',
        'yuran',
    ];

    public function __invoke(Request $request)
    {
        $this->validate($request, [
            'file' => 'required|file|max:10240',
        ]);

        $file = $request->file('file');
        $extension = strtolower($file->getClientOriginalExtension() ?: '');
        if ($extension !== 'json') {
            return response()->json([
                'status' => 'failed',
                'message' => 'Fail mestilah format .json.',
            ], 422);
        }

        $raw = file_get_contents($file->getRealPath());
        $rows = json_decode($raw, true);

        if (!is_array($rows)) {
            return response()->json([
                'status' => 'failed',
                'message' => 'JSON tidak sah. Jangkaan array objek.',
            ], 422);
        }

        $map = [];
        foreach ($rows as $row) {
            if (!is_array($row)) {
                continue;
            }

            $noAnggota = isset($row['no_anggota']) ? trim((string) $row['no_anggota']) : '';
            if ($noAnggota === '') {
                continue;
            }

            $payload = [];
            foreach (self::UPDATABLE_FIELDS as $field) {
                if (array_key_exists($field, $row)) {
                    $payload[$field] = $this->cleanNumber($row[$field]);
                }
            }

            if (count($payload) === 0) {
                continue;
            }

            $map[$noAnggota] = $payload;
        }

        if (count($map) === 0) {
            return response()->json([
                'status' => 'failed',
                'message' => 'Tiada baris sah dalam JSON (perlu no_anggota dan sekurang-kurangnya satu medan).',
            ], 422);
        }

        $electionId = (int) Util::getCurrentElection();
        if ($electionId <= 0) {
            return response()->json([
                'status' => 'failed',
                'message' => 'Tidak dapat mengenal pasti election semasa.',
            ], 422);
        }

        $stats = [
            'election_id' => $electionId,
            'json_rows' => count($map),
            'matched' => 0,
            'updated' => 0,
            'unchanged' => 0,
            'missing_in_voter' => 0,
            'missing_in_json' => 0,
        ];

        $matchedKeys = [];

        DB::table('voter')
            ->select(array_merge(['id', 'no_anggota'], self::UPDATABLE_FIELDS))
            ->where('election_id', $electionId)
            ->orderBy('id')
            ->chunkById(500, function ($chunk) use ($map, &$stats, &$matchedKeys) {
                foreach ($chunk as $voter) {
                    $noAnggota = $voter->no_anggota !== null ? trim((string) $voter->no_anggota) : '';

                    if ($noAnggota === '' || !array_key_exists($noAnggota, $map)) {
                        $stats['missing_in_json']++;
                        continue;
                    }

                    $stats['matched']++;
                    $matchedKeys[$noAnggota] = true;
                    $jsonRow = $map[$noAnggota];

                    $update = [];
                    foreach ($jsonRow as $field => $newValue) {
                        $oldValue = $voter->{$field} !== null ? (float) $voter->{$field} : 0.0;
                        if (abs($oldValue - $newValue) >= 0.00001) {
                            $update[$field] = $newValue;
                        }
                    }

                    if (count($update) === 0) {
                        $stats['unchanged']++;
                        continue;
                    }

                    $update['updated_at'] = now();
                    DB::table('voter')->where('id', $voter->id)->update($update);
                    $stats['updated']++;
                }
            }, 'id');

        foreach ($map as $noAnggota => $_payload) {
            if (!isset($matchedKeys[$noAnggota])) {
                $stats['missing_in_voter']++;
            }
        }

        activity()
            ->withProperties([
                'election_id' => $electionId,
                'filename' => $file->getClientOriginalName(),
                'stats' => $stats,
                'ip' => $request->ip(),
                'user_agent' => $request->userAgent(),
            ])
            ->log('import keanggotaan json');

        return response()->json([
            'status' => 'success',
            'message' => 'Import keanggotaan berjaya.',
            'data' => $stats,
        ]);
    }

    private function cleanNumber($value): float
    {
        if ($value === null || $value === '') {
            return 0.0;
        }

        $value = (string) $value;
        $value = str_replace(['RM', ',', ' '], '', $value);

        if (preg_match('/^\((.*)\)$/', $value, $matches)) {
            $value = $matches[1];
        }

        $value = preg_replace('/[^0-9\.\-]/', '', $value);

        return is_numeric($value) ? (float) $value : 0.0;
    }
}