<?php

namespace Modules\Maintenance\Services;

use App\Business;
use App\User;
use Carbon\Carbon;
use Illuminate\Support\Facades\DB;
use Modules\Maintenance\Models\Equipment;
use Modules\Maintenance\Models\RebuildPhase;
use Modules\Maintenance\Models\RebuildProject;

class RebuildProcessService
{
    public const PHASES = [
        ['key' => 'assessment', 'title' => 'ارزیابی و بازرسی اولیه'],
        ['key' => 'planning', 'title' => 'برنامه‌ریزی و تأیید'],
        ['key' => 'dismantling', 'title' => 'دمونتاژ و تخلیه'],
        ['key' => 'rebuilding', 'title' => 'بازسازی و مونتاژ'],
        ['key' => 'testing', 'title' => 'تست و راه‌اندازی آزمایشی'],
        ['key' => 'commissioning', 'title' => 'تحویل و بهره‌برداری'],
    ];

    public const WORKFLOW_STATUSES = [
        'draft',
        'assessment',
        'planning',
        'approved',
        'dismantling',
        'rebuilding',
        'testing',
        'commissioning',
        'completed',
        'on_hold',
        'cancelled',
    ];

    public function generateNumber(Business $business): string
    {
        $prefix = 'RB-'.now()->format('ym');
        $last = RebuildProject::where('business_id', $business->id)
            ->where('rebuild_number', 'like', $prefix.'%')
            ->orderByDesc('id')
            ->value('rebuild_number');

        $seq = 1;
        if ($last && preg_match('/(\d+)$/', $last, $m)) {
            $seq = (int) $m[1] + 1;
        }

        return $prefix.str_pad((string) $seq, 4, '0', STR_PAD_LEFT);
    }

    public function resolveEquipmentIds(string $scopeType, array $data): array
    {
        if ($scopeType === 'production_line') {
            if (empty($data['production_line_id'])) {
                return [];
            }

            return Equipment::where('business_id', $data['business_id'])
                ->where('production_line_id', $data['production_line_id'])
                ->pluck('id')
                ->map(fn ($id) => (int) $id)
                ->all();
        }

        if (! empty($data['equipment_ids']) && is_array($data['equipment_ids'])) {
            return array_values(array_unique(array_map('intval', $data['equipment_ids'])));
        }

        if (! empty($data['equipment_id'])) {
            return [(int) $data['equipment_id']];
        }

        return [];
    }

    public function createProject(Business $business, array $data, array $equipmentIds, ?User $user = null): RebuildProject
    {
        return DB::transaction(function () use ($business, $data, $equipmentIds, $user) {
            $status = $data['status'] ?? 'draft';
            $project = RebuildProject::create(array_merge($data, [
                'business_id' => $business->id,
                'rebuild_number' => $data['rebuild_number'] ?? $this->generateNumber($business),
                'status' => $status,
                'progress_percent' => $status === 'draft' ? 0 : 5,
            ]));

            $this->initializePhases($project);
            $this->syncEquipmentPivot($project, $equipmentIds);

            if ($status !== 'draft') {
                $this->startWorkflow($project, $user);
            }

            return $project->fresh(['phases', 'equipmentItems', 'productionLine', 'supervisor']);
        });
    }

    public function initializePhases(RebuildProject $project): void
    {
        if ($project->phases()->exists()) {
            return;
        }

        foreach (self::PHASES as $index => $phase) {
            RebuildPhase::create([
                'rebuild_project_id' => $project->id,
                'phase_key' => $phase['key'],
                'title' => $phase['title'],
                'sort_order' => $index + 1,
                'status' => 'pending',
            ]);
        }
    }

    public function syncEquipmentPivot(RebuildProject $project, array $equipmentIds): void
    {
        $sync = [];
        foreach ($equipmentIds as $equipmentId) {
            $equipment = Equipment::find($equipmentId);
            $sync[$equipmentId] = [
                'pre_rebuild_health' => $equipment?->health_percentage,
                'status' => 'pending',
            ];
        }

        $project->equipmentItems()->sync($sync);
    }

    public function startWorkflow(RebuildProject $project, ?User $user = null): RebuildProject
    {
        return DB::transaction(function () use ($project, $user) {
            if ($project->status === 'cancelled' || $project->status === 'completed') {
                throw new \InvalidArgumentException('پروژه بازسازی در وضعیت فعلی قابل شروع نیست.');
            }

            if ($project->equipmentItems()->count() === 0) {
                throw new \InvalidArgumentException('حداقل یک تجهیز برای شروع بازسازی لازم است.');
            }

            $project->update([
                'status' => 'assessment',
                'actual_start_date' => $project->actual_start_date ?? now()->toDateString(),
                'progress_percent' => max($project->progress_percent, 10),
            ]);

            $this->activatePhase($project, 'assessment', $user);
            $this->syncEquipmentOperationalStatus($project);

            return $project->fresh(['phases', 'equipmentItems']);
        });
    }

    public function advancePhase(RebuildProject $project, ?string $notes = null, ?User $user = null): RebuildProject
    {
        return DB::transaction(function () use ($project, $notes, $user) {
            $currentKey = $this->currentPhaseKey($project);
            if (! $currentKey) {
                throw new \InvalidArgumentException('فاز فعالی برای پیش‌برد یافت نشد.');
            }

            $this->completePhase($project, $currentKey, $notes, $user);

            $nextKey = $this->nextPhaseKey($currentKey);
            if ($nextKey === null) {
                return $this->completeProject($project, $user);
            }

            $statusMap = [
                'planning' => ['status' => 'planning', 'progress' => 25],
                'dismantling' => ['status' => 'dismantling', 'progress' => 45],
                'rebuilding' => ['status' => 'rebuilding', 'progress' => 60],
                'testing' => ['status' => 'testing', 'progress' => 80],
                'commissioning' => ['status' => 'commissioning', 'progress' => 95],
            ];

            if (isset($statusMap[$nextKey])) {
                $project->update([
                    'status' => $statusMap[$nextKey]['status'],
                    'progress_percent' => $statusMap[$nextKey]['progress'],
                ]);
                $this->activatePhase($project, $nextKey, $user);
                $this->syncEquipmentOperationalStatus($project);
            }

            return $project->fresh(['phases', 'equipmentItems']);
        });
    }

    public function completeProject(RebuildProject $project, ?User $user = null): RebuildProject
    {
        $project->update([
            'status' => 'completed',
            'progress_percent' => 100,
            'actual_end_date' => now()->toDateString(),
        ]);

        foreach ($project->equipmentItems as $equipment) {
            $postHealth = $equipment->pivot->post_rebuild_health ?? $equipment->health_percentage ?? 100;
            $equipment->update([
                'status' => 'active',
                'health_percentage' => $postHealth,
            ]);
            $project->equipmentItems()->updateExistingPivot($equipment->id, ['status' => 'completed']);
        }

        return $project->fresh(['phases', 'equipmentItems']);
    }

    public function holdProject(RebuildProject $project): RebuildProject
    {
        $project->update(['status' => 'on_hold']);

        return $project;
    }

    public function cancelProject(RebuildProject $project): RebuildProject
    {
        return DB::transaction(function () use ($project) {
            $project->update([
                'status' => 'cancelled',
                'actual_end_date' => now()->toDateString(),
            ]);

            foreach ($project->equipmentItems as $equipment) {
                if (in_array($equipment->status, ['under_rebuild', 'under_maintenance'], true)) {
                    $equipment->update(['status' => 'active']);
                }
            }

            $project->phases()->where('status', 'in_progress')->update(['status' => 'pending']);

            return $project->fresh(['phases', 'equipmentItems']);
        });
    }

    protected function currentPhaseKey(RebuildProject $project): ?string
    {
        $phase = $project->phases()->where('status', 'in_progress')->orderBy('sort_order')->first();

        return $phase?->phase_key;
    }

    protected function nextPhaseKey(string $currentKey): ?string
    {
        $keys = array_column(self::PHASES, 'key');
        $index = array_search($currentKey, $keys, true);

        if ($index === false || $index >= count($keys) - 1) {
            return null;
        }

        return $keys[$index + 1];
    }

    protected function activatePhase(RebuildProject $project, string $phaseKey, ?User $user = null): void
    {
        $phase = $project->phases()->where('phase_key', $phaseKey)->first();
        if (! $phase) {
            return;
        }

        $phase->update([
            'status' => 'in_progress',
            'actual_start' => $phase->actual_start ?? now()->toDateString(),
        ]);
    }

    protected function completePhase(RebuildProject $project, string $phaseKey, ?string $notes, ?User $user): void
    {
        $phase = $project->phases()->where('phase_key', $phaseKey)->first();
        if (! $phase) {
            return;
        }

        $phase->update([
            'status' => 'completed',
            'actual_end' => now()->toDateString(),
            'notes' => $notes ? trim(($phase->notes ? $phase->notes."\n" : '').$notes) : $phase->notes,
            'completed_by' => $user?->id,
        ]);

        if ($phaseKey === 'planning') {
            $project->update(['status' => 'approved', 'progress_percent' => 40]);
        }
    }

    protected function syncEquipmentOperationalStatus(RebuildProject $project): void
    {
        $rebuildStatuses = ['dismantling', 'rebuilding', 'testing', 'commissioning', 'approved'];
        $equipmentStatus = in_array($project->status, $rebuildStatuses, true) ? 'under_rebuild' : 'under_maintenance';

        foreach ($project->equipmentItems as $equipment) {
            if ($project->status === 'completed' || $project->status === 'cancelled') {
                continue;
            }

            $equipment->update(['status' => $equipmentStatus]);
            $project->equipmentItems()->updateExistingPivot($equipment->id, [
                'status' => in_array($project->status, ['testing', 'commissioning'], true) ? 'in_progress' : 'pending',
            ]);
        }
    }

    public function phaseLabels(): array
    {
        return collect(self::PHASES)->mapWithKeys(fn ($p) => [$p['key'] => $p['title']])->all();
    }

    public function rebuildStatusLabels(): array
    {
        return [
            'draft' => 'پیش‌نویس',
            'assessment' => 'ارزیابی',
            'planning' => 'برنامه‌ریزی',
            'approved' => 'تأیید‌شده',
            'dismantling' => 'دمونتاژ',
            'rebuilding' => 'بازسازی',
            'testing' => 'تست',
            'commissioning' => 'تحویل',
            'completed' => 'تکمیل‌شده',
            'on_hold' => 'معلق',
            'cancelled' => 'لغو‌شده',
        ];
    }

    public function scopeTypeLabels(): array
    {
        return [
            'equipment' => 'تجهیز',
            'production_line' => 'خط تولید',
        ];
    }
}