<?php

namespace Dashboard\Ticketing\Http\Controllers;

use Dashboard\Ticketing\Models\PriorityLevel;
use Dashboard\Ticketing\Models\Ticket;
use Dashboard\Ticketing\Models\TicketingAgentAccess;
use Dashboard\Ticketing\Models\TicketingGroup;
use Dashboard\Ticketing\Models\TicketingProject;
use Illuminate\Http\Request;
use Illuminate\Routing\Controller;
use Illuminate\Support\Facades\Auth;
use Inertia\Inertia;
use Inertia\Response;

class TicketController extends Controller
{
    private function agentGroupIds(): array
    {
        return TicketingAgentAccess::where('user_id', Auth::id())
            ->pluck('group_id')
            ->toArray();
    }

    private function isAgent(int $groupId = null): bool
    {
        $query = TicketingAgentAccess::where('user_id', Auth::id());
        if ($groupId) {
            $query->where('group_id', $groupId);
        }
        return $query->exists();
    }

    private function isManager(int $groupId): bool
    {
        return TicketingAgentAccess::where('user_id', Auth::id())
            ->where('group_id', $groupId)
            ->where('role', 'manager')
            ->exists();
    }

    public function index(Request $request): Response
    {
        $user = Auth::user();
        $agentGroupIds = $this->agentGroupIds();
        $isAgent = count($agentGroupIds) > 0;

        $query = Ticket::with(['group', 'priority', 'project']);

        if ($isAgent) {
            $query->whereIn('group_id', $agentGroupIds);

            // Filters
            if ($request->filled('group_id')) {
                $query->where('group_id', $request->group_id);
            }
            if ($request->filled('status')) {
                $query->where('status', $request->status);
            }
            if ($request->filled('priority_id')) {
                $query->where('priority_id', $request->priority_id);
            }
            if ($request->filter === 'mine') {
                $query->where('assigned_to', $user->id);
            } elseif ($request->filter === 'unassigned') {
                $query->whereNull('assigned_to');
            } elseif ($request->filter === 'pending') {
                $query->where('status', 'pending');
            } elseif (!$request->filled('status')) {
                $query->whereNotIn('status', ['resolved', 'closed']);
            }
        } else {
            $query->where('submitter_id', $user->id);
        }

        $tickets = $query->latest()->paginate(30)->withQueryString();

        // Enrich with submitter name
        $userIds = $tickets->pluck('submitter_id')->merge($tickets->pluck('assigned_to'))->filter()->unique();
        $users = \DB::table('users')->whereIn('id', $userIds)->get(['id', 'name', 'email'])->keyBy('id');

        $tickets->getCollection()->transform(function ($ticket) use ($users) {
            $ticket->submitter = $users[$ticket->submitter_id] ?? null;
            $ticket->assignee = $ticket->assigned_to ? ($users[$ticket->assigned_to] ?? null) : null;
            return $ticket;
        });

        $groups = TicketingGroup::when($isAgent, fn($q) => $q->whereIn('id', $agentGroupIds))->get();
        $priorities = PriorityLevel::whereNull('group_id')
            ->orWhenIn('group_id', $agentGroupIds ?? [])
            ->orderBy('sort_order')
            ->get();
        $projects = TicketingProject::when($isAgent, fn($q) => $q->whereIn('group_id', $agentGroupIds))
            ->where('status', 'active')
            ->get();

        return Inertia::render('Ticketing/Index', [
            'tickets' => $tickets,
            'groups' => $groups,
            'priorities' => $priorities,
            'projects' => $projects,
            'isAgent' => $isAgent,
            'filters' => $request->only(['group_id', 'status', 'priority_id', 'filter']),
        ]);
    }

    public function create(): Response
    {
        $user = Auth::user();
        $agentGroupIds = $this->agentGroupIds();
        $isAgent = count($agentGroupIds) > 0;

        $groups = TicketingGroup::when($isAgent, fn($q) => $q->whereIn('id', $agentGroupIds))->get();
        $priorities = PriorityLevel::orderBy('sort_order')->get();

        return Inertia::render('Ticketing/Create', [
            'groups' => $groups,
            'priorities' => $priorities,
        ]);
    }

    public function store(Request $request)
    {
        $validated = $request->validate([
            'title' => 'required|string|max:255',
            'description' => 'required|string',
            'group_id' => 'required|exists:ticketing_groups,id',
            'priority_id' => 'nullable|exists:ticketing_priority_levels,id',
            'due_date' => 'nullable|date',
        ]);

        $group = TicketingGroup::findOrFail($validated['group_id']);
        $number = $group->nextTicketNumber();

        $ticket = Ticket::create([
            ...$validated,
            'number' => $number,
            'submitter_id' => Auth::id(),
            'status' => 'open',
        ]);

        return redirect()->route('ticketing.show', $ticket);
    }

    public function show(Ticket $ticket): Response
    {
        $user = Auth::user();
        $isAgent = $this->isAgent($ticket->group_id);
        $isSubmitter = $ticket->submitter_id === $user->id;

        if (!$isAgent && !$isSubmitter) {
            abort(403);
        }

        $ticket->load(['group', 'priority', 'project', 'messages', 'attachments']);

        // Enrich messages with user data
        $userIds = $ticket->messages->pluck('user_id')->filter()->unique();
        $users = \DB::table('users')->whereIn('id', $userIds)->get(['id', 'name', 'email'])->keyBy('id');

        $ticket->messages->each(function ($msg) use ($users) {
            $msg->author = $msg->user_id ? ($users[$msg->user_id] ?? null) : null;
        });

        // Agents for assignment picker
        $agents = [];
        if ($isAgent) {
            $agentIds = TicketingAgentAccess::where('group_id', $ticket->group_id)->pluck('user_id');
            $agents = \DB::table('users')->whereIn('id', $agentIds)->get(['id', 'name', 'email']);
        }

        $priorities = PriorityLevel::where(fn($q) => $q->whereNull('group_id')->orWhere('group_id', $ticket->group_id))
            ->orderBy('sort_order')->get();

        return Inertia::render('Ticketing/Show', [
            'ticket' => $ticket,
            'isAgent' => $isAgent,
            'isManager' => $isAgent && $this->isManager($ticket->group_id),
            'agents' => $agents,
            'priorities' => $priorities,
        ]);
    }

    public function edit(Ticket $ticket): Response
    {
        if (!$this->isAgent($ticket->group_id)) {
            abort(403);
        }

        $ticket->load(['group', 'priority', 'project']);
        $priorities = PriorityLevel::where(fn($q) => $q->whereNull('group_id')->orWhere('group_id', $ticket->group_id))
            ->orderBy('sort_order')->get();
        $agentIds = TicketingAgentAccess::where('group_id', $ticket->group_id)->pluck('user_id');
        $agents = \DB::table('users')->whereIn('id', $agentIds)->get(['id', 'name', 'email']);
        $projects = TicketingProject::where('group_id', $ticket->group_id)->get();

        return Inertia::render('Ticketing/Edit', [
            'ticket' => $ticket,
            'priorities' => $priorities,
            'agents' => $agents,
            'projects' => $projects,
        ]);
    }

    public function update(Request $request, Ticket $ticket)
    {
        if (!$this->isAgent($ticket->group_id)) {
            abort(403);
        }

        $rules = [
            'title' => 'sometimes|required|string|max:255',
            'description' => 'sometimes|required|string',
            'status' => 'sometimes|in:open,in_progress,pending,resolved,closed',
            'priority_id' => 'nullable|exists:ticketing_priority_levels,id',
            'due_date' => 'nullable|date',
            'project_id' => 'nullable|exists:ticketing_projects,id',
        ];

        // assigned_to only settable by agents
        if ($this->isAgent($ticket->group_id)) {
            $rules['assigned_to'] = 'nullable|exists:users,id';
        }

        $ticket->update($request->validate($rules));

        return back()->with('success', 'Ticket updated.');
    }

    public function destroy(Ticket $ticket)
    {
        if (!$this->isManager($ticket->group_id)) {
            abort(403);
        }

        $ticket->delete();
        return redirect()->route('ticketing.index');
    }

    public function myTickets(): Response
    {
        $tickets = Ticket::where('submitter_id', Auth::id())
            ->with(['group', 'priority'])
            ->latest()
            ->paginate(20);

        return Inertia::render('Ticketing/MyTickets', [
            'tickets' => $tickets,
        ]);
    }
}