<?php

namespace App\Console\Commands;

use Illuminate\Console\Command;
use App\Models\User;
use App\Models\AttendanceRecord;
use Illuminate\Support\Facades\DB;
use Carbon\Carbon;

class SyncLegacyDailyShifts extends Command
{
    protected $signature = 'import:legacy-shifts {start_date?} {end_date?}';
    protected $description = 'Sweeps legacy employee_daily_shifts to synchronize proper working/rest day tracking into the core attendance engine natively.';

    public function handle()
    {
        $startDate = $this->argument('start_date') ?: '2026-01-11';
        $endDate = $this->argument('end_date') ?: '2026-01-25';

        $this->info("Initializing Legacy Shift Matrix Sync: $startDate to $endDate");

        $employees = User::where('type', 'employee')->whereHas('employee')->get();
        $bar = $this->output->createProgressBar(count($employees));

        $legacyUsers = DB::connection('legacy')->table('users')->get(['id', 'name']);
        
        $newUserIdMap = [];
        foreach ($legacyUsers as $lu) {
            $matchingLocal = User::where('name', $lu->name)->first();
            if ($matchingLocal) {
                $newUserIdMap[$matchingLocal->id] = $lu->id;
            }
        }

        $synced = 0;
        $patterned = 0;

        foreach ($employees as $user) {
            if (!isset($newUserIdMap[$user->id])) {
                $bar->advance();
                continue;
            }
            
            $legacyUserId = $newUserIdMap[$user->id];

            // Check if legacy has data for the requested date range
            $hasDirectData = DB::connection('legacy')
                ->table('employee_daily_shifts')
                ->where('user_id', $legacyUserId)
                ->whereBetween('date', [$startDate, $endDate])
                ->exists();

            // Build a 7-day pattern from their last known week if no direct data
            $weeklyPattern = null;
            if (!$hasDirectData) {
                $lastRecords = DB::connection('legacy')
                    ->table('employee_daily_shifts')
                    ->where('user_id', $legacyUserId)
                    ->orderByDesc('date')
                    ->limit(7)
                    ->get();

                if ($lastRecords->isNotEmpty()) {
                    // Build pattern keyed by day-of-week (0=Sunday, 6=Saturday)
                    $weeklyPattern = [];
                    foreach ($lastRecords as $rec) {
                        $dow = Carbon::parse($rec->date)->dayOfWeek;
                        $weeklyPattern[$dow] = $rec->shift_id;
                    }
                    $this->line(" → {$user->name}: No legacy data for range. Repeating last known weekly pattern.");
                }
            }

            $currentDate = Carbon::parse($startDate);
            $periodEndObj = Carbon::parse($endDate);

            while ($currentDate->lte($periodEndObj)) {
                $dateString = $currentDate->toDateString();
                $shiftId = null;
                $isRestDay = true;

                if ($hasDirectData) {
                    // Direct lookup from legacy DB
                    $shiftRecord = DB::connection('legacy')
                        ->table('employee_daily_shifts')
                        ->where('user_id', $legacyUserId)
                        ->where('date', $dateString)
                        ->first();

                    $isRestDay = (!$shiftRecord || empty($shiftRecord->shift_id));
                    $shiftId = $shiftRecord->shift_id ?? null;
                } elseif ($weeklyPattern !== null) {
                    // Use the repeating weekly pattern
                    $dow = $currentDate->dayOfWeek;
                    $shiftId = $weeklyPattern[$dow] ?? null;
                    $isRestDay = empty($shiftId);
                }

                if ($isRestDay) {
                    AttendanceRecord::updateOrCreate(
                        [
                            'employee_id' => $user->id,
                            'date' => $dateString
                        ],
                        [
                            'is_rest_day' => true,
                            'is_absent' => false,
                            'status' => 'present',
                            'created_by' => 1,
                            'shift_id' => null
                        ]
                    );
                } else {
                    AttendanceRecord::updateOrCreate(
                        [
                            'employee_id' => $user->id,
                            'date' => $dateString
                        ],
                        [
                            'is_rest_day' => false,
                            'shift_id' => $shiftId,
                            'created_by' => 1
                        ]
                    );
                }

                $hasDirectData ? $synced++ : $patterned++;
                $currentDate->addDay();
            }

            $bar->advance();
        }

        $bar->finish();
        $this->info("\nMatrix Sync Complete. Direct synced: {$synced} | Pattern-filled: {$patterned}");
    }
}