<?php

namespace App\Services\Families;

use App\Models\StudentClass;
use Illuminate\Contracts\Pagination\LengthAwarePaginator;
use Illuminate\Support\Facades\DB;

class ParentProfileAdminQueryService
{
    public function __construct(private FamilyFinanceService $finance) {}

    public function index(string $schoolYear, string $search = '', int $perPage = 25): LengthAwarePaginator
    {
        $query = DB::table('users as u')
            ->select(
                'u.id',
                'u.firstname',
                'u.lastname',
                'u.email',
                'u.cellphone',
                'u.status',
                DB::raw('COUNT(DISTINCT fg.family_id) as families_count'),
                DB::raw('COUNT(DISTINCT s.id) as selected_year_students_count'),
                DB::raw('COALESCE(SUM(DISTINCT i.balance), 0) as balance')
            )
            ->leftJoin('family_guardians as fg', 'fg.user_id', '=', 'u.id')
            ->leftJoin('family_students as fs', 'fs.family_id', '=', 'fg.family_id')
            ->leftJoin('students as s', function ($join) use ($schoolYear) {
                $join->on('s.id', '=', 'fs.student_id')
                    ->where('s.school_year', '=', $schoolYear);
            })
            ->leftJoin('invoices as i', function ($join) use ($schoolYear) {
                $join->on('i.parent_id', '=', 'u.id')
                    ->where('i.school_year', '=', $schoolYear);
            })
            ->where($this->relevantParentConstraint($schoolYear))
            ->groupBy('u.id', 'u.firstname', 'u.lastname', 'u.email', 'u.cellphone', 'u.status')
            ->orderBy('u.lastname')
            ->orderBy('u.firstname');

        if ($search !== '') {
            $needle = '%'.str_replace(['%', '_'], ['\\%', '\\_'], $search).'%';
            $query->where(function ($inner) use ($needle) {
                $inner->whereRaw("CONCAT_WS(' ', u.firstname, u.lastname) LIKE ?", [$needle])
                    ->orWhere('u.email', 'like', $needle)
                    ->orWhere('u.cellphone', 'like', $needle)
                    ->orWhereExists(function ($exists) use ($needle) {
                        $exists->selectRaw('1')
                            ->from('family_guardians as sfg')
                            ->join('family_students as sfs', 'sfs.family_id', '=', 'sfg.family_id')
                            ->join('students as ss', 'ss.id', '=', 'sfs.student_id')
                            ->whereColumn('sfg.user_id', 'u.id')
                            ->where(function ($student) use ($needle) {
                                $student->whereRaw("CONCAT_WS(' ', ss.firstname, ss.lastname) LIKE ?", [$needle]);
                            });
                    });
            });
        }

        return $query->paginate(max(1, min($perPage, 100)));
    }

    public function search(string $schoolYear, string $search, int $limit = 10): array
    {
        if (trim($search) === '') {
            return [];
        }

        return $this->index($schoolYear, $search, $limit)
            ->getCollection()
            ->map(fn ($row) => $this->parentSummary((array) $row, $schoolYear))
            ->all();
    }

    public function show(int $parentId, string $schoolYear): ?array
    {
        $parent = DB::table('users')
            ->select('id', 'firstname', 'lastname', 'email', 'cellphone', 'address_street', 'city', 'state', 'zip', 'status')
            ->where('id', $parentId)
            ->first();

        if (! $parent) {
            return null;
        }

        $guardians = [
            [
                'user_id' => $parentId,
                'firstname' => $parent->firstname,
                'lastname' => $parent->lastname,
            ],
        ];
        $finance = $this->finance->loadFinancialsForParents([$parentId], $schoolYear);

        return [
            'parent' => (array) $parent,
            'families' => $this->familiesForParent($parentId, $schoolYear),
            'students' => $this->studentsForParent($parentId, $schoolYear),
            'emergency_contacts' => $this->emergencyContactsForParents($guardians, $schoolYear),
            'invoices' => $finance['invoices'],
            'payments' => $finance['payments'],
            'finance_summary' => $finance['summary'],
        ];
    }

    public function updateParent(int $parentId, array $payload): ?array
    {
        $allowed = array_intersect_key($payload, array_flip([
            'firstname',
            'lastname',
            'email',
            'cellphone',
            'address_street',
            'city',
            'state',
            'zip',
            'status',
        ]));

        if ($allowed !== []) {
            $allowed['updated_at'] = now();
            DB::table('users')->where('id', $parentId)->update($allowed);
        }

        $parent = DB::table('users')->where('id', $parentId)->first();

        return $parent ? (array) $parent : null;
    }

    public function parentSummary(array $row, string $schoolYear): array
    {
        $balance = (float) ($row['balance'] ?? 0);
        $primaryFamily = DB::table('family_guardians as fg')
            ->join('families as f', 'f.id', '=', 'fg.family_id')
            ->where('fg.user_id', (int) ($row['id'] ?? 0))
            ->orderByDesc('fg.is_primary')
            ->orderBy('f.household_name')
            ->select('f.id', 'f.household_name')
            ->first();

        return [
            'id' => (int) ($row['id'] ?? 0),
            'firstname' => $row['firstname'] ?? null,
            'lastname' => $row['lastname'] ?? null,
            'email' => $row['email'] ?? null,
            'cellphone' => $row['cellphone'] ?? null,
            'is_active' => strtolower((string) ($row['status'] ?? '')) === 'active',
            'families_count' => (int) ($row['families_count'] ?? 0),
            'students_count' => (int) ($row['selected_year_students_count'] ?? 0),
            'selected_year_students_count' => (int) ($row['selected_year_students_count'] ?? 0),
            'balance' => $balance,
            'positive_unpaid_balance' => max(0, $balance),
            'credit_balance' => $balance < 0 ? abs($balance) : 0.0,
            'primary_family' => $primaryFamily ? (array) $primaryFamily : null,
            'school_year' => $schoolYear,
        ];
    }

    private function relevantParentConstraint(string $schoolYear): callable
    {
        return function ($query) use ($schoolYear) {
            $query->whereExists(function ($exists) use ($schoolYear) {
                $exists->selectRaw('1')
                    ->from('family_guardians as rfg')
                    ->join('family_students as rfs', 'rfs.family_id', '=', 'rfg.family_id')
                    ->join('students as rs', 'rs.id', '=', 'rfs.student_id')
                    ->whereColumn('rfg.user_id', 'u.id')
                    ->where('rs.school_year', $schoolYear);
            })->orWhereExists(function ($exists) use ($schoolYear) {
                $exists->selectRaw('1')
                    ->from('students as direct_students')
                    ->whereColumn('direct_students.parent_id', 'u.id')
                    ->where('direct_students.school_year', $schoolYear);
            })->orWhereExists(function ($exists) use ($schoolYear) {
                $exists->selectRaw('1')
                    ->from('invoices as ri')
                    ->whereColumn('ri.parent_id', 'u.id')
                    ->where('ri.school_year', $schoolYear);
            })->orWhereExists(function ($exists) use ($schoolYear) {
                $exists->selectRaw('1')
                    ->from('parent_accounts as pa')
                    ->whereColumn('pa.parent_id', 'u.id')
                    ->where('pa.school_year', $schoolYear);
            })->orWhereExists(function ($exists) use ($schoolYear) {
                $exists->selectRaw('1')
                    ->from('emergency_contacts as ec')
                    ->whereColumn('ec.parent_id', 'u.id')
                    ->where('ec.school_year', $schoolYear);
            });
        };
    }

    private function familiesForParent(int $parentId, string $schoolYear): array
    {
        return DB::table('family_guardians as fg')
            ->join('families as f', 'f.id', '=', 'fg.family_id')
            ->where('fg.user_id', $parentId)
            ->whereExists(function ($exists) use ($schoolYear) {
                $exists->selectRaw('1')
                    ->from('family_students as fs')
                    ->join('students as s', 's.id', '=', 'fs.student_id')
                    ->whereColumn('fs.family_id', 'f.id')
                    ->where('s.school_year', $schoolYear);
            })
            ->orderBy('f.household_name')
            ->select('f.*', 'fg.relation', 'fg.is_primary', 'fg.receive_emails', 'fg.receive_sms')
            ->get()
            ->map(fn ($row) => (array) $row)
            ->all();
    }

    private function studentsForParent(int $parentId, string $schoolYear): array
    {
        $rows = DB::table('students as s')
            ->select('s.id', 's.firstname', 's.lastname', 's.parent_id')
            ->where('s.school_year', $schoolYear)
            ->where(function ($query) use ($parentId) {
                $query->where('s.parent_id', $parentId)
                    ->orWhereExists(function ($exists) use ($parentId) {
                        $exists->selectRaw('1')
                            ->from('family_guardians as fg')
                            ->join('family_students as fs', 'fs.family_id', '=', 'fg.family_id')
                            ->whereColumn('fs.student_id', 's.id')
                            ->where('fg.user_id', $parentId);
                    });
            })
            ->orderBy('s.lastname')
            ->orderBy('s.firstname')
            ->get()
            ->map(fn ($row) => (array) $row)
            ->all();

        foreach ($rows as &$row) {
            $studentId = (int) ($row['id'] ?? 0);
            $classSectionName = $studentId > 0
                ? (string) (StudentClass::getClassSectionsByStudentId($studentId, $schoolYear) ?? '')
                : '';
            $row['class_section_name'] = $classSectionName;
            $row['grade'] = $classSectionName;
        }
        unset($row);

        return $rows;
    }

    private function emergencyContactsForParents(array $guardians, string $schoolYear): array
    {
        $parentIds = array_values(array_filter(array_map(
            static fn ($g) => (int) ($g['user_id'] ?? 0),
            $guardians
        )));

        if ($parentIds === []) {
            return [];
        }

        return DB::table('emergency_contacts')
            ->select('id', 'parent_id', 'emergency_contact_name', 'relation', 'cellphone', 'email', 'school_year', 'semester', 'created_at', 'updated_at')
            ->whereIn('parent_id', $parentIds)
            ->where('school_year', $schoolYear)
            ->orderByDesc('updated_at')
            ->get()
            ->map(fn ($row) => (array) $row)
            ->all();
    }
}