<?php

declare(strict_types=1);

namespace App\Models;

use DateInterval;
use DatePeriod;
use DateTimeImmutable;
use RuntimeException;

final class AnnualOverviewModel extends BaseModel
{
    private const CELL_KEYS = ['AP', 'PP', 'AE', 'PE'];

    public function overview(int $agentId, int $year): array
    {
        $agentModel = new AgentModel($this->pdo);
        $agent = $agentModel->findActive($agentId);
        if ($agent === null) {
            throw new RuntimeException('Agent introuvable.');
        }

        $start = sprintf('%04d-01-01', $year);
        $end = sprintf('%04d-12-31', $year);
        $entries = $agentModel->entriesForDateRange($agentId, $start, $end);
        $vacations = (new VacationModel($this->pdo))->periodsBetween($start, $end);
        $quotaPeriods = $this->quotaPeriodsForYear($agentId, $year, $agent);

        $entriesByDate = [];
        foreach ($entries as $entry) {
            $entriesByDate[(string) $entry['date_jour']][] = $entry;
        }

        $months = [];
        $yearTotals = array_fill_keys(self::CELL_KEYS, 0);
        $statusTotals = ['VALIDE' => 0, 'BROUILLON' => 0];
        $specialTotals = [];

        for ($month = 1; $month <= 12; $month++) {
            $monthStart = new DateTimeImmutable(sprintf('%04d-%02d-01', $year, $month));
            $monthEnd = $monthStart->modify('last day of this month');
            $days = [];
            $monthTotals = array_fill_keys(self::CELL_KEYS, 0);

            $period = new DatePeriod($monthStart, new DateInterval('P1D'), $monthEnd->modify('+1 day'));
            foreach ($period as $date) {
                $dateValue = $date->format('Y-m-d');
                $vacation = $this->vacationForDate($dateValue, $vacations);
                $day = $this->buildDay($date, $entriesByDate[$dateValue] ?? [], $vacation, $agent);
                $days[] = $day;

                foreach (self::CELL_KEYS as $key) {
                    $minutes = (int) $day['cells'][$key]['minutes'];
                    $monthTotals[$key] += $minutes;
                    $yearTotals[$key] += $minutes;
                }
                foreach ($day['status_minutes'] as $status => $minutes) {
                    $statusTotals[$status] = ($statusTotals[$status] ?? 0) + $minutes;
                }
                foreach ($day['special_minutes'] as $code => $minutes) {
                    $specialTotals[$code] = ($specialTotals[$code] ?? 0) + $minutes;
                }
            }

            $months[] = [
                'number' => $month,
                'name' => $this->monthName($month),
                'days' => $days,
                'totals' => $this->formatTotals($monthTotals),
            ];
        }

        $calendarMinutes = array_sum($yearTotals);

        return [
            'agent' => $agent,
            'year' => $year,
            'generated_at' => (new DateTimeImmutable())->format('Y-m-d H:i:s'),
            'quota_periods' => $quotaPeriods,
            'calendar_totals' => [
                'minutes' => $calendarMinutes,
                'duration' => $this->formatMinutes($calendarMinutes),
                'cells' => $this->formatTotals($yearTotals),
                'validated' => $this->formatMinutes((int) ($statusTotals['VALIDE'] ?? 0)),
                'draft' => $this->formatMinutes((int) ($statusTotals['BROUILLON'] ?? 0)),
                'specials' => array_map(fn(int $minutes): string => $this->formatMinutes($minutes), $specialTotals),
            ],
            'months' => $months,
            'legend' => [
                ['code' => 'TRAVAIL', 'label' => 'Temps de travail', 'class' => 'annual-work'],
                ['code' => 'PREPA', 'label' => 'Temps de préparation', 'class' => 'annual-preparation'],
                ['code' => 'FOR', 'label' => 'Formation', 'class' => 'annual-training'],
                ['code' => 'CA', 'label' => 'Congé annuel', 'class' => 'annual-leave'],
                ['code' => 'ABS', 'label' => 'Absence', 'class' => 'annual-absence'],
                ['code' => 'JNT', 'label' => 'Journée non travaillée', 'class' => 'annual-jnt'],
                ['code' => 'JF', 'label' => 'Journée de fractionnement', 'class' => 'annual-fraction'],
                ['code' => 'VAC', 'label' => 'Vacances scolaires', 'class' => 'annual-vacation'],
            ],
        ];
    }

    private function buildDay(DateTimeImmutable $date, array $entries, ?array $vacation, array $agent): array
    {
        $cells = [];
        foreach (self::CELL_KEYS as $key) {
            $cells[$key] = [
                'minutes' => 0,
                'display' => '',
                'details' => [],
                'codes' => [],
                'class' => '',
                'structure_id' => null,
            ];
        }

        $statusMinutes = ['VALIDE' => 0, 'BROUILLON' => 0];
        $specialMinutes = [];
        $hasDraft = false;
        $firstStructureId = null;

        foreach ($entries as $entry) {
            $minutes = $this->minutesBetween((string) $entry['heure_debut'], (string) $entry['heure_fin']);
            if ($minutes <= 0) {
                continue;
            }

            $code = strtoupper((string) $entry['motif_code']);
            $cellKey = $this->cellForEntry($code, $vacation !== null);
            $shortCode = $this->shortCode($code);
            $status = strtoupper((string) $entry['statut']) === 'VALIDE' ? 'VALIDE' : 'BROUILLON';
            $statusMinutes[$status] += $minutes;
            $hasDraft = $hasDraft || $status === 'BROUILLON';
            $firstStructureId ??= isset($entry['id_structure']) ? (int) $entry['id_structure'] : null;

            $cells[$cellKey]['minutes'] += $minutes;
            $cells[$cellKey]['structure_id'] ??= isset($entry['id_structure']) ? (int) $entry['id_structure'] : null;
            $cells[$cellKey]['details'][] = sprintf(
                '%s–%s · %s · %s%s',
                (string) $entry['heure_debut'],
                (string) $entry['heure_fin'],
                (string) $entry['motif_libelle'],
                (string) $entry['structure_nom'],
                $status === 'BROUILLON' ? ' · Brouillon' : ''
            );
            if ($shortCode !== null) {
                $cells[$cellKey]['codes'][$shortCode] = true;
                $specialMinutes[$code] = ($specialMinutes[$code] ?? 0) + $minutes;
            }
            $cells[$cellKey]['class'] = $this->strongestClass(
                (string) $cells[$cellKey]['class'],
                $this->classForCode($code, $cellKey)
            );
        }

        foreach (self::CELL_KEYS as $key) {
            $codes = array_keys($cells[$key]['codes']);
            $cells[$key]['display'] = $this->cellDisplay((int) $cells[$key]['minutes'], $codes);
            $cells[$key]['title'] = implode("\n", $cells[$key]['details']);
            unset($cells[$key]['details'], $cells[$key]['codes']);
        }

        $weekday = (int) $date->format('N');
        $week = (int) $date->format('W');
        $principalStructure = isset($agent['id_structure']) && $agent['id_structure'] !== null
            ? (int) $agent['id_structure']
            : null;

        return [
            'date' => $date->format('Y-m-d'),
            'day' => (int) $date->format('j'),
            'weekday' => $weekday,
            'weekday_short' => $this->weekdayShort($weekday),
            'week' => $week,
            'week_year' => (int) $date->format('o'),
            'show_week' => $weekday === 1 || (int) $date->format('j') === 1,
            'is_weekend' => $weekday >= 6,
            'is_vacation' => $vacation !== null,
            'vacation_label' => $vacation['libelle'] ?? null,
            'has_entries' => $entries !== [],
            'has_draft' => $hasDraft,
            'structure_id' => $firstStructureId ?? $principalStructure,
            'cells' => $cells,
            'status_minutes' => $statusMinutes,
            'special_minutes' => $specialMinutes,
        ];
    }

    private function quotaPeriodsForYear(int $agentId, int $year, array $agent): array
    {
        $quotaModel = new QuotaModel($this->pdo);
        $contexts = [sprintf('%04d-01-01', $year), sprintf('%04d-12-31', $year)];
        $contractStart = trim((string) ($agent['date_debut_contrat'] ?? ''));
        if ($contractStart !== '' && str_starts_with($contractStart, (string) $year)) {
            $contexts[] = $contractStart;
        }

        $periods = [];
        foreach ($contexts as $context) {
            $quota = $quotaModel->forDateForApi($agentId, $context);
            $key = $quota['date_debut_periode'] . '|' . $quota['date_fin_periode'];
            $periods[$key] = $quota;
        }

        uasort($periods, static fn(array $a, array $b): int => strcmp(
            (string) $a['date_debut_periode'],
            (string) $b['date_debut_periode']
        ));

        return array_values($periods);
    }

    private function cellForEntry(string $code, bool $isVacation): string
    {
        return match ($code) {
            'PREPARATION_PERISCOLAIRE', 'PREPARATION_LUNDI' => 'PP',
            'PREPARATION_EXTRASCOLAIRE' => 'PE',
            'EXTRASCOLAIRE' => 'AE',
            'ALP_MATIN', 'RESTAURATION', 'ALP_SOIR', 'MERCREDI_PERISCOLAIRE' => 'AP',
            'JOUR_FRACTIONNEMENT' => 'AP',
            default => $isVacation ? 'AE' : 'AP',
        };
    }

    private function shortCode(string $code): ?string
    {
        return match ($code) {
            'FORMATION' => 'FOR',
            'CONGE' => 'CA',
            'ABSENCE', 'MALADIE' => 'ABS',
            'AUTRE_ABSENCE' => 'A.ND',
            'JNT' => 'JNT',
            'JOUR_FRACTIONNEMENT' => 'JF',
            'MENAGE_FOND' => 'MF',
            default => null,
        };
    }

    private function classForCode(string $code, string $cellKey): string
    {
        return match ($code) {
            'FORMATION' => 'annual-training',
            'CONGE' => 'annual-leave',
            'ABSENCE', 'MALADIE' => 'annual-absence',
            'AUTRE_ABSENCE' => 'annual-other-absence',
            'JNT' => 'annual-jnt',
            'JOUR_FRACTIONNEMENT' => 'annual-fraction',
            'PREPARATION_PERISCOLAIRE', 'PREPARATION_EXTRASCOLAIRE', 'PREPARATION_LUNDI' => 'annual-preparation',
            'EXTRASCOLAIRE' => 'annual-extra',
            default => in_array($cellKey, ['PP', 'PE'], true) ? 'annual-preparation' : 'annual-work',
        };
    }

    private function strongestClass(string $current, string $candidate): string
    {
        $priority = [
            '' => 0,
            'annual-work' => 1,
            'annual-extra' => 2,
            'annual-preparation' => 3,
            'annual-fraction' => 4,
            'annual-training' => 5,
            'annual-leave' => 6,
            'annual-other-absence' => 7,
            'annual-absence' => 8,
            'annual-jnt' => 9,
        ];
        return ($priority[$candidate] ?? 0) >= ($priority[$current] ?? 0) ? $candidate : $current;
    }

    private function cellDisplay(int $minutes, array $codes): string
    {
        if ($minutes <= 0) {
            return '';
        }
        if ($codes !== []) {
            return implode('/', $codes);
        }
        return $this->formatCompactMinutes($minutes);
    }

    private function vacationForDate(string $date, array $vacations): ?array
    {
        foreach ($vacations as $vacation) {
            if ($date >= (string) $vacation['date_debut'] && $date <= (string) $vacation['date_fin']) {
                return $vacation;
            }
        }
        return null;
    }

    private function minutesBetween(string $start, string $end): int
    {
        [$startHour, $startMinute] = array_map('intval', explode(':', $start));
        [$endHour, $endMinute] = array_map('intval', explode(':', $end));
        return max(0, ($endHour * 60 + $endMinute) - ($startHour * 60 + $startMinute));
    }

    private function formatTotals(array $totals): array
    {
        $formatted = [];
        foreach ($totals as $key => $minutes) {
            $formatted[$key] = [
                'minutes' => (int) $minutes,
                'duration' => $this->formatMinutes((int) $minutes),
                'compact' => $this->formatCompactMinutes((int) $minutes),
            ];
        }
        return $formatted;
    }

    private function formatMinutes(int $minutes): string
    {
        $sign = $minutes < 0 ? '-' : '';
        $minutes = abs($minutes);
        return sprintf('%s%d h %02d', $sign, intdiv($minutes, 60), $minutes % 60);
    }

    private function formatCompactMinutes(int $minutes): string
    {
        if ($minutes <= 0) {
            return '';
        }
        $hours = intdiv($minutes, 60);
        $mins = $minutes % 60;
        return $mins === 0 ? $hours . 'h' : sprintf('%dh%02d', $hours, $mins);
    }

    private function monthName(int $month): string
    {
        return [
            1 => 'Janvier', 2 => 'Février', 3 => 'Mars', 4 => 'Avril',
            5 => 'Mai', 6 => 'Juin', 7 => 'Juillet', 8 => 'Août',
            9 => 'Septembre', 10 => 'Octobre', 11 => 'Novembre', 12 => 'Décembre',
        ][$month];
    }

    private function weekdayShort(int $weekday): string
    {
        return [1 => 'L', 2 => 'M', 3 => 'M', 4 => 'J', 5 => 'V', 6 => 'S', 7 => 'D'][$weekday];
    }
}