<?php

namespace App\Services\Ticket;

use App\Models\Ticket;
use App\Models\TicketLog;
use App\Models\TicketApproval;
use App\Models\TicketAssignment;
use App\Services\Ticket\TicketWorkflowValidator;
use Illuminate\Support\Facades\DB;
use Illuminate\Validation\ValidationException;

class TicketWorkflowService
{
    /**
     * Workflow History
     */
    public function history(Ticket $ticket)
    {
        return TicketLog::where('ticket_id', $ticket->id)
            ->orderByDesc('id')
            ->get();
    }

    /**
     * =========================
     * VALIDATION RULE ENGINE
     * =========================
     */

    private function type(Ticket $ticket)
    {
        return $ticket->ticketType;
    }

    private function ensureRequiredAssets(Ticket $ticket, array $payload = [])
    {
        $type = $this->type($ticket);

        // PHOTO VALIDATION
        if ($type?->require_photo) {
            $photoCount = $payload['photo_count'] ?? ($ticket->customer?->images()->count() ?? 0);

            if ($photoCount <= 0) {
                throw ValidationException::withMessages([
                    'photo' => 'Foto wajib diupload untuk ticket ini'
                ]);
            }
        }

        // MATERIAL VALIDATION
        if ($type?->require_material) {
            $materialCount = $payload['material_count'] ?? \App\Models\TicketMaterial::where('ticket_id', $ticket->id)->count();

            if ($materialCount <= 0) {
                throw ValidationException::withMessages([
                    'material' => 'Material wajib diinput untuk ticket ini'
                ]);
            }
        }
    }

    private function ensureCustomer(Ticket $ticket)
    {
        $type = $this->type($ticket);

        if ($type?->need_customer && empty($ticket->customer_id)) {
            throw ValidationException::withMessages([
                'customer_id' => 'Customer wajib ada untuk ticket ini'
            ]);
        }
    }

    /**
     * =========================
     * ASSIGN / REASSIGN
     * =========================
     */

    public function assign(
        Ticket $ticket,
        array $technicians,
        int $leaderId,
        int $userId
    ): Ticket {

        TicketWorkflowValidator::allow($ticket, ['approved']);
        $validCount=\App\Models\UserTenant::where('tenant_id',$ticket->tenant_id)->whereIn('user_id',$technicians)->distinct('user_id')->count('user_id');
        if($validCount!==count(array_unique($technicians)))throw ValidationException::withMessages(['technicians'=>'Semua teknisi harus terdaftar pada tenant ticket.']);

        DB::transaction(function () use (
            $ticket,
            $technicians,
            $leaderId,
            $userId
        ) {

            foreach ($technicians as $technicianId) {
                TicketAssignment::create([
                    'ticket_id'   => $ticket->id,
                    'user_id'     => $technicianId,
                    'is_leader'   => ($technicianId == $leaderId),
                    'assigned_by' => $userId,
                    'assigned_at' => now(),
                    'status'      => 'assigned'
                ]);
            }

            $ticket->update([
                'status'      => 'assigned',
                'assigned_at' => now()
            ]);

            $this->log($ticket->id, $userId, 'Assign', 'Teknisi ditugaskan');
        });

        return $ticket->fresh();
    }

    public function reassign(
        Ticket $ticket,
        array $technicians,
        int $leaderId,
        int $userId
    ): Ticket {

        DB::transaction(function () use (
            $ticket,
            $technicians,
            $leaderId,
            $userId
        ) {

            TicketAssignment::where('ticket_id', $ticket->id)->delete();

            foreach ($technicians as $technicianId) {
                TicketAssignment::create([
                    'ticket_id'   => $ticket->id,
                    'user_id'     => $technicianId,
                    'is_leader'   => ($technicianId == $leaderId),
                    'assigned_by' => $userId,
                    'assigned_at' => now(),
                    'status'      => 'assigned'
                ]);
            }

            $this->log($ticket->id, $userId, 'Reassign', 'Penugasan diperbarui');
        });

        return $ticket->fresh();
    }

    /**
     * =========================
     * APPROVAL FLOW
     * =========================
     */

    public function approve(
        Ticket $ticket,
        ?string $notes,
        int $userId
    ): Ticket {

        TicketWorkflowValidator::allow($ticket, ['open']);

        DB::transaction(function () use ($ticket, $notes, $userId) {

            TicketApproval::create([
                'ticket_id'   => $ticket->id,
                'approver_id' => $userId,
                'status'      => 'approved',
                'notes'       => $notes,
                'approved_at' => now(),
                'created_at'  => now()
            ]);

            $ticket->update([
                'status'       => 'approved',
                'approved_by'  => $userId,
                'approved_at'  => now()
            ]);

            $this->log($ticket->id, $userId, 'Approved', $notes);
        });

        return $ticket->fresh();
    }

    public function reject(Ticket $ticket, string $reason, int $userId): Ticket
    {
        DB::transaction(function () use ($ticket, $reason, $userId) {

            TicketApproval::create([
                'ticket_id'   => $ticket->id,
                'approver_id' => $userId,
                'status'      => 'rejected',
                'notes'       => $reason,
                'created_at'  => now()
            ]);

            $ticket->update([
                'status'           => 'rejected',
                'rejected_by'      => $userId,
                'rejected_at'      => now(),
                'rejection_reason' => $reason
            ]);

            $this->log($ticket->id, $userId, 'Rejected', $reason);
        });

        return $ticket->fresh();
    }

    /**
     * =========================
     * WORKFLOW START
     * =========================
     */

    public function start(Ticket $ticket, array $location, int $userId): Ticket
    {
        TicketWorkflowValidator::allow($ticket, ['assigned']);
        $this->ensureAssignedActor($ticket,$userId);

        DB::transaction(function () use ($ticket, $location, $userId) {
            $this->attachFiles($ticket,$location['stored_file_ids'],'start',$userId,$location['notes']??null);

            $ticket->update([
                'status' => 'progress'
            ]);

            $this->log(
                $ticket->id,
                $userId,
                'Start Work',
                'Pekerjaan dimulai'
            );
        });

        return $ticket->fresh();
    }

    public function pending(Ticket $ticket, string $reason, int $userId, array $fileIds=[]): Ticket
    {
        TicketWorkflowValidator::allow($ticket, ['progress']);$this->ensureAssignedActor($ticket,$userId);
        DB::transaction(function()use($ticket,$reason,$userId,$fileIds){$this->attachFiles($ticket,$fileIds,'pending',$userId,$reason);$ticket->update(['status'=>'pending']);$this->log($ticket->id,$userId,'Pending',$reason);});

        return $ticket->fresh();
    }

    public function resume(Ticket $ticket, int $userId): Ticket
    {
        TicketWorkflowValidator::allow($ticket, ['pending']);$this->ensureAssignedActor($ticket,$userId);
        $ticket->update(['status' => 'progress']);

        $this->log($ticket->id, $userId, 'Resume', 'Dilanjutkan');

        return $ticket->fresh();
    }

    /**
     * =========================
     * RESOLVE (VALIDATION POINT)
     * =========================
     */

    public function resolve(
        Ticket $ticket,
        string $notes,
        int $userId,
        array $payload = []
    ): Ticket {

        TicketWorkflowValidator::allow($ticket, ['progress']);
        $this->ensureAssignedActor($ticket,$userId);
        if ($ticket->source === 'new_installation' && $ticket->installation_step !== 'completed') throw ValidationException::withMessages(['installation_step'=>'Seluruh proses pemasangan dan aktivasi harus diselesaikan terlebih dahulu.']);

        // 🔥 VALIDASI MATERIAL + PHOTO + CUSTOMER
        $this->ensureRequiredAssets($ticket, $payload);
        $this->ensureCustomer($ticket);

        DB::transaction(function () use ($ticket, $notes, $userId, $payload) {
            $this->attachFiles($ticket,$payload['stored_file_ids']??[],'resolve',$userId,$notes);

            $ticket->update([
                'status'      => 'resolved',
                'resolved_at' => now()
            ]);

            $this->log($ticket->id, $userId, 'Resolved', $notes);
        });

        return $ticket->fresh();
    }

    public function close(Ticket $ticket, ?string $notes, int $userId): Ticket
    {
        TicketWorkflowValidator::allow($ticket, ['resolved']);
        if (! $ticket->verified_at) throw ValidationException::withMessages(['verification'=>'Ticket harus diverifikasi sebelum ditutup.']);

        $ticket->update([
            'status'    => 'closed',
            'closed_at' => now()
        ]);

        $this->log($ticket->id, $userId, 'Closed', $notes);

        return $ticket->fresh();
    }

    public function cancel(Ticket $ticket, string $reason, int $userId): Ticket
    {
        $ticket->update(['status' => 'cancelled']);

        $this->log($ticket->id, $userId, 'Cancelled', $reason);

        return $ticket->fresh();
    }

    public function escalate(Ticket $ticket, string $reason, int $userId): Ticket
    {
        $this->log($ticket->id, $userId, 'Escalated', $reason);

        return $ticket->fresh();
    }

    /**
     * =========================
     * LOG SYSTEM
     * =========================
     */

    private function log(
        int $ticketId,
        int $userId,
        string $activity,
        ?string $notes = null
    ): void {

        TicketLog::create([
            'ticket_id' => $ticketId,
            'user_id'   => $userId,
            'activity'  => $activity,
            'notes'     => $notes,
            'created_at'=> now()
        ]);
    }

    private function ensureAssignedActor(Ticket $ticket,int $userId):void
    {
        $user=\App\Models\User::findOrFail($userId);
        if($user->isMasterAdmin()||$user->isTenantOwner($ticket->tenant_id))return;
        abort_unless(TicketAssignment::where('ticket_id',$ticket->id)->where('user_id',$userId)->whereIn('status',['assigned','accepted'])->exists(),403,'Pekerjaan hanya dapat diproses teknisi yang ditugaskan.');
    }
    private function attachFiles(Ticket $ticket,array $ids,string $stage,int $userId,?string $notes=null):void
    {
        foreach(array_unique($ids) as $id){$file=\App\Models\StoredFile::findOrFail($id);abort_unless((int)$file->tenant_id===(int)$ticket->tenant_id,422,'File bukan milik tenant ticket.');\App\Models\TicketAttachment::firstOrCreate(['ticket_id'=>$ticket->id,'stored_file_id'=>$id,'stage'=>$stage],['uploaded_by'=>$userId,'notes'=>$notes]);}
    }
}