<?php

namespace App\Controllers;

use App\Models\AppointmentModel;
use App\Models\DoctorModel;
use App\Models\DoctorSpecializationModel;
use App\Models\SpecializationModel;
use CodeIgniter\HTTP\RedirectResponse;
use CodeIgniter\HTTP\ResponseInterface;

class Doctor extends BaseController
{
    private function parseSpecializations($specializationInput): array
    {
        $specializations = [];

        if (is_array($specializationInput)) {
            foreach ($specializationInput as $item) {
                $item = trim((string) $item);
                if ($item !== '' && ! in_array($item, $specializations, true)) {
                    $specializations[] = $item;
                }
            }
        } else {
            $parts = explode(',', (string) $specializationInput);
            foreach ($parts as $item) {
                $item = trim($item);
                if ($item !== '' && ! in_array($item, $specializations, true)) {
                    $specializations[] = $item;
                }
            }
        }

        return $specializations;
    }

    private function getDoctorSpecializationNames(int $doctorId): array
    {
        $db = \Config\Database::connect();

        $rows = $db->table('doctor_specializations ds')
            ->select('s.name')
            ->join('specializations s', 's.id = ds.specialization_id')
            ->where('ds.doctor_id', $doctorId)
            ->orderBy('s.name', 'ASC')
            ->get()
            ->getResultArray();

        return array_map(static fn ($row) => $row['name'], $rows);
    }

    public function dashboard()
    {
        if ($r = $this->requireRole('doctor')) {
            return $r;
        }

        $db       = \Config\Database::connect();
        $userId   = (int) session()->get('id');
        $doctorModel = new DoctorModel();

        $doctor = $doctorModel->where('user_id', $userId)->first();
        if (! $doctor) {
            return redirect()->to(site_url('/'))->with('error', 'Doctor profile not found.');
        }

        $doctorId = (int) $doctor['id'];

        $query = $db->query('
            SELECT a.*,
                   TRIM(CONCAT(COALESCE(u.first_name, \'\'), \' \', COALESCE(u.last_name, \'\'))) AS patient_name
            FROM appointments a
            JOIN patients p ON p.id = a.patient_id
            JOIN users u ON u.id = p.user_id
            WHERE a.doctor_id = ?
        ', [$doctorId]);

        $data['appointments'] = $query->getResult();

        return view('doctor/dashboard', $data);
    }

    public function profile()
    {
        if ($r = $this->requireRole('doctor')) {
            return $r;
        }

        $doctorModel = new DoctorModel();
        $specializationModel = new SpecializationModel();
        $userId      = (int) session()->get('id');
        $doctor      = $doctorModel->where('user_id', $userId)->first();

        if (! $doctor) {
            return redirect()->to(site_url('/'))->with('error', 'Doctor profile not found.');
        }

        if ($this->request->is('post')) {
            $rules = [
                'specialization' => 'required',
                'experience'     => 'required|max_length[100]',
                'fees'             => 'permit_empty|decimal',
            ];

            if (! $this->validate($rules)) {
                return redirect()->back()->withInput();
            }

            $specializations = $this->parseSpecializations($this->request->getPost('specialization'));

            if ($specializations === []) {
                return redirect()->back()->withInput()->with('error', 'Please select at least one specialization.');
            }

            $update = [
                'specialization' => implode(', ', $specializations),
                'experience'     => $this->request->getPost('experience') ?: null,
                'fees'           => $this->request->getPost('fees') !== '' && $this->request->getPost('fees') !== null
                    ? $this->request->getPost('fees')
                    : null,
            ];

            if (! $doctorModel->update($doctor['id'], $update)) {
                return redirect()->back()->withInput()->with('error', 'Could not update profile.');
            }

            $specializationMap = $specializationModel->ensureNamesExist($specializations);
            $doctorSpecializationModel = new DoctorSpecializationModel();
            $doctorSpecializationModel->syncDoctorSpecializations($doctor['id'], array_values($specializationMap), (int) session()->get('id'));

            return redirect()->to(site_url('doctor/profile'))->with('success', 'Profile updated.');
        }

        $selectedSpecializations = $this->getDoctorSpecializationNames((int) $doctor['id']);
        if ($selectedSpecializations === [] && ! empty($doctor['specialization'])) {
            $selectedSpecializations = $this->parseSpecializations($doctor['specialization']);
        }

        return view('doctor/profile', [
            'doctor'                  => $doctor,
            'specializationOptions'   => $specializationModel->getOptionNames(),
            'selectedSpecializations' => $selectedSpecializations,
        ]);
    }

    public function accept($id): ResponseInterface
    {
        if ($r = $this->requireRole('doctor')) {
            return $r;
        }

        if (! $this->request->is('post')) {
            return redirect()->to(site_url('doctor/dashboard'))->with('error', 'Invalid request.');
        }

        return $this->updateAppointmentStatus((int) $id, 'approved');
    }

    public function reject($id): ResponseInterface
    {
        if ($r = $this->requireRole('doctor')) {
            return $r;
        }

        if (! $this->request->is('post')) {
            return redirect()->to(site_url('doctor/dashboard'))->with('error', 'Invalid request.');
        }

        return $this->updateAppointmentStatus((int) $id, 'rejected');
    }

    private function updateAppointmentStatus(int $appointmentId, string $status): RedirectResponse
    {
        if ($appointmentId < 1) {
            return redirect()->back();
        }

        $appointmentModel = new AppointmentModel();
        $doctorModel      = new DoctorModel();

        $userId = (int) session()->get('id');
        $doctor = $doctorModel->where('user_id', $userId)->first();
        if (! $doctor) {
            return redirect()->to(site_url('/'))->with('error', 'Doctor profile not found.');
        }

        $appointment = $appointmentModel->find($appointmentId);
        if (! $appointment || (int) $appointment['doctor_id'] !== (int) $doctor['id']) {
            return redirect()->back()->with('error', 'Invalid appointment.');
        }

        $status = AppointmentModel::normalizeStatus($status);
        $appointmentModel->update($appointmentId, ['status' => $status]);

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