<?php

namespace App\Controllers\Administrator;

use App\Controllers\BaseController;
use App\Models\SchoolYearModel;
use App\Support\SchoolYear\SchoolYearStatus;
use Throwable;

class SchoolYearClosingController extends BaseController
{
    public function preview(int $id)
    {
        try {
            $targetId = $this->normalizeInt($this->request->getGet('target_school_year_id'));
            $source = (new SchoolYearModel())->find($id);
            if ($targetId === null && (string) ($source['status'] ?? '') === SchoolYearStatus::ACTIVE) {
                $target = service('schoolYearManagement')->ensureNextDraftForClosing($id, $this->userId());
                $targetId = (int) ($target['id'] ?? 0) ?: null;
            }
            $preview = service('schoolYearClosing')->preview($id, $targetId);
            $promotionTable = $this->promotionTablePayload($preview['promotion']['rows'] ?? []);
            $carryForwardTable = $this->carryForwardTablePayload($preview['carry_forward'] ?? []);
            $latestBatch = service('schoolYearClosing')->latestBatch($id);

            return view('school_years/closing_preview', [
                'preview' => $preview,
                'promotionTable' => $promotionTable,
                'carryForwardTable' => $carryForwardTable,
                'latestBatch' => $latestBatch,
                'missingCarryForwardInvoices' => $this->missingCarryForwardInvoiceCount($latestBatch),
                'schoolYears' => (new SchoolYearModel())->orderBy('name', 'DESC')->findAll(),
            ]);
        } catch (Throwable $e) {
            return redirect()->to('/administrator/school-years')->with('error', $e->getMessage());
        }
    }

    public function previewByName(string $name)
    {
        try {
            $year = (new SchoolYearModel())
                ->where('name', rawurldecode($name))
                ->first();

            if ($year === null) {
                return redirect()->to('/administrator/school-years')->with('error', 'School year was not found.');
            }

            return $this->preview((int) $year['id']);
        } catch (Throwable $e) {
            return redirect()->to('/administrator/school-years')->with('error', $e->getMessage());
        }
    }

    public function start(int $id)
    {
        try {
            $targetId = $this->normalizeInt($this->request->getPost('target_school_year_id'));
            if ($targetId === null) {
                return redirect()->back()->with('error', 'Select a target school year.');
            }

            service('schoolYearClosing')->start($id, $targetId, $this->userId());
            return redirect()->to('/administrator/school-years/' . $id . '/closing/preview?close_flow=1')->with('success', 'End-year process started.');
        } catch (Throwable $e) {
            return redirect()->back()->with('error', $e->getMessage());
        }
    }

    public function execute(int $id)
    {
        try {
            service('schoolYearClosing')->execute($id, $this->userId());
            return redirect()->to('/administrator/school-years/' . $id . '/closing/preview?close_flow=1')->with('success', 'Carry-forward confirmed.');
        } catch (Throwable $e) {
            return redirect()->back()->with('error', $e->getMessage());
        }
    }

    public function complete(int $id)
    {
        try {
            service('schoolYearClosing')->complete($id, $this->userId());
            return redirect()->to('/administrator/school-years/' . $id . '/closing/preview?close_flow=1')->with('success', 'School year ended and closed.');
        } catch (Throwable $e) {
            return redirect()->back()->with('error', $e->getMessage());
        }
    }

    public function cancel(int $id)
    {
        try {
            service('schoolYearClosing')->cancel($id, $this->userId());
            return redirect()->to('/administrator/school-years')->with('success', 'End-year process cancelled.');
        } catch (Throwable $e) {
            return redirect()->back()->with('error', $e->getMessage());
        }
    }

    private function normalizeInt(mixed $value): ?int
    {
        return is_numeric($value) && (int) $value > 0 ? (int) $value : null;
    }

    private function missingCarryForwardInvoiceCount(?array $batch): int
    {
        if ($batch === null || ! in_array((string) ($batch['status'] ?? ''), ['executed', 'completed'], true)) {
            return 0;
        }

        $db = \Config\Database::connect();
        if (! $db->tableExists('school_year_closing_items')) {
            return 0;
        }

        return $db->table('school_year_closing_items')
            ->where('closing_batch_id', (int) $batch['id'])
            ->groupStart()
                ->where('target_invoice_id', null)
                ->orWhere('target_invoice_id', 0)
            ->groupEnd()
            ->countAllResults();
    }

    private function promotionTablePayload(array $rows): array
    {
        $allowedSorts = ['student', 'school_id', 'class', 'year_score', 'decision', 'source', 'queue', 'target', 'status'];
        $sort = 'class';
        $order = 'asc';
        $perPage = 25;
        $allowedPerPage = [10, 25, 50, 100];

        usort($rows, function (array $a, array $b) use ($sort, $order): int {
            $comparison = $this->comparePromotionRows($a, $b, $sort);
            if ($comparison === 0 && $sort !== 'class') {
                $comparison = $this->comparePromotionRows($a, $b, 'class');
            }
            if ($comparison === 0 && $sort !== 'student') {
                $comparison = $this->comparePromotionRows($a, $b, 'student');
            }
            if ($comparison === 0) {
                $comparison = ((int) ($a['student_id'] ?? 0)) <=> ((int) ($b['student_id'] ?? 0));
            }

            return $order === 'desc' ? -$comparison : $comparison;
        });

        $total = count($rows);

        return [
            'rows' => $rows,
            'sort' => $sort,
            'order' => $order,
            'page' => 1,
            'perPage' => $perPage,
            'total' => $total,
            'pageCount' => 1,
            'allowedPerPage' => $allowedPerPage,
            'from' => $total === 0 ? 0 : 1,
            'to' => $total,
        ];
    }

    private function comparePromotionRows(array $a, array $b, string $sort): int
    {
        $aValue = $this->promotionSortValue($a, $sort);
        $bValue = $this->promotionSortValue($b, $sort);

        if ($sort === 'year_score') {
            if ($aValue === null && $bValue === null) {
                return 0;
            }
            if ($aValue === null) {
                return 1;
            }
            if ($bValue === null) {
                return -1;
            }

            return $aValue <=> $bValue;
        }

        return strnatcasecmp((string) $aValue, (string) $bValue);
    }

    private function promotionSortValue(array $row, string $sort): mixed
    {
        return match ($sort) {
            'student' => (string) ($row['student_name'] ?? ''),
            'school_id' => (string) ($row['school_id'] ?? ''),
            'class' => (string) ($row['class_section_name'] ?? ''),
            'year_score' => is_numeric($row['year_score'] ?? null) ? (float) $row['year_score'] : null,
            'decision' => (string) ($row['decision'] ?? ''),
            'source' => (string) ($row['source'] ?? ''),
            'queue' => (string) ($row['queue_status'] ?? ''),
            'target' => trim((string) ($row['target_section'] ?? '') . ' ' . (string) ($row['target_class'] ?? '')),
            'status' => (string) ($row['status'] ?? ''),
            default => '',
        };
    }

    private function carryForwardTablePayload(array $rows): array
    {
        $allowedSorts = ['family', 'parent', 'source_balance', 'credits', 'adjustments', 'net'];
        $sort = (string) ($this->request->getGet('cf_sort') ?? 'family');
        $sort = in_array($sort, $allowedSorts, true) ? $sort : 'family';
        $order = strtolower((string) ($this->request->getGet('cf_order') ?? 'asc')) === 'desc' ? 'desc' : 'asc';

        usort($rows, function (array $a, array $b) use ($sort, $order): int {
            $comparison = $this->compareCarryForwardRows($a, $b, $sort);
            if ($comparison === 0 && $sort !== 'family') {
                $comparison = $this->compareCarryForwardRows($a, $b, 'family');
            }
            if ($comparison === 0) {
                $comparison = ((int) ($a['family_id'] ?? 0)) <=> ((int) ($b['family_id'] ?? 0));
            }

            return $order === 'desc' ? -$comparison : $comparison;
        });

        return [
            'rows' => $rows,
            'sort' => $sort,
            'order' => $order,
        ];
    }

    private function compareCarryForwardRows(array $a, array $b, string $sort): int
    {
        $numericSorts = ['source_balance', 'credits', 'adjustments', 'net'];
        $aValue = $this->carryForwardSortValue($a, $sort);
        $bValue = $this->carryForwardSortValue($b, $sort);

        if (in_array($sort, $numericSorts, true)) {
            return (float) $aValue <=> (float) $bValue;
        }

        return strnatcasecmp((string) $aValue, (string) $bValue);
    }

    private function carryForwardSortValue(array $row, string $sort): mixed
    {
        return match ($sort) {
            'family' => (string) ($row['family'] ?? ''),
            'parent' => trim((string) ($row['parent'] ?? '') . ' ' . (string) ($row['parent_email'] ?? '')),
            'source_balance' => (float) ($row['source_balance'] ?? 0),
            'credits' => (float) ($row['credit_amount'] ?? 0),
            'adjustments' => (float) ($row['adjustment_amount'] ?? 0),
            'net' => (float) ($row['carry_forward_amount'] ?? 0),
            default => '',
        };
    }

    private function userId(): ?int
    {
        $id = session('user_id') ?? session('id');

        return is_numeric($id) ? (int) $id : null;
    }
}